Four chloride carbon. Laboratory work on organic chemistry: Tutorial Toxic concentrations causing acute poisoning

23.04.2020

Strip substances at a temperature significantly less than their boiling point. The essence of distillation with water ferry is that high-boiling, non-mixing or little mixing, i.e. Multistable substances in the water will be disappeared when water vapor is passed into them; Then they, together with the ferry condense in the refrigerator. In order to establish, a volatile substance with a water vapor, a small amount should be heated in a test tube with 2 ml of water. The bottom of the second test tube is held above this test tube, in which ice is laid. If the dull droplets are condensing on the cold day, then a volatile stuff with water vapor. Table 6 Data on some substances distilled with water vapor Substance Boiling temperature, 0s Clean content of a mixture of substance with a substance in a water vapor distillate,% Aniline 184.4 98,5 23 Brombohenzene 156.2 95,5,61 Naphthalene 218.2 99 , 3 14 Phenol 182.0 98.6 21 Nitrobenzene 210,9 99.3 15 O-cresol 190.1 98.8 19 The sequence of work is as follows. It is recommended to first heat the flask with the liquid and water almost to the boil. This pre-heating aims to prevent too much increase in the volume of the mixture in the flask due to the condensation of water vapor during distillation. In the future, the distillation flask can not be heated. When a steam steam, a rubber tube is closed with a rubber tube, bowed on a tee, and start distillation with steam. Through the fluid located in the flask should be a rather strong jet of steam. A sign of the end of distillation is the appearance of a transparent distillate (pure water). If the distilmed substance has a noticeable solubility in water (for example, aniline), a small amount of transparent distillate should be collected. At the end of the distillation, they open the clamp and only after that the burners are quenched (thereby eliminating the danger of pulling the liquid from the distillation flask in the steamer). In the receiver after distillation, two layers are obtained: water and organic matter. The latter is separated from water in a dividing funnel, dried in the usual way and distilled with the purpose of final cleaning. Sometimes to reduce the loss of the substance due to its partial solubility in water, planting and extraction is used. High boiling substances, difficult to distinguish with water vapor, having a temperature of 100 ° C, it is possible to distinguish with a superheated water vapor, unless there is no danger of decomposition of the substance at a higher temperature. For the formation of superheated steam, steam steampers of various devices are used. Usually, steam from the steamer enters a metal coil having a nozzle for measuring the temperature and heated by the flame of a strong burner. It is necessary to maintain a certain temperature of the superheated steam to control the speed of distillation and avoid decomposition of the substance. The distillation flask should be loaded into the oil or metal bath heated to the desired temperature, and the throat of the flasks tightly wrap asbestos cord. If the distillation is conducted at temperatures above 120-130 ° C, it is necessary to connect the air consistently first to the distillation flask, and then water refrigerators. The use of superheated steam allows many times to increase the speed of distillation of hardening substances (Fig. 39). In contrast to the usual, simple distillation, during which steam and condensate pass through the device once in the direction, with countercurrent distillation, or distillation, part of the condensate constantly flows towards a pair. This principle is implemented in distillation distillation columns. Rectification is a method of separation or purification of liquids with sufficiently close boiling temperatures by distillation using special columns in which the rising pairs interact with the liquid flowing towards them (phlegm) resulting from partial condensation of vapors. As a result of a multiple repetition of evaporation and condensation processes, the pairs are enriched with an elbow component, and phlegm enriched with a high-boiling component flows into a distillation flask. On the effective columns used in industry or in scientific research, liquids can be divided, differing in the boiling point of less than 1 ° C. Conventional laboratory columns allow separating fluids with a temperature difference of boiling temperatures at least 10 ° C. The distillation column should be thermally insulated so that the processes occurring in it in conditions are as close as possible to adiabatic. With a significant external cooling or overheating of the column walls, its correct operation is impossible. To ensure the close contact of the vapor with the liquid, the distillation columns are filled with a nozzle. Glass beads, glass or porcelain rings, short trimming of glass tubes or stainless steel wires, glass spirals are used as nozzles. The distillation columns and with a Christmas tree chill type are used. The efficiency of the column depends on the amount of phlegm coming into irrigation. To obtain a sufficient amount of phlegm, the distillation column must be connected to the capacitor. The role of the capacitor with partial condensation of vapors can perform a conventional deflegemaker. A simple installation for separating the mixture of liquids is shown in Fig. 38. 52 Widespread applications received condensers in which the complete condensation of all vapors passed through the column. Such capacitors are equipped with a tap for the selection of distillates. Rectification can be guided as atmospheric pressure and in vacuum. As a rule, in vacuum, the rectification is carried out high-boiling or thermally unstable mixtures. Questions for control: 1. Tell the types and methods of distillation. 2. In which cases, the distillation is used at atmospheric pressure, with a decreased pressure (in vacuo) and with water vapor. Why? 3. Tell us the principle of operation and the device of the distillation device at atmospheric pressure. 4. Tell us the principle of operation and the device of the distillation device with water vapor. Practical part 4.1.4.1. Distillation at atmospheric pressure reagents: purified substance. Equipment: Device for simple distillation. Collect the device for simple distillation at atmospheric pressure as shown in Fig. 38. Fig. 38. Device for simple distillation: 1 - flask of Wawza; 2 - thermometer; 3 - downward refrigerator libid; 4 - allezh; 5 - the receiving flask of the distillation flask 1 with the help of a funnel fill in no more than two thirds of the distilled liquid. Before filling the instrument, the volume or weight of the liquid is measured. The distillation device is collected from dry clean parts and secured on tripods. Include water for cooling. As a heater, use a bath (water, oil) or a column heater. By controlling the temperature of the bath with the second, fixed on the thermometer 2 tripod, establish such heating, which ensures uniform, 53 slow boiling of the contents of the flask. The receiver should fall no more than two drops of pure and transparent distillates per second. Only under such conditions, the thermometer in the flask shows the temperature corresponding to the point of equilibrium between the ferry and the liquid; With too fast distillation, the pair easily overheat. The distillation temperature is recorded. Distillation can not be continuing to dryness! It finishes at the moment when the boiling point will be 2-3 degrees above the one at which the main fraction has passed. At the end of the distillation, the volume or weight of the distillate, as well as the residue in the distillation flask. The task. Clean one of the proposed solvents by instructing the teacher. In organic synthesis, the cleanliness of the solvents used is very important. Often even small impurities prevent the reaction to flow, so the cleaning of solvents is an urgent task for the synthetic chemist. Chloroform 0 20 TKIP \u003d 61.2 s; nd \u003d 1,4455; D415 \u003d 1.4985 Azeotropic mixture (chloroform-water-ethanol) contains 3.5% water and 4% alcohol, it boils at 55.5 ° C. The sale chloroform contains alcohol as a stabilizer that binds the phosgene formed during decomposition. Cleaning. Shake with concentrated sulfuric acid, washed with water, dried over calcium chloride and distilled. Attention! Due to the danger of the explosion of chloroform, it is impossible to contact sodium. Tour chloride carbon 0 20 TKIP. \u003d 76.8 C; Nd \u003d 1,4603 Azeotropic mixture with water boils at 66 ° C and contains 95.9% carbon four-chloride. Triple azeotropic mixture with water (4.3%) and ethanol (9.7%) boils at 61.8 ° C. Cleaning and drying. Usually distillation. The water is removed in the form of azeotropic mixture (the first parts of the distillate are discarded). If high demands are made to dry and clean, the carbon tetrachloride is boiled under the reflux of 18 hours with phosphorus oxide (V), are distilled with a reflux. Tour chloride carbon can not be dried with sodium (the danger of the explosion!). Ethanol 0 TKIP \u003d 78.33 C; ND20 \u003d 1.3616; D415 \u003d 0.789 Ethanol is mixed with water, ether, chloroform, benzene in any ratios. Azeotropic mixture with water boils at 78.17 ° C and contains 96% ethanol. Triple azeotropic mixture with water (7.4%) and benzene (74.1%) boils at 64.85 ° C. 54 impurities. Synthetic alcohol is contaminated with acetic aldehyde and acetone, ethyl alcohol obtained during fermentation - higher alcohols (sigh oil). For denaturation, pyridine, methanol and gasoline are added. Drying. In 1 liter of the "absolute" alcohol, 7 g sodium is dissolved, 27.5 g of phthalic acid diethyl ether is added and 1 hour is refluxed. Then distilted with a small column. The distilling alcohol contains less than 0.05 water. Of the sales "absolute" alcohol, the tracks of water can be removed in another way: 5 g of magnesium 2-3 hours boil with 50 ml of "absolute" alcohol, to which 1 ml of carbon tetrachloride was added, then 950 ml of "absolute" alcohol is added, 5 more With reflux. In conclusion distilled. Water detection. A alcohol containing more than 0.05% water is precipitated by a bulk white precipitate from a benzene solution of aluminum triethylate. 4.1.4.2. Distillation with water vapor reagents: purified substance. Equipment: Device for simple distillation. Collect the device distillation with steam as shown in fig. 39. Fig. 39. The device for distillation with water vapor: 1 warehouse; 2 - a tee with a clamp; 3 - distillation flask; 4 - refrigerator; 5 - allezh; 6 - receiving flask; 7 - safety tube; 8 - applying tube; 9 - Tube, the pairs of pairs are formed in a steam 1 (instead of it is suitable and flask). The safety tube 7 serves to equalize the pressure, the connecting link - for the release of condensate. Steam through the supply tube 8 enters the distillation flask 3, in which the shared mixture is located. Usually this flask is also heated. The distillate enters the refrigerator 4, condenses through the allezh 5 flows into the receiver 6. Small amounts of the substance can be distilled, without using a steam, and adding a certain amount of water directly into the distillese flask. Task 1. To distilute with water ferry of natural raw materials (rose petals, fir needles) in order to obtain an aqueous extract of essential oil. For 55 of this, natural raw materials are loaded into the flask, water is filled with water and a distillation with water vapor is carried out. Task 2. To obtain anhydrous oxalic acid from its mixture with water, by azeotropic water distillation. Distillation of a mixture of two liquids, insoluble in each other, also applied to dry organic substances by the so-called azeotropic distillation of water. For this purpose, the drained substance is mixed with an organic solvent, for example, benzene or carbon tetrachloride, and is subjected to a mixture with heating in a distillation instrument. In this case, water is distilled off with a ferry of an organic matter (at a temperature lying below than the boiling point of the lowest mixture component, for example, benzene or CCL4). With a sufficiently large number of organic solvent, complete dehydration of the drying substance can be achieved. 4.1.4.3. Rectification reagents: purified substance. Equipment: device for fractional distillation. Rectification at atmospheric pressure collect the device for distillation of the mixture as shown in Fig. 40. Fig. 40. Device for fractional distillation: 1 - distillation flask; 2 - reflux; 3 - thermometer; 4 - refrigerator; 5 - allezh; 6 - receiving flask task. Divide the mixture of ethanol and butanol by rectification at atmospheric pressure. Collect the following fractions: a) up to 82 ° C ("pure ethanol"); b) from 83 to 110 ° C (intermediate fraction); c) residue. Measure the volume of the fraction and residue. 4.1.4.4. Distillation in vacuum reagents: purified substance. Equipment: Device for distillation under reduced pressure. 56 Fig. 41. The device for distillation under reduced pressure: 1 - Claisen flask or round bottom flask with klaisen nozzle; 2 - capillary connected to a rubber hose with a clamp; 3 - thermometer; 4 - refrigerator; 5 - allezh; 6 - receiving flask; 7 - safety flask; 8 - Task Manometer. Perform distillation of quinoline under reduced pressure. T kip. Hinolina at atmospheric pressure -237,7 ° C, and at 17 mm Hg. Art. -114 ° C. Questions for Colloquium: 1. What are the deflements using a fractional distillation? 2. What is azeotropic mixtures? What are the methods of their separation? 3. At what temperature (above or below 100 ° C) will boil water in the mountains? Reply explain the answer. 4. Where are impurities when cleaning organic compounds by distillation? 4.1.5. The thin-layer chromatography (TLC) chromatography is called a whole group of physicochemical methods of separation based on the works of color (1903) and Kuna (1931). They distinguish chromatography in columns, thin layer, on paper, gas. The separation of substances in these cases occurs either as a result of the distribution between the two liquid phases (distribution chromatography), or as a result of various adsorbity of the substance, by any adsorbent (adsorption chromatography). Chromatography in a thin layer is to use, for example, aluminum oxide as a sorbent. In this case, the separation plays a role both distribution and adsorption. The moving phase, in the flow of which the separable mixture moves, is called the eluent, and the solution coming out of the fixed phase layer and containing the dissolved components of the mixture - eloate. Depending on whether the eluent is moving along the plate, differ:  ascending thin layer chromatography 57  downward thin-layer chromatography  horizontal thin-layer chromatography  radial thin-layer chromatography. Ascending thin layer chromatography This type of chromatography is most common and is based on the fact that the front of the chromatographic system rises along the plate under the action of capillary forces, i.e. The front of the chromatographic system is moving from below. For this method, the most simple equipment is used, since any container with a flat bottom and a tightly closing lid can be used as a chromatographic chamber, into which the chromatographic plate is freely placed. The method of ascending thin layer chromatography has a number of their drawbacks. For example, the speed of the edge of the front on the plate occurs unevenly, i.e. At the bottom, it is the highest, and as the front raises, it decreases. This is due to the fact that in the upper part of the chamber, the saturation of the solvent pairs is smaller, therefore the solvent from the chromatographic plate evaporates more intense, therefore, its concentration and movement speed slows down. To eliminate this disadvantage of the chromatographic chamber walls, the filter paper strips are attached, along which the lifting chromatographic system satuates in pairs of the chamber throughout the volume. Some chromatographic chambers have on the bottom division into two baths. This improvement makes it possible not only to reduce the consumption of the chromatographic system (to obtain the necessary height of the chromatographic system, less volume is required) but also use an additional cuvette for the solvent that increases the pressure of saturated vapor in the chamber. The disadvantage can also be considered the need to follow the front of the solvent, since it is possible "Running" of the line of the solvent front to the top edge. In this case, it is not possible to determine the actual RF value. Downward thin layer chromatography This method of chromatography is based on the fact that the front of the chromatographic system is lowered on the plate mainly under the action of gravity forces, i.e. The front of the mobile phase is moving from top to bottom. For this method, a cuvette is attached to the top of the chromatographic chamber in the upper part of the chromatographic chamber with a chromatographic plate using a wick to a chromatographic plate that flows and chromatography of the studied sample occurs. The disadvantages of this method include the complication of the equipment. This method is used mainly in paper chromatography. 58 Horizontal thin layer chromatography This method is most complicated in hardware, but most convenient. Thus, in the chromatographic chamber, the plate is placed horizontally and the supply of the system occurs on one edge of the plate using a wick. The front of the solvent is moving in the opposite direction. There is another reception that allows you to simplify the camera. To do this, the chromatographic plate on an aluminum base is slightly bent and placed in the chamber. In this case, the system will come on both sides at the same time. For this purpose, only plates with an aluminum substrate are suitable, since the plastic and glass base "non-beam", i.e. Does not keep a form. The advantages of this method include the fact that in the horizontal cuvette, the saturation of the system couples occurs much faster, the speed of movement is permanent. And when chromatographed on both sides, the front does not "run away." Radial thin-layer chromatography Radial thin layer chromatography is that the substance has been applied to the center of the plate and the eluent is applied there, which moves from the center to the edge of the plate. The distribution of the components of the mixture occurs between the water absorbed by the carrier1, and moving through this fixed phase of the solvent (moving phase). At the same time there is a law of Nednes. The component of the mixture, which is easier dissolved in water, moves slower than one that is easier to soluble in the movable phase. Adsorption is that adsorption equilibrium is installed between the carrier and components of the mixture - for each component of its own, the result of which is a different speed of movement of components. Quantitative measure of the transfer rate of the substance when using a specific adsorbent and solvent is the RF (deceleration factor or mobility factor). RF magnitude is defined as a private from dividing the distance from stains to the starting line by the scale of the solvent (front line) from the starting line: the distance from the stain to the starting line RF \u003d distance from the terminal of the solvent to the start of the RF value is always less than one, it does not depend on the length Chromatograms, but depends on the nature of the selected solvent and adsorbent, temperature, concentration of the substance, the presence of impurities. So at a low temperature of the substance moves slower than with higher. Pollution contained in a mixture of solvents used, adsorbent non-homogeneity, foreign ions in the analyzed solution can change the RF magnitude. 1 carrier is an adsorbent, for example aluminum oxide, starch, cellulose, and water form a fixed phase. 59 Sometimes used factor RS: The distance traveled by the substance from the line to the start RS \u003d distance traveled by the substance adopted for the standard, from the line to the start, as opposed to RF, the RS value may be greater or less 1. The RF value is determined by three main factors. The first factor is the degree of affinity of the chromatographic organic compound to the sorbent, which increases in the next row: alkanes< алкены < простые эфиры < нитросоединения < альдегиды < нитрилы < амиды < спирты < тиофенолы < карбоновые кислоты По мере увеличения числа функциональных групп энергия адсорбции возрастает (Rf уменьшается). Наличие внутримолекулярных взаимодействий, например водородных связей, наоборот уменьшает ее способность к адсорбции (Rf увеличивается). Так, о-нитрофенолы и о-нитроанилины имеют большее значение Rf , чем м- и п-изомеры. Плоские молекулы адсорбируются лучше, чем неплоские. ВТОРОЙ ФАКТОР - свойства самого сорбента, которые определяются не только химической природой вещества, но и микроструктурой его активной поверхности. В качестве сорбентов чаще всего используются оксид алюминия, силикагель, гипс с размером гранул 5-50 мкм. Оксид алюминия обладает удельной поверхностью 100- 200 м2/г, имеет несколько адсорбционных центров. Одни из них избирательно сорбируют кислоты, другие - основания. При этом для кислот c рКа <5 и оснований c рКа >9 is characteristic of hemosorption. Aluminum oxide is also effective for separating acyclic hydrocarbons with different numbers of double and triple bonds. Silica gel (SiO2 × H2O), has a significantly greater sorption capacity than aluminum oxide. In TLC, coenpores of the Selikahel are used with a pore size of 10-20 nm and a specific surface area 50-500 m2 / g. The silica gel is chemically inert to most active organic compounds, however, due to acidic properties (pH 3-5), the bases from the PKA\u003e 9 are quite strongly sorbit. Gypsum is a sorbent with a small sorption capacity and small activity. Used for chromatography of polar compounds, as well as compounds containing a large number of different functional groups. The third factor is the nature of the eluent that displaces the molecules adsorbed on the active centers. Ascending the eluting ability, eluents can be located in the following row: 60

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Introduction

Cleanliness of solvents

The requirements for the cleanliness of the solvent undoubtedly depend on how this solvent will then be used. Therefore, there are no adequate experimental criteria for the ideal purity of solvents; With the use of conventional cleaning methods, it is possible to obtain a solvent only about 100% purity. From a practical point of view, purity is determined as follows: "The material is considered quite clean if it does not contain impurities of such nature and in such quantities that could prevent its use in order for which it is intended"

Basic precautions

Below are some rules that should be observed when cleaning solvents and working with them;

A) Under no circumstances should the sodium and other active metals or metal hydrides should be used to dry liquids or acidic compounds (or halogen-containing compounds) that can act as oxidizing agents.

B) should not be used energetic drying agents (such as Na, San 2, LiAlh 4, H 2 SO 4, P 2 O 5) until the pre-coarse drying has been performed using conventional agents (Na 2 SO 4 and Dr.) or in the substance is not guaranteed a low water content.

C) before distillation and drying of ethers and other solvents, it is necessary to check the presence of peroxide in them and delete them. In order to avoid the formation of peroxide, most of the ethers should not be stored in the light and in air for a long time.

D) it should be remembered that many solvents (for example, benzene, etc.) are toxic and have the ability to accumulate in the body; Therefore, it is necessary to avoid inhalation of the vapors of these solvents. It should also be remembered that many solvents, with the exception, for example, SL 4 and SNSL 3, are easily ignited; Diethyl ether and CS 2 are especially dangerous in this regard.

E) Carefully purified solvents are recommended to be stored in a hermetic glass dishes in an inert atmosphere (usually N 2, free from O 2). If the tightness is not possible, it is possible to create an overpressure of an inert gas above the surface of the fluid. The long-term storage of some solvents is ensured by sealed paraffin closed capacitance.

Methods of rapid determination of peroxide in liquids

1. The most sensitive method (allows to determine up to 0.001% peroxide); Under the influence drops Liquid containing peroxide, colorless ferrotiocyanate turns into a red ferrityocyanate. The reagent is prepared as follows: 9 g FESO 4 7H 2 o is dissolved in 50 ml of 18% HCl. A slightly granulated Zn and 5 g of sodium thiocyanate are added; After the disappearance of red staining, another 12 g of sodium thiocyanate is added and the solution is decanted with unreacted Zn into a clean flask.

2. Several milliliters of the liquid are placed in a flask with a glass stopper. Add 1 ml of freshly prepared 10% aqueous Ki aqueous solution, shake and leave to stand for 1 min. The appearance of yellow painting indicates the presence of peroxide. The faster method is as follows: about 1 ml of liquid is added to an equal volume of ice acetic acidcontaining about 100 mg of NAI or Ki. The yellow color of the solution indicates the presence of low concentration, brown - high concentration of peroxide.

3. The method of determining peroxides in liquids insoluble in water is as follows: Several milliliters of the liquid are added to a solution containing about 1 mg of sodium bichromate, 1 ml of water and 1 drop of diluted H 2 SO 4. The blue coloration of the organic layer (ion of the debris) indicates the presence of peroxide.

4. Some amount of liquid "shake with a drop of pure mercury; In the presence of peroxide, a black film of mercury oxide is formed.

Removal of peroxide (in particular, from ethers)

1. Large amounts of peroxides are removed, withstanding liquids over aluminum oxide or passing them through short columns filled with aluminum oxide. The use of activated aluminum oxide allows you to simultaneously dry the solvent. Precautions: When solvents pass through the column, it is necessary to ensure that aluminum oxide is completely moistened with solvent; Adsorbed peroxide should elute or flush, for example, with a 5% FESO 4 aqueous solution (see below).

2. From liquids insoluble in water, peroxide is removed by shaking with a concentrated solution of bivalent iron salts (100 g of iron (II) sulfate, 42 ml of concentrated HCl, 85 ml of water). With such a treatment in some ethers, small amounts of aldehydes can be formed, which are removed by washing with a 1% melt MCNO 4 solution, then 5%. An aqueous solution of NaOH and water.

3. One of the most effective reagents to remove the peroxide is an aqueous solution of sodium pyrosulfite (also called Na 2 S 2 O 5 metabisulphite), which quickly reacts with shifts in stoichiometric ratios.

4. Packs in large concentrations are completely removed from the esters of washing on the cold triethyleneteramine (25% ester weight).

5. Two SNCL 2 two-rod is the only inorganic reagent, which is effective in solid state.

6. From esters soluble in water, peroxide is usually removed by boiling with reflux in the presence of 0.5 wt.% Cu 2 Cl 2 and subsequent distillation.

Cleaning methods

The use of the cleaning methods below makes it possible to obtain solvents with a purity degree satisfying in most cases the requirements of the chemical and physical experiment (synthesis, kinetic studies, spectroscopy, determination of dipole moments, etc.). It is assumed that the experimenter uses solvents with a certain standard degree of purity produced by the industry (see ch. 1), and not technical solvents containing a large amount of impurities. If special reservations are not made, distillation of the solvent. It is carried out at atmospheric pressure. If the solvent crystallization method is not specified from other fluids, under crystallization implies the freezing of the cleaned solvent; At the same time, with a crystalline mass, up to 20% of the fluid is drained. In addition to the methods set out here in many cases, the so-called "adsorption filtering" can be recommended to clean the solvents using activated aluminum oxide.

Aromatic hydrocarbons

Benzene is very high purity (T. Kip. 80.1 °; T. pl. 5.53 °) are obtained by fractional crystallization from ethanol or methanol followed by distillation. When using the traditional method of purification, benzene shake or stirred with concentrated sulfuric acid (100 ml per 1 liter of benzene) and then a layer of acid is removed; The operation is repeated until the acid layer will have a very weak color. Benzene decanted and distilled. Cleaning using sulfuric acid allows you to remove thiophene, olefins and water from benzene.

Toluene (t. Kip. 110.6 °) and xylene purified in the same way; It should be remembered, however, that these hydrocarbons have a higher than benzene, the ability to sulphide, therefore, when processing their sulfuric acid, it is necessary to cool the mixture, maintaining the temperature below 30 ° C. In addition to sulfuric acid, it is also recommended to use Sasl 2 drying, although, generally speaking, there may be quite simple distillation, since the specified hydrocarbons form azeotropic mixtures with water or have a significantly higher boiling point than water.

Acetone (t. Kip. 56.2 °)

Acetone is very difficult to dry; The use of many of the usually used dried agents (even MgSO 4) leads to acetone condensation. To dry, it is convenient to use molecular sieve 4a and to 2 CO 3. Distillation over a small amount of KMNO 4 allows you to destroy impurities contained in acetone, such as aldehydes. Very pure acetone is obtained as follows: saturated with dry NAI at 25-30 ° C, the solution is decanted and cooled to -10 ° C; NAI crystals are formed with acetone complex, which is filtered and heated to 30 ° C; The resulting liquid is distilled.

Acetonitrile (t. Kip. 81.6 °)

The acetonitrile containing water is previously dried, then stirred from San 2 to the cessation of gas release and are distilled over P 2 O 5 (≤5 g / l) in glass equipment with a reflux with a high phlegm number. The distillate is boiled under reflux over San 2 (5 g / l) at least 1 hour, then slowly distilled, throwing the first 5% and the last 10% distillate in order to reduce the content of acrylonitrile. If acetonitrile contains benzene as an impurity (absorption band in the UV spectrum at 260 nm, an intense "tail" at 220 nm), the latter is removed by azeotropic distillation with water before processing P 2 O 5.

tert-Butyl alcohol (T. Kip. 82 °)

To obtain a very high purity alcohol (m. 25.4 °), it is distilled over SAO with subsequent multiple crystallization.

Dimethyl sulfoxide [t. kip. 189 ° (Split)]

Dimethyl sulfoxide may contain, in addition to water, dimethyl sulfide impurities and sulfon. It is kept for cleaning it for 12 or more hours over fresh aluminum-activated aluminum oxide, dreerite, WA or NaOH. Then distilled under reduced pressure (~ 2-3 mm Hg. Art., So hard 50 °) above the granules of NaOH or WAO and stored over molecular sieve 4a.

Dimethylformamide (t. Kip. 152 °)

N, N-dimethylformamide may contain water and formic acid impurities. The solvent is stirred or shaken with con and distinguish between CAO or WAO.

1,4-dioxane (T. Kip. 102 °)

Dioxane may contain a large number of impurities, so it is difficult to clean it. It is known that many of the described methods are ineffective when cleaning this solvent, as they lead to the decomposition of the fluid. Traditional method Cleaning is as follows. A mixture of 300 ml of water, 40 ml of concentrated HCI and 3 liters of dioxane is boiled under reflux for 12 hours in a slow nitrogen current (to remove acetaldehyde, which is formed during hydrolysis of glycol acetal hydrolysis). The solution is cooled and the Cover granules are added until they stop dissolving and the separation of layers will not occur. The dioxane layer (upper layer) is decanted and dried over fresh potassium hydroxide. Dried dioxane boil over Na for 12 hours or as long as Na does not save a brilliant surface. The rolling solvent is distilled over Na and stored in the dark in the atmosphere N 2.

To dry dioxane, LIALH 4 should not be used, as it can be detected at the boiling point of the solvent. In order to ensure the absence of oxygen and peroxide in the purified dioxane, it is recommended to use benzophenonkel.

Diethyl ether (t. Kip. 34.5 °)

In all cases, with the exception of those using the ready-made "absolute" ether, the solvent should be checked for the presence of peroxides and process it accordingly. When working with ether, additional precautions must be observed associated with the mild solvent flammability. A sufficient dry ether can be obtained drying and distillation over the sodium wire, but the most effective method is distillation over LiAlh 4 (or San 2).

Methanol (T. Kip. 64.5 °)

In methanol, in addition to water, impurities of carbonyl and hydroxyl-containing compounds are found with the number of atoms from 1 to 4, but the solvent with the degree of purity "REAGENT GRADE" usually contains only traces of such impurities. Acetone is removed from methanol in the form of iodoform after NaOi processing. Most of the water can be removed by distillation, since methanol does not form azeotropic mixtures with water. Very dry methanol is obtained, withstanding the solvent over molecular sieves 3a or 4a or passing through the column filled with these molecular sieves; Then the solvent is dried over calcium hydride. As a drying agent for methanol is not recommended to use dreerite! Water residues can also be removed using Methyl magnesium as follows: a mixture of 50 ml of methanol, 5 g Mg in the form of chips and 0.5 g of a sublimated iodine boiling under reflux to discoloration of the solution and cessation of hydrogen discharge. Then add 1 liters of methanol, boiled with reflux for about 30 minutes and carefully distilled.

Nitroleany

Consistent compounds with the number of carbon atoms from 1 to 3 can be quite well cleaned by drying over calcium chloride or P 2 O 5 followed by careful distillation. High purity nitromethane is also obtained by fractional crystallization (T. pl. -28.6 °).

Nitrobenzene (t. Kip. 211 °)

Nitrobenzene, purified by fractional crystallization (vol. 5.76 °) and distillation over P 2 O 5, Besmetell. The solvent containing impurities is quickly stained over P 2 O 5; The pure solvent remains colorless even after a long contact with P 2 O 5.

Pyridine (t. Kip. 115.3 °)

Pyridine is dried for a long time over the granules of the con, then distilled over the WAO. It should be borne in mind that pyridine is very hygroscopic (forms a hydrate, t. Kip. 94.5 °), so it is necessary to ensure that moisture does not fall into the purified solvent.

2-propanol [iso-propanol] (t. Kip. 82.4 °)

2-propanol forms an azeotropic mixture with water (9% water, t. Kip. 80.3 °); Water can be removed with reflux or distillation over lime. The solvent is inclined to the formation of peroxides, which are usually destroyed with reflux over SNCL 2. A sufficiently dry and pure solvent is obtained by distillation over anhydrous calcium sulfate; Very dry alcohol is obtained using MG according to the method described for methanol.

Sulfuric acid (t. Kip. About 305 °)

According to Jolly, 100% acid is usually obtained by adding smoking sulfuric acid to standard 96% acid until the water contained in it does not turn into sulfuric acid. The end time of this procedure is determined as follows: through acid with a small rubber syringe blows wet air; The formation of fog testifies to excess SO 3; If the acid is not yet 100%, the fog is not formed. This method allows you to regulate the composition of the acid with an accuracy of 0.02% (!). Sulfuric acid Very hygroscopic, so it is necessary to ensure that moisture does not fall into it.

Seroublerod (t. Kip. 46.2 °)

The servo carbon is easily flammable and toxic liquid, so when working with it, special precautions must be observed. The solvent should be distilled very carefully using a water bath, which is recommended to heat up to a temperature that slightly exceeding the boiling point of the CS 2. Sulfur sulfur impurities are removed, shaking solvent first with Hg, then with a cold saturated solution of NgSl 2 and then with a cold saturated CMNO 4 solution, after which they are dried over P 2 O 5 and distilled.

Tetrahydrofuran (t. Kip. 66 °)

The solvent must be checked for peroxide and process peroxide and appropriately; Traces of peroxides are removed with a boiling of 0.5% suspension Cu 2 Cl 2 in tetrahydrofuran for 30 minutes, after which the solvent is distilled. Then the tetrahydrofuran is dried over the granules of the con, boil with reflux and are distilled over lithium aluminum hydride or calcium hydride. This method allows you to get a very dry solvent.

Acetic acid (T. Kip. 118 °)

Ice acetic acid that comes on sale (~ 99.5%) contains the impurities of carbonyl compounds, which are removed with reflux with reflux in the presence of 2 to 5 wt.% KmNO 4 or excess 3, after which the acid is distilled. Footprints are removed when heated by treatment with double or triple excess triacetylroom, which is prepared by heating at 60 ° C of a mixture of boric acid and acetic anhydride (in the ratio of 1: 5 by weight); A mixture of acetic acid with triacetylbora is cooled and the formed crystals are filtered off. After distillation, anhydrous acid is obtained. Acetic acid is also dehydrated by distillation over P 2 O 5.

Tour chloride carbon (T. Kip. 76,5 °)

CS 2 impurities from CCl 4 are removed by stirring a hot solvent with 10 vol.% Concentrated alcohol solution con. This procedure is repeated several times, after which the solvent is washed with water, dried over the SACL 2 and distilled over P 2 O 5.

Chloroform (t. Kip. 61.2 °)

Chloroform coming on sale most often contains about 1% ethanol as a stabilizer that protects chloroform from oxidation of air oxygen into phosgene. To clean the solvent, one of the following methods is recommended:

A) chloroform shakes with concentrated H 2 SO 4, washed with water, dried over soles 2 or 2 CO 3 and distilled.

B) Chloroforms are passed through a column filled with activated aluminum oxide (degree of activity 1) (about 25 g per 500 ml of CHCI 3).

C) chloroforms are shaken several times with water (about half of the volume of the solvent), dried over CACL 2 and distilled over P 2 O 5.

The solvent, purified according to any of these methods, is stored in the dark in the atmosphere N 2.

Ethanol (t. Kip. 78.3 °)

Incoming in. The sale "absolute" ethanol contains about 0.1-0.5% water and, as a rule, 0.5-10% of the denaturing agent (acetone, benzene, diethyl ether or methanol, etc.). A more affordable and less expensive solvent is usually a omeotropic mixture with water (4.5%) (95% ethanol or PPIT-Recotted) (T. Kip. 78.2 °). It is this solvent most often used in UV spectrophotometry (ethanol with a degree of purity "REAGENT GRADE" or USP does not contain benzene impurities and other denaturing agents). Pure ethanol is very hygroscopic and easily absorbs moisture; This circumstance should be read when producing a dry solvent.

To remove traces of water from absolute ethanol, the following method is recommended. A mixture of 60 ml of absolute ethanol, 5 g of Mg (chips) and several drops of CCl 4 or SNSL 3 (catalyst) boil with reflux until the entire MG turns into ethylate. Another 900 ml of absolute ethanol is added, refluxed for 1 hour and distilled. If it is necessary to ensure the absence of halogen compounds in the absolute solvent, instead of CCL 4 or SHSL 3, the volatile ethyl bromide can be used as a catalyst. The formation of a bulk precipitate when the benzene solution of aluminum is added to ethanol, it allows you to detect the presence in a solvent to 0.05% of water. Storage of absolute ethanol over molecular sieve for allows to maintain a solvent with water content of not more than 0.005%.

Most of the water from 95% of the alcohol is removed with reflux over fresh lime (SAO) and subsequent distillation. As a different method, azeotropic distillation is recommended: water is distilled off from a triple azeotropic mixture, for example benzene ethanol-water (T. Kip. 64.48 °); Then benzene from the double azeotropic mixture of benzene ethanol is distilled off (T. Kip. 68.24 °).

Ethyl acetate (t. Kip. 77.1 °)

The ethyl acetate coming on sale most often contains the quality of impurities water, ethanol and acid; It is removed by washing the solvent with a 5% aqueous sodium carbonate solution, then a saturated solution of calcium chloride, after which he dried over anhydrous potassium carbonate and distilled over p 2 o 5.

Other solvents

Cellosoles and carbitols are cleaned with drying over calcium sulfate and distillation. Acid anhydrides are purified by fractional distillation from melts of salts of appropriate acids; High molecular weight anhydrides (with 6 carbon atoms, etc.) decompose in the process of distillation at atmospheric pressure.

The invention relates to the production of chlororganic products, in particular to the region of their purification by distillation. Installation for cleaning with distillation of chlororganic solvents contains a cube connected to the source of the original solvent, which is installed on the last and communicated with it, the rectification column of the periodic action, the top of which is connected to the deflector, and the last exit side is connected to the top of the distillation column and to the gathering tanks Product distillation, and the installation is additionally equipped with at least two tanks for the selection of reactive qualifications products and the selection separator of the aqueous intermediate fraction installed at the output from the reflux and connected to the distillation column and the tank collecting through the separator, the distillation column is composed of three Glass Tsarg of the same height, hermetically interconnected, and the diameter of the nozzle distillation column is from 0.06 to 0.07 the height of the distillation column at the height of the last from 2800 to 3200 mm, the cube is made of enameled cast iron, and Phlegmator and capacity for collecting distillation products - from glass. The invention allows to improve the efficiency of the installation for cleaning with distillation of chlororganic products and carry out deep cleaning of carbon four chloride, chloroform, trichloroethylene, methylene chloride and perchlorethylene. 6 N.P. F-lies, 1 yl.

Pictures to the Patent of the Russian Federation 2241513

The invention relates to the production of chlororganic products, in particular to the region of their purification by distillation.

Known the installation for distillation of small industrial batches of solvents containing a water evaporation chamber with electric heaters, a steam tube, a water cooling system (see Patent of the Russian Federation 2068729, cl. At 01 d 3/32, 10.11.1996.

This installation is quite simple. However, it does not make it possible to obtain particularly clean chemicals, which narrows the area of \u200b\u200busing this installation.

Known the installation of purification of chlororganic solvents, in particular methyl chloride, containing a distillation column and a system of condense refrigerators (see application WO 98/37044, cl. From 07 from 17/38, 27.08.1998).

This installation allows you to remove impurities from methyl chloride. However, it also does not allow to achieve a high purity of the product obtained, which is associated with limited product separation capabilities after its release from the top of the distillation column.

The closest to the invention for the technical essence and the resulting result in the device, as an object of the invention, is an installation for cleaning with distillation of chlororganic solvents, containing a cube connected to the source of the original solvent, which is installed on the last and reported ones with it, the rectification column of the periodic action, which is connected To the deflectman, and the last exit from it is connected to the top of the distillation column and to the containers for collecting the distillation product (see Japan's patent JP 2001072623, cl. from 07 from 17/383, 21.03.2001).

This installation allows cleaning of chlororganic products. However, the effectiveness of this installation is not fully used, which is due to the fact that it does not allow to obtain several distillation products of different degrees of purity.

There is a method of purification of methane chlorogenic sodes, in particular chloroform and methyl chloride, as well as the release of methylene chloride in the form of distillates of the distillation column. In this case, the purification of chloroform is carried out by sulfuric acid (see Patent of the Russian Federation 2127245, cl. From 07 from 17/16, 10.03.1999).

However, this method does not allow to obtain products of reactive qualifications. In particular, methylene chloride is obtained by purity of only 99.7%.

There is a method of purification of chloroform in distillation mode using five chicken resistant as an oxidizing agent (see Patent RF №2096400, cl. From 07 from 17/383, 11/20/1997).

However, the use of the solvent can create problems in the disposal of production waste, which also narrows the scope of using this method of purification of chlororganic solvents.

There is a method of purification of chlororganic products from resin and soot, in particular methylene chloride, chloroform, carbon tetrachloride and trichloroethylene. The cleaning method is that in chlororganic products before evaporation or distillation, fuel is injected with buses from 150 to 500 ° C (see Patent RF 2051887, cl. From 07 from 17/42, 01/10/1996).

This method allows to achieve cleaning of chlororganic products from resin and soot, but does not make it possible to achieve the purity of products of distillation of reactive qualifications, for example, "clean for analysis".

The most close to the invention in terms of the method, as an object of the invention, is the method of purification of chlororganic solvents, which consists in the fact that the cube loads the source solvent, heats it into Cuba to the boiling point and send pairs to the distillation column, from the last pair enter the deflements, where they are condensed, and from the reflux of condensate through the separator is fed into the upper part of the distillation column in the form of phlegm, which, in contact with the solvent pairs, condens its hardening components, and the solvent in the form of a liquid phase enriched with hard components is sent back to the cube with the formation in Cuba Thus, the residue, and the solvent pairs, enriched with volatile neglected components, are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is sent as a reflux into a distillation column, and another part of the condensate as a different part of the condensation Product distillation - in the container for collecting the distillation product, (see The above Japan patent JP 2001072623).

However, this well-known method of purification of chlororganic products does not take into account the peculiarities of cleaning with distillation of products such as carbon tetrachloride, chloroform, trichloroethylene, methylene chloride and perchlorethylene, which does not fully use the possibilities of distillation installation and obtain products of the required high purity, in particular qualification products "Chemically clean" or "special purity."

The task of which the present invention is directed to the solution is to increase the efficiency of the installation for cleaning the distillation of chlororganic products and carrying out deep purification of carbon four chloride, chloroform, trichloroethylene, methylene chloride and perchlorethylene.

The specified task in the device part of the device, as an object of the invention, is solved due to the fact that the unit for cleaning with distillation of chlororganic solvents contains a cube connected to the source of the original solvent, which is installed on the last and reported to the rectification column of the periodic action, which is connected to the deflector, and The end of the exit from it is connected to the top of the distillation column and to the containers for collecting the distillation product, while the installation is additionally equipped with at least two tanks for the selection of products of reactive qualifications and the separator installed at the output from the reflux and connected to the distillation column and Tanks for collecting aqueous intermediate fraction and a preign through the separator, the distillation column is composed of the three glass karg of the same height, hermetically interconnected, and the diameter of the planting distillation column is from 0.06 to 0.07 the height of the distillation column. With a height of the last from 2800 to 3200 mm, the cube is made of enameled cast iron, and a deflectman and containers for collecting distillation products - from glass.

In terms of the method, as an object of the invention, the specified task is solved due to the fact that the method of cleaning the distillation of the carbon tetrachloride is that the carbon tetrachloride (CHCH) is loaded into the cube, heated it in Cuba to the boiling point and send pairs to the distillation column and guide. Next to the reflux, where they are condensed from the deflements of condensate through the separator is fed into the upper part of the distillation column in the form of phlegm, which, in contact with CHCH pairs, condenses its hardship components, CHCU in the form of a liquid phase enriched with hard components, send back to the cube with The formation of the balance in Cuba in the Cuba, and the CHCH pairs, enriched with volatile neglected components, are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is sent in the form of phlegm to the distillation column, and another part of the condensate as a product as a product distillation in EM. bones for collecting a distillation product, while supporting a phlegm number equal to 4, the loading of the CHCU technical in the cube is produced at room temperature CHSU, while in Cuba maintain a pressure equal to atmospheric, produce heating of CHCH to a temperature of 75-77 ° C and for 30-40 minutes, the entire condensate from the reflux is directed back to the distillation column in the form of phlegm and support phlegm flow from 180 to 200 dm 3 / h, and the condensate from the reflux is fed into the distillation column through the separator through which the aqueous intermediate fraction and prepression is selected from condensate, and then part of the condensate are taken after a reflux - the products of reactive qualifications in separate containers in the following sequence: "clean", "clean For analysis "," chemically pure ", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 2.5% OB, a prevention from 2 to 6% about," clean "- from 28 to 30% about "Clean for analysis" - from 25 to 28% of the "chemically clean" - from 28 to 30% of the OB, everything from the number of CHCU loaded into the cube, after that the distillation process stops, the cubic residue is disposed of, and products You distillation are sent by destination.

Another method, as an object of the invention, is a method of purification of a chloroform, which is that chloroforms are loaded into the cube, it is heated in Cuba to a boiling point and send pairs to a distillation column and further into a reflux, where they are condensed from the condensate reflux. Through the separator, it is felled into the upper part of the distillation column in the form of a phlegm, which, in contact with the chloroform pairs, condenses its hardening components, chloroform in the form of a liquid phase enriched with hardhery components, is sent back to the cube with the formation of the residue in Cuba, and the chloroform pairs, and the chloroform pairs, The vulture-rich non-interconnected components are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is sent as a reflux into a distillation column, and another part of the condensate as a distillation product - in the container for collecting distillation products, etc. And this is supported by a phlegm number, equal to 4, the loading chloroform of technical in the cube is produced at room temperature of chloroform, while in Cuba maintain a pressure equal to atmospheric, produce heating chloroform to a temperature of 60-65 ° C and within 30-40 minutes the entire condensate from Deflegmators are directed back to the distillation column in the form of phlegm and support the flow of phlegm from 110 to 130 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and prepression is taken from condensate, and then selected after a deflectman Part of condensate - products of reactive qualifications in separate containers in the following sequence: "Clean", "clean for analysis", "chemically clean", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 3.0% about , a prevention from 10 to 12% about, "pure" - from 20 to 25% about, "clean for analysis" - from 28 to 30% of both "chemically clean" - from 12 to 15% o, everything from the amount of chloroform loaded into the cube, after that the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

Another way as an object of the invention is the method of purification of trichloroethylene distillation, which is that trichloroethylene technical is loaded into the cube, it is heated in Cuba to the boiling point and send pairs to the distillation column and continue to the deflements where they are condensed, and from The condensate defleurator through the separator is fed into the upper part of the distillation column in the form of phlegm, which, in contact with trichloroethylene pairs, condensing its hardening components, trichloroethylene in the form of a liquid phase enriched with hard-to-hard components, is sent back to the cube with the formation of the residue in Cuba. Trichlorethylene, enriched with volatile non-interconnected components, are sent to a reflux in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is directed as a reflux into a distillation column, and another part of the condensate as a distillation product - in the tank for collecting A product of distillations, while maintaining a phlegm number, equal to 4, the loading of trichloroethylene technical in the cube is produced at room temperature of trichloroethylene, while in Cuba maintain a pressure equal to atmospheric, produce heating trichloroethylene to a temperature of 89-95 ° C and for 30-40 MIN The entire condensate from the reflux is sent back to the distillation column in the form of phlegm, support the fllegum flow from 100 to 120 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and prepression is taken from condensate, and after This is selected after a reflux of condensate - products of reactive qualifications in separate containers in the following sequence: "clean", "chemically clean", "special purity", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 1.0 to 2, 0% OB, Preconight from 15 to 17%, "Clean" - from 18 to 20% of the "chemically clean" - from 28 to 3 0% of both "special purity" - from 10 to 12% OB, everything from the amount of trichloroethylene loaded to the cube, after that the distillation process is stopped, the duct residue is disposed of, and distillation products are sent to the destination.

Another method, as an object of the invention, is the method of cleaning with a distillation of methylene chloride, which is that the chloride of methylene technical is loaded into the cube, heats it in Cuba to the boiling point and send pairs to the distillation column and continue to the deflements where they are condensed, and From the reflux of condensate through the separator is fed into the upper part of the distillation column in the form of phlegm, which, in contact with the methylene chloride pairs, condenses its hardness components, methylene chloride in the form of a liquid phase enriched in hard components, send back to the cube with the formation of the residue in Cuba , and the pairs of methylene chloride, enriched with volatile neglected components, are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is directed in the form of phlegm to the distillation column, and another part of the condensate as a distillation product - in the container for collecting the distillation product, while they support a phlegm number equal to 4, the loading of methylene technical chlorine in the cube is carried out at room temperature of methylene chloride, while in Cuba maintain a pressure equal to atmospheric, produce heating of the initial solvent to a temperature of 40-44 ° C and for 30-40 minutes, the entire condensate from the reflux is directed back to the distillation column in the form of phlegm and maintain the fllegum flow from 200 to 240 dm 3 / h, and the condensate from the reflux is fed to the distillation column through the separator, through which the water intermediate is taken from condensate The fraction and prevention, and then selected after a reflux portion of condensate - products of reactive qualifications in separate containers in the following sequence: "clean" and "chemically clean", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 1 to 3% about , preconight from 13 to 15% about, "pure" - from 20 to 23.5% of and "chemical Both clean "- from 45 to 50% o, all from the amount of methylene chloride-loaded chloride, after that the distillation process is stopped, the cubic residue is disposed of, and distillation products are directed by purpose.

And one more method of cleaning with distillation perchlorethylene consisting in the fact that perchlorethylene technical was loaded into the cube, heats it in Cuba to the boiling point and send pairs to the distillation column and further into the deflements where they are condensed, and from a reflux of condensate through the separator is fed to the upper part. The distillation column in the form of phlegm, which, in contact with pairs of perchlorethylene, condens its hard-breasted components, perchlorethylene in the form of a liquid phase enriched with hardhery components, is sent back to the cube with the formation of a residue in Cuba, and pairs of perchlorethylene enriched with volatile neglected components directly In a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is directed as a reflux into a distillation column, and another part of the condensate as a distillation product - in the container for collecting a distillation product, while supporting phlegm The number equal to 4, the loading of the perchlorethylene of the technical in the cube is produced at room temperature of perchlorethylene, while in Cuba maintain a pressure equal to atmospheric, produce heating of perchlorethylene to a temperature of 125-130 ° C and within 30-40 minutes the entire condensate from the deflegeman is directed back The rectification column in the form of phlegm, the flow of phlegm is maintained from 120 to 150 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator through which the aqueous intermediate fraction and prepression is taken from condensate, and then part of the condensate is taken after a reflux. Products of reactive qualifications in separate containers in the following sequence: "Clean", "chemically clean", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 5.0% OB, a prevention from 7 to 9% of "Clean" - from 40 to 43% of both "chemically pure" - from 38 to 40% OB, everything from the amount of perchlorethylene loaded to the cube, after This distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by purpose.

In the course of the analysis, it was revealed that the implementation of the distillation column, the deflegram and containers for collecting a glass distillation from glass, for example, from the SIMAX glass, assembled from the three Tsarg of the same height, hermetically interconnected with a diameter of 0.06 to 0.07 from The height of the distillation column at the total height of the distillation column from 2800 to 3200 mm, allows to obtain the products of the qualifications "chemically clean" and "clean for analysis" during the rectification pure Product Up to 75% of its initial quantity, which is quite economically justified. In addition, when installing the installation, materials were used, the use of which during the distillation purification makes it possible to obtain products of jet qualifications, namely the cast-iron cube with enamelled coating and fluoro-tank pads in the locations of the installation design elements.

In the course of the study, optimal conditions for purification of distillation of carbon four chloride, chloroform, trichloroethylene, methylene chloride and perchlorethylene were obtained. For carbon tetrachloride, the following parameters were set: a phlegm number equal to 4, the loading of the original solvent into the cube at room temperature and heating the source product to a temperature of 75-77 ° C. Heating to a lower temperature does not allow to organize the distillation process, and the heating over the specified range does not allow to achieve stable operation of the column. The work of the distillation column "on ourselves" for 30-40 minutes, when the entire condensate from the reflux is directed back to the distillation column as a phlegm and support the fllegum flow from 180 to 200 l / h to reach a stable operation mode at which you can achieve the required The degree of purification of carbon tetrachloride. The flow of condensate from the reflux into a distillation column through the separator makes it possible to select the condensate of the aqueous intermediate fraction and the preign. All of the above allows you to start selection after a deflector of products of reactive qualifications in separate containers in the following sequence: "Clean", "clean for analysis", "chemically clean."

Given the stable nature of the work of the distillation column, it is possible to determine the amount of the selected purified product of the distillation of each of the qualifications of purity, namely the selection in the following quantities: aqueous intermediate fraction of 2.0 to 2.5% OB, a prevention from 2 to 6% OB, "Clean "- from 28 to 30% of the" clean for analysis "- from 25 to 28% of the ones and" chemically pure "- from 28 to 30% of the OB, all on the amount of loaded source solvent.

Similarly, the above modes of operation during purification of chloroform, trichloroethylene, methylene chloride and perchlorethylene were experimentally obtained. As a result, it was possible to solve the problem posed in the invention - to increase the efficiency of the installation for cleaning the distillation of chlororganic products and to carry out high-quality purification of carbon four chloride, chloroform, trichloroethylene, methylene chloride and perchlorethylene.

The drawing presents a schematic diagram of the installation for purification by distillation of chlororganic solvents.

The unit for cleaning with distillation of chlororganic solvents contains a Cube 1-connected to the source, which is installed on the last and reported by the rectification column 2 of the periodic action, the top of which is connected to the deflements of 3, and the last exit side is connected to the top of the distillation column 2, And to the containers 4, 5, 6 to collect the product distillation of reactive qualifications. The installation is additionally provided with a separator 8 installed at the output from the reflux 3 and connected to the distillation column 2 and the tanks 7, 9, respectively, to collect the preign and selection of the aqueous intermediate fraction. The distillation column 2 is made of the three glass tsarg of the same height, hermetically interconnected using fluorocus gaskets. The diameter "D" of the nozzle distillation column is from 0.06 to 0.07 height "H" of the distillation column 2 at a height of the last from 2800 to 3200 mm. Cube 1 is made of enameled cast iron, and capacity 4, 5, 6 for collecting distillation products - from glass.

The method of cleaning with distillation of carbon tetrachloride is made as follows. Loading in Cube 1 Tetrochloride carbon technical, heat it in Cuba 1 to the boiling point and guide pairs to the distillation column 2 and then the pairs are directed to the reflux port 3, where the pairs by cooling are condensed. Next, phlegm is supplied to the distillation column 2, which, in contact with carbon tetrachloride pairs, condenses the hardening components of the carbon four-chloride with the formation of the residue, the latter is sent back to the cube, and the pairs of carbon tetrachloride with volatile neglected components are sent to reflue 3, in which the volatile component is cooled and condensed. After that, part of the condensate is directed in the form of phlegm to the distillation column 2, and another part as a distillation product - in the container 4, 5, 6 to collect a distillation product. During the distillation, a felm number is supported. 4. The loading of carbon four-chloride in Cube 1 is produced at room temperature of the carbon four-chloride, while in Cuba 1 maintain pressure equal to atmospheric. Then produce heating of carbon tetrachloride to a temperature of 75-77 ° C and for 30-40 minutes the entire condensate from the reflux 3 is directed back to the distillation column 2 in the form of phlegm and support the fllegum flow from 180 to 200 dm 3 / h, and the condensate from the reflux Fixed into the distillation column 2 through the separator 8, through which the condensate of the an aqueous intermediate fraction is selected into a special capacity 9, and after that, it takes a selection after the preign separator in the tank 7 and then the deflements produce the selection of condensate - the product of reactive qualifications in separate containers in the following sequence : "Clean" in the capacity 4, "clean for analysis" in the capacity 5 and "chemically clean" in the container 6, and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 2.5% by, preconight from 2 to 6% of the "clean" - from 28 to 30% of the "clean for analysis" - from 25 to 28% of both "chemically pure" - from 28 to 30% of, all from the amount of loaded in Cube 1 carbon four-chloride. After that, the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

Similarly, but taking into account the above-mentioned modest parameters and the parameters of the selection of rectification products, chloroform, trichloroethylene, methylene chloride and perchlorethylene chloride are purified.

Raw materials - Technical carbon Four-chloride GOST 4-84 "highest" and "first grades" is loaded from the barrels a collection under vacuum (p \u003d 0.5 at).

Cube 1 is heated by steam (p \u003d 0.7-1.2 at).

The carbon pairs of the four-chloride rises along the planting part of the distillation column 2, and then pass the temperature of the vapor in which the thermometer is measured (T \u003d 75-77 ° C). Passing the steam pipe, the pairs are condensed in a reflux of 3 cooling cold water.

The condensed pairs fall into the separator 8 and return back to the distillation column 2. Returns phlegm 180-200 dm 3 / hour. The distillation column 2 works in "on itself" 30-40 minutes.

During the operation of the distillation column 2 "on itself", the aqueous intermediate fraction accumulating in the upper layer of the separator 8 is selected, for which the valve is opened and the aqueous fraction is discharged into the collection 9. As the water is selected, the product in the separator 8 gradually brightens. The distillation column 2 works "on itself" to complete lightening of the carbon of the quadshlorister.

The number of selections depends on the quality of the feedstock, namely the presence of water in it, and fluctuates in a volume of 8 to 10 dm 3.

After the operation of the distillation column 2 "on itself", the selection of the preign in the amount of 8-24 dm 3 begins. Open the valve and the preconight enters the collection (capacity) 7. After selecting a pre-ahead, the temperature at the top of the distillation column changes. When the temperature changes in two subsequent preign selection in the range of 1-0.5 ° C and obtaining a positive laboratory analysis, you can switch to the selection of the finished product.

First, the product qualification product is "clean" in the amount of 112-120 dm 3 to the capacity (collection) 4, for which the valves open at its entrance, then select the product qualification product "clean for analysis" in the amount of 100-112 DM 3, for this, the valve is closed On the tank 4 and open the valve on the container 5. By filling out the capacity 5, the valve closes on this container and open the valve to the tank 6 to select the product of the qualification "chemically pure" in the amount of 112-120 dm 3. Having finished the selection of the finished product, closes the valves at the outlet of the reflux.

To complete the operation of the column, the steam supply to the cube shirt 1. Cool the top of the distillation column 2 to room temperature is cooled, then the water is turned off on a reflux. 3. Cube is cooled to 30 ° C. Preconight, product and cubic residue physico-chemical methods quality analysis. The cubic residue is drained into waste barrels. The distillation column 2 begins to prepare to the next start, as described above.

Raw materials (chloroform GOST 20015-88, the highest and first grade or technical) is loaded from the barrels a collection under vacuum (p \u003d 0.5 at). From the latter, the initial raw material is poured into a cube in the amount of 400 dm 3.

Chloroform pairs rise across the pumping part of the distillation column 2, steam pipes pass, the temperature of the steam in which is measured by the thermometer (T \u003d 60-65 ° C). Passing the steam pipe, the pairs are condensed in a reflux of 3 cooling cold water.

The condensed pairs fall into the separator 8 and return to the distillation column 2. The column 2 operates in "on itself" 30-40 minutes.

During the operation of the column "on itself", the aqueous intermediate fraction accumulating in the upper layer of the separator 8 is selected, for which the valve is opened at the inlet to the container (collection) 9. The number of selections depends on the quality of the feedstock, namely from the presence of water in it. The total amount of selection is 8-12 dm 3.

After working, the column "on itself" begins the selection of the preign in the amount of 40-48 DM 3. Preconight enters the capacity 7. After the preign selection ( average temperature In Cuba 62 ° C, and in the upper part of the distillation column - 61.2 ° C) proceed to the selection of the commodity product.

First, the product qualification product is "clean" in the amount of 80-100 dm 3 to the capacity 4, for which we open the valves at its inlet, then select the product qualification product "clean for analysis" in the amount of 112-120 dm 3, for this we close the valve on the tank 4 and open the valve on the tank 5. By filling out the container 5, we close the valve on this container 5 and open the valve of the tank 6 for the selection of the qualification product "chemically pure" in the amount of 48-60 DM 3. Having finished the selection of the finished product, closed the valves.

To complete the operation of the distillation column 2, the steam supply is stopped into the cube shirt 1. Cube 1 is cooled with water through the shirt. Cooled the top of the distillation column 2 to room temperature, then turn off the cooling water on a reflux of 3. Cube is cooled to 30 ° C. Previously an advance, product and cubic residue are subjected to physicochemical methods for analyzing quality, 21 dm 3 chloroforms are on washing. The cubic residue is drained into waste barrels. Preconight merge into waste barrels. The product from containers 4, 5, 6 is directed to the packaging, having previously stabilized with ethyl alcohol (1% of the mass of the finished product), the column is started to prepare to the next start, as described above.

Raw materials (trichlorethylene technical) is loaded from the barrels a collection under vacuum (p \u003d 0.5 at). From the latter, the initial raw material is poured into a cube in the amount of 400 dm 3.

Before starting work, the columns open the airline. Cube 1 is heated by steam (p \u003d 0.5 at). What is the corresponding valve on the steam feed line from the steam generator and the valves for the selection of condensate steam.

The trichloroethylene pairs rise across the pumping part of the distillation column 2, passing the steam room, the temperature of the vapor in which is measured by the thermometer (T \u003d 89-95 ° C). Passing the steam pipe, the pairs are condensed in a reflux of 3 cooling cold water.

The condensed pairs fall into the separator 8 and return to the distillation column 2. The column 2 operates in "on itself" 30-40 minutes. FLEGRE consumption 100-120 dm 3 / h.

After working the column "on itself" begins the selection of the preign in the amount of 60-68 DM 3. The prevention enters the container 7. After the pregnancy selection, the commercial product is selected.

First, the product qualification product is "clean" in the amount of 72-80 dm 3 in the capacity 4, for which the valves open at its entrance, then select the product qualification product "chemically pure" in the amount of 112-120 dm 3, for this, the valve is closed on the tank 4 and Open the valve on the container 5. Filling out the container 5, closed the valve on this container 5 and open the valve 6 for the selection of the qualification product "special clean" in the amount of 40-48 dm 3. Having finished the selection of the finished product, closed the valves.

To complete the operation of the distillation column 2, the steam supply is stopped into the cube shirt 1. Cube 1 is cooled with water through the shirt. Cooled the top of the distillation column 2 to room temperature, then turn off the cooling water on a reflux of 3. Cube is cooled to 30 ° C. Previously an advance, product and cubic residue are subject to physicochemical methods for quality analysis. The cubic residue is drained into waste barrels. Preconight merge into waste barrels. The product from tanks 4, 5, 6 is directed to the packaging, the column is started to prepare to the next start, as described above.

Raw materials (methylene chloride technical) is loaded from the barrels a collection under vacuum (p \u003d 0.5 at). From the latter, the initial raw material is poured into a cube in the amount of 400 dm 3.

The methylene chloride pairs rise across the pumping part of the distillation column 2, pass steam pipes, the temperature of the steam in which is measured by the thermometer (T \u003d 40-44 ° C). Passing the steam pipe, the pairs are condensed in a reflux of 3 cooling cold water.

The condensed pairs fall into the separator 8 and return to the distillation column 2. The column 2 operates in "on itself" 30-40 minutes. FLEGRA consumption 200-240 DM 3 / h.

After working the column "on itself" begins the selection of the preign in the amount of 52-60 DM 3. The prevention enters the container 7. After the pregnancy selection, the commercial product is selected.

First, the product qualification product is "clean" in the amount of 80-94 dm 3 to the capacity 4, for which the valves open at its entrance, then the product of the qualification product "chemically pure" in the amount of 180-200 DM 3 is selected, for this, the valve is closed on the tank 4 and Open the valve on the container 5. Having finished the selection of the finished product, closes the valves.

Raw materials (perchlorethylene technical) is loaded from the barrels a collection under vacuum (p \u003d 0.5 at). From the latter, the initial raw material is poured into a cube in the amount of 400 dm 3.

The pairs of perchlorethylene rise through the nozzle part of the distillation column 2, pass the steam pipe, the temperature of the steam in which is measured by the thermometer (T \u003d 125-130 ° C). Passing the steam pipe, the pairs are condensed in a reflux of 3 cooling cold water.

The condensed pairs fall into the separator 8 and return to the distillation column 2. The column 2 operates in "on itself" 30-40 minutes. FLEGMA consumption is 120-150 DM 3 / h.

After working the column "on itself" begins the selection of the pregrown in the amount of 28-36 dm 3. The prevention enters the container 7. After the pregnancy selection, the commercial product is selected.

First, the product qualification product is "clean" in the amount of 160-172 dm 3 in the capacity 4, for which the valves open at its entrance, then the product qualification product is "chemically pure" in the amount of 152-160 DM 3, for this, the valve is closed on the tank 4 and Open the valve on the container 5. Having finished the selection of the finished product, closes the valves.

To complete the operation of the distillation column 2, the steam supply is stopped into the cube shirt 1. Cube 1 is cooled with water through the shirt. Cooled the top of the distillation column 2 to room temperature, then turn off the cooling water on a reflux of 3. Cube is cooled to 30 ° C. Previously an advance, product and cubic residue are subject to physicochemical methods for quality analysis. The cubic residue is drained into waste barrels. Preconight merge into waste barrels. The product from tanks 4, 5 is directed to the packaging, the column is started to prepare to the next start, as described above.

The present invention can be used in the chemical and perfume industry.

CLAIM

1. Installation for cleaning with distillation of chlororganic solvents, containing a cube connected to the source of the original solvent, installed on the last and reported to the rectification column of a periodic action, the top of which is connected to the deflegmator, and the last from the output side is connected to the top of the distillation column and to The containers for collecting a distillation product, characterized in that the installation is additionally equipped with at least two tanks for the selection of products of reactive qualifications and the separator installed at the output from the reflux and connected to the distillation column and the tanks for collecting the aqueous intermediate fraction and the preign through the separator, The distillation column is composed of the three glass tsarg of the same height, hermetically interconnected, and the diameter of the pumping distillation column is from 0.06 to 0.07 the height of the distillation column at a height of the last from 2800 to 3200 mm, the cube is made of enamelled wow cast iron, and a deflectman and containers for collecting distillation products - from glass.

2. Carbon tetrachloride carbon (CHCT) is loaded into the cube, heated in Cuba to the boiling temperature, and send pairs to the distillation column and continue to the reflux, where they are condensed, from refluxing condensation through the separator Served in the upper part of the distillation column in the form of phlegm, which, in contact with CHCH pairs, condenses its hardship components, CHCH in the form of a liquid phase enriched with hard-heavier components, is sent back to the cube with the formation of the balance in Cuba, and the CHCH pairs enriched with volatile The non-progenited components are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is sent in the form of a reflux into a distillation column, and another part of the condensate as a distillation product - in the container for collecting distillation, characterized by the topics What are supported by phlegmo Number equal to 4, the loading of CHCU technical in the cube is produced at room temperature CHCU, while the pressure is maintained in Cuba equal to atmospheric, the CHCH is heated to a temperature of 75-77 ° C and for 30-40 minutes the entire condensate from the reflux is directed back to the distillation FLEGRE column and support the flow of phlegm from 180 to 200 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and prepression is selected from condensate, and then selected after a reflux of condensate products - jet products Qualifications in separate containers in the following sequence: "Clean", "clean for analysis", "chemically clean", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 2.5% by volume, prevention from 2 up to 6 vol.%, "Clean" - from 28 to 30% by volume, "clean for analysis" - from 25 to 28% by volume and "chemically clean" - from 28 to 30% by volume, all from quantity is loaded Wow to Cube CHCH, after that the distillation process is stopped, the cubic residue is disposed of, and the products of distillation are sent by destination.

3. The method of purification of the chloroform, which consists in the fact that chloroforms are loaded into the cube, heated in Cuba to the boiling point and send pairs to the distillation column and further into the reflux, where they are condensed, from a reflux of condensate through the separator is fed to the upper part of the distillation The columns in the form of phlegm, which, in contact with the chloroform pairs, condenses its hardly hard components, chloroform in the form of a liquid phase enriched with hardening components, are sent back to the cube with the formation of the residue in Cuba, and the chloroform pair, enriched with volatile neglected components, are sent to The reflegemator in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate are directed in the form of phlegm to the distillation column, and another part of the condensate as a distillation product - in the container for collecting a distillation product, characterized in that it is supported by a phlegm number 4, the loading of the chloroform of technical in the cube is produced at room temperature of chloroform, while the pressure is maintained in Cuba equal to atmospheric, the chloroform is heated to a temperature of 60-65 ° C and for 30-40 minutes the entire condensate from the reflux is sent back to the distillation column in the form of FLEGMA and support the flow of phlegm from 110 to 130 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator through which the aqueous intermediate fraction and prepression is selected from condensate, and then part of the condensate are taken from a reflux. Capacities in the following sequence: "Clean", "clean for analysis", "chemically pure", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 3.0% by volume, a prevention from 10 to 12 about .%, "Clean" - from 20 to 25% by volume, "clean for analysis" - from 28 to 30% by volume and "chemically clean" - from 12 to 15% by volume, all on the number of knocked Chloroform contaminated in the cube, after that the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

4. The method of cleaning the distillation of trichloroethylene, which consists in the fact that trichloroethylene technical is loaded into the cube, it is heated in Cuba to a boiling point and send pairs to a distillation column and further to a reflux, where they are condensed, and from a reflux of condensate through the separator is supplied to the upper part. The distillation column in the form of phlegm, which, in contact with vapors of trichloroethylene, condenses its hard components, trichloroethylene in the form of a liquid phase enriched with hardening components, is directed back to the cube with the formation of the residue in Cuba, and trichloroethylene pairs, enriched with volatile neglected components are sent to The deflements in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate are directed in the form of phlegm to the distillation column, and another part of the condensate as a distillation product - in a container for collecting a distillation product, characterized in that The GMO number is equal to 4, the loading of trichloroethylene technical in the cube is made at room temperature of trichloroethylene, while the pressure is maintained in Cuba equal to atmospheric, produce heating trichloroethylene to a temperature of 89-95 ° C and for 30-40 minutes, the entire condensate from the reflux is sent back to the distillation FLEGMA column and maintain a fllegum stream from 100 to 120 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and preconight is selected from condensate, and then selected after a reflux of condensate products - jet products qualifications in separate containers in the following sequence: "Clean", "chemically clean", "special purity", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 1.0 to 2.0% by volume, preconight from 15 to 17 vol.%, "Clean" - from 18 to 20% by volume, "chemically pure" - from 28 to 30% by volume and "special purity" - from 10 to 12% by volume, All from the quantity of trichloroethylene loaded into the cube, after that the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

5. The method of purification of the distillation of methylene chloride, which consists in the fact that chloride methylene chloride is loaded in cube, heats it into the cube to the boiling point and send pairs to the distillation column and further into the reflux, where they are condensed, and from the reflux of condensate through the separator is supplied to The top of the distillation column in the form of a phlegm, which, in contact with the methylene chloride pairs, condensate its hardening components, methylene chloride as a liquid phase enriched with hard components, is sent back to the cube with the formation of the residue in Cuba in the Cuba, and the pairs of methylene chloride, enriched The abnormal non-projected components are sent to a reflux, in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate is directed as a reflux into a distillation column, and another part of the condensate as a distillation product - in a distillation product capacity, which is different In the fact that the phlegm number is supported 4, the loading of methylene chloride technical in the cube is produced at room temperature of methylene chloride, while the pressure is maintained in Cuba equal to atmospheric, produce heating of the initial solvent to a temperature of 40-44 ° C and for 30-40 min. The condensate from the reflux is directed back to the distillation column in the form of phlegm and support the flow of phlegm from 200 to 240 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and prepression is taken from condensate, and then select After a refluxer, part of the condensate - products of reactive qualifications in separate containers in the following sequence: "clean" and "chemically clean", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 1 to 3% by weight, an advancement from 13 to 15 about %, "Pure" - from 20 to 23.5% by volume and "chemically clean" - from 45 to 50% by volume, all from count The arranging of methylene chloride Cube, after that the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

6. The method of cleaning with distillation of perchlorethylene, which consists in the fact that the chloroethylene technical is loaded into the cube, heats it in Cuba to the boiling point and send pairs to the distillation column and further into the deflements where they are condensed, and from a reflux of condensate through the separator is fed to the upper part. The distillation column in the form of phlegm, which, in contact with pairs of perchlorethylene, condens its hard-breasted components, perchlorethylene in the form of a liquid phase enriched with hardhery components, is sent back to the cube with the formation of a residue in Cuba, and pairs of perchlorethylene enriched with volatile neglected components directly The deflements in which they are cooled and condensed, and then after stabilizing the operation of the distillation column, part of the condensate are directed in the form of phlegm to the distillation column, and another part of the condensate as a distillation product - in the container for collecting a distillation product, characterized in that The Legal Number is 4, the loading of the perchlorethylene of the technical in the cube is carried out at room temperature of the perchlorethylene, while the pressure is maintained in Cuba, the pressure equal to the atmospheric, produce the heating of perchlorethylene to a temperature of 125-130 ° C and for 30-40 minutes the entire condensate from the reflux is sent back to the distillation FLEGMA column and maintain a flow of phlegm from 120 to 150 dm 3 / h, and the condensate from the reflux is supplied to the distillation column through the separator, through which the aqueous intermediate fraction and prediment is taken from condensate, and then selected after a reflux of condensate products - jet products qualifications in separate containers in the following sequence: "clean", "chemically pure", and the selection of the specified condensate is carried out in the following quantities: aqueous intermediate fraction from 2.0 to 5.0% by volume, a prevention from 7 to 9% by volume, "Clean" - from 40 to 43% by volume and "chemically clean" - from 38 to 40% by volume, all from the amount of perchlorethylene loaded in the cube A, after that, the distillation process is stopped, the cubic residue is disposed of, and distillation products are sent by intended purpose.

Methods for cleaning organic solvents depend on the nature and purpose of the solvent. In most cases, organic solvents are individual compounds and can be characterized by their physicochemical indicators. The most elementary solvent cleaning operation is a simple or fractional distillation. However, distillation often fails to be freed from a number of impurities, including from small amounts of water.

Conventional cleaning methods can be obtained by a solvent of approximately 100% purity. With the help of adsorbents, in particular molecular sieves (zeolites), this task is solved more efficiently and with less considerable time. In the laboratory conditions for this purpose, ionics are most often used - zeolites brands NAA or ka.

In the preparation of pure anhydrous solvents, precautions should be particularly strictly observed, since most of the organic solvents - combustible substances, the pairs of which are formed with air explosive mixtures, and in some of them (ethers), with long-term storage, explosive peroxidation compounds are formed. Many organic solvents are very toxic, both inhaling their vapors and when they are on the skin.

All operations with flammable and combustible organic solvents should be carried out in the exhaust cabinet when performing ventilation, turned off gas burners and electric heating devices. Heat and distilled liquids in the exhaust cabinet on preheated baths filled with the corresponding coolant. When distilling organic fluid, it is necessary to constantly monitor the operation of the refrigerator.

If flammable solvents (gasoline, diethyl ether, servo-carbon, etc.) are randomly shed, it is necessary to immediately pay all the sources of open fire and turn off the electric heating devices (during the day to de-energize the work room). The place where the liquid is spilled, it is necessary to fall asleep with sand, polluted sand assemble a wooden scoop and pour out a garbage container mounted in the outdoor.

When drying solvents, active drying agents should not be used until the pre-coarse drying is carried out using conventional drying agents. So, it is forbidden to dry the crude diethyl ether with a metallic sodium without preliminary drying with calcined CaCl2.

When working with simple ethers and other substances (diethyl ether, dioxane, tetrahydrofuran), during the storage process of which peroxide compounds can form, first remove the peroxide, and then distilled and dried. Distilted anhydrous organic solvents should be carefully. All elements of the installation for distillation (distillation flask, reflux, refrigerator, alone, distillate receiver) are pre-dried in a drying cabinet. The distillation is carried out without air access, and the along is supplied with a chlocaltizive tube filled with ascaritis and melted CaCl2 to absorb CO2 and H2O. The first portion of the distillate, serving for washing all the equipment, is advisable to discard.

Below are the methods of cleaning and dehydration of the most common solvents.

Acetone

Acetone CH3SN3 is a colorless liquid; D25-4 \u003d 0.7899; Tkip \u003d 56.24 ° C; N20 - D \u003d 1,3591. Easy flammable. Couples form explosive mixtures with air. Technical acetone usually contains water with which it is mixed in any ratios. Sometimes acetone is contaminated with methyl alcohol, acetic acid and regenerating substances.

The sample on the presence of regenerating substances in acetone is carried out as follows. To 10 ml of acetone add 1 drop of 0.1% KMNO4 aqueous solution; After 15 minutes at room temperature, the solution should not be discouraged.

For cleaning acetone, several hours are heated with anhydrous K2CO3 (5% (mass)) in the flask under reflux, then the liquid is transferred to another flap with a reflux agent 25-30 cm and distilled over anhydrous K2CO3 (about 2% (mass.) ) and crystalline KMNO4, which is added to the acetone before the appearance of stable purple color in the water bath. There is no methyl alcohol in the resulting acetone, but there is a slight amount of water.

For complete water removal, acetone is rebuilt over anhydrous CaCl2. To do this, in a 2-liter round-bottom flask, equipped with an effective reflux, a closed chlocalcium tube with CaCl2, is poured 1 liter of acetone, 120 g CaCl2 is made and boiled on a water bath with a closed electrical heating 5-6 hours. The reaction flask is cooled and overflow acetone In another similar flask with a fresh portion of CaCl2 and boil 5-6 hours. After that, the refrigerator is replaced with the downward, to which, with the help of an alone connected to a chloricalized tube, filled with CaCl2, join the flask-receiver cooled with ice and distilled acetone over CaCl2.

Instead of such a long and time-consuming operation, which often leads to condensation of acetone, it is better to use Zeolite NAA. With long-term maintenance of acetone above this zeolite (5% (mass)), the absoluting of acetone is achieved.

In small quantities, a very pure acetone can be obtained from the adduct (product of attachment) of acetone and NAI, which is already decomposed at low heating, highlighting acetone. To do this, when heating in the water bath is dissolved 100 g of NAI in 440 ml of dry freshly-perched acetone. The resulting solution is quickly cooled to -3 ° C, immersing a vessel in a mixture of ice with NaCl. The allocated solid adduct NAI-C3H6O is separated on the Buchner funnel, tolerate the installation for distillation and heated in a water bath. With easier heating, the adduct decomposes, and the released acetone is distilled off. The distillate is dried with anhydrous CaCl2 and re-distinguish with a reflux over CaCl2. NAI regenerated can be renewed for the same reaction.

The express method of purification of acetone from methyl alcohol and reducing substances is as follows: 700 ml of acetone in the flask with a capacity of 1 liter is a solution of 3 g of AGNO3. In 20 ml of distilled water and 20 ml of 1N. NaOH solution. The mixture is shaken for 10 minutes, after which the precipitate is filtered off on a funnel with a glass filter, and the filtrate is dried Caso4 and distilled with a reflux over CaCl2.

Acetonitrile

CH3CN acetonitrile is a colorless liquid with a characteristic essential smell; d20-4 \u003d 0,7828; Tkip \u003d 81.6 ° C; N20 - D \u003d 1.3442. With water mixed in all respects and forms azeotropic mixture (16% (mass.) H2O) with Tkip \u003d 76 ° C. A good solvent for a number of organic substances, in particular, amine chlorohydrates. It is also used as a medium for carrying out some reactions that it accelerates catalytically.

Acetonitrile is a strong inhalation poison and is capable of absorbed through the skin.

To absolute acetonitrile, doublely distilled over P4O10, followed by distillation over anhydrous K2CO3 to remove traces of P4O10.

You can pre-dry acetonitrph over Na2SO4 or MgSO4, then mix it from San2 to stop the separation of gas (hydrogen) and overtake over P4O10 (4-5 g / l). The distillate is boiled under reflux over San2 (5 g / l) at least 1 hour, then slowly distinguished by discarding the first 5 and the last 10% distillate.

Benzene

Benzole C6H6 is a colorless liquid; D20-4 \u003d 0.8790; TPL \u003d 5.54 ° C; Tkip \u003d 80 10 ° C; N20 - D \u003d 1,5011. Benzole and its homologue - toluene and xylenes - are widely used as solvents and medium for azeotropic drying. Working with benzene should be carefully due to its flammability and toxicity, as well as due to the formation with air of explosive mixtures.

A pairs of benzene with repeated effects violate the normal function of the blood-forming organs; In a liquid state, benzene is strongly absorbed through the skin and annoys it.

Technical benzene contains up to 0.02% (waters), slight thiophene and some other impurities.

Benzole forms azeotropic mixture with water (8.83% (mass.) H2O) with Tkip \u003d 69.25 ° C. Therefore, with distillation of wet benzene, water is almost completely distilled off with the first portions of distillate (turbid liquid), which are discarded. As soon as the transparent distillate will be distilled, you can consider the drainage process by completed. The removal of the disturbed benzene is usually produced by calcined CaCl2 (for 2-3 days) and sodium wire.

In the cold season, it is necessary to ensure that the distillation benzene does not crystallized in the tube of the refrigerator, washed with cold water (4-5 ° C).

Benzole and other hydrocarbons dried with metallic sodium, hygroscopic, i.e. can absorb moisture.

Commodity technical benzene contains up to 0.05% (mass.) Tiophen C4H4S (TKIP \u003d 84.12 ° C; TPL \u003d 38.3 ° C), which cannot be separated from benzene to a fractional distillation or crystallization (freezing). Tiophen in benzene is detected as follows: a solution of 10 mg of izin in 10 ml of conc. H2SO4 shake with 3 ml of benzene. In the presence of thiophene, the sulfuric acid layer is painted in a blue-green color.

Benzol is purified from thiophen repeated shaking with conc. H2SO4 at room temperature. Under these conditions, it is primarily thiophene, and not benzene. On 1 l benzene take 80 ml of acid. The first portion of H2SO4 is painted in blue-green. The lower layer is separated, and the benzene shake with a new portion of the acid. Cleaning leads until weakly yellow acid staining is reached. After separation of the acid layer, benzene was washed with water, then a 10% solution of Na2CO3 and again with water, after which the benzene is distilled.

A more efficient and simple method for cleaning benzene from thiophene - boiling 1 l benzene with 100 g of Renhea nickel in a reflux flask for 15-30 minutes.

Another method of purification of benzene from thiophene is fractional crystallization from ethyl alcohol. The saturated solution of benzene in alcohol is cooled to about -15 ° C, the solid benzene is rapidly filtered and distilled.

Dimethyl sulfoxide

Dimethyl sulfoxide (CH3) 2SO is a colorless syrupy liquid without a pronounced smell; D25-4 \u003d 1,1014; Tkip \u003d 189 ° C (with decomposition); tpl \u003d 18,45 ° С; N25-D \u003d 1,4770. Mixed with water, alcohols, acetone, ethyl acetone, dioxane, pyridine and aromatic hydrocarbons, but is not mixed with aliphatic hydrocarbons. Universal solvent for organic compounds: ethylene oxide, heterocyclic compounds, camphor, resins, sugars, fats, etc. It also dissolves many inorganic compounds, for example, at 60 ° C dissolves 10.6% (mass.) KnO3 and 21.8% CaCl2. Dimethyl sulfoxide is practically not toxic.

For purification, dimethyl sulfoxide is kept over the day over the active Al2O3, after which they are blown twice at a pressure of 267-400 Pa (2-3 mm Hg. Art.) Over the melted con (or WAO) and stored above the NAA zeolite.

Under the action of reducing agents, dimethyl sulfoxide is converted to sulphide (CH3) 2S, and under the action of oxidizers - in sulfon (CH3) 2SO2, incompatible with chloride hydrhydrides of inorganic and organic acids.

N, N-dimethylformamide

N, n-dimethylformamide HCon (CH3) 2 - colorless light-giving fluid with a weak specific smell; D25-4 \u003d 0.9445; Tkip \u003d 153 ° C; N24-D \u003d 1,4269. Mixed in any respects with water, alcohol, acetone, ether, chloroform, servo-carbon, halogen-containing and aromatic compounds; Aliphatic hydrocarbons dissolve only when heated.

Dimethylformamide is distilled at atmospheric pressure without decomposition; decomposes under the action of ultraviolet rays with the formation of dimethylamine and formaldehyde. The dimethyl formamide reagent, besides methylamine and formaldehyde, may contain methyl formamide, ammonia and water as impurities.

Dimethylformamide is purified as follows: 10 g of benzene and 4 ml of water are added to 85 g of dimethylformamide and the mixture is distilled. Initially, benzene with water and other impurities is distilled off, and then a clean product.

Diethyl ether

Diethyl ether (C2H5) 2O - colorless light-giving volatile liquid with a peculiar smell; D20-4 \u003d 0.7135; Tkip \u003d 35.6 ° C; N20-D \u003d 1,3526. Extremely easily flammable; Couples form explosive mixtures with air. Couples are heavier than 2.6 times and can step on the surface of the desktop. Therefore, it is necessary to ensure that all gas burners have been passed nearby (up to 2-3 m) from the place of work with the ether, and the open spiral electric shields are disconnected from the network.

When storing diethyl ether under the action of light and air oxygen, it forms explosive peroxide compounds and acetaldehyde. The peroxidation compounds are the cause of extremely strong explosions, especially when trying to overtake the ether to dryness. Therefore, when determining the boiling point and non-volatile residue, the ether should be previously checked for the content of peroxide. If there are peroxides, these definitions cannot be carried out.

For detection of peroxide in diethyl ether, many reactions are proposed.

1. Reaction with potassium ki iodide. Several milliliters of ether shake with an equal volume of 2% Ki aqueous solution, acidified with 1-2 drops of HCl. The appearance of brown staining indicates the presence of peroxide.

2. TIOSO4 titanyl sulfate reaction. The reagent is prepared by dissolving 0.05 g of Tioso4 in 100 ml of water, acidified with 5 ml of diluted H2SO4 (1: 5). When shaking 2-3 ml of this react with 5 ml of the test ether containing peroxide compounds, yellow color appears.

3. Reaction with sodium bichromate Na2Cr2O7. 2-3 ml of 0.01% aqueous solution Na2Cr2O7 and one drop of diluted H2SO4 (1: 5) is added to 3 ml of ether. The mixture is greatly shaken. The blue color of the ethereal layer indicates the presence of peroxide.

4. Reaction with FE Ferrotiocyanate (SCN) 2. A colorless solution Fe (SCN) 2 under the action of a drop of liquid containing the peroxide, is painted in red due to the formation of ferrityiocyanate (Fe2 +\u003e Fe3 +). This reaction allows you to detect peroxide at a concentration to 0.001% (mass.). The reagent is prepared as follows: 9 g FESO4-7H2O is dissolved in 50 ml of 18% NCl. To the solution in an open vessel, a granular zinc and 5 g of sodium thiocyanate NASCN are added; After the disappearance of red staining, another 12 g of NASCN is added, carefully shackled and the solution is separated from decintation.

To remove peroxide, iron (II) sulphate is used. When baking 1 l ether usually take 20 ml of a solution prepared from 30 g FESO4-7H2O, 55 ml of H2O and 2 ml of conc. H2SO4. After washing, the ether is shaken with a 0.5% KmnO4 solution for oxidation of acetaldehyde into acetic acid. Then, the ether was washed with 5% NaOH and water, dried 24 hours over CaCl2 (150-200 g CaCl2 per 1 liter of ether). After that, CaCl2 is filtered on a large folded paper filter and assemble the air into a dark glass flasher. The flask is tightly closed with a cortical cork with an inserted into it curved under a sharp angle of a chlocalcium tube filled with CaCl2 and glass wool tampon. Then, opening the flask, the sodium wire is quickly made, at the rate of 5 g per 1 liter of ether.

After 24 hours, when the bubbles of hydrogen cease to be released, another 3 g of sodium wire per 1 liter of ether and after 12 hours, the air is transferred to the flask for distillation and distilled over the sodium wire. The receiver must be protected by a chlocalcium tube with CaCl2. Distillates are collected in a dark glass in a flask, which, after making 1 g, sodium wire per 1 liter of ether is closed with a cortical cork with a chlocalcium tube and stored in a cold and dark place.

If the surface of the wire has changed a lot and when adding wires, hydrogen bubbles are released again, the ether should be filtered into another flask and add a portion of the sodium wire.

Comfortable and very effective method Purification of diethyl ether from peroxide and at the same time from moisture - transmitting ether through a column with active Al2O3. The columns with a height of 60-80 cm and a diameter of 2-4 cm filled with 82 g of Al2O3, sufficient for purification of 700 ml of ether containing a significant number of peroxidation connections. The exhaust Al2O3 is easy to regenerate if the acidified aqueous solution of FESO4-7H2O is flushed through a 50% column, rinse with water, dry and carry out thermal activation at 400-450 ° C.

Absolute ether is a very hygroscopic fluid. The degree of absorption of moisture by ether during its storage can be judged by the formation of anhydrous white Cuso4 powder when making it on the air (a painted CUSO4-5H2O hydrate) is formed.

Dioxan

Dioxane (CH2) 4O - colorless combustible liquid with a weak odor; D20-4 \u003d 1,03375; Tkip \u003d 101.32 ° C; tpl \u003d 11.80 ° C; N20-D \u003d 1,4224. Mixed with water, alcohol and ether in any respect. Forms azeotropic mixtures with water and alcohol.

Technical dioxane contains ethylene glycol, water, acetaldehyde and peroxide as impurities. The method of purification of dioxane should be chosen depending on the degree of contamination, which is determined by adding metal sodium to dioxane. If a brown sediment is formed, the dioxane is severely contaminated; If the sodium surface varies slightly, the dioxane contains little impurities and purify it, distilling over the sodium wire.

Highly contaminated dioxane is purified as follows: 0.5 liters of dioxane, 6 ml conc. HCl and 50 ml of H2O are heated on silicone (oil) bath in a nitrogen current in a refrigerator flask at 115-120 ° C for 12 hours.

After cooling, the liquid shakes with small portions of the melted con removing water and acid. Dioxan forms the upper layer, it is separated and dried with fresh portion of the con. The dioxane is then transferred to a clean distillation flask and heated under reflux over 3-4 g of sodium wire for 12 hours. Cleaning is considered to be finished if the sodium surface remains unchanged. If the sodium reacted all, then you need to add a fresh portion and continue drying. Dioxane, not containing peroxide compounds, is distilled on a column or with an effective reflux for normal pressure. Purification of dioxane from peroxide is carried out, as well as the purification of diethyl ether.

Methyl alcohol (methanol)

Methyl alcohol (methanol) CH3on is a colorless light-grazing combustible liquid, with a smell like a smell of ethyl alcohol; D20-4 \u003d 0.7928; Tkip \u003d 64,51 ° C; N20-D \u003d 1,3288. Mixed in all respects with water, alcohols, acetone and other organic solvents; Does not mix with aliphatic hydrocarbons. Forms azeotropic mixtures with acetone (Tkip \u003d 55.7 ° C), benzene (TKIP \u003d 57.5 ° C), servo-carbon (Tkip \u003d 37.65 ° C), as well as with many other connections. With water, methyl alcohol does not form azeotropic mixtures, so most of the water can be removed by distillation of alcohol.

Methyl alcohol - a strong poison affecting mainly nervous system and blood vessels. In the human body, he can go through the respiratory tract and the skin. Especially dangerous when taking inside. The use of methyl alcohol in laboratory practice is allowed only in cases where it cannot be replaced by other, less toxic substances.

Synthetic comprehensive methyl alcohol manufactured by industry contains only traces of acetone and up to 0.1% (waters). In the laboratory conditions, it can be prepared from the technical CH3on, in which the content of these impurities can reach 0.6 and even 1.0%. In the flask with a capacity of 1.5 liters with reflux, protected by a chlorcaltizium tube with CaCl2, 5 g of magnesium chips are placed, the 60-70 ml of methyl alcohol is poured, containing no more than 1% water, add the initiator - 0.5 g of iodine (or appropriate The amount of methylodide, ethyl bromide) and heated to dissolving the latter. When the whole magnesium goes into the methylate (white precipitate is formed at the bottom of the flask), 800-900 ml of technical CH3on is added to the resulting solution, boil in the flask with reflux for 30 minutes, after which the alcohol from the flap with a flammator is 50 cm high, collecting The fraction with a boiling point of 64.5-64.7 ° C (at normal pressure). The receiver is supplied with a cotton tube with CaCl2. The content of water in the alcohol obtained in this method does not exceed 0.05% (mass.). The absolute methyl alcohol is retained in a vessel, protected from air moisture.

The accumulation of methyl alcohol containing 0.5-1% water can be carried out with metallic magnesium and without initiation of the reaction. To do this, 10 g of magnesium chips is added to 1 l, the mixture is allowed in a reflux with a reflux, protected by a chlocalcium tube with CaCl2. The reaction begins spontaneously, and soon the alcohol boils. When the whole magnesium is dissolved, boiling is maintained by heating in a water bath for some time, after which the alcohol is distilled by discarding the first portion of the distillate.

Anhydrous methyl alcohol is also obtained, withsting it over the Naa zeolite or ka or passing through the column filled with these molecular sieves. To do this, you can use a laboratory type column.

The presence of acetone in methyl alcohol is set to sodium nitroprusside. The alcohol is diluted with water, alkaline and add several drops of freshly prepared saturated aqueous solution of nitroprusside sodium. In the presence of acetone, a red color appears, increasing when acidified with acetic acid.

To remove acetone, the following method is proposed: 500 ml CH3on boil several hours with 25 ml of furfurol and 60 ml of 10% NaOH solution in a reflux flask, and then distinguishes alcohol on an effective column. The resin remains in the flask - the product of the interaction of Furfurol with acetone.

Petroleum ether, gasoline and ligroin

In the distillation of light gasoline, a number of low-coating hydrocarbon fractions are obtained, which are used as solvents. A pairs of these hydrocarbons have a narcotic action.

Industry manufactures the following reagents:

Large volatility of petroleum ether, gasoline and ligrine, their easy flammability and formation with air of explosive mixtures requires special caution when working with them.

Petroleum ether, gasoline and ligroin should not contain impurities of unsaturated and aromatic hydrocarbons.

The presence of unsaturated hydrocarbons is usually installed by two reagents: 2% BR2 solution in CCl4 and 2% KMNO4 aqueous solution in acetone. To do this, 0.2 ml of hydrocarbon in 2 ml of CCl4 is added dropwise a solution of the reagent and observed the color change. The sample is considered negative if no more than 2-3 drops of the bromine solution or the KMNO4 solution are discolored.

Unsaturated hydrocarbons can be removed by multiple 30-minute shaking on the mechanical rocking of the portion of hydrocarbons from 10% (about.) Conf. H2SO4. After shaking with each portion of the acid, the mixture is allowed to stand, then separated the bottom layer. When the acid layer ceases to be stained, the hydrocarbon layer is vigorously shaken with several portions of 2% KmnO4 solution in a 10% solution of H2SO4, while the color of the KMNO4 solution will no longer change. At the same time, unsaturated hydrocarbons and partially aromatic are almost completely removed. To completely remove aromatic hydrocarbons, you need to shake the hydrocarbons on the rocking chair (petroleum ether, etc.) with oleum containing 8-10% (mass.) SO3. A flask with a fitting plug in which shaking is made, wrapped in a towel. After separating the acid layer, the hydrocarbon fraction was washed with water, a 10% Na2CO3 solution, again with water, dried over anhydrous CaCl2 and distilled over sodium wire. It is recommended to store petroleum ether over Caso4 and distinguish before use.

The traditional chemical method of cleaning saturated hydrocarbons from unsaturated very time consuming and can be replaced by adsorption. The impurities of many unsaturated compounds are removed when the solvent is passed through a glass column with an active Al2O3 and especially on zeolites, such as NAA.

Tetrahydrofuran

Tetrahydrofuran (CH2) 4O - colorless movable liquid with essential smell; D20-4 \u003d 0.8892; Tkip \u003d 66 ° C; N20-D \u003d 1.4050. Dissolves in water and most organic solvents. Forms azeotropic mixture with water (6% (mass.) H2O), Tkip \u003d 64 ° C. Tetrahydrofuran is inclined to form peroxide compounds, so it is necessary to check the presence of peroxide in it (see Diethyl ether). Remove peroxide can be boiled with 0.5% Cu2Cl2 suspension for 30 minutes, after which the solvent is distilled and shaken with melted con. The upper layer of tetrahydrofuran is separated, 16% (mass) con and boil the mixture of 1 h in the reflux to it again. Then the tetrahydrofuran is distilled over San2 or LiAlh4, discard 10-15% of the head fraction and leave about 10% of the remainder in Cuba. The head fraction and the cubic residue attach to technical products intended for cleaning, and the assembled medium fraction is peeling over the sodium wire. The purified product is stored without air access and moisture.

Chloroform

Chloroform CHCl3 is a colorless movable liquid with a characteristic sweet odor; D20-4 \u003d 1.4880; Tkip \u003d 61.15 ° C; N20-D \u003d 1,4455. Soluble in most organic solvents; Practically insoluble in water. Forms azeotropic mixture with water (2.2% (mass.) H2O), Tkip \u003d 56.1 ° C. Non-flamm and does not form explosive mixtures with air, but toxic - acts on the internal organs, especially on the liver.

Chloroform almost always contains up to 1% (mass.) Ethyl alcohol, which is added to it as a stabilizer. Another admixture of chloroform may be phosgene formed during the oxidation of chloroform in the light.

The probem on the presence of phosgene is performed as follows: 1 ml of 1% solution of N-dimethylaminobenzaldehyde and diphenylamine in acetone shake with chloroform. In the presence of phosgene (up to 0.005%) after 15 min, intensive yellow color occurs. Chloroform is purified by three-time shaking with separate portions conc. H2SO4. On 100 ml of chloroform each time it takes 5 ml of acid. Chloroform is separated, washed 3-4 times with water, dried on CaCl2 and distilled.

Cleaning chloroform is also achieved by slow transmission of the preparation through a column filled with al2O3 in an amount of 50 g per 1 liter of chloroform.

Chloroform should be stored in dark glass flasks.

Tour chloride carbon

CCL4 carbon tetrachloride - colorless non-combustible fluid with a sweet odor; D20-4 \u003d 1,5950; Tkip \u003d 76.7 ° C; N25 - D \u003d 1,4631. Practically insoluble in water. With water forms azeotropic mixture (4.1% (mass.) H2O), Tkip \u003d 66 ° C. Dissolves a variety of organic compounds. It has less than chloroform, narcotic action, but toxicity exceeds it, causing severe liver damage.

The carbon tetrachloride is sometimes contaminated with a servo-carbon, which is removed by mixing CCl4 at 60 ° C in a reflux with a reflux from 10% (about.) Concentrated alcohol solution con. This procedure is repeated 2-3 times, after which the solvent is washed with water, stirred at room temperature with small portions of the conc. H2SO4 as long as she stops staining. Then the solvent is again washed with water, dried over CaCl2 and distilled over P4O10.

CCL4 drying is achieved by azeotropic distillation. Water is removed with the first turbid portions of the distillate. As soon as the transparent liquid starts over, it can be considered anhydrous.

Ethyl acetate

Ethyl acetate CH3SO2N5 is a colorless liquid with a pleasant fruit smell; D20-4 \u003d 0.901; Tkip \u003d 77.15 ° C; N20-D \u003d 1.3728. Forms azeotropic mixture with water (8.2% (mass.) H2O), Tkip \u003d 70.4 ° C.

Technical ethyl acetate contains water, acetic acid and ethyl alcohol. A lot of methods for cleaning ethyl acetate are proposed. According to one of them, ethyl acetate shakes with an equal volume of 5% NaHCO3 solution and then with a saturated CaCl2 solution. After that, ethyl acetate is dried K2CO3 and distilled in a water bath. For the final drying, 5% P4O10 is added to the distillate and shaken vigorously, then filtered and distilled over the sodium wire.

Ethanol

Ethyl alcohol C2H5on is a colorless liquid with a characteristic odor; D20-4 \u003d 0.7893; Tkip \u003d 78.39 ° C; N20 - D \u003d 1,3611. Forms azeotropic mixture with water (4.4% (mass.) H2O). It has a high dissolving ability with respect to a variety of compounds and is unlimited mixed with water and with all conventional organic solvents. Technical alcohol contains impurities, the qualitative and quantitative composition of which depends on the conditions for its production.

The output absolute alcohol, which is obtained by azeotropic distillation of 95% of the technical alcohol with benzene, may contain small amounts of water and benzene (up to 0.5% (mass.)).

Dehydration 95% of alcohol can be made of long-term boiling with calcined CAO. On 1 liter of alcohol take 250 g of SAO. The mixture is boiled in a 2-liter flask with reflux, a closed tube with SAO, for 6-10 hours. After cooling, the flask is attached to the unit for distillation at atmospheric pressure and distinguishes alcohol. Yield 99-99.5% alcohol 65-70%.

High dehydrating properties have barium oxide WAO. In addition, WAO is able to dissolve a little in almost absolute alcohol, painting it in yellow. This feature is determined when the absoluting process is completed.

Further dehydration 99-99.5% of alcohol can be carried out in several methods: using magnesium (ethyl alcohol with water content of not more than 0.05%), sodium sodium and oxal diethyl ester.

In the round bottom flask with a capacity of 1.5 liters with reflux and a cotton tube with CaCl2 poured 1 liter. 99% of ethyl alcohol, after which 7 g of sodium wire contributes to small portions. Under the dissolution of sodium, 25 g of oxalic acid diethyl ester is added to the mixture, 2 hours are boiled and the alcohol is distilled off.

Similarly, absolute alcohol is obtained using orthophthalic acid diethyl ether. In the flask, equipped with reflux and a chlocalcium tube with CaCl2, is placed 1 l 95% alcohol and dissolve in it 7 g of sodium wire, after which 27.5 g of phthalic acid diethyl ether is added, the mixture is boiled by about 1 h and the alcohol is distilled off. If a small amount of precipitate is formed in the flask, it proves that the original alcohol was quite good quality. And on the contrary, if a large amount of sediment drops and boiling is accompanied by the impetus, the initial alcohol was not sufficiently dried.

Drain of ethyl alcohol is currently carried out in column type apparatus with NAA zeolite as nozzle. Ethyl alcohol, containing 4.43% water, is supplied to dryer in a column with a diameter of 18 mm with a layer height of 650 mm at a speed of 175 ml / h. Under these conditions, one cycle can obtain 300 ml of alcohol with water content not higher than 0.1-0.12%. The zeolite regeneration is performed in a column in nitrogen current at 320 ° C for 2 hours. With a distillation of ethyl alcohol, it is recommended to use devices on the sands; At the same time, the grinders are carefully cleaned and not lubricated. The first part of the distillate is advisable to discard and complete the distillation when a little alcohol remains in the distillation flask.

Since carbon tetrachloride (CHCH) in accordance with the Montreal Protocol is a prohibited ozone-depleting substance, but inevitably formed as a by-product in the production of chloromethane, the choice of the most effective method CHCH processing is an urgent task.
Various transformations of CHCU were especially intensively investigated lately, there are a large number of experimental data. Below will be the evaluation different options Transforming CHCU based on their own research and data from other authors.
The work considered the problem of CHCC processing into environmentally friendly products, but they are not fully covered by possible processing options, as well as, in our opinion, there is no objectively reflecting the advantages and disadvantages of individual methods of Disposal CHCU.
Some contradictions can be noted in articles. . Thus, the theme of articles is the processing of CHCH into environmentally friendly products, in text and conclusions as promising methods, it is recommended that the conversion of CHCH in chloromethane is recommended, and in the introduction of chloromethane is called the main chemical environmental pollutants. In reality, chloromethanes are not included in the Stockholm Convention on persistent organic pollutants, and toxicity, the volume of chloromethane is not the main pollutants even among other chlororganic compounds.
The articles referred to the high peacurity of chloromethane. At the same time, it is known that all chloromethanes, except for methyl chloride, are unstable products and to preserve their properties require stabilization. The decomposition of chloromethane occurs in the boilers of distillation columns, in the evaporator for feeding CHCU to the reactor. According to the encyclopedia of chloroform without a stabilizer, it is unlikely to last without changing its properties during the day, if in contact with the atmosphere.
CHCH processing processes can be classified according to the degree of usefulness of the recycling products. This does not mean that in the same sequence and the usefulness of the ECCU disposal processes themselves will be located, since much will depend on the cost of processing and the subsequent allocation of the products obtained.
The presence of a large number of other products in the processing of the method has a certain impact on the choice of the method, except for the large number of other products (for example, in cubic rectification of chloromethane production), when the selection of CHCH from these waste may require considerable costs. The same situation consists of neutralizing the CHCH contained in small quantities in gas emissions. In this case, non-selective complete combustion to obtain CO2 and HCl with almost zero utility due to the low profitability of their allocation may be the most acceptable solution. Therefore, in each particular case, the choice can be made only after a technical and economic comparison.

Burning CHCH
When combing CHCH using air, a simultaneous supply of hydrocarbon fuel for the supply of heat and chlorine binding to hydrogen chloride is required. As an option, with a small amount of hydrogen chloride, it can be converted into sodium chloride by injection into the gas hydroxide solution of sodium. Otherwise, hydrogen chloride is isolated from gases of burning in the form of hydrochloric acid.
The utilization of the hydrochloric acid itself may be a problem due to exceeding supply over demand. The release of hydrogen chloride from hydrochloric acid by stripping leads to the fact that it becomes more expensive than chlorine. In addition, hydrogen chloride has limited use in oxychlorination and hydrochlorination processes. The conversion of hydrogen chloride into chlorine with the electrolysis of hydrochloric acid or oxidation of oxygen (dicon process) is quite expensive and difficult in terms of technology operation.
The authors of work as a method of complete oxidation of CSCI preference is given to catalytic oxidation compared to conventional thermal burning. According to compared with the incineration, the processes of catalytic oxidation are characterized by a greater depth of the destruction of chlororganic waste and are not accompanied by the formation of dioxins.
These statements do not correspond to reality and can lead to the transformation representation of the effectiveness of compared methods. The article does not provide any data in confirmation of higher degrees of transformation during catalytic oxidation. In the references given in favor of such approval, for example, the degree of transformation is really high 98-99%, but this is not the level that is achieved during thermal burning. Even if the degree of conversion of 100% or 100.0% is indicated, this means only that the accuracy of this data is 0.1%.
In accordance with the US law on maintaining and restoring resources for basic organic hazardous pollution, the effectiveness of destructive removal should be at least 99.9999%. In Europe, it is also recommended to adhere to this minimum degree of decomposition of unsuitable pesticides and polychlorubiphenyls in the incineration facilities.
A number of problems have been developed for the incineration process, named BAT - BEST AVAILABLE TECHNIQUE (the best acceptable method). One of the requirements on a par with a temperature of  1200 ° C and the residence time  2 C is the turbulence of the reaction flow, which allows, mainly to eliminate the problem of the sloping of the incinerated substance in the trim layer and ensure the mode of perfect displacement. Apparently, in the tubular reactor filled with a catalyst, it is harder to eliminate the slosh of the incinerated substance in the clump layer. In addition, there are difficulties in the uniform distribution of the reaction flow through the tubes. At the same time, further successes in the elimination of the "trim effect" allowed when burning in a liquid rocket engine to achieve a degree of transformation of 99.999999%.
Another controversial approval of the authors is the absence of PCDD and PCDF in catalytic oxidation products. No digits in confirmation is provided. In the work there are only two references confirming the fact of the absence of dioxins during catalytic oxidation. However, one of the references seems to be due to any error does not have any relations to catalytic oxidation, since biotransformation of organic acids is devoted. In another work, catalytic oxidation is considered, but no information about the absence of dioxins is reported. On the contrary, it provides data on the formation of another persistent organic pollutant - polychlorubiphenyl with the catalytic oxidation of dichlorobenzene, which can indirectly talk about the possibility of formation and dioxins.
The work fairly notes that the temperature range of catalytic oxidation of chlororganic waste is favorable for the formation of PCDD and PCDF, but the absence of PCDD and PCDF may be due to the catalytic destruction of the sources of their formation. At the same time, it is known that the synthesis of high molecular compounds are successfully involved in the catalysts, even from compounds C1.
In European countries, environmental requirements for incineration of waste, for which the limiting amount of emissions into dioxin atmosphere is 0.1 ng TE / NM3.
The above environmental indicators of the process of thermo-oxidative (fire) neutralization of liquid chlororganic waste are available in. Finally, it should be noted that in the "register of existing capacities for the destruction of polychlorubiphenyls" the most widely used and proven method of destruction of PCB is high-temperature combustion. Catalytic oxidation for this purpose is not applied.
In our opinion, catalytic oxidation, despite the use of precious metals as a catalyst on the carrier, has an advantage in the destruction of residual amounts of toxic substances in gas emissions, since due to the low temperature of the process, a significantly smaller fuel consumption is required to heat the reaction gas than with thermal burning. . The same situation is developing when the optimal conditions for burning are difficult to create, for example, in catalytic survices in automotive engines. In addition, the catalytic oxidation of chlororganic waste under pressure ("corkside process") was used by the company "Goodrich" to directly supply gas gases containing hydrogen chloride into the oxidative chlorination reactor to obtain dichloroethane.
It is reported that with a combination of thermal and catalytic oxidation of gaseous waste, a higher efficiency is achieved than with purely catalytic oxidation. Qualified processing of chlororganic waste is also considered in. In our opinion, for the combustion of CHCH in the form of a concentrated product, it is advisable to use the usual thermal burning.
In conclusion of this section, it is advisable to consider another aspect of the oxidation of CHCU. According to ChCU is a non-combustible substance, therefore its combustion can be carried out only in the presence of additional fuel. This is true when using air as an oxidizing agent. In oxygen, the CHCH is able to burn with a minor thermal effect, the calorific value is 242 kcal / kg. According to another heat combustion directory, the heat combustion is 156.2 kJ / mol (37.3 kcal / mol), and the heat combustion heat is 365.5 kJ / mol (87.3 kcal / mol).
Oxygen oxidation can be one of the methods of processing CHCH, in which the carbon component is lost, but chlorine is regenerated, spent on obtaining CHCU. Such a process has an advantage over normal incineration due to the production of concentrated products.
CCL4 + O2 → CO2 + 2CL2
The process of oxidative dechlorination of CHCU allows to obtain carbon dioxide, and phosgene if necessary.
2CCL4 + O2 → 2COCL2 + 2CL2

Hydrolysis CHCH

Another interesting, in our opinion, the processing process of CHCH in carbon dioxide and hydrogen chloride is hydrolysis.
CCL4 + 2N2O → CO2 + 4NCL
Publications in this area there is little. The interaction of ON groups with chloromethane in the gas phase is discussed in the article. Catalytic hydrolysis of CHCU to HCl and CO2 on magnesium oxide at temperatures more than 400 ° C studied. The rate constants of homogeneous hydrolysis of CHCU in the liquid phase are obtained in operation.
The process goes well, according to our data, at relatively low temperatures 150-200 ° C, uses the most affordable reagent and should not be accompanied by the formation of dioxins and furan. It is necessary only to hydrochloric acid reactor, for example, coated inside with fluoroplastic. Perhaps such a cheap and environmentally friendly processing method can be used to destroy and other waste.

CHCH interaction with methanol
Close to hydrolysis and actually flowing through this stage is the process of pary-phase interaction of CHCH with methanol to produce methyl chloride in the presence of a catalyst - zinc chloride on an activated carbon. Relatively recently, this process was first patented by Shin-Etsu Chemical (Japan). The process proceeds with high close to 100% CHCH and methanol conversion.
CCL4 + 4Sn3on → 4Ch3CL + CO2 + 2N2O
The authors believe that the interaction of the CHCU with methanol flows in 2 stages: first there is a HYDROOLS OF CHCU to carbon dioxide and hydrogen chloride (see above), and then chloride hydrogen reacts with methanol to form methyl and water chloride.
CH3OH + NCL → CN3Cl + H2O
At the same time, a sufficiently small amount of water is sufficient to initiate a reaction that is present in the atmosphere. It is believed that limit the speed of the total process of the first stage.
With close to the stoichiometric ratio of CHCU to methanol (1: 3.64), the reaction has steadily proceeded during an experiment, which lasted 100 hours, with CHSTU conversion 97.0% and methanol 99.2%. The selectivity of the formation of methyl chloride was close to 100%, since only traces of dimethyl ether were discovered. The temperature in the catalyst layer was 200 ° C.
Then it was proposed to divide the process into two reaction zones: in the first it is a hydrolysis of CHCU, and in the second - the interaction of hydrogen chloride with methanol entered into this zone. Finally, the same firm was patented a method for obtaining chloromethanes without the formation of CHCU, which includes the following stages:
. obtaining chloromethane chlorination of methane;
. The interaction of hydrogen chloride, highlighted in the first stage, with methanol with the formation of methyl chloride and dilute hydrochloric acid;
. Hydrolysis CHCH dilute hydrochloric acid In the presence of a catalyst - chlorides or metal oxides on a carrier.
The disadvantage of the heterogeneous catalytic process of interaction of the CHCH with methanol is the relatively low life of the catalyst due to its charging. At the same time, high-temperature regeneration for the burning of angry deposits is undesirable due to the volatile zinc chloride, and when using activated carbon, it is not possible as a carrier.
In conclusion of this section, we can mention that we have attempts to get away from the solid catalyst during the processing of CHCU with methanol. In the absence of a catalyst for a molly ratio of methanol: CHCH \u003d 4: 1 and with increasing temperature from 130 to 190 ° C, CHCU conversion increased from 15 to 65%. For the manufacture of the reactor requires materials resistant under these conditions.
Conducting a catalytic liquid-phase process at relatively low temperatures 100-130 ° C and a molar methanol ratio: CHCH \u003d 4: 1 without pressure made it possible to achieve CHCH conversion only 8%, and almost 100% transformation of methanol and 100% selectivity for methyl chloride can be obtained. To increase the conversion, the CHCH requires an increase in temperature and pressure, which in the laboratory could not be implemented.
Patented method of alcoholis CHCU, which includes simultaneous CHCH and ³ 1 alcohol ROH (R \u003d alkyl C 1 - C 10) into a catalytic system representing an aqueous solution of metal halides, especially chloride I.B, I. I.B, V. I.B and V. I. I. I. Group. With a liquid-phase interaction of methanol and CHCh (in a ratio of 4: 1) in a laboratory reactor with a magnetic stirrer in the presence of a catalytic solution of zinc chloride at a temperature of 180 ° C and a pressure of 3.8 bar of CHCH and methanol conversion accounted for 77%.

Chlorination with CHC
CHCU is a safe chloride agent, for example, when producing metals chlorides from their oxides. In the process of such a CHCU reaction turns into carbon dioxide.
2M2O3 + 3CCL4 → 4MCL3 + 3SO2
Work was carried out to obtain iron chlorides using the CHCH as chloride agent, the process goes at a temperature of about 700 ° C. Chlorination with CHCH in industry is obtained from the oxides of elements 3-5 groups of the periodic system of their chlorides.

CHCH interaction with methane

The easiest solution to the problem of processing CHCU would be the interaction of CHCH with methane in the methane chlorination reactor to obtain less chlorinated chloromethane, since in this case it would take almost only the reconmark organization without reacted CHCU, and the subsequent release and separation of the reaction products can be carried out on the main system production.
Previously, in the study of the process of oxidative chlorination of methane, both in the laboratory and on an experimental installation, it was observed that when the reactor of the reaction gas was submitted from the process of direct chlorination of methane containing all chloromethanes, including CHCU, the number of last after the oxy chlorination reactor decreases, although it should It was with an increase in the number of other chloromethane to increase.
In this regard, it was a certain interest to carry out the thermodynamic analysis of the reactions of interaction of methane with ChCU and other chloromethanes. It turned out that the most thermodynamically probable is the interaction of CHCH with methane. At the same time, the equilibrium degree of CHCH conversion in the conditions of excess methane, which is implemented in an industrial chlorinator, is close to 100% even at the highest temperature (the lowest equilibrium constant).
However, the real flow of the thermodynamically likely process depends on the kinetic factors. In addition, other reactions can occur in the CHCU system with methane: for example, pyrolysis of CHCU to hexachloroethane and perchlorethylene, the formation of other chlorine derivatives with 2 due to the recombination of radicals.
An experimental study of the reaction of the interaction of CHCH with methane was carried out in a flow reactor at temperatures of 450-525 ° C and atmospheric pressure, at a time of interaction of 4.9 s. The processing of experimental data gave the following equation for the methane methane reaction rate with CHCU:
r \u003d 1014.94 EXP (-49150 / RT). [CCl 4] 0.5. [CH 4], mole / cm 3.
The data obtained allowed to evaluate the contribution of the exchange interaction of the CHCH with methane in the process of chlorination of methane, calculate the necessary recycling of CHCU for its complete transformation. Table 1 shows the CHCH conversion, depending on the reaction temperature and CHCH concentration with a roughly identical concentration of methane, which is implemented in an industrial chlorinator.
The CHCU conversion is naturally falling with a decrease in the temperature of the process. The acceptable conversion of the CHHC is observed only at temperatures of 500-525 o C, which is close to the temperature of volume chlorine chlorination on the current production of chloromethane 480-520 o C.
The total transformations of CHCU and methane can be characterized by the following total equation and material balance:
CCL 4 + CH 4 → CH 3 Cl + CH 2 Cl 2 + CHCl 3 + 1,1-C 2 H 2 Cl 2 + C2Cl 4 + HCl
100.0 95.6 78.3 14.9 15.2 7.7 35,9 87.2 mol
In the second line, the amount of reacted methane and the products obtained are given in a moles per 100 moles reacted CHCU. The selectivity of the conversion of CHCH in chloromethane is 71.3%.
Since the allocation of commodity CHCH from cubic rectification of chloromethane production was a certain problem, and with the sale of cubic rectification, difficulties periodically arose, the processing of CHCU in the methane chlorination reactor was of interest before the prohibition of CHCH issuance due to its ozone-depleting ability.
Experienced CHCH processing tests in methane chlorination reactor were carried out on Cheboksarsky P.O. "Himprom". The results obtained mainly confirmed laboratory data. The selectivity of the conversion of CHCH in chloromethane was higher than in laboratory conditions.
The fact that the selectivity of the CHCH interaction process in the industrial reactor was higher than in the laboratory can be explained by the fact that when chlorination of methane in the laboratory reactor, there is overheating of the outer walls heated by the casing with electrospiral. So, at a temperature in the reaction zone 500 ° C, the temperature of the walls of the laboratory chlorinator was 550 o C.
In the industrial reactor, heat accumulation of the central brick column and the lining, and the outer walls of the chlorinator, on the contrary, are cooled.
Experienced testing of CHCU in the methane chlorination reactor was previously carried out on Volgograd P.O. "Himprom". The CHCH in the industrial chlorinator was supplied without selection as part of cubic rectification together with all impurities of chlorational hydrogen s 2. As a result, about 100 m3 of cubic rectification were reworked over the month. However, the processing of the data obtained caused difficulties due to the large number of components in a low concentration and insufficient accuracy of analyzes.
To suppress the formation of the formation of cells of ethylene series, when interacting with CHCH with methane, it is proposed to be administered to the reaction mixture of chlorine at a chlorine ratio to CHCU  0.5.
Obtaining chloromethanes and other products with interaction of CHCU with methane at temperatures of 400-650 ° C in the floor reactor described in Patent. An example is given, where the CHCH conversion was in% mol.: In chloroform - 10.75, methylene chloride - 2.04, methyl chloride - 9.25, vinylidene chloride - 8.3 and trichloroethylene - 1.28.
Then the same company "Stauffer" was patented a method for producing chloroform interaction with CHCH with hydrocarbons C2-C3 and C1-C3 chloroorilodors. According to the examples of CHC and methylene chloride at a temperature of 450 ° C, only chloroform is obtained in the floor reactor, and at a temperature of 580 ° C - chloroform and perchloroethylene. From CHC and methyl chloride at a temperature of 490 ° C, only methylene chloride and chloroforms are formed in equal amounts, and trichloeted appeared at a temperature of 575 ° C.
The process of obtaining methyl chloride and methylene chloride with chlorine interaction with chlorine and CHCU in a boiling layer of contact at 350-450 o C was also proposed. The process of chlorination of methane is described to chloroform in a boiling layer of contact with the introduction of the CHCU to the reaction zone to ensure heat power. In this case, the CHCH with methane simultaneously occurs.
The exchange reaction between the CHCH and Paraffin leads to the formation of chloroform and chloroparaphin.
When developing the process of oxidative chlorination of methane, it was found that the oxidative dechlorination of the CHCH in the presence of methane proceeds more efficiently than the interaction of methane and CHCH in the absence of oxygen and catalyst.
The obtained evidence suggests that the process of oxidative chloride dechlorination in the presence of methane and catalyst based on copper chlorides occurs at a lower temperature than the interaction of CHCH with methane in the absence of oxygen, to obtain only chloromethanes without the formation of side chloroorrhodes. Thus, the CHCH conversion at temperatures 400, 425 and 450 ° C was on average, respectively 25, 34 and 51%.
An additional advantage of the oxidative processing of CHCU is the lack of a catalyst charming. However, the need for catalyst and oxygen reduces the advantages this method.
A patent method of obtaining chloromethanes oxidative chlorination of methane without obtaining CHCU in the final products due to its full recycle into the reaction zone. In one of the subparagraphs of the claims, this application is argued that one chloroform can be obtained as a final product returning to the reaction zone methane and all chloromethanes except chloroform.

CHCH processing with hydrogen
Hidden CHCH hydroxide with hydrogen (as well as methane), in contrast to oxidative transformations with oxygen, it makes it possible to use the carbon component of CHCU with the benefit. Catalysts, kinetics, mechanism and other aspects of hydrodechlorination reactions are considered in reviews.
One of the main problems of the process of hydrodechlorination of CHCU is selectivity, often the reaction goes to methane formation, and the yield of chloroform, as the most desirable product, is not high enough. Another problem is the rather fast deactivation of the catalyst, mainly due to the corruption during the decomposition of CHC and the reaction products. At the same time, it is possible to achieve the selective production of chloroform more easily than the stability of the catalyst. Recently, quite a lot of work appeared, where high selectivity for chloroform is achieved, the data in the stability of the catalyst is much smaller.
Patent as catalysts of CHCH hydrogenolysis and chloroform offer RU, RH, PD, OS, IR, PT, CU, AG or AU. On a catalyst containing 0.5% platinum on aluminum oxide, at temperatures of 70-180 o CHH obtained 97.7-84.8% chloroform and 2.3-15.2% methane; At higher temperatures, methylene chloride is also formed.
In the works of Hidrachlorination of CHCU was carried out on platinum catalysts. The choice of MGO as a carrier was made on the basis of a higher selectivity for chloroform and the duration of the catalyst, compared with other media: Al2O3, TiO2, ZrO2, SiO2, aluminosilicate and zeolite Nay. It is shown that for stable operation of the PT / MGO catalyst with CHSTA conversion, more than 90% must be maintained to maintain the reaction temperature 140 ° C, the ratio of H2 / CHH of more than 9 and the volumetric speed of 9000 l / kg. The effect of the nature of the original compounds of platinum on the activity of the obtained catalyst is 1% PT / AL2O3. On catalysts prepared from Pt (NH 3) 4 Cl 2, Pt (NH3) 2 (NO3) 2 and PT (NH3) 4 (NO3) 2, CHCU conversion is close to 100%, and selectivity for chloroform - to 80%.
Catalyst modification - 0.25% Pt / Al2O3 Lanthan Oxide allowed at 120 ° C, volumetric speed of 3000 H-1 and mole ratio H2: CCl4 \u003d 10 to obtain a yield of chloroform 88% with selectivity of 92%.
According to the calcination of the carrier - aluminum oxide at temperatures of 800 - 900 ° C reduces Lewis acid, thereby increasing the stability and selectivity of the catalyst. On aluminum oxide with a specific surface area of \u200b\u200b80 m2 / g containing 0.5% PT, the conversion of CHCH 92.7% in selectivity by chloroform is 83% held within 118 hours.
In contrast to the data in patent in the preparation of methylene chloride and chloroform, CHCH hydraulic chloride is recommended to process the carrier with hydrochloric acid or hydrochloric acid and chlorine, and the platinum is promoted by small amounts of metals, such as tin. This reduces the formation of by-products and increase the stability of the catalyst.
In the hydrodechlorination of the CHCH on catalysts containing 0.5-5% PD on the cube (angle) or TiO2, at a temperature of 150-200 ° C. CHCH conversion was 100%. Non-chlorized C2-C5 hydrocarbons were formed as by-products. Stable catalysts worked more than 4 hours, after that, the regeneration of argon purge was carried out during heating.
It is reported that when using the bimetallic composition of platinum and iridium, promoted by small amounts of third metals, such as tin, titanium, germanium, rhenium, etc., the formation of by-products decreases, and the duration of the catalyst operation increases.
In the study of the noncatalithic interaction of the CHCH with hydrogen by pulse compression in free-pointed installation, with characteristic times of process 10-3 C, two areas of reaction occurred were found. At a temperature of 1150k (degree of conversion up to 20%), the process proceeds relatively slowly. Adjusting the composition of the initial mixture and the temperature of the process, you can obtain a 16% yield of chloroform with selectivity close to 100%. In a certain area of \u200b\u200btemperatures under the conditions of self-ignition mixture, the reaction can be sent to the predominant formation of perchlorethylene.
Large successes in the development of an active, stable and selective catalyst for gas-phase hydraulic chip chip hydrogen were achieved by Sud Chemie MT. The catalyst is the noble metals V groups applied to the microphospheric oxide of aluminum (the composition of the catalyst is not disclosed). The process is carried out in the fluidized bed of the catalyst at temperatures of 100-150 ° C, pressure 2-4 of the Ata, the contact time is 0.5-2 seconds and the ratio of hydrogen: CHCU in the reaction zone 6-8: 1 (mol.).
CHCH conversion under these conditions reaches 90%, chloroform selectivity - 80-85%. The main by-product is methane, methyl chloride and methylene chloride are formed in minor quantities.
The works studied the hydraulic chip of CHCH on palladium catalysts in the liquid phase. At temperatures of 20-80 ° C on palladium acetate with the addition of acetic acid and using paraffin solvents C7 -C12, methyl ethyl ketone, dimethylformamide, dioxane and benzyl alcohol, the single product of the reaction turned out to be methane. Reaction in isopropyl and tert-butyl alcohols as solvents made it possible to obtain chloroform chloride as the main products and methyl chloride, the formation of methane ranged from trace amounts to 5%.
It is noted that the adverse reaction of the hydrochlorination of alcohols used as solvents proceeds with the conversion of 7-12% of the submitted amount and the formation of chloro-derivative isomers, which creates the problem of their disposal and make it difficult to allocate commodity products. Therefore, the implementation of this method is not planned yet.
Apparently, to eliminate by-products in patent, the reaction of Hidproof CHCHO to chloroform is proposed in a halogenated aliphatic solvent, in particular in chloroform. The catalyst is the suspension of platinum on the carrier. CHCH conversion is 98.1% in the selectivity of chloroform formation 99.3%.
The same process of obtaining chloroform in the presence of PT and PD-catalysts on a carrier using  1 solvent (pentane, hexane, heptane, benzene, etc.) is described in patent. It is argued that the process is carried out continuously or periodically on an industrial scale.
The most commonly used catalysts for CHCH hydraulic chloride to chloroforms and other chloromethane are palladium, platinum, rhodium and ruthenium on the carrier. In such a catalyst, they spray and suspend in liquid CHCU and are treated with hydrogen at a pressure of 8000 kPa and temperatures below 250 ° C. It is reported that the method is suitable for obtaining chloroforms on an industrial scale.
In the study of the CHCH hydrochlorination in a liquid-phase bubbling reactor, it was shown that the most active and selective catalyst is palladium applied to activated coal. The advantage of activated carbon as a carrier is due to a more uniform distribution of metal on its surface compared with such inorganic carriers as an oxide of aluminum and silica gel. According to metals, catalysts can be positioned in PD / C  PT / C  RH / C  RU / C  Ni / C. The main by-product is hexakhloretan.
In the future, it was found that the speed of the process is limited to the chemical reaction on the surface.

CHCH transformations in PEE

In hard temperature conditions The formation of perchlorethylene from CHSU occurs. The process of obtaining perchlorethylene from CHCU goes with the absorption of heat and the release of chlorine, which is fundamentally different from the production of perchlorubarodes (perchlorethylene and CHCH) from methane or waste production of epichlorohydrin, where processes are coming when chlorine is supplied and with heat release.
At 600 ° C \u003d 45.2 kcal / mol, and the equilibrium degree of conversion at atmospheric pressure is 11.7% 5. It should be noted that the data of various authors about the magnitude of the thermal effect of the reaction are significantly different, which caused doubts about the possibility of full processing of CHCU in perchloroethylene in the production of perchlorubarodes due to lack of heat for this reaction. However, the full recycling CHCU is currently implemented in the production of perchlorubarodes at Sterlitamak Caustik CJSC.
The thermal transformation of the CHCH increases significantly in the presence of chlorine acceptors. Obviously, the acceptor associating chlorine, shifts the equilibrium of the reaction:
2CCl 4 → C 2 Cl 4 + 2Cl 2
in the direction of the perchlorethylene formation.
The conversion of the CHCH in the perchlorethylene in the presence of a chlorine acceptor performs another very important function - turns the endothermic process into exothermic and eliminates the almost unreal heat supply through the wall at such temperatures in the presence of chlorine.
The introduction of chlorine organic acceptors (methane, ethylene, 1,2-dichloroethane) in the process of thermal dechlorination of CHCH made it possible to increase the yield of the PCE to 50% of the mass. However, at the same time, the number of by-products (hexahloroethane, hexahlorobutadiene, resin) increased sykschloroethane. Therefore, in the work of 53, an acceptor (methane or ethylene) in the amount of 0.3 of stoichiometry is recommended to implement the process in industry.
In Patent 54, it is proposed to conduct a process of noncatalithic thermal transformation of CHCH in perchlorethylene at a temperature of 500-700 ° C using hydrogen chlorine as an acceptor, thereby producing few side chloroorrods.
The conversion of the CHCH in the PCE in the presence of the sales of the latter has very important advantages over other methods of CHCH processing from the production of chloromethane:
. For processing, it is not necessary to allocate CHCH from cubic rectification;
. C2 chloroorrodes are also converted to PCUs contained in cubic meters.
The process of transforming the CHCH in perchlorethylene in the presence of CH4 is accompanied by the formation of a large number of by-products, some of which (hexahloroethane, hexachlorobutadiene) are processed in the process, other (hexahlorobenzene) are sent to burial. At the same time, methane, tying chlorine, turns into a CHCH, which should also be recycled, i.e. CHCH processing capacity increases.
When using hydrogen as a chlorine acceptor, the number of by-products will decrease, only the yield of hydrogen chloride increases. The process is carried out in a fluidized bed of silica gel. Process temperature 550-600 ° C, CHCH ratio: H2 \u003d 1: 0.8-1.3 (mol.), Contact time 10-20 s. CHCH conversion reaches 50% 55. The disadvantage of this process is the need to create a separate large technological scheme, as well as the presence of a hard waste - hexachlorobenzene.
It is possible to minimize the formation of heavy by-products in the preparation of perchlorethylene chlorination of hydrocarbons and their chlorine derivatives in the presence of CHC and hydrogen.

Other CHCH processing methods
Some CHCU restoration methods are offered. For example, it is possible to obtain chloroform with a slow reduction of CCL4 with hydrochloric acid, zinc dust with a 50% NH4Cl solution at 50-60 o C, ethanol at 200 o C.
In case of electrochemical reduction, the CHCH is obtained mainly chloroform and methylene chloride. In the presence of chloride aluminum CHSU alkylates aromatic compounds. In free radical reactions and responses of televomerization, CHCU serves as a halogen carrier.

conclusions

1. Since the CHCU is inevitably formed during the chlorination of methane and chloromethane, the development of methods for its effective processing is an urgent task.
2. In the destruction of CHCH high-temperature burning, existing environmental requirements are achieved on the efficiency of destructive removal of 99.9999% and the content of dioxins in emissions of no more than 0.1 ng TE / NM3. Similar indicators for catalytic oxidation CHCH was not detected.
With catalytic oxidation of chchu oxygen, it is possible to obtain chlorine and / or phosgene.
3. An interesting method of processing ChCU in terms of cheap reagent and low process temperature is hydrolysis to carbon dioxide and hydrogen chloride.
4. The combination of CHCH hydrolysis and the interaction of the resulting HCl with methanol also gives enough interesting process CHCH processing with methanol to produce methyl chloride and CO 2.
5. Hidden hydrogenation allows you to dispose of CHCU to obtain the necessary less chlorinated chloromethane. The main disadvantage of this process, as well as interacting with methanol is the gradual drop in the activity of the catalyst due to the charming.
6. The easiest solution to the problem of CHCU processing is the interaction of CHCH with methane when it is returned to the methane chlorination reactor. However, in addition to chloromethutans, the impurities of chloration hydrocarbons are formed from 2. It is possible to avoid the formation of impurities in the interaction of CHCH with methane in the presence of a catalyst and oxygen at a lower temperature, but this requires the creation of a separate stage and the presence of oxygen.
7. Pyrolysis of CHCH in the presence of methane, hydrogen or other chlorine acceptors allows you to get perchloroethylene. The process is complicated by the formation of by-high molecular weight products.
8. CHCU is a safe chlorinating agent, for example, when producing metal chlorides from their oxides.
9. There are a number of other CHCU processing methods, for example, electrochemical recovery or with reagents - reducing agents. You can use ChCU and as an alkylated agent.

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Table 1. CHCH interaction with methane

	T-ra	Concentration,% mol.		CHCH conversion,%
p / P.	About S.	SS L 4.	CH 4.	by chlorine	by carbon
1	525	22,5	53,4	27,4	25,4
2	525	9,7	53,0	29,4	31,9
3	500	24,9	48,8	12,0	11,9
4	475	23,4	47,8	6,4	5,7
5	450	29,5	51,1	2,9	1,9