KR790001552B1 - Production of trichloro-ethylene from waste c2 chlorinated hydrocarbons - Google Patents

Abstract

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Description

Process for producing trichloroethylene from spent C2 chlorinated hydrocarbons

1 is a schematic process diagram of a reaction portion.

2 is a schematic process diagram for the recovery portion of FIG.

The present invention relates to a process for the treatment of waste streams, that is to say for the treatment of C ₂ chlorinated hydrocarbon waste streams, more particularly for the treatment of C ₂ chlorinated hydrocarbon waste streams, to produce trichloroethylene or tetrachloroethylene.

Chlorination of hydrocarbon waste streams occurs during various chemical operations. For example, when producing vinyl chloride, the C ₂ chlorinated hydrocarbon waste stream comprising ethyl chloride, dichloroethylene, dichlorethane, trichlorethane, trichlorethylene, tetrachlorethane and C ₂ chlorinated hydrocarbons As a form, 4-8% of the yield is produced. These waste streams are burned to convert the contained chlorine to hydrogen chloride and then neutralized or recovered in the form of acids or anhydrides.

The process is not economical because it does not use chlorine directly and also loses all hydrocarbons.

The object of the present invention will be understood in detail by referring to the following description and drawings.

These objects of the present invention can all be met, for example, by preparing trichlorethylene or tetrachlorethylene in C ₂ chlorinated hydrocarbon waste streams. According to the present invention, the chlorinated hydrocarbon waste stream can be fractionally distilled to recover the C ₂ chlorinated hydrocarbon fraction and converted into trichlorethylene or tetrachlorethylene. All or part of the recovered portion was brought into contact with a molten mixture of chloride and oxychloride of this metal by contacting hydrogen chloride, chlorine or a mixture thereof, a high valence and a low valence of a polyvalent metal in a chlorine treatment chamber as a trichlorethylene or tetra A chlorinated effluent containing chlorethylene is produced. The chlorinated effluent also contains C ₂ chlorinated hydrocarbons that can be converted to trichlorethylene or tetrachlorethylene to recycle all or part of it to the chlorination chamber.

The chlorine fraction can be recovered as chlorine or hydrogen chloride by burning all or part of the chlorinated hydrocarbon fraction in the waste stream and the chlorinated effluent not recycled to the chlorination chamber.

The effluent is contacted with the melt in the chlorine treatment chamber to recover chlorine from the combustion effluent, and the melt and oxygen are contacted to produce oxychloride, and the chlorine-containing melt containing oxy chloride is recycled to the chlorine treatment chamber.

According to the invention trichlor ethylene or tetrachlorethylene or both are produced as reaction products in C ₂ chlorinated hydrocarbon waste streams.

The melt contains chlorides of polyvalent metals such as manganese, iron, copper, cobalt and chromium (preferably copper) having one or more bivalent atoms. In the case of the chloride of a polyvalent metal having a high melting point such as copper chloride, the melting point is lowered by adding a metal salt melting point lowering agent that is nonvolatile under the reaction conditions and inhibits the activity of oxygen, such as chloride of a monovalent metal or a metal having a bivalent monovalent monovalent metal. A molten salt mixture is obtained. Preferred monovalent metal chlorides are alkali metal chlorides such as potassium chloride and sodium chloride, but heavy metal chlorides heavier than copper in Groups I, II, III and IV of the periodic table, for example chlorides of other metals such as chlorides of zinc, silver and thallium, It can be seen that mixtures thereof can also be used. Metal chloride melting point depressants are added sufficiently to keep the salt mixture molten at the reaction temperature and generally enough to bring the melting point of the molten salt mixture below 260 ° C. In the case of a salt mixture of copper chloride and potassium chloride, potassium chloride is 20-40% by weight, preferably 30% by weight, and the rest is composed of copper chloride. In some cases, however, the melt, the catalyst to be fed, is present in the form of a melt in the preprocessing step and may have a high melting point of at least 260 ° C. It is also possible to add mixtures of polyvalent metal chlorides or other reaction promoters to the melt.

In some cases, the metal chloride may be kept in a molten state without adding a monovalent metal halide compound.

C ₂ chlorinated hydrocarbon waste streams contain spent chlorinated hydrocarbons that can be converted to trichlorethylene or tetrachlor ethylene, which include the following C ₂ monochlorinated hydrocarbons (vinyl chloride and ethyl chloride) and C ₂ chlorinated hydrocarbons: (Dichloroethanes and dichloroethylenes), C ₂ trichlorinated saturated hydrocarbons (trichloroethanes), tetrachlorethanes, pentachlorethanes and hexachlorethanes, and the like. Waste streams recovered in conventional vinyl chloride plants contain all of the above components in various proportions. According to the present invention, all or part of the components (some of these components may be recovered as separate products when they are marketable or can be burned by the following method) are introduced into the chlorine treatment reaction chamber (in this reaction chamber, Dehydrogenation, dehydrochlorination and dechlorination may also occur but are called chlorinated reaction chambers), converted to trichlorethylene or tetrachlorethylene, some of which are represented by the following equation.

C ₂ H ₅ Cl + 2HCl + 3 / 2O ₂ ―――――― → C ₂ HCl ₃ + 3H ₂ O

C ₂ H ₅ Cl + Cl ₂ + O ₂ ―――――― → C ₂ HCl ₃ + 2H ₂ O

C ₂ H ₃ Cl + Cl ₂ + 1 / 2O ₂ ―――――― → C ₂ HCl ₃ + H ₂ O

C ₂ H ₃ Cl + 2HCl + O ₂ ―――――― → C ₂ HCl ₃ + 2H ₂ O

C ₂ H ₄ Cl ₂ + HCl + O ₂ ―――――― → C ₂ HCl ₃ + 2H ₂ O

C ₂ H ₄ Cl ₂ + 1 / 2Cl ₂ + 3 / 4O ₂ ――――― → C ₂ HCl ₃ + 3 / 2H ₂ O

C ₂ H ₂ Cl ₂ + 1 / 2Cl ₂ + 1 / 4O ₂ ――――― → C ₂ HCl ₃ + 1 / 2H ₂ O

C ₂ H ₂ Cl ₂ + HCl + 1 / 2O ₂ ―――――― → C ₂ HCl ₃ + H ₂ O

C ₂ H ₃ Cl ₃ + 1 / 2O ₂ ――――――― → C ₂ HCl ₃ + H ₂ O

C ₂ H ₂ Cl ₄ ――――――― → C ₂ HCl ₃ + HCl

C ₂ H ₅ Cl + 3HCl + 2O ₂ ――――――― → C ₂ Cl ₄ + 4H ₂ O

C ₂ H ₅ Cl + 1 1 / 2Cl ₂ +1 _1/4 O ₂ ―――― → C ₂ Cl ₄ +2 1 / 2H ₂ O

C ₂ H ₃ Cl + HCl + O ₂ ―――――― → C ₂ Cl ₄ +2 1 / 2O

C ₂ H ₃ Cl + 1 1 / 2Cl ₂ +1 3 / 4O ₂ ―――― → C ₂ Cl ₄ +1 1 / 2H ₂ O

C ₂ H ₄ Cl ₂ + HCl + 1 1 / 4O ₂ ―――――― → C ₂ Cl ₄ +2 1 / 2H ₂ O

C ₂ H ₃ Cl ₃ + HCl + O ₂ ―――――― → C ₂ Cl ₄ + 2H ₂ O

C ₂ H ₃ Cl ₃ + 1 / 2Cl ₂ + 3 / 4O ₂ ――――― → C ₂ Cl ₄ +1 1 / 2H ₂ O

C ₂ H ₂ Cl ₄ + 1 / 2O ₂ ―――――― → C ₂ Cl ₄ +1 1 / 2O

C ₂ HCl ₅ ―――――― → C ₂ Cl ₄ + HCl

C ₂ HCl ₃ + HCl + 1 / 2O ₂ ―――――― → C ₂ Cl ₄ + H ₂ O

C ₂ HCl ₃ + 1 / 2Cl ₂ + 1 / 4O ₂ ――――― → C ₂ Cl ₄ + 1 / 2H ₂ O

C ₂ Cl ₆ ―――――― → C ₂ Cl ₄ + Cl ₂

Thus, in the presence of the melt mixture described above, the waste C ₂ chlorinated hydrocarbons are chlorinated, dehydrogenated, dechlorinated or dehydrogenated to produce trichlorethylene or tetrachlor ethylene. As a representative example, it is thought that the typical chlorination reaction of trichlorethane and copper chloride proceeds in the following reaction sequence in the chlorine treatment chamber.

C ₂ H ₃ Cl + 2CuCl ₂ ―――――― → C ₂ H ₂ Cl ₄ + HCl + 2CuCl

C ₂ H ₃ Cl ₃ + Cl ₂ ――――― → C ₂ H ₂ Cl ₄ + HCl

C ₂ H ₂ Cl ₄ ―――――― → C ₂ HCl ₃ + HCl

_{CuO · CuCl 2 + 2HCl ----- →} 2CuCl 2 + H 2 O

C ₂ H ₂ Cl ₂ ―――――― → C ₂ HCl ₃ + HCl

Oxygen required in this process is supplied by contacting molecular oxygen with air in a separate oxidation reaction chamber with air, and the reaction formula when copper chloride is used is as follows.

2CuCl + 1 / 2O ₂ ――――― → CuOCuCl ₂

Thus, oxygen required for this process is supplied without directly contacting oxygen and the raw material.

The temperature of the chlorine treatment chamber is usually from 370 ° C. to 660 ° C., preferably from 400 ° C. to 540 ° C., and can be operated at lower temperatures, namely 300 ° C. and 1-20 atmospheres. The raw material and the melt are brought into contact with a countercurrent, preferably in a continuous vapor phase, and the residence time may be about 1-60 seconds or longer. Chlorine or hydrogen chloride is usually introduced into the chlorine treatment chamber in stoichiometric proportions so that they are not present in the effluent (the effluent contains an equilibrium amount of hydrogen chloride). Preferred molten salts are copper chlorides consisting of a molten mixture containing about 20-40% by weight potassium chloride as a melting point depressant.

The cupric chloride content of the melt is at least about 20% by weight of the melt and usually about 30-40% by weight to provide sufficient cupric chloride for the reaction. On the other hand, it is possible to reduce the amount of cupric chloride by increasing the reaction temperature and residence time. The molecular oxygen is preferably introduced into the oxidation reaction chamber by adjusting the flow rate and flow rate so that the melting point is a molten mixture containing about 0.5-5.5% by weight of copper oxychloride, preferably 1-3% by weight.

The effluent in the chlorine treatment chamber contains the components as described above in addition to trichlor ethylene or tetrachlorethylene and the effluent can be converted to trichlorethylene or tetrachlorethylene. According to the present invention, these components are recovered from the chlorinated effluent and all or part of them are recycled to the chlorine treatment chamber to produce more trichloroethylene or more trichlorethylene.

Waste streams and chlorinated effluents also contain chlorinated hydrocarbon components that are not converted to trichlorethylene or tetrachlor ethylene. If only trichlor ethylene is the intended reaction product, chlorinated hydrocarbon components contain heavier C ₂ chlorination than tetrachlorethanes. Hydrocarbons ("heavy" means that the boiling point of the bicomponent is higher than the boiling points of tetrachlorethanes), pentachlorethane, hexachlorethane and chlorinated hydrocarbons having 2 or more carbon atoms, and according to the present invention, such heavy Some or all of the C ₂ chlorinated hydrocarbon components (some of these heavy components can be recovered as by-products when marketable) are combusted to recover chlorine fractions to chlorine or hydrogen chloride. When tetrachlorethylene is a desired reaction product, chlorine fraction is recovered by burning chlorinated hydrocarbons having more than 2 carbon atoms. When a small amount of a component capable of converting to trichlorethylene or tetrachlorethylene is contained, it may be recycled to a chlorine treatment chamber for combustion instead of recovery. Combustion conditions are extensive, with combustion temperatures of 540 ° C-1,650 ° C and pressures of 1-30 atmospheres. Molecular oxygen required for combustion is usually air, and the amount of oxygen requires oxygen of about 1 mole or more per atom of carbon and about 0.25 mole or more of oxygen per atom of hydrogen. In some cases, fuel is added to the raw materials to be burned to maintain the combustion conditions, in which case sufficient oxygen must be supplied according to the oxygen demand of the fuel. The effluent from combustion contains steam carbon oxides (carbon dioxide and / or carbon monoxide) and nitrogen, in addition to hydrogen chloride or chlorine, and is treated to recover chlorine fraction.

Since the above conditions are for illustration and the optimum conditions are various, those skilled in the art can adopt the optimum conditions.

Chlorine or hydrogen chloride is recovered from combustion effluents by contacting combustion effluents and molecular oxygen-containing gases in the oxidation reaction chamber with melts containing polyvalent metal chlorides in the form of both low and high valences, resulting in various reactions. When copper is used as the metal, it can be represented as follows.

2CuCl + Cl ₂ ―――――― → 2CuCl ₂

2CuCl + 1 / 2O ₂ ――――― → CuOCuCl ₂

_{CuO · CuCl 2 + 2HCl ------ →} 2CuCl 2 + H 2 O

By contacting the combustion effluent with the melt or oxygen containing gas, chlorine or hydrogen chloride is selectively absorbed from the combustion effluent, thereby increasing the chlorine content in the melt. Ie cupric chloride increases in the melt. The temperature at the contact in the oxidation reaction chamber is 315 ° C.-480 ° C. (of course higher temperatures, 650 ° C. can be raised but are not preferred because the oxygen absorption of the melt is poor). The pressure may be about 1-20 atmospheres and the residence time may be about 1-60 seconds or longer. It is desirable to contact the combustion effluent with the oxygenous gas in a continuous vapor phase countercurrent.

The oxygen required to absorb hydrogen chloride in the melt is supplied from the outside, or by burning the chlorinated hydrocarbons and excess oxygen together with the combustion effluent, the molecular oxygen required for the reaction. As described above, when supplied to the chlorine treatment chamber, the melt from the oxidation reaction chamber and the melt recovered in the third reaction chamber also contain oxychloride. The oxygen supplied to the oxidation chamber should therefore be sufficient to recover the hydrogen chloride from the combustion effluent and to produce pure oxychloride for use in the chlorine treatment chamber.

It is clear from the above reaction sequence that the melt containing polyvalent metal chlorides does not only act as a catalyst by participating in the reaction in order. For example, the melt serves to transport oxygen, and as can be seen from the above equation, oxychloride must be sufficiently formed to supply oxygen for the reaction, and the oxygen demand is higher when hydrogen chloride is used compared to chlorine.

The melt is not only a reactant or catalyst but also a temperature regulator.

Since the heat absorption capacity of the circulating melt is large, the exothermic reaction in the chlorine treatment and oxygen contacting step, which is exothermic, is prevented. The absorbed heat of reaction heats the various reactants to the reaction temperature and provides the heat necessary for the endothermic dehydrochlorination reaction. When it is necessary to heat or cool further, it can be heated or cooled externally.

As a specific example of the present invention, only trichlorethylene is recovered as a reaction product. In this example, chlorinated components that are heavier than tetrachlorethylene and tetrachlorethane can be burned to recover the chlorine component.

As another specific example, trichlorethylene and tetrachlorethylene can be recovered as reaction products, in which case residual C ₂ chlorinated hydrocarbons heavier than tetrachlorethane are recycled and converted or burned into the product.

In another specific example, only tetrachlor ethylene is recovered as the reaction product, in which case trichloroethylene is also recycled and ultimately converted to tetrachlor ethylene.

As another specific example, it may be recovered as a reaction product in 1,1,1-trichlorethanol waste stream and effluent of the chlorine treatment chamber.

As another specific example, ethane or ethylene is added as a new raw material to the chlorine treatment chamber to recover trichlorethylene and other C ₂ chlorinated hydrocarbons such as 1,1,1-trichlorethane or tetrachlorethylene as reaction products. .

It is clear from the above description that waste streams containing C ₂ chlorinated hydrocarbons can be usefully used to prepare trichlor ethylene and other useful products. According to the present invention, chlorine and hydrocarbons in the waste stream are sufficiently converted into products.

The content of the present invention is explained in more detail according to specific examples illustrated in the accompanying drawings. It should be understood that the scope of the present invention is not limited only to this. In addition, molten copper chloride salts are corrosive and must be properly protected for the treatment equipment. In other words, the reactor must be coated with ceramic. In addition, the use of pumps for melting point transfer must also protect the pumps. The molten salt is preferably transferred to the reaction period using a gas raising device known in the art.

In FIG. 1, the molten chloride salt, such as a mixture of potassium chloride, cuprous chloride, and cupric chloride, is maintained at an appropriate temperature and pressure for oxidation of the molten salt, as described above via line 10, in the reaction section of the reaction vessel 11. To be introduced.

As described below, combustion effluents containing hydrogen chloride and chlorine, carbon dioxide, water vapor, nitrogen and sometimes even molecular oxygen are introduced into vessel 11 through line 12a.

If necessary (when the oxygen content of the combustion effluent is not sufficient), a pressurized oxygen-containing gas, such as air, is introduced into the bottom of vessel 11 via line 12 and passes in countercurrent contact with the molten salt that descends with the combustion effluent. As a result, the salt is oxidized to release heat to form copper oxychloride, which recovers hydrogen chloride and chlorine from the combustion effluent, resulting in an increase in the content of cupric chloride in the melt.

Effluent gas free of chlorine or hydrogen chloride (which contains an equilibrium amount of chlorine or hydrogen chloride) rises to the top of vessel 11 where the outflowing gas is combined with the rising gas as described below and introduced into line 13. The effluent gas is cooled by sparging the quench liquid at the top of vessel 11 and sparging with an aqueous solution of hydrogen chloride introduced through line 14 to remove the salts contained in the vapor phase. The effluent gas containing the evaporated quench liquid is recovered from vessel 11 through line 15 and introduced into a direct contact quench tower 16 of the type known in the art to be cooled by direct contact with a suitable cooling liquid, in particular an aqueous solution of hydrogen chloride. Introduction through line 17 removes the quench liquid evaporated from the effluent gas.

The quench liquid is withdrawn from the bottom of tower 16 via line 18, where the first portion is moved through line 14 to quench the effluent gas in vessel 11 and the second portion is passed through line 19 with cooler 21 to line 17 Introduced into cold tower 16.

Effluent gas is withdrawn from quench tower 16 via line 22 and part is introduced into line 23. The remainder of the effluent gas is compressed in compressor 24 and after the temperature is controlled in heat exchanger 63, passes through lines 25 and 26 and is used as the rising gas for molten salt transfer as described below.

Molten salts containing oxychloride of copper are recovered at the bottom of vessel 11 via line 31 and ascended by the rising gas of line 25 and introduced into separation vessel 32 beside the top of the reaction section of reaction vessel 33. In separator 32, the molten salt and the rising gas are separated and the separated rising gas is recovered via line 35 and combined with the rising gas of the oxidation chamber and introduced into the quench portion of vessel 11 via line 13.

Molten salts containing cuprous chloride, cupric chloride, copper oxychloride, and potassium chloride, the melting point depressant, are separated via line 34 and introduced into reaction vessel 33 at line 32.

Fresh raw chlorine or hydrogen chloride is introduced into the bottom of reaction vessel 33 via line 43. The C ₂ chlorinated hydrocarbon raw material preferably contains one or more of the following components. That is, C ₂ monochlorinated hydrocarbons, C ₂ dichlorinated hydrocarbons, C ₂ trichlorinated saturated hydrocarbons and ethane tetrachloride are introduced into the reaction chamber 33 through line 46. The C ₂ chlorinated hydrocarbon raw material is composed of the three raw materials recovered from the waste stream and the recycle components as described below.

The reaction vessel 33 is operated under the conditions described above to produce trichlorethylene by dehydrogenation, chlorination and dehydrochlorination of various C ₂ chlorinated hydrocarbon components.

In addition to trichlorethylene, the effluent contains C ₂ chlorinated hydrocarbons, C ₂ dichlorinated hydrocarbons, chlorine and ethane, tetrachlorethylene, tetrachlorethanes, C ₂ chlorinated hydrocarbons, and water vapors, which are heavier than tetrachlorethanes. And cooling the effluent containing some hydrogen chloride (generally equilibrium) by direct contact with the cooling liquid by sparging at the top of vessel 33, in particular one or more chlorinated hydrocarbons prepared in reaction vessel 33 introduced into line 53. The effluent gas is cooled to remove the vapor phase heat contained in the effluent gas.

The effluent gas containing the evaporated cooling liquid is recovered in vessel 33 via line 54 and then introduced into a separation and recovery section (FIG. 2) to recover various components.

The molten salt recovered via line 61 at the bottom of reactor 33 is lifted by the rising gas of line 26 and introduced into separation vessel 62 next to the top of reactor 11.

The molten salt and rising gas are separated in separator 62 and enter vessel 11 via line 10. The rising gas is withdrawn from separator 62 via line 64 and combined with the rising gas of line 35 and introduced via line 13 into the upper cooling section of vessel 11.

In FIG. 2, the reaction effluent of line 54 is introduced into the pretreatment chamber 110 and separated into water and hydrogen chloride by a method known in the art, and the chlorinated hydrocarbon to be used as a quench liquid is recovered and recycled to line 53.

The dried chlorinated hydrocarbons of line 12 are combined with the waste stream, which is the raw material of line 123 containing C ₂ chlorinated hydrocarbons. As mentioned above, the waste stream of line 123 contains a mixture of one or more of C ₂ day, _two , three, four, five and hexachlorinated hydrocarbons and generally all of these components.

The mixed steam of line 124 is introduced into fractional distillation column 125 and the fractionation column contains at least one of the components lighter than trichlorethylene, in particular monochlorinated hydrocarbons, C ₂ dichlorinated hydrocarbons and 1,1,1-trichlorethane. Operate at a temperature and pressure that can be recovered from the top. The overhead fraction exits tower 125 via line 126 and is recycled to reactor 33 via line 46.

At the bottom of the column, trichlorethylene and its heavier components exit the tower 125 through line 127 and are introduced into the fractionation column 128, where the fractionation tower is operated at a temperature and pressure to recover trichlorethylene from the top of the column. Trichlorethylene, the pure reaction product, exits distillation column 128 through line 129.

The column bottoms effluent, consisting of components heavier than trichlorethylene, is discharged from the distillation tower 128 through line 131 and introduced into the fractionation tower 132, where components lighter than tetrachlorethylene are recovered from the tower, especially 1,1, 2-trichlor ethane is recovered. Lighter top components than tetrachlorethylene are recovered from distillation column 132 via line 133 and recycled to reactor 33 on line 46.

The bottom component, consisting of tetrachlorethylene and its heavier components, consists in particular of tetrachlorethylene, tetrachlorethanes, C ₂ chlorinated hydrocarbons containing at least 5 chlorine atoms and chlorinated hydrocarbons containing at least 2 carbon atoms. And if present they are recovered from distillation column 132 via line 134. The bottom part contains components which can be converted into trichlorethylene, namely tetrachlorethylene, tetrachlorethanes, pentachlorethane and hexachlorethane. The use of the bottom of the column depends on the economics of the recovery of various components.

In accordance with a preferred operation for recovering tetrachlorethylene as the reaction product, the column bottom component of line 134 is introduced into the fractionation tower 135 to recover tetrachlorethylene as the tower component. The top component consisting of tetrachlorethylene as the reaction product is recovered via distillation column 135 via line 136.

The tower bottom component, which is composed of components heavier than tetrachlorethylene, is recovered from the distillation column 135 in 137 and introduced into the fractionation tower 138, and the fractionation column is operated to recover the tetrachlorethanes from the top. At the top of the column, tetrachlorethane is recovered via line 140 and recycled to reactor 33 via line 46.

The top bottom component, consisting of components heavier than tetrachlorethane, is recovered from the distillation column 138 via line 139 and introduced into the combustion chamber 141 and combusted as described above with the oxygen containing gas introduced into 142. The combustion effluent containing chlorine hydrogen and chlorine is recovered through line 12a and introduced into the reaction chamber 11, and the chlorine fraction is recovered as described above.

Tetrachlorethylene as the reaction product is not required and when the recovery of tetrachlorethylene is not economical, the bottom component of line 134 is sent directly to the combustion chamber. In a similar manner, tetrachlorethylene is recovered as a product, and when the recovery of tetrachlorethane is not economical, the bottom component of line 137 is sent directly to the combustion chamber.

In addition to tetrachlorethanes, namely tetrachlorethylene, penta- and hexa-chlorethanes, trichlorethylene can be made by converting C ₂ chlorinated hydrocarbons that are heavier than 1,1,2-trichlorethane, and in some cases such components One or more may be recycled to reactor 33.

The specific examples described above may be variously changed or changed within the purpose and scope of the present invention. For example, instead of combining waste streams and chlorine effluents as described above, their recovery units can be installed separately.

In addition, ethane or ethylene can be introduced into the chlorine treatment chamber as a new raw material. In this case, the recycle stream also contains ethane or ethylene.

In addition, 1,1,2-trichlorethane can be recovered as a by-product. In this case, tube 125 proceeds to recover lighter components than 1,1,1-trichlorethane as the top product, in which case 1,1,1-trichloroethane is recovered as top fraction from trichlorethylene and heavier components. A distillation column is required to separate.

In addition, only tetrachloroethylene may be recovered by a reaction product. In this case, the distillation towers 128 and 132 are excluded, and the distillation tower 125 is recycled to the reactor 33 by proceeding to recover components lighter than tetrachlorethylene from the top of the tower. The bottom bottom component of the distillation column 125 is introduced into the distillation column 135 to recover tetrapicchlorethylene as a top product, and the bottom bottom component is burned or introduced into the distillation column 138 to recover the tetrachloroethanes. Chlorethanes and hexachlorethanes are also recovered and recycled to reactor 33. The residual chlorinated hydrocarbons are burned to recover the chlorine fraction as described above.

The foregoing variations and other matters are apparent to those skilled in the art having been taught the contents of this specification.

The present invention has the advantage of minimizing the loss of chlorinated hydrocarbon content while producing useful products using C ₂ chlorinated hydrocarbon waste streams such as those produced in known processes for producing vinyl chloride.

According to the preferred method of the present invention, as described above, trichlorethylene and tetrachlorethylene are recovered as products, and C ₂ chlorinated hydrocarbons which are lighter than tetrachlorethane and tetrachlorethylene present in the waste stream and the chlorine effluent are chlorine treatment chambers. The chlorinated hydrocarbons, which are recycled to and are heavier than tetrachlorethanes, are combusted to recover the chlorine fraction.

The present invention can be practiced differently from the above-described method within the scope of the claims because various modifications and changes can be made by teaching the above matters.

Claims (1)

In the method for producing a chlorinated product selected from the group consisting of trichlorethylene, tetrachloroethylene, and mixtures thereof, the following processes occur during the production of vinyl chloride, C ₂ monochlorinated hydrocarbons, the chlorination C ₂ chlorinated hydrocarbon wastes containing complex C ₂ chlorinated hydrocarbons and chlorine treatments and products which can be converted into chlorine treatments and products selected from the group consisting of hydrocarbons, trichlorethanes, tetrachlorethanes and pentachlorethanes Is introduced into a separation chamber and the chlorinated product and the complex C ₂ chlorinated hydrocarbons which can be converted into the chlorinated product from the waste stream in the separation chamber are recovered, C ₂ monochlorinated hydrocarbons, C ₂ is chlorinated hydrocarbons, Group consisting of trichlorethanes, tetrachlorethanes and pentachlorethane In order to produce a reaction effluent containing the complexed C ₂ chlorinated hydrocarbons of the chlorinated product and the by-product convertible to the chlorinated product selected from A molten mixture consisting of a chlorine treatment agent selected from the group consisting of chlorine treatment agents selected from the group consisting of chlorinated chloride and metal oxychloride and hydrogen chloride, chlorine and mixtures thereof, in contact with a temperature range of 371 ° C. to 649 ° C. Process for producing trichlorethylene from spent C ₂ chlorinated hydrocarbons.

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