Chloroprene removal from pyrolyzed 1,2-dichlorethane

Claim 2

IN A PROCESS FOR THE PURIFICATION OF VINYL CHLORIDE OBTAINED BY PYROLYZING 1,2-DICHLORETHANE TO FORM A RAW GASEOUS PRODUCT CONTAINING VINYL CHLORIDE, HYDROGEN CHLORIDE, CHLOROPRENE, BUTADIENE AND UNCONVERTED 1.2-DICHLORETHANE, AND COOLING THE RAW GASEOUS PRODUCT TO FORM A GASEOUS PHASE AND A LIQUID CONDENSATE PHASE, SAID LIQUID CONDENSATE PHASE CONTAINING 11,2-DECHLORETHANE, VINYL CHLORIDE, HYDROGEN CHLORIDE, CHLOROPRENE AND BUTADIENE, THE IMPROVEMENT WHICH COMPRISES ADMIXING CHLORINE WITH SAID LIQUID CONDENSATE OF THE RAW GASEOUS PRODUCT TO FORM A LIQUID MIXTURE, THE AMOUNT OF CHLORINE BEING FROM 0.01 TO 5 PERCENT BY WIEGHT, BASED ON THE WEIGHT OF UNCONVERTED 1,2-DICHLORETHANE IN THE LIQUID CONDENSATE, REMOVING HYDROGEN CHLORIDE FORM THE LIQUID MIXTURE AND

Claim 3

A process for treating the raw gaseous product coming from the pyrolysis of 1,2-dichlorethane to obtain vinyl chloride, comprising the steps of: cooling the gaseous product coming from the pyrolysis under a pressure greater than atmospheric to obtain a gaseous phase and a liquid phase; treating the resulting liquid phase with chlorine in an amount of between 0.01 and 5 percent by weight with respect to the quantity of 1,2-dichlorethane not converted by the pyrolysis, separating hydrogen chloride from the mixture resulting from said treating step and distilling the liquid mixture resulting from said separating step to obtain

Claim 4

A process for treating the raw gaseous product coming from the pyrolysis of 1,2-dichlorethane to obtain vinyl chloride, comprising the steps of: cooling the gaseous product coming from the pyrolysis under a pressure greater than atmospheric to obtain a gaseous phase and a liquid phase; treating the resulting liquid phase with chlorine in an amount of between 0.01 and 5 percent by weight with respect to the quantity of 1,2-dichlorethane not converted by the pyrolysis, separating hydrogen chloride from the mixture resulting from said treating step and distilling the liquid mixture resulting from said separating step to obtain

Claim 5

A process as defined in claim 2 wherein said step of cooling is carried out as to obtain a gaseous phase and a liquid phase at a temperature of between 0 and 100.degree.C and comprising the further step of washing the gaseous phase produced by said cooling step with part of the liquid mixture produced by said treating step, and subsequently returning the liquid employed in said washing step to be subjected anew to said treating

Claim 6

A process as defined in claim 2 wherein the quantity of chlorine utilized in said treating step is between 0.02 and 1 percent by weight with respect to the amount of 1,2-dichlorethane which was not converted by

Claim 7

A process for treating the raw gaseous product of the pyrolysis of 1,2-dichlorethane, which product contains principally vinyl chloride in mixture with hydrogen chloride, non-converted 1,2-dichlorethane and small quantities of chloroprene, the process being for the purpose of eliminating the chloroprene and obtaining pure vinyl chloride and comprising the steps of: a. cooling the product of the pyrolysis of 1,2-dichlorethane to a temperature of between 0.degree. and 300.degree.C by quenching it with liquid 1,2-dichlorethane under a pressure greater than atmospheric; b. condensing the mixture obtained by said cooling step under a pressure of between 0 and 30 kg/cm.sup.2 and at a temperature of between 0.degree. and 100.degree.C for obtaining a liquid phase and a gaseous phase, the liquid phase principally containing 1,2-dichlorethane, vinyl chloride, a small quantity of hydrogen chloride and a small quantity of chloroprene, and the gaseous phase principally containing hydrogen chloride and vinyl chloride; c. treating the liquid phase obtained by said condensing step with chlorine in an amount of 0.01 to 5 percent by weight with respect to the quantity of 1,2-dichlorethane which was not converted by the pyrolysis and which is contained in the liquid phase for producing a liquid mixture substantially free of chloroprene; d. separating hydrogen chloride from the mixture resulting from said treating step; e. separating the liquid mixture obtained by step (d) by distillation to obtain polymerizable vinyl chloride; and f. separating the gaseous phase obtained by said condensing step, by

Claim 8

A process for treating the raw gaseous product of the pyrolysis of 1,2-dichlorethane, which product contains principally vinyl chloride in mixture with hydrogen chloride, non-converted 1,2-dichlorethane and small quantities of chloroprene, the process being for the purpose of eliminating the chloroprene and obtaining pure vinyl chloride and comprising the steps of: a. cooling the product of the pyrolysis of 1,2-dichlorethane to a temperature of between 0.degree. and 300.degree.C by quenching it with liquid 1,2-dichlorethane under a pressure greater than atmospheric; b. condensing the mixture obtained by said cooling step under a pressure of between 0 and 30 kg/cm.sup.2 and at a temperature of between 0.degree. and 100.degree.C for obtaining a liquid phase and a gaseous phase, the liquid phase principally containing 1,2-dichlorethane, vinyl chloride, a small quantity of hydrogen chloride and a small quantity of chloroprene, and the gaseous phase principally containing hydrogen chloride and vinyl chloride; c. treating the liquid phase obtained by said condensing step with chlorine in an amount of 0.01 to 5 percent by weight with respect to the quantity of 1,2-dichlorethane which was not converted by the pyrolysis and which is contained in the liquid phase for producing a liquid mixture substantially free of chloroprene; d. separating hydrogen chloride from the mixture resulting from said treating step; e. separating the liquid mixture obtained by step (d) by distillation to obtain polymerizable vinyl chloride; and f. separating the gaseous phase obtained by said condensing step, by

Claim 9

A process as defined in claim 5 wherein said step of cooling is carried

Claim 10

A process as defined in claim 5 wherein said two separating steps are

Claim 11

A process as defined in claim 5 wherein each of the liquid phase and gaseous phase produced by said condensing step additionally contains a small quantity of butadiene, and said treating step produces a liquid mixture which is also substantially free of butadiene; and comprising the further step of washing the gaseous phase produced by said condensing step with a portion of the liquid mixture produced by said treating step for obtaining a gaseous phase substantially free of butadiene, and subsequently again subjecting said portion of the liquid mixture to said

Claim 12

A method as defined in claim 5 wherein the quantity of chlorine employed in said treating step is between 0.02 and 1 percent by weight with respect to the quantity of 1,2-dichlorethane not converted by the pyrolysis and

Claim 13

A process according to claim 1 which comprises maintaining the chlorine in admixture with the liquid condensate for a period sufficient to remove all but at most a negligible quantity of chloroprene from said liquid condensate.