Abstract A purification separation of the residual ethylene dichloride from the higher boiling chlorinated materials found in the bottoms fraction of a heavy ends column in a vinyl chloride monomer plant is carried out by passing the bottoms fraction to a vaporization zone maintained at about 112* C. The ethylene dichloride rich overhead from the vaporization zone is then passed to a fractionation column maintained between about 87* and about 117* C. The overhead from the fractionation column contains ethylene dichloride essentially free of higher boiling chlorinated materials and tars. This ethylene dichloride purified of ''''tars and carbon'''' and containing principally only 1,1,2trichloroethane impurity, can be returned to the conventional VCM process distillation purification system which then separates this stream to yield high-quality ethylene dichloride for use as feed to an ethylene dichloride pyrolysis unit or for production of saleable ethylene dichloride product of high commercial quality.
Inventors
👤 Robert P Obrecht
👤 Thomas Dao
👤 Gilbert E Klingman
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-08 00:11
CPC Classifications
C; C07; C07C; C07C17/00; C07C17/38
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
27 words
The process of claim 1 in which the bottoms materials from the distillation column contains from about 10 mole percent to about 90 mole percent ethylene dichloride.
Claim 2
Dependent Claim
29 words
The process of claim 2 wherein the bottoms fraction containing a major percentage of 1,1,2-trichloroethane and a small percentage of other chlorinated hydrocarbons is then contacted with sulfuric acid.
Claim 3
Dependent Claim
21 words
The method of claim 2 wherein a portion of the overhead from the fractionation zone is recycled to the distillation column.
Claim 4
Dependent Claim
143 words
A process wherein crude ethylene dichloride containing low-boiling and high-boiling impurities is passed to a light ends distillation column and low-boiling impurities are removed as overhead and the ethylene dichloride and high-boiling impurities are removed as bottoms, the ethylene dichloride and high-boiling impurities are passed to a heavy ends distillation column in which ethylene dichloride is removed as overhead and residual ethylene dichloride and the high-boiling impurities are removed as bottoms materials, the improvement comprising, passing the bottoms materials containing residual ethylene dichloride and high-boiling impurities to a vaporization zone maintained under conditions to separate as overhead, an essentially tar-free vapor stream containing ethylene dichloride, passing the essentially tar-free vapor stream to a fractionation zone maintained under conditions to separate an overhead comprising ethylene dichloride from a bottoms fraction containing a major percentage of 1,1,2-trichloroethane and a small percentage of other chlorinated hydrocarbons.
Claim 5
Dependent Claim
29 words
The process of claim 5 in which the bottoms materials from the heavy ends distillation column contains from about 10 mole percent to about 90 mole percent ethylene dichloride.
Claim 6
Dependent Claim
29 words
The process of claim 6 wherein the bottoms fraction containing a major percentage of 1,1,2-trichloroethane and a small percentage of other chlorinated hydrocarbons is then contacted with sulfuric acid.
Claim 7
Dependent Claim
23 words
The process of claim 6 wherein a portion of the overhead from the fractionation zone is recycled to the heavy ends distillation column.