The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 11, 2007
Filed:
Apr. 29, 2004
Clark S. Graybill, Lake Charles, LA (US);
Stephen R. Lester, Pittsburgh, PA (US);
Clark S. Graybill, Lake Charles, LA (US);
Stephen R. Lester, Pittsburgh, PA (US);
PPG Industries Ohio, Inc., Cleveland, OH (US);
Abstract
Describes a method for recovering trans-1,2-dichloroethene from a liquid feed composition comprising both the cis-and trans-isomers of 1,2-dichloroethene and contaminating amounts of other chlorinated hydrocarbons, e.g., lower alkyl chlorinated hydrocarbons, such as CCchlorinated hydrocarbons. In one of the described methods, the liquid feed composition is introduced into a first distillation columnwherein the stereoisomers and chlorinated hydrocarbons more volatile than the stereoisomers are removed as overheadand charged to a second distillation column. In column, the stereoisomers are separated from the more volatile chlorinated hydrocarbons, and a bottoms fractioncomprising the stereoisomers is charged to a reactive distillation columnwherein the cis-isomer is isomerized to the trans-isomer in the liquid phase and in the presence of an organic free-radical initiator, e.g., an azonitrile initiator. Substantially pure trans 1,2-dichloroethene is recovered as overhead 32 from reactive distillation column