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:
Feb. 06, 1990
Filed:
Aug. 30, 1988
Hartmut Voigt, Winhoring, DE;
Reinhold Freudenreich, Burgkirchen, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
A process is described for the production of pure tetrafluoroethylene from a gas formed in the pyrolysis of a fluorocarbon compound having 1 to 4 carbon atoms, which can contain a hydrogen atom and a chlorine atom. The pyrolysis gas, after hydrogen chloride or hydrogen fluoride and also if necessary steam have been separated off, is condensed under pressure and distilled in a plurality of columns, in the first column the low boilers being distilled off, preferably with a reflux ratio of 6 to 15 kg per kg of tetrafluoroethylene produced, and in the second column tetrafluoroethylene, preferably with a reflux ratio of 3 to 5 kg per kg of tetrafluoroethylene produced. Per kg of tetrafluoroethylene produced, from 0.6 to 2 kg of difluoromonochloromethane are fed into the second column as a distillation aid. The novel process makes it possible to produce pure tetrafluoroethylene at comparatively reduced energy and apparatus costs.