Patent · US Expired

Process for the manufacture of defluoromethane

US6635790B1 · kind B1 · utility

3Cited by
8References
14Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 28, 2000
Grant dateOct 21, 2003
Priority date
Expiry dateSep 27, 2020

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P20/582
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

The subject of the invention is a continuous process for the manufacture of difluoromethane (F32) from methylene chloride (F30) and hydrogen fluoride in the presence of chlorine, in the gas phase, over a fluorination catalyst.According to the invention, the gas flow exiting from the reactor is subjected to a distillation in order to separate, at the top, a flow containing virtually all the HCl and at least 90% of the F32 produced by the reaction and, at the bottom, a flow containing at least 90% of the unconverted reactants (F31, F30 and HF) and the latter flow is recycled directly to the reactor, without any purification operation.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.