Difluoromethane → Cfc-115 hfc-32

A particularly desirable process permitted by the instant invention relates to HFC-32 that is synthecised with, or subsequently added to an HFC-125 stream which contains HF and CFC-115. The presence of HFC-32 permits the HFC-125 to be separated from the HF in a first column via removal of an HFC-32/HFC-125 azeotrope as distillate, wherein the HF may then be recycled from the bottoms to a fluorination reactor. The presence of HFC-32 also allows for separating CFC-115 from the HFC-125 in a second column by forming the CFC-115/HFC-32 azeotrope and distilling the CFC-115/HFC-32 azeotrope overhead, recovering the HFC-125 from the bottoms as product substantially-free of HF and CFC-115. By "substantially-free" is meant that the HFC-125 product contains less than about 500 ppm of HF and CFC-115, more typically less than about 50 ppm HF and CFC-115.

1. customto be separated from the HF in a first column via removal of an HFC-32/HFC-125
2. customfor separating CFC-115 from the HFC-125 in a second column

ORD record

ord-c6e5fd212b4542ad92e5d30d15fe4aa6

Source dataset

uspto-grants-2000_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06156161