Patent ID: 6844474

Claim:
A process for producing difluoromethane comprising the steps of: (A) preheating a composition comprising hydrogen fluoride and dichloromethane to form a vaporized and superheated composition; (B) reacting the preheated composition of step (A) in the presence of a fluorination catalyst under conditions suitable to form a product stream comprising difluoromethane, chlorofluoromethane, hydrogen chloride, dichloromethane and hydrogen fluoride; (C) recovering by distillation from the product stream of step (B) a high boiling fraction comprising hydrogen fluoride, dichloromethane, and chlorofluoromethane and a low boiling fraction comprising difluoromethane, hydrogen chloride, hydrogen fluoride, and reaction byproducts; and (D) recovering substantially pure difluoromethane from the low boiling fraction of step (C), wherein the hydrogen fluoride and the chlorofluoromethane are present in the product stream in a mole ratio of from about 25:1 to about 75:1.