Process for the manufacture of difluoromethane
AssigneeAtofina
InventorsBenoit Requieme, Sylvain Perdrieux, Bernard Cheminal, Eric Lacroix, Andre Lantz
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Abstract
The invention relates to the synthesis of difluoromethane by gas-phase catalytic fluorination of methylene chloride. To lengthen the lifetime of the catalyst the operation is carried out in the presence of chlorine.
Claims18
Process for the manufacture of difluoromethane by gas-phase catalytic fluorination of methylene chloride by means of anhydrous hydrofluoric acid, characterized in that the operation is carried out in the presence of chlorine.
Process for the manufacture of difluoromethane comprising gas-phase catalytic fluorination of methylene chloride with anhydrous hydrofluoric acid, carrying out the operation in the presence of chlorine and a fluorination catalyst, a Cl2/CH2Cl2 molar ratio is between 0.01% and 10%, the operation is carried out at a temperature between 25° C. and 450° C., and contact time is between 0.01 and 20 seconds.
Dependencies are inferred from the claim text.