Abstract: A improved process is described for the preparation of a substantially pure, liquefied stream of 1,1,1,2-tetrafluoroethane by the catalyzed reaction of trichloroethylene with hydrogen fluoride to form the intermediate 2-chloro-1,1,1-trifluoroethane and then reacting said intermediate 2-chloro-1,1,1-trifluoroethane with hydrogen fluoride, in the presence of a hydrofluorination catalyst to form a reaction stream containing 1,1,1,2-tetrafluoroethane. The improvement comprises liquefying the by-product hydrogen chloride formed in the preparation of the intermediate 2-chloro-1,1,1-trifluoroethane and countercurrently passing said liquefied hydrogen chloride thru the reaction stream containing 1,1,1,2-tetrafluoroethane thereby forming a substantially pure, liquefied stream of 1,1,1,2-tetrafluoroethane and an effluent comprising gaseous hydrogen chloride.

Abstract: A process for producing sodium hydrosulfide solutions substantially free of sodium carbonate from a refinery sour gas by contacting refinery sour gas with a fresh aqueous sodium hydroxide solution in cocurrent interfacial two-phase flow and separating a sweet gas substantially free of hydrogen sulfide. There is also disclosed a novel liquid-gas two-phase interfacial flow reactor designed for use in the process. The sodium carbonate free solutions of sodium hydrosulfide are useful in the sulfate paper industry.