Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.

Abstract: According to a process for producing difluoromethane and difluorochloromethane, which comprises fluorinating dichloromethane and trichloromethane with hydrogen fluoride in a liquid phase in the presence of a catalyst in one reaction apparatus under the conditions that a reaction pressure is from 1 to 20 kg/cm2 and a reaction temperature is from 50 to 150° C., difluoromethane and difluorochloroethane can be simultaneously or alternatively produced in an economical/safe manner by one reaction apparatus.

Abstract: A process is disclosed for producing difluoromethane by fluorinating dichloromethane with hydrogen fluoride in a liquid phase in the presence of a catalyst, wherein the reaction is conducted at a temperature within the range from 80 to 150° C. under a pressure within the range from 8 to 80 kg/cm2 using a mixture of antimony pentafluoride and antimony trifluoride, or antimony pentafluoride as the fluorinating catalyst. The process economically and safely produces difluoromethane from dichloromethane and hydrogen fluoride.

Abstract: A process for refining difluoromethane by removing hydrogen fluoride, which is contained in difluoromethane difficult to remove. The process involves distilling a mixture of difluoromethane with hydrogen fluoride where the mixture is in contact with sulfuric acid. The hydrogen fluoride remains in the liquid phase and the difluoromethane goes into the vapor phase.

Abstract: A process for refining difluoromethane by removing water which is contained in difluoromethane and has been believed to be difficult to be removed includes distilling difluoromethane which contains water so as to obtain difluoromethane as a distillate and a mixture as a bottom product of difluoromethane and chlorofluoromethane and/or dichloromethane which mixture contains water. The bottom product is recycled to a reaction step to be reused together with a feedstock.

Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.

Abstract: There is provided a process for producing HFC-125 and/or HCFC-124 from PCE, characterized by the first reaction step of fluorinating PCE in the presence of catalyst in a liquid phase to form HCFC-123 and/or HCFC-122 and the second reaction step of fluorinating HCFC-123 and/or HCFC-122 in the presence of catalyst in a vapor phase to form HFC-125 and/or HCFC-124.This process is improved in the yield of objective products, and life of catalyst, and the controllability of reaction temperature.

Abstract: There is provided a process for producing HFC-125 and/or HCFC-124 from PCE, characterized by the first reaction step of fluorinating PCE in the presence of catalyst in a liquid phase to form HCFC-123 and/or HCFC-122 and the second reaction step of fluorinating HCFC-123 and/or HCFC-122 in the presence of catalyst in a vapor phase to form HFC-125 and/or HCFC-124.This process is improved in the yield of objective products, and life of catalyst, and the controllability of reaction temperature.

Abstract: There is provided an azeotropic mixture of hydrogen fluoride (HF) and 1,1-difluoroethane (HFC152a). In addition, there is provided a process for the production of HFC152a having a step of more effectively recovering HF which does not contain HFC152a or HFC152a which does not contain HF in which step an azeotropic mixture is distilled off from a column top by subjecting a mixture containing HFC152a and HF, so that HF which does not contain HFC152a or HFC152a which does not contain HF is recovered from a column bottom.

Abstract: Difluoromethane is prepared by reacting dichloromethane and hydrogen fluoride in a liquid phase in the presence of a fluorination catalyst under reaction conditions in which the reaction pressure is between 1 and 10 kg/cm.sup.2 ab., and the reaction temperature is between 50 and 150.degree. C., provided that the selected reaction temperature is higher than a temperature at which hydrogen fluoride is not liquefied under the selected reaction pressure.Under the above conditions, the conversions of dichloromethane and HF are very high, and amounts of by-products other than R30 are very low, typically less than 0.1% per difluoromethane, when the unreacted materials are recycled.A material of a reactor is hardly corroded by the reaction using an antimony chlorofluoride and HF which are highly corrosive, as long as the above conditions are maintained.

Abstract: Hydrogen fluoride is effectively removed from a mixture of hydrogen fluoride, dichloromethane, chlorofluoromethane and/or difluoromethane by distilling the mixture so that two-component azeotropic mixtures of hydrogen fluoride and dichloromethane, hydrogen fluoride and chlorofluoromethane and hydrogen fluoride and difluoromethane are removed, or by liquid-separating the mixture into an upper liquid phase rich in hydrogen fluoride and a lower liquid phase not rich in hydrogen fluoride before each liquid phase is distilled as described above.

Abstract: A process for preparing 1,1,1-trifluoro-2-chloroethane and/or 1,1,1,2-tetrafluoroethane, comprising the steps of reacting trichloroethylene and/or 1,1,1-trifluoro-2-chloroethane with hydrogen fluoride in the presence of a fluorinating catalyst in a gas pase, separating 1,1,1-trifluoro-2-chloroethane, hydrogen fluoride, and optionally trichloroethylene, from the reaction mixture obtained by the above reaction which contains 1,1,1-trifluoro-2-chloroethane, 1,1,1,2-tetrafluoroethane, hydrogen fluoride, and optionally trichloroethylene, and recycling them to the reaction step above, characterized in that at least a part of the reaction mixture is distilled in a distillation tower, 1,1,1,2-tetrafluoroethane-rich components are discharged from the top of the tower, and a mixture of 1,1,1-trifluoro-2-chloroethane and hydrogen fluoride, and optionally trichloroethylene, is discharged in the form of gas from the middle part of the tower at a temperature which is above the boiling point of the azeotropic mixture of 1,1

Abstract: Hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane forms an azeotropic mixture of which molar ratio of HF/1,1,1-trifluoro-2-chloroethane varies, for example, from about 60/40 at a pressure of 1.5 Kg/cm.sup.2 G and a temperature of 20.degree. C. to about 45/55 at a pressure of 15 Kg/cm.sup.2 G and a temperature of 87.degree.C.

Abstract: Hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane forms an azeotropic mixture. A mixture comprising hydrogen fluoride and 1,1,1-trifluoro-2-chloroethane is phase separated when it is cooled to a temperature below 7.degree. C. 1,1,1-Trifluoro-2-chloroethane is purified effectively from the mixture by cooling the mixture to form an upper liquid phase and a lower liquid phase and distilling the lower liquid phase so that the hydrogen fluoride is removed as an azeotropic distillate and 1,1,1-trifluoro-2-chloroethane substantially free from hydrogen fluoride is obtained as a bottom product.