Method for co-production of hydrofluorocarbons

A method for co-production of hydrofluorocarbons, comprising the following steps of:

• (a) preheating a mixture of chlorinated olefin and hydrogen fluoride;
• transferring the mixture to the top of a reactor;
• simultaneously introducing 1,1,1,2,3,3-hexafluoropropene and dichloromethane to the middle of the reactor for reaction;
• dividing the reactor into three to six sections;
• filling each section with a catalyst;
• obtaining reaction products at an outlet of the reactor;
• (b) separating the reaction products obtained in the step (a) in a first rectifying tower to obtain a fraction at the top of the first rectifying tower and a product at the bottom of the first rectifying tower;
• (c) separating the fraction at the top of the first rectifying tower obtained in the step (b) in a second rectifying tower to obtain hydrogen chloride at the top of the second rectifying tower and a product at the bottom of the second rectifying tower;
• and
• (d) separating the product at the bottom of the second rectifying tower obtained in the step (c) in a third rectifying tower to obtain a difluoromethane product or a mixture containing difluoromethane at the top of the third rectifying tower as well as a 1,1,1,2,3,3,3-heptafluoropropane product or a mixture containing 1,1,1,2,3,3,3-heptafluoropropane at the bottom of the third rectifying tower;
• if there is a mixture containing difluoromethane obtained at the top of the third rectifying tower, conducting further separation to obtain a difluoromethane product;
• and if there is a mixture containing 1,1,1,2,3,3,3-heptafluoropropane obtained at the bottom of the third rectifying tower, conducting further separation to obtain a 1,1,1,2,3,3,3-heptafluoropropane product.