Patent ID: 6849163

Claim:
A process for producing tetrafluoroethylene wherein a tetrafluoroethylene mixture is obtained as an intended mixture from a raw material mixture which comprises tetrafluoroethylene, at least one component of which boiling point is lower than that of tetrafluoroethylene and at least one component of which boiling point is higher than that of tetrafluoroethylene, and a tetrafluoroethylene concentration of the tetrafluoroethylene intended mixture is larger than that of the raw material mixture, the process comprising: (1) subjecting said raw material mixture to a preliminary distillation treatment so as to obtain: (a) a first fraction which comprises at least a portion of said higher boiling component, and (b) a second fraction as the balance of the raw material mixture which fraction comprises tetrafluoroethylene and said lower boiling component, and (2) then subjecting the second fraction to a main distillation treatment so as to obtain: (c) a third faction formed by distilling off said lower boiling component, and (d) a fourth fraction as the intended mixture being the balance of the second fraction which fraction comprises tetrafluoroethylene.