Tetrafluoroethylene manufacturing steps

Preparation. The manufacture of tetrafluoroethylene [116-14-3] (TEE) involves the following steps (2—9). The pyrolysis is often conducted at a PTFE manufacturing site because of the difficulty of handling TFE. 

The first step is set up to produce hydrogen fluoride and the second yields trichlo-romethane (chloroform). Chloroform is then partially fluorinated with hydrogen fluoride to chlorodifluoromethane using antimony fluoride as catalyst in the third step. Finally, in the fourth step, chlorodifluoromethane is subjected to pyrolysis in which it is converted to tetrafluoroethylene. The pyrolysis is a noncatalytic gas-phase process carried out in a flow reactor at atmospheric or subatmospheric pressure and at temperatures 590 to 900°C (1094 to 1652°F) with yields as high as 95%. This last step is often conducted at the manufacturing site for PTFE because of the difficulty of handling the monomer.9... 

PTFE is homopolymer of tetrafluoroethylene (TFE) and it is industrially manufactured from chloroform by a three-step process as shown below ... 

The starting materials of the telomerization process are tetrafluoroethylene and a perfluoroalkyl iodide. Of the various perfluoroalkyl iodides used in telomerization processes, pentafluoroethyl iodide is the most important (see Section 2.3). The one-step process for manufacturing pentafluoroethyl iodide is based on the addition of iodine fluoride to tetrafluoroethylene. Iodine fluoride, IF, is too unstable to be isolated and is therefore formed from iodine pentafluoride and iodine in situ. Iodine pentafluoride is synthesized from iodine and elemental fluorine [12] ... 

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