Synthesis of tetrafluoroethylene
AssigneeE. I. Du Pont de Nemours and Company
InventorsPatrick Michael Murphy, Henry Max Schleinitz, David John Van Bramer
Life of this patent
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Abstract
In the process of pyrolyzing chlorodifluoromethane to form tetrafluoroethylene, yield is improved by having a controlled concentration of perfluorocyclobutane in the feed to pyrolysis.
Claims6
Process comprising pyrolyzing CF.sub.2 HCl to obtain tetrafluoroethylene as desired reaction product and C.sub.4 F.sub.8 as undesired reaction product, and further comprising co-feeding C.sub.4 F.sub.8 along with said CF.sub.2 HCl to the pyrolysis reaction in an amount effective to reduce the formation of C.sub.4 F.sub.8 as said undesired reaction product, essentially without consuming C.sub.4 F.sub.8 in the pyrolysis reaction, thereby increasing the yield of said tetrafluoroethylene reaction product, said CF.sub.2 HCl and said C.sub.4 F.sub.8 co-fed with said CF.sub.2 HCl being the essential compounds fed to the pyrolysis reaction, said pyrolysis reaction being carried out under a total pressure of 0.8 to 1.2 atmospheres to a conversion of CF.sub.2 HCl of from 10% to 50%, the concentration of said C.sub.4 F.sub.8 being 5% to 10% based on the combined weight of C.sub.4 F.sub.8 and CF.sub.2 HCl.
Process comprising pyrolyzing CF.sub.2 HCl to obtain tetrafluoroethylene as desired reaction product and C.sub.4 F.sub.8 as undesired reaction product and further comprising co-feeding C.sub.4 F.sub.8 along with said CF.sub.2 HCl to the pyrolysis reaction in an amount effective to reduce the formation of C.sub.4 F.sub.8 as undesired reaction product, essentially without consuming C.sub.4 F.sub.8 in the pyrolysis reaction, thereby increasing the yield of said tetrafluoroethylene reaction product, said CF.sub.2 HCl and said C.sub.4 F.sub.8 co-fed with said CF.sub.2 HCl being the essential compounds fed to said pyrolysis reaction, said pyrolysis reaction being carried out in the presence of inert diluent providing 25% to 95% of the total pressure of said pyrolysis reaction, said pyrolysis reaction being carried out at a total pressure of 0.8 to 1.2 atmosphere and conversion of said CF.sub.2 HCl of from 30% to 90%, the concentration of said C.sub.4 F.sub.8 being 6% to 16% based on the combined weight of C.sub.4 F.sub.8 and CF.sub.2 HCl.
Dependencies are inferred from the claim text.