Treatment method for decomposing perfluorocompound, decomposing catalyst and treatment apparatus

Abstract

An object of the present invention is to improve the decomposition at low temperatures of perfluorocompounds containing only fluorine as a halogen, such as CF 4 , C 2 F 6 and the like. In the present invention, a perfluorocompound containing only fluorine as a halogen is brought into contact with a catalyst comprising Al, Ni and W as catalytically active ingredients and comprising a mixed oxide or complex oxide of Ni and Al and a mixed oxide or complex oxide of W and Ni, in the presence of steam or a combination of steam and air at a temperature of 500 to 800° C. to convert the fluorine in the perfluorocompound to hydrogen fluoride. Employment of the catalyst of the present invention improves the decomposition at low temperatures and hence makes it possible to decompose the perfluoro-compound at a high percentage of decomposition at a lower temperature.

1 . A method for decomposing a perfluorocompound comprising bringing a gas flow containing a perfluorocompound containing only fluorine as a halogen, into contact with a catalyst comprising Ni, W and Al as catalytically active ingredients and comprising a mixed oxide or complex oxide of Ni and Al and a mixed oxide or complex oxide of Ni and W, in the presence of steam or a combination of steam and air at a temperature of 500 to 800° C. to convert the fluorine in said perfluorocompound to hydrogen fluoride. 
   
   
       2 . A method for decomposing a perfluorocompound according to  claim 1 , wherein said catalyst comprises Ni and Al in a mole ratio of 5/95 to 40/60 and contains W in a proportion of 0.1 to 10 wt % based on the total weight of said catalyst comprising a mixed oxide or complex oxide of Ni and Al.