PATENTS

3540.   ------.  [SOCIETA ANON. PRODOTTI ITALIANI SINTETICI.]  Purification of a Contaminated Catalyst.  British Patent 615,647, Jan. 10, 1949.  Chem. Abs., vol. 43, 1949, p. 3994.

Solid Fischer-Tropsch catalyst, which contains an active hydrogenating constituent and is contaminated with waxy and oily deposits, is purified by first subjecting it to the action of a H₂-containing gas under conditions to cause destructive hydrogenation of at least a part of the deposits and thereafter extracting the catalyst with a solvent for these deposits.  Desirable conditions for the destructive hydrogenation are:  182°-260° and 0-300 lb. per in.² gage pressure when a Co-type catalyst is used and 232°-399° and 25-350 lb. with an Fe-type catalyst.