724. FRANCEWAY, J. A. (Standard Oil Development Co.). Restoring the Activity of Hydrogenation Catalysts. United States Patent 1,904,218. Apr. 18, 1933. Chem. Abs., vol. 27, 1933. p. 3320.

Patent Abstracts

For reactivation of catalysts used in the hydrogenation of carbonaceous materials with free H₂ under a pressure > 20 atm., the bulk of the carbonaceous material is removed from the catalyst and the surface of the catalyst is etched (suitable with a mixture of steam and NH₃).