Patent ID: 7833510
Filing Date: 2010-11-16
Classification: B01J,C01B,Y02P

Abstract:
1. A method for producing hydrogen peroxide by an anthraquinone process, comprising the steps of: reducing with hydrogen a working solution containing an organic solvent and anthraquinone in the presence of a hydrogenation catalyst; and activating the hydrogenation catalyst when a hydrogenation selectivity has decreased due to repeated use, wherein the catalyst activation step includes a step of treating the hydrogenation catalyst with a first alkaline aqueous solution of a pH in the range of from 11.0 to 13.5 containing an alkali metal, and then washing the treated hydrogenation catalyst with water or a second alkaline aqueous solution of a pH in a range of from 7.1 to 7.5 so as to set a catalyst soak solution comprising 5 parts weight of pure water in admixture with 1 part by weight of the activated hydrogenation catalyst, wherein washing is carried out so as to set the catalyst soak solution to a pH in a range of from 8.0 to 11.5, and wherein said hydrogenation catalyst comprises a carrier which comprises at least one oxide selected from the group consisting of silica, silica alumina, alumina, titania, zirconia, silica-alumina double oxides, silica-titania double oxides, silica-alumina-titania composite oxides and physical mixtures thereof, and has a total pore volume of from 0.02 to 2 ml/g.