Process for preparing hydrogen peroxide

摘要

The present invention discloses a process for the production of hydrogen peroxide from hydrazine hydrate or hydrazine salt, represented by a general formula: N₂H₄.nX, wherein, X is H₂O, H₂SO₄, HNO₃, HCl, HBr, HI or CH₃COOH; n is 0.5, 1 or 2; N is nitrogen; H is hydrogen; S is sulfur; Cl is chlorine; Br is bromine; and I is iodine, by its liquid phase oxidation with oxygen, using a solid catalyst comprising palladium but with or without halogen promoter, in an aqueous reaction medium with or without comprising a mineral acid and/or halide anions, which comprises: i) contacting the solid catalyst with a hydrazine hydrate or hydrazine salt and oxygen containing gas selected from oxygen, air and oxygen enriched air, in aqueous reaction medium at the following reaction conditions: the concentration of hydrazine hydrate or hydrazine salt in the reaction medium above 0.001 mol/dm³, the concentration of mineral acid in the reaction medium in the range from zero mol/dm³ to 10 mol/dm³, the concentration of halide anions added to the reaction medium in the range from zero mmol/dm³ to 100 mmol/dm³, the concentration of the solid catalyst in the reaction medium in the range from 0.01 g/dm³ to 100 g/dm³, the space velocity of the oxygen containing gas in the range from 100 cm³/g catalyst/h to 100,000 cm³/g catalyst/h, the mass ratio of hydrazine hydrate or hydrazine salt to solid catalyst in the range from 0.01 to 100, the temperature below 100° C., the pressure at least 0.95 atm, and the reaction contact time above 0.02 h; and ii) separating the H₂O₂ from the reaction mixture.