ES255288A1 - Improvements in or relating to the production of hydrogen peroxide - Google Patents

Abstract

At least a portion of a working solution comprising an anthraquinone dissolved in a solvent therefor which has become degraded by use in the cyclic anthraquinone/anthrahydroquinone process for the production of hydrogen peroxide is regenerated by contact with a Group II metal silicate after a hydrogenation stage and before the next hydrogenation stage to which it is submitted. The metal silicate is preferably one of calcium, magnesium or zinc, or a mixture, especially magnesium trisilicate, in a pelleted or granulated form, and may be used in amount 5-10% based on the weight of the solution to be treated. The degraded solution is regenerated at at least 75 DEG C., e.g. 85 DEG -140 DEG C. Regeneration of the solution may be effected at any stage in the cyclic process, preferably of the oxidized solution. As a continuous process regeneration may be effected by removing a portion, e.g. 10% by volume of the working solution after oxidation and H2O2 extraction, contacting it with a bed of metal silicate and returning it to the main bulk of working solution cycling in the process prior to entry into the hydrogenator. The degree of regeneration is related to the mesh size of the silicate, the precise formula relationship being given in the Specification. For practical purposes a particle size of not less than 360 microns is employed. Working solutions may combine 2-ethyl, methyl, propyl, isopropyl or butyl anthraquinones in solvents such as mixtures of xylene and methyl cyclohexanol acetate. Specifications 465,070, 798,237 and 838,939 are referred to.