GB896346A - Process for the regeneration of degraded solutions from a hydrogen peroxide synthesizing process - Google Patents

Abstract

A degraded working solution of a quinone and/or quinol in a solvent, which has become degraded during the production of hydrogen peroxide involving the successive reduction, oxidation, and water extraction of a quinone in a cyclic process, is regenerated by heating the solution to at least 50 DEG C. in the presence of a hydrated amorphous sodium aluminium silicate having a composition corresponding to the formula Na2O .yAlO3 zSiO2, where y is from 0,56 to 3 and z is from 0,5 to 10. Preferred temperatures in excess of 50 DEG C. are from 100 DEG C. to 200 DEG C., the use of higher temperatures by utilization of superatmospheric pressure being also referred to. The working solution may comprise a quinone, examples being 2-ethyl-, 2-isopropyl-, 2-secondary butyl-, 2-tert. butyl, 2 secondary allyl-, and 1:2, 1:3, 1:4 or 2:7 dimethylanthraquinone, dissolved in such solvents as (i) 1-methylnaphthalene, benzene or trimethyl benzene and/or (ii) ketones, esters or alcohols, such as diisobutylcarbinol or methylcyclohexylacetate. In operation, the working solution, and from which some of the solvent may be removed or, if a solvent mixture has been employed, from which one or more of the solvent constituents has been completely removed is taken from the process preferably immediately after extraction of the hydrogen peroxide, is subjected to regeneration and subsequently returned to the process. Alternatively, a small portion, e.g. 1-10% of the total volume of working solution is continuously removed from the cycle, regenerated, and returned to the cycle. A further aspect of the invention consists in adding sodium aluminium silicate in a concentration say 1-40% wt. of the circulating working solution and effecting regeneration, by subsequently heating to at least 50 DEG C., of solution from any stage of the process.