Process for the continuous preparation of percarboxylic acids in organic solutions

Claim 1

In the process for the continuous production of an organic solution of percarboxylic acid which comprises contacting aqueous hydrogen peroxide with the corresponding carboxylic acid for the reaction of the hydrogen peroxide and carboxylic acid to form the percarboxylic acid and water in an reaction mixture, in the presence of an acid, water soluble catalyst for the reaction, extracting the reaction mixture with organic solvent selected from the group consisting of aliphatic, cycloaliphatic and aromatic hydrocarbons, chlorinated hydrocarbons, esters of carboxylic acids and ethers to form a solvent phase rich in the carboxylic acid and an aqueous raffinate phase rich in hydrogen peroxide and catalyst, distilling the raffinate to remove water therefrom and form a concentrated aqueous, hydrogen peroxide, acid solution and recycling the concentrated solution, said contacting, wherein aqueous make-up hydrogen peroxide and make-up carboxylic acid are introduced into said contacting to replace hydrogen peroxide and carboxylic acid consumed in the reaction, the improvement which comprises introducing at least part of the make-up aqueous hydrogen peroxide into said distillation for distillation thereof together with distillation of the raffinate, the amount of water removed in the distillation being about equal to the sum of the water formed in the reaction and the water introduced into the process, said distillation being performed at 10-250 mm Hg. and 40°-120° C to provide the distilled water as overhead and said concentrated solutions as sump product, and recycling the sump product to said contacting.