IMPROVEMENTS IN OR RELATING TO THE PRODUCTION OF HYDROGEN PEROXIDE

1,216,998. Hydrogen peroxide extraction. PETROCARBON DEVELOPMENTS Ltd. 8 April, 1969 [5 April, 1968], No. 16578/68. Heading C1A. Hydrogen peroxide is transferred from one solvent to another by reacting first an organic H 2 O 2 solution with a solution of urea to give a precipitate of a 1 : 1 adduct, mixing the adduct with an extracting solvent selected from dialkyl ketones with up to a total of 7 carbon atoms, alkyl esters with up to a total of 7 carbon atoms and alkyl (C 1 -C 4 ) ortho-phosphates, whereby the hydrogen peroxide is dissolved in the extracting solvent and the urea is precipitated, the process being carried out in the absence of heavy metal ions and under conditions minimizing decomposition. The concentration of H 2 O 2 in the first solvent is preferably 1-25% by weight, the urea solution should preferably be saturated and aqueous, and the preferred extracting solvents are acetone, n-propyl acetate, or ethyl acetate. The first H 2 O 2 solution is preferably formed by the oxidation of a secondary C 3 -C 6 alcohol (for example isopropyl (alcohol) with oxygen or a free-oxygen containing gas at an elevated temperature, in the absence of heavy metal ions at a pressure sufficient to maintain the alcohol and the reaction products in the liquid phase, the ketone produced being removed prior to the addition of the urea solution. In the examples a temperature of 105‹ C. was used for the initial reaction and 50‹ C. for the extraction.