Fremgangsmåde til udvinding af dihydrogenperoxider af blandinger fra oxidationen af dialkylerede aromatiske carbonhydrider.

摘要

Dihydro-peroxides are recovered from mixtures of oxidation products of dialkyl benzenes of the formula wherein each R represents an alkyl group, by a two-phase counter-current non-alkaline solvent system, comprising liquids of different polarities, the separation of the dihydroperoxide being affected in two separation columns connected in series, the solvent of greater polarity being exclusively or preponderantly used as counter-current extraction solvent in the first column and the less polar solvent being exclusively or preponderantly used as counter-current extraction solvent in the second column. Water may be used as the strongly polar liquid and petroleum ether as the less polar liquid. Instead of petroleum ether, hydrocarbons such as hexane, octane, decane, 2-methyl pentane, benzene, isopropyl benzene, 1,3,5-tri-methyl benzene, and 1-methyl-4-isopropyl benzene, or ethers such as dipropyl and dibutyl ethers, may be used. Instead of water there may be used formamide, furfurol, acetonyl-acetone, diethylene glycol, benzyl alcohol, or other strongly polar liquid. The oxidation mixture may be passed into the lower part of the first extraction column and upwardly in countercurrent to a flowing body of water. The dihydroperoxide is almost completely washed out of the oxidation mixture by the water. The aqueous liquid is led from the bottom of the first column to the upper part of the second column down which it flows in countercurrent to the less polar extraction liquid. The oxidation mixture extracted with water, and containing the mono-hydroperoxide is led from the top of the first column back to the oxidation stage. From the bottom of the second extraction column, the aqueous phase containing pure di-hydroperoxide is removed and fed to a further column in which it is subjected to extraction treatment with methyl isobutyl ketone, benzene, or other ketone or aromatic hydrocarbon, capable of extracting the dihydroperoxide from the water. The organic solvent may subsequently be removed e.g. by vacuum distillation. The organic phase leaving the top of the second extraction column may be passed through an adsorption tower, containing alumina, where it is freed from any monohydroperoxide. If desired the organic phase may be circulated several times through the second extraction column, without passing through the adsorption tower, and the monohydroperoxide from this phase may be recovered by distillation or other means and returned to the oxidation stage. Examples describe the recovery of m-di-isopropyl-benzene dihydroperoxide and of p-di-sec.butyl-benzene dihydroperoxide from appropriate oxidation mixtures.