METHOD OF PURIFICATION OF RECOVERY ETHYLBENZENE FROM LOW-BOILING HYDROCARBON FRACTION IN PRODUCTION OF PROPYLENE OXIDE AND STYRENE Russian patent published in 1999 - IPC

FIELD: chemical technology. SUBSTANCE: invention relates to production of propylene oxide and styrene, in part, a method of purification of recovery ethylbenzene from low-boiling fraction of the total recycle current. Recovery ethylbenzene is formed at the stages of oxidation of ethylbenzene, epoxidation of propylene with ethylbenzene hydroperoxide and separation of epoxidation products. Method of purification is based on the use of hydroperoxide method. Method involves the use of ethylbenzene current isolated from exhaust air in ethylbenzene oxidation, current from the stage of separation of epoxidate heavy fraction after reaction of propylene epoxidation with ethylbenzene hydroperoxide obtained by an alkaline washing out an epoxidate heavy fraction from acid impurities and ethylbenzene isolation from this fraction by rectification. Current or its part of recovery ethylbenzene isolated from exhaust air in the process of ethylbenzene oxidation is purified after washing out from low-boiling hydrocarbons by rectification and ethylbenzene from the stage of separation of epoxidate heavy fraction after an alkaline washing out is isolated by rectification using a single fractionating column. It is desirable to perform the purification of ethylbenzene current isolated from exhaust air in the process of oxidation from low-boiling hydrocarbons by rectification at 150 C, not above, in the column vat and the isolation of recovery ethylbenzene to perform by rectification at 145-155 C in the column vat. The most efficient procedure involves the purification of 5-10% of recovery ethylbenzene isolated from exhaust air in the process of oxidation from low-boiling hydrocarbons. EFFECT: improved method of purification. 3 cl, 2 tbl, 1 dwg, 3 ex