A gas-phase process for the separation of ethylbenzene and/or propylbenzene from gas containing ethylene and/or propylene

Abstract

The invention belongs to the field of petrochemical industry. The invention discloses a process for separating ethylbenzene and / or propylbenzene products from gas containing ethylene and / or propylene by gas phase method, which comprises the following steps: 1) alkylation reaction from an alkylation reactor The product and the anti-alkylation reaction product from the anti-alkylation reactor enter the benzene tower separately or after being mixed; 2) the separated benzene tower top gas phase material enters the absorption tower after being extracted from the benzene tower top; 3) the separated The liquid phase material in the upper part of the benzene tower is withdrawn from the top or side of the benzene tower and then returned to the reaction part; 4) The bottom material of the benzene tower is separated from toluene, ethylbenzene, propylbenzene, diethylbenzene, and high-boiling substances through the subsequent separation tower. some or all of them. By adopting the present invention, by directly bringing the heat of the reaction product including the reaction heat into the benzene tower, the heat supply at the bottom of the benzene tower is reduced, and the energy consumption is reduced; the heat utilization is reasonable. Adopting the present invention does not increase the number of towers required for separation, and reduces the equipment for indirect heat exchange.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and in particular relates to a product separation process for preparing ethylbenzene and / or propylbenzene from gas containing ethylene and / or propylene by gas phase method. Background technique [0002] Ethylbenzene is an important chemical raw material. Since the end of the 1930s, a variety of methods for producing ethylbenzene using ethylene and benzene as raw materials have been developed, but most of these methods use ethylene volume content greater than 99% polymer grade ethylene as raw material. With the development of petroleum processing scale, the refinery tail gas containing low concentration of ethylene and / or propylene is increasing day by day, and the utilization of ethylene and / or propylene in these tail gases has developed several kinds of low Concentrated ethylene and / or propylene gas is used as raw material to react with benzene to produce ethylbenzene and / or propylbenzene....

AI Technical Summary

Problems solved by technology

[0024] The purpose of the present invention is to provide a gas-phase method for the separation of ethylbenzene and / or propylbenzene products from gas containing ethylene and / or propylene, so as to solve the problem of high energy consumption in the separation process caused by multiple phase transitions of benzene in the prior art

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