Separation process for producing ethylbenzene and/or propylbenzene product from gas containing ethylene and/or propylene by gas phase process

Abstract

The invention belongs to the field of petrochemical industry and discloses a separation process for producing an ethylbenzene and / or propylbenzene product from gas containing ethylene and / or propylene by a gas phase process. The separation process comprises the following steps: 1) feeding alkylation reaction products getting out of an alkylation reactor and anti-alkylation reaction products getting out of an anti-alkylation reactor into a benzene tower respectively or after mixing; 2) feeding gas-phase materials at the top of the benzene tower after separation into an absorption tower after the gas-phase materials are drawn out of the tower top of the benzene tower; 3) drawing out liquid-phase materials at the upper part of the benzene tower after separation from the tower top or the side of the benzene tower and then returning the liquid-phase materials into the reaction part; and 4) performing corresponding separation on the materials at the tower bottom of the benzene tower by a subsequent separation tower to obtain several or all of methylbenzene, ethylbenzene, propylbenzene, diethylbenzene and high-boiling residues. By adopting the separation process disclosed by the invention, by directly bringing heat of the reaction products, including reaction heat, into the benzene tower, the heat supply at the tower bottom of the benzene tower is reduced and the energy consumption is reduced; and the utilization of the heat is reasonable. By adopting the separation process disclosed by the invention, the number of the towers required for separation is not increased, and indirect heat exchange equipment is reduced.

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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