Energy-saving and environment-friendly method for preparing ethylbenzene from dry gas

Abstract

The invention provides an energy-saving and environment-friendly method for preparing ethylbenzene from dry gas. The method is mainly used for gas-liquid separation and tail gas debenzolization of a reaction product of preparing ethylbenzene from dry gas. The method is characterized in that gas-liquid separation and tail gas absorption of a reaction product of ethylbenzene preparation from dry gasare carried out in a same tower, an absorption and separation tower is divided into four sections, a tower upper section is a packing section, a tower middle section is a tube nest cooling section, atower lower section is a plate type tower, and a tower bottom section is a tower kettle. The reaction product enters from the upper part of the tower kettle and an absorbent enters from the top of the packing section; after the tail gas is absorbed and separated by the absorption and separation tower, the tail gas enters a fuel gas pipe network from the tower top, and rich absorption liquid is mixed with condensed liquid in the reaction product and flows out from the bottom of the tower kettle to enter a benzene tower. Non-condensable gas at the top of the benzene tower returns to the absorption and separation tower, circulating benzene 1 is extracted from the upper section of the benzene tower and enters an alkylation reactor, circulating benzene 2 at the bottom of a benzene tower refluxtank enters an alkyl transfer reactor, materials at the bottom of the benzene tower enter an ethylbenzene tower to obtain a product ethylbenzene at the top of the ethylbenzene tower, and tower bottomliquid of the ethylbenzene tower is divided into three parts, one stream returns to the absorption and separation tower as an absorbent, one stream is sent to the transalkylation reactor, and the other stream is aromatic hydrocarbon oil. The separation process is simple and reliable, tower equipment is reduced while reaction heat is fully utilized, equipment investment and subsequent operation cost are saved, and energy consumption of the device is reduced. According to the separation method, the recovery rate of benzene carried by the tail gas is greater than 99.9%, and the purity of an ethylbenzene product is greater than 99.8%.

Description

technical field [0001] The invention provides an energy-saving and environment-friendly method for producing ethylbenzene from dry gas, which mainly includes the gas-liquid separation of the reaction product of producing ethylbenzene from dry gas and the removal of benzene from tail gas. The separation process of the method is simple and reliable, and the gas-liquid separation of reaction products and tail gas absorption are carried out in the same tower, which makes full use of heat energy while reducing tower equipment, saving equipment investment and subsequent operation costs, and reducing device energy consumption. The recovery rate of benzene carried by the tail gas of the invention is high, and the purity of the ethylbenzene product meets the requirements, which greatly improves the economic benefit and environmental benefit of the refinery. Background technique [0002] Ethylbenzene is an important organic chemical raw material, mainly used to produce styrene, and th...

AI Technical Summary

Problems solved by technology

The ethylbenzene purity of this method is 99.7%, wherein the xylene content is 945ppm, and the total selectivity of ethylene to generate ethylbenzene is 99%, and the recovery rate of benzene carried by the tail gas is not given.

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