Energy-saving reaction process for producing ethylbenzene from pure ethylene

Abstract

The invention relates to an energy-saving reaction process for producing ethylbenzene from pure ethylene. The process comprises the following steps: treating raw material benzene to enable the water content of benzene discharged from the tower top of a benzene recovery tower to be 30-600PPM; carrying out protective adsorption reaction to enable the content of basic nitrogen in a material enteringan alkylation reactor to be less than 0.001 PPM; carrying out alkylation reaction, correspondingly arranging a steam generator on every two catalyst bed layers, enabling a staged discharge material formed after the reaction of every two catalyst bed layers to enter the steam generator for heat exchange, and then entering the next stage of alkylation reaction; recovering benzene; carrying out ethylbenzene recovery; recovering polyethylbenzene; and carrying out anti-alkylation reaction. According to the process provided by the invention, the influence of raw material impurities on the device iseliminated, the stability of an ethylbenzene reaction system is improved, and the production cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a raw material treatment and energy-saving reaction process for producing ethylbenzene from pure ethylene. Background technique [0002] The invention belongs to raw material treatment and low-pressure-drop reaction energy-saving technology for producing ethylbenzene by alkylation of pure ethylene and benzene (also called "alkylation"), mainly including raw material benzene impurity treatment technology and low-pressure drop alkylation reaction energy-saving technology, and the The energy-saving process is combined with the ethylbenzene separation process to realize the overall energy saving of the device, increase the stability of the device, and improve the economical efficiency of the ethylbenzene device. [0003] Ethylbenzene is an important chemical raw material. It is mainly used for dehydrogenation to produce chemical raw material monomer styrene. It ...

AI Technical Summary

Problems solved by technology

This patent does not consider the actual industrial operation and the performance of the alkylation catalyst. At present, the industrial equipment basically adopts the method of nine-stage feeding and three-stage heat extraction, and due to the reasonable setting of the ethylene distributor, two-stage catalyst beds and three-stage catalyst beds are used. In addition, the reaction temperature of the alkylation catalyst needs to be controlled below 250°C. If the reaction temperature is too high, more residual oil components will be generated. However, it is reported in this paper that high-pressure steam above 3.5MPaG is produced by-product. The reaction temperature of the material is increased to above 250°C, which will lead to an increase in residual oil and an increase in the material consumption of the device. Considering the conditions of use of the catalyst, the ethylbenzene alkylation reaction system is not suitable for generating high-pressure steam above 3.5MPaG, and there is no such case in industrialized devices.

[0012] The CN103539599A invention relates to a method for producing ethylbenzene by liquid-phase alkylation of benzene and ethylene, which mainly solves the problem of uneven mixing of materials between stages caused by the uniform spacing between two adjacent catalyst beds in multi-stage adiabatic fixed-bed reactors in the previous literature, thereby affecting the catalyst. The question of reaction selectivity

In addition, patent CN105566050A, patent CN101688130A, patent CN101190871A, etc. have also improved the preparation process of acidic catalysts and improved the control of raw material impurities in the alkylation reaction system, but none of them have achieved industrialization

[0014] Therefore, it can be seen that the above patents mainly use the method of catalyst performance improvement to improve the stability of the ethylbenzene reaction system. There are few reports on process solutions, and they are out of the actual situation of industrial operation, and fail to solve the problem of raw material impurities on the stability of the device. Impact, energy saving and production cost reduction

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