Study On The Optimum Process Of Ethylbenzene Prepared By Liquid Phase Alkylation Of Ethylene

A 160 kt/a ethylbenzene unit was set up in Jilin Petrochemical Company according to Lummus/UOP technology in which ethylbenzene was synthesized by using ethylene and benzene as raw materials under the zeolite catalyst. Ethylene was added into the alkylation reactor and then reacted with extraneous benzene under catalyst EBZ-500 to generate alkylation fluid which got into the rectification position. The extraneous benzene and diethylbenzene separated from rectification position were added into transalkylation reactor to produce transalkylation fluid under catalyst EBZ-100. The formed transalkylation fluid accessed to rectification position again for rectification. Alkylation fluid and transalkylation fluid were collected from alkylation and transalkylation positions and then accessed to rectification position. Semi-finished ethylbenzene, by product diethylbenzene, and residual oil etc were generated by multiple rectifications of alkylation fluid and transalkylation fluid through benzene tower, light component removal tower, ethylbenzene tower, multi-ethylbenzene tower.In the ethylbenzene production system, three alkylation reactors in series and one transalkylation reactor in parallel were connected to the ethylbenzene rectification system. In the ethylbenzene rectification system, the recycled pure benzene from benzene tower retuned to the reaction system to rejoin the reaction. Therefore, although the system is compact and trustful, the whole system would be affected heavily when a certain parameter fluctuated. In daily production and operation, stable running of the system is an important condition to keep a stable ethylbenzene conversion rate.In three alkylation reactors in series, the ethylene feed was divided into six strands, accessed to these three reactors from their middle and bottom beds, respectively. Therefore, with the pressure control of each reactor, how to allocatesix strands of ethylene to make the heat transfer of three reactors in the best condition was an important factor of ensuring each reactor in its best condition.The life of alkylation and transalkylation catalysts is six years. During the usage period of the catalysts, they should be regenerated through hot nitrogen purge once every two years. Therefore, with the suitable regeneration temperature and regeneration time, how to achieve the best regeneration efficiency via the optimized regeneration purge route is an important condition to ensure catalysts being stable performance when used in the next cycle.Through the optimization, can make the device ethylbenzene yield increases 1%, reduce the energy consumption of about 5%.