苯乙烯装置尾气吸收系统改造

Renovation of off-gas absorption system in styrene project

苯乙烯装置尾气吸收系统不仅充分回收了乙苯脱氢尾气中乙苯、苯乙烯等芳烃物质,使之循环回反应系统进行再利用,同时经洗涤的脱氢尾气作为蒸汽过热炉的燃料或者氢气压缩系统的原料输出界外。原有装置尾气吸收系统中经洗涤的脱氢尾气仍然饱和有许多水和烃化物,对下游装置产生一定的不利影响。考虑在尾气吸收工艺流程基本不变以及设备充分利旧的前提下,对原有吸收系统进行改造,充分吸收脱氢尾气中的芳烃物质以及水分,使之满足下游装置的需要。对尾气吸收改造系统进行流程模拟计算,脱氢尾气中水和烃化物的质量分数有大幅度降低;同时对改造系统换热器、系统压降、能耗等进行核算,确定尾气吸收改造总体方案切实可行。改造后的尾气吸收系统实际运行效果良好。

The off-gas absorption system in the styrene plant fully absorbed aromatic compound such as ethylbenzene and styrene of ethylbenzene dehydrogenation off-gas to make it recycle to the reaction system, and the absorbed off- gas was used as fuel of steam superheater or crude material of hydrogen gas compressor. However the absorbed off-gas in the existing plant still saturated lots of water and hydrocarbon compound, which was not good to the downstream plant. On the premise of maintaining the existed technology process and making use of the existed equipment, the existing off-gas absorption system was renovated in order to absorb water and hydrocarbon compound adequately, thus meeting the requirement of downstream plant. The process was simulated by Aspen Plus, and the mass fraction of water and hydrocarbon compound in dehydrogenation off-gas drops greatly; meanwhile, the heat exchanger, pressure loss, and energy consumption in the system were calculated, which revealed the feasibility of renovation scheme for off-gas absorption system. The practical operation effect of the renovated off-gas absorption system is good.