乙苯脱氢制苯乙烯的脱氢尾气吸收工艺的研究

在苯乙烯工业装置上进行了乙苯脱氢制苯乙烯的脱氢尾气吸收工艺的研究。考察了进气温度、吸收剂组成和温度、吸收剂与脱氢尾气的质量比(液气比)对吸收塔(塔顶绝对操作压力140kPa)的芳烃回收效果的影响。试验结果表明,在液气比小于5.0时,进气温度、吸收剂温度和液气比对脱氢尾气中苯含量和芳烃回收率的影响显著;在液气比大于5.0时,进气温度、吸收剂温度和液气比对脱氢尾气中苯含量和芳烃回收率影响较小;进气温度和液气比对脱氢尾气中乙苯含量的影响不显著,而吸收剂温度对脱氢尾气中乙苯含量的影响显著;多乙苯残油吸收剂组成对芳烃回收效果的影响显著,吸收剂中乙苯质量分数应小于0.30%。优化的吸收塔操作条件为:液气比5.0～6.0,进气温度和吸收剂的温度10～15℃。

Absorption Process for Vent Gas from Dehydrogenation of Ethylbenzene to Styrene

Absorption process for vent gas from dehydrogenation of ethylbenzene to styrene was studied in an industrial styrene unit.Influences of dehydrogenation vent gas temperature at the inlet,Absorbent temperature,Absorbent composition and liquid-gas mass ratio on recovery of aromatics in the Absorption tower were investigated with the tower top pressure 140 kPa.When the liquid-gas mass ratio was less than 5.0,the dehydrogenation vent gas temperature at the inlet,the Absorbent temperature and the liquid-gas mass ratio significantly affected benzene content in the dehydrogenation vent gas at the outlet and the aromatics recovery.When the liquid-gas mass ratio was higher than 5.0,the influence became smaller.Influences of dehydrogenation vent gas temperature at the inlet and the liquid-gas mass ratio on ethylbenzene content in the dehydrogenation vent gas at the outlet was not obvious,but the influence of the Absorbent temperature was obvious.Polyethylbenzene residual oil was used as Absorbent,its composition evidently affected the aromatics recovery and the ethylbenzene mass fraction in the Absorbent should be under 0.30%.The optimized operating conditions for the Absorption tower were suggested.