乙苯脱氢多孔膜反应器的研究

采用管形结构的填充床纳滤不对称γ－Ａｌ２Ｏ３／α－Ａｌ２Ｏ３膜反应器，考察了膜反应器的操作条件：进样速度、吹气流量、水和乙苯摩尔比和反应温度等对转化率和苯乙烯选择性的影响。结果表明，膜反应器中乙苯脱氢转化率以及苯乙烯选择性均高于相同操作条件下填充床反应器中的值，转化率平均提高约４．５％，苯乙烯选择性约２％左右。试验还表明，降低进样速度，提高乙苯和水的比例或提高吹气速率均可提高膜反应器中乙苯转化率，同时可保持选择性基本不变。并且用动态毛细凝聚法和扫描电子显微镜研究了纳滤膜反应前后的稳定性。结果表明，膜的Ｋｅｌｖｉｎ孔径在反应前后有明显变化。

Experimental Study on Porous Membrane Reactor for Dehydrogenation of Ethylbenzene

Catalytic dehydrogenation of ethylbenzene has been studied in a packed bed asymmetric alumina membrane reactor.Ethylbenzene conversion and styrene selectivity in the membrane reactor was investigated under different conditions such as temperature,inlet flow rate of ethylbenzene and sweep argon rate.It was shown that high sweep gas rate or space time resulting in increasing conversion.Experimental results showed an enhancement in the membrane reactor of 7% in the conversion of ethylbenzene dehydrogenation and 2% in styrene selectivity.When ethylbenzene flow rate decreased from 7.8×10 -6 mol/s to 2.0×10 -6 mol/s,the conversion increased from 44% to 77% at 600℃.An enhancement of 4% conversion resulted from an increase in sweep argon rate without corresponding decrease in selectivity to styrene in the membrane reactor.The stability of the membrane used in the experiment was checked by capillary condensation porometry.The results showed membrane pore growth occurred in the process of ethylbenzene dehydrogenation.