【摘要】 在固定床反应器中以HZSM-5分子筛为催化剂,进行了苯与氯乙烷烷基化反应的实验。考察了HZSM-5分子筛的n(SiO2)∶n(Al2O3)、反应温度、n(苯)∶n(氯乙烷)和液态空速(LHSV)等因素对烷基化反应的影响。实验结果表明,随n(SiO2)∶n(Al2O3)的增大,HZSM-5分子筛的酸量减少,酸强度减弱;n(SiO2)∶n(Al2O3)=25的HZSM-5分子筛的催化活性较高;采用HZSM-5分子筛(n(SiO2)∶n(Al2O3)=25)催化苯与氯乙烷的烷基化反应的适宜操作条件为:573～613K,n(苯)∶n(氯乙烷)=8.0～10.0,LHSV=4～6h-1。在593K时,苯的转化率达到9.56%(x),乙苯选择性达到97.44%(x)。低温时烷基化反应中未发现二甲苯异构体生成,高温时有极少量的二甲苯异构体生成。更多还原

【Abstract】 HZSM-5 molecular sieve catalysts were used to catalyze the alkylation reaction of benzene and ethyl chloride to form ethyl benzene in a fixed-bed reactor.The effects of n(SiO2)∶n(Al2O3) in the HZSM-5,reaction temperature,n(benzene)∶n(ethyl chloride) and LHSV on the alkylation were studied.With increase of n(SiO2)∶n(Al2O3),the acidic sites on the HZSM-5 molecular sieves decreased and the acid strength lowered.Under the optimum conditions: n(SiO2)∶n(Al2O3) in the HZSM-5 molecular sieves 25,reaction temperature 573-613 K,n(benzene) ∶n(ethyl chloride) 8.0-10.0 and LHSV 4-6 h-1,the benzene conversation was 9.56% and the ethyl benzene selectivity reached 97.44%.At low temperature the xylene isomers were not found in the alkylation,and when the temperature rose,a little of xylenes was observed更多还原