Fe、La改性β沸石催化苯/正丁烯烷基化反应

Alkylation of benzene with 1-butylene over β-zeolite modified by Fe or La

在小型固定床反应器上研究了Fe、La改性β沸石催化苯和正丁烯的烷基化反应,考察了金属负载量以及反应温度、进料质量空速比等工艺条件对改性β沸石催化性能的影响。采用XRD、BET、NH3-TPD和TG-DTA等表征手段研究了Fe、La改性β沸石催化性能提高的机理。研究表明,Fe、La改性后β沸石表面的强、弱酸量都明显下降,相比较而言,La改性β沸石拥有较强的表面酸性,在催化苯和正丁烯的烷基化反应中显示出了更好的催化性能,具有更强的抗积炭能力,这也与BET和TG-DTA的结果一致。在以2.0%La/β沸石为催化剂、反应温度180℃、苯的进料空速1.2 h-1、正丁烯的进料空速0.6 h-1、反应6 h条件下,正丁烯的转化率为87.9%,仲丁基苯的选择性为88.2%。

The catalytic performance of β-zeolites modified by Fe or La was investigated in the alkylation of benzene with 1-butylene in a fixed-bed reactor. Effects of metal content, temperature and feed ratio on the reaction were studied. The structure and acidity of modified β-zeolites were characterized by XRD, BET, NH3-TPD and TG-DTA. The quantities of both strong and weak acid decreased evidently. Especially, the acidity of the β-zeolite modified by La is higher than that modified by Fe, and the La modified β-zeolite shows better catalytic performance and stronger coke-resistance, which is supported by the results obtained by BET and TG-DTA. Both of Fe and La modified β-zeolites show better catalytic performance than the original one. After 6 h reaction over 2.0% La/ β-zeolites at 453 K with WHSV of 0.6 h ^-1 for 1-butylene and of 1.2 h^-1 for benzene, the conversion of 1-butylene is 87.9% with the selectivity of 88.2% for sec-butylbenzene.