SAPO-11分子筛催化丁烯异构化反应的研究

在连续流动固定床反应装置上，考察了温度、空速及添加水蒸汽对混合丁烯在SAPO-11分子筛催化剂上骨架异构化的影响。结合催化剂的NH₃-TPD表征与Al₂O₃催化剂的评价结果，对催化剂酸性能和孔结构与丁烯骨架异构化进行了关联。结果表明，对于丁烯骨架异构，分子筛催化剂优于Al₂O₃催化剂，显示出催化剂孔结构的重要作用。SAPO-11分子筛酸量越小,转化率越低，酸量过小时催化剂基本没有活性,说明丁烯异构转化与表面酸量有密切关系。分子筛催化剂上，添加少量的水蒸汽使转化率有所降低，但异丁烯选择性明显增加。

Skeletal isomerization of butene over SAPO-11 catalyst

The effects of reaction temperature WHSV and addition of water vapor on skeletal isomerization of butene over SAPO-11 catalyst were investigated in a fixed-bed down-flow reactor. With further test on Al₂O₃ and NH₃-TPD characterization， the skeletal isomerization was correlated with catalyst acidity and pore structure. It was shown that selectivity to isobutene was higher over SAPO-11 than over alumina catalyst, indicating the important role of catalyst pore structure. For SAPO-11 catalyst, the catalytic activity had close relationship with the amount of surface acidity. Little conversion was observed when catalyst had too low acidity. Addition of a small amount of water vapor decreased conversion slightly but enhanced the selectivity to isobutene remarkably.