半纤维素改性HZSM-5分子筛上丁烯齐聚反应研究

Research on butene oligomerization reaction over the hemicellulose modified HZSM-5

摘要: 以半纤维素为添加剂对HZSM-5分子筛进行改性，采用XRD、SEM、N₂物理吸附-脱附、NH₃-TPD及Py-FTIR手段对其形貌、织构、酸性进行研究。并以丁烯齐聚为探针反应，考察半纤维素改性HZSM-5分子筛对低碳烯烃齐聚的催化能力。结果表明，当半纤维素质量分数为1.6%时，改性分子筛的比表面积、介孔体积最大，酸性最强，催化丁烯齐聚反应表现出了明显的优势，反应140 h转化率仍维持在80%左右，且三聚、四聚产物最多，柴油组分选择性最高。

Abstract: The HZSM-5 synthesized with modifying by different contents of hemicellulose.The morphology, texture and acidity were characterized with XRD, SEM, N₂ adsorption-desorption, NH₃-TPD and Py-FTIR. Butene oligomerization over the modified HZSM-5 was tested. The results indicate that the HZSM-5 with the 1.6% hemicellulose exhibits the best activity and stability on the butene oligomerization reaction, the conversion can maintain about 80% after 140 h on stream, with the highest selectivities of the trimer, tetramer and diesel component in the products. These may be related with its high BET surface and mesoporous volume, and the strongest acidity.