半纤维素改性HZSM-5分子筛上丁烯齐聚反应研究

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.%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.