Abstract:

A series of in-situ modified ZSM-5 catalysts were prepared by hydrothermal synthesis method through adding Mg or/and polyethylene glycol. The catalysts were characterized by XRD, SEM, EDS-Mapping, BET and NH₃-TPD. The results showed that the modified ZSM-5 catalysts had improved pore size, pore volume, acid content and acid strength. The modified catalysts were further used for catalytic cracking of bagasse. The catalytic cracking had significantly improved the selectivity of 2,3-dihydrobenzofuran product as compared with direct pyrolysis of bagasse, and the introduction of metal Mg, acid type, and the pore size and volume are the main factors affecting the formation of 2,3-dihydrobenzofuran. At the same time, there was a synergistic effect between Mg and polyethylene glycol. The selectivity of furans in bio-oil from bagasse pyrolysis was 40.12%, and the selectivity of 2,3-dihydrobenzofurans was 23.16%.

Key words: catalyst, pyrolysis, molecular sieves, biomass, 2,3-dihydrobenzofuran

摘要：

采用水热合成法，在制备ZSM-5的过程中添加Mg或/和聚乙二醇（PEG），制备了一系列原位改性的ZSM-5催化剂，并运用XRD、SEM、EDS-Mapping、BET、NH₃-TPD等大型仪器对所制备的催化剂进行表征分析。结果表明：改性后的ZSM-5催化剂在孔径、孔容、酸量和酸强度方面均有不同程度的提高。进一步将改性的ZSM-5催化剂用于甘蔗渣催化裂解反应。评价结果显示，相较于甘蔗渣直接裂解，催化裂解可以显著提高2,3-二氢苯并呋喃产物的选择性，而金属Mg的引入、酸型、孔径和孔容是影响2,3-二氢苯并呋喃生成的主要因素。同时，金属Mg和聚乙二醇之间存在一定的协同作用。金属Mg和聚乙二醇协同改性的ZSM-5催化剂催化裂解甘蔗渣得到的生物油中呋喃类选择性高达40.12%，其中2,3-二氢苯并呋喃的选择性达到23.16%。

关键词: 催化剂, 热解, 分子筛, 生物质, 2,3-二氢苯并呋喃