多级孔分子筛在生物质催化热裂解制备芳烃中的研究进展

Recent advances in aromatic production from biomass via catalytic fast pyrolysis over hierarchical zeolite

芳烃是石化工业的一种重要基础原料,目前主要来源于石油和煤焦油。随着化石能源的日益枯竭、全球环境问题的日益严重和芳烃需求量的不断增长,芳烃的传统生产工艺压力越来越大。生物质催化热解制备芳烃技术由于其绿色、原料来源广以及可持续等优点,近年来备受关注。微孔分子筛因其大比表面积、强酸性、微孔择形性和良好的水热稳定性等优点成为理想的催化热解催化剂,但是微孔分子筛扩散阻力大、易积碳致使催化剂寿命低,使其在生物质催化热解制备芳烃的应用方面受到很大限制。在微孔分子筛中引入介孔得到多级孔分子筛,可以有效解决分子传质问题,并且保留微孔的强酸性以及择形选择,提高催化反应活性的同时提高催化剂的使用寿命,因此,多级孔分子筛成为了近年来生物质催化热解的热点。本文中,笔者详细综述了近年来生物质催化热裂解制备芳烃过程中所需要的原料和反应机制,重点综述了多级孔分子筛的优势以及其在生物质催化热解制备芳烃方面的应用前景和研究进展,最后总结了该技术面临的挑战和发展方向。

Aromatics are important platform chemicals in the petrochemical industry,and are produced primarily on the catalytic reforming of petroleum resources. With the declining resources of crude oil,increasing global environmental concerns and the growing demand for aromatics,the traditional aromatics production technology is facing severe challenges. In recent years,catalytic fast pyrolysis (CFP) of biomass to produce aromatics attracts great attentions owing to its green and sustainable characteristics. Microporous zeolite is known as the best catalyst in CFP process due to its high surface area,strong acidity,shape-selectivity and superior hydrothermal stability. However,the low mass-transfer rates and high yield of coke during CFP results in the short lifetime of catalysts. The introduction of mesopores in microporous zeolite to form the hierarchical zeolite can not only improve the mass transfer but also keep the strong acidity and shape-selectivity to improve the catalytic activity and decrease coke deposition. We review the biomass feedstock and reaction chemistry in the CFP of biomass,and mainly reviews the advantages of hierarchical zeolite as well as its application and innovation. Finally,the challenges and perspectives of catalytic fast pyrolysis technique are summarized.