生物质热解气合成航空燃油多功能催化体系的构建和机理研究

This project focuses on the efficient conversion of complicated biomass pyrolysis gas to high-valued jet fuel orientated hydrocarbons.The new processe for efficient utilization of biomass pyrolysis gas are pointed. The biomass pyrolysis gas is first synthesized into jet fuel orientated hydrocarbons (C8-C18) or C2-C7 olefins by Fischer-Tropsch process. Then the C2-C7 olefins derived from biomass pyrolysis gas and F-T synthesis are further converted into the isomerized C8-C18 alkanes and aromatics by oligomerization and aromatization.Based on the construction of the multifunctional catalytic system, the high performed catalysts and product control methodology are deeply investigated. The effect of microstructure on catalytic reaction, the key factor on jet fuel synthesis and the synergy catalytic mechanism are also studied.Therefore, the key scientific issues including the cooperative transformation of complicated biomass pyrolysis gas and target products control can be resolved. The theoretical system for efficient and high-valued conversion of biomass pyrolysis gas to liquid hydrocarbon fuels will also be established. The investigation of this project will afford the theoretical horizon and technological support for the effective transformation and high-valued utilization of biomass.

本项目围绕生物质热解气高值化利用的关键科学问题，提出利用FT合成和烯烃齐聚高效合成航空燃油的路线：①生物质热解气在Fe基催化剂上选择性合成C8-C18烃类/C2-C7烯烃，②C2-C7烯烃在固体酸催化剂上齐聚并耦合加氢生成富含C8-C18异构烷烃和芳烃的航空燃油，③构建FT—烯烃齐聚多功能催化体系，实现生物质热解气一步合成航空燃油。通过纳米Fe基催化剂的设计和金属修饰，提高C8-C18烃类/C2-C7烯烃的选择性，研究影响产物选择性的控制因素；通过固体酸催化剂的合成、改性以及加氢活性组分的引入，控制烯烃的选择性聚合，深入研究C2-C7烯烃齐聚合成航空燃油的选择性调控规律；探索FT合成-烯烃齐聚多功能催化体系的耦合机制，阐明多功能催化剂的协同作用机制。形成生物质热解气多组分一步转化为航空燃油的理论体系，为生物质高效转化及高值利用提供理论基础和技术支撑。

本项目围绕生物质热解气高值化利用的问题，采用费托合成耦合烯烃齐聚的方法，将生物质热解气高效转化为富含异构烃的航空汽油。研究了Fe3O4纳米催化剂晶粒尺寸对费托合成性能的影响，发现通过调节Fe3O4纳米催化剂的晶粒尺寸，可以将链增长因子控制在0.7~0.8之间，有利于航空汽油馏分段烃类的合成。研究了固体酸催化剂的生物质热解气齐聚反应性能，发现Ni基催化剂虽然能够促进低碳烯烃转化，但导致了原料烯烃的加氢，不利于热解气向航空汽油的转化。采用Fe3O4纳米催化剂和多级孔HZSM-5分子筛进行耦合，考察了生物质热解气的费托-齐聚耦合性能，研究发现生物质热解气中烯烃和CO的竞争加氢是影响费托-齐聚耦合反应性能的关键，采用先齐聚后费托的分级耦合方式，在富氢条件下，生物质热解气CO和C3H6转化率分别达到90%以上，油相收率可达60%以上，异构烃达到80%。费托-齐聚耦合能够有效提高碳原子经济性，为高辛烷值航空汽油的制备提供理论基础和技术支撑。