生物质原位富钙热解与在线Fe-ZSM催化制取低碳烯烃的机理研究

Light olefins are the important basic raw materials of organic chemical industry, and the production of light olefins from non-petroleum routes is an effective way to alleviate shortage of petroleum and environment pollution pressures. Therefore, a new process of calcium-rich in-situ pyrolysis of biomass and on-line Fe-ZSM catalysis for light olefins preparation is proposed in the project. The reaction mechanism on the co-transformation of oxygen-containing small molecules and CO on Fe-ZSM catalyst is explored in order to effectively improve the yield of light olefins. Through experiment research, theoretical analysis and quantum chemistry simulation, the transformation behavior of oxygen-containing small molecules on Fe-ZSM will be further studied. The conversion mechanism of light olefins from the co-transformation of oxygen-containing small molecules and CO under pyrolysis conditions will be explored. The coupling mechanism of the effective regulation of target component and the high-efficient adsorption of CO2 will be investigated. Through the proposed study, the formation mechanism of light olefins from biomass with in-situ calcium-rich pyrolysis and on-line Fe-ZSM catalysis will be revealed. The research achievements will not only benefit the production of light olefins from non-petroleum materials, but also provide a new way to high efficient conversion and high value utilization of abundant renewable biomass resources in China.

低碳烯烃是重要的基本有机化工原料，开发非石油路线的生物质基低碳烯烃制备方法与工艺是缓解石油资源短缺和环境污染压力的有效途径之一。本项目将基于富钙热解与Fe-ZSM催化有机结合，提出生物质原位富钙热解与在线Fe-ZSM催化制备低碳烯烃的新工艺。通过探索含氧小分子与CO在Fe-ZSM上同时转化为低碳烯烃的反应机理，有效提升低碳烯烃产率。本项目将采用实验研究、理论分析与量子化学模拟相结合的方法，深入研究含氧小分子在Fe-ZSM催化作用下向低碳烯烃转化的反应过程机理，掌握热解气氛下调控含氧小分子与CO同时转化为低碳烯烃的协同机制，探索目标组分调变与CO2高效吸收的耦合机制，揭示生物质原位富钙热解与Fe-ZSM在线催化制取低碳烯烃的关联耦合机制。本项目的研究成果可为低碳烯烃的制备提供理论基础和科学依据，也将为我国丰富的可再生生物质资源的高效转化与高值化利用提供一条新的途径。

低碳烯烃（乙烯、丙烯和丁烯）是重要的基本有机化工原料，开发非石油路线的生物质基低碳烯烃制备方法与工艺是缓解石油资源短缺和环境污染压力的有效途径之一。本项目采用生物质原位富钙热解与分子筛在线催化有机结合的新工艺，对生物质定向制备低碳烯烃的催化热解反应过程机理进行了深入研究，为更好掌握生物质定向催化的调控机制，本项目对任务书的内容进行了适当的调整，拓展性的研究了不同金属负载改性ZSM分子筛对低碳烯烃生成的影响机制，考察了热解中间产物模型化合物向低碳烯烃的转化机制，并进一步探究了低碳烯烃和芳香烃联产的协同调控机制。结果表明：Fe负载量为3wt.%，温度为600oC，催化剂/原料比为2，载气流速为100ml/min时得到的纤维素催化热解低碳烯烃碳产率最大。金属硝酸盐的负载改性能够有效的增加ZSM-5催化剂的总酸性和中强酸酸性位点分布，同时促进了低碳烯烃的产生，在Cu和Ce负载时最大，Fe、Al、La负载时次之，Mg负载时效果最差。相关性协方差分析表明，乙烯与催化剂中强酸酸性位点分布相关性最大，而丙烯和丁烯则分别与弱酸和强酸酸性位点分布相关性最大。模型化合物转化为低碳烯烃的能力依次为丙酮，愈创木酚，乙酸和糠醛。生物质原位富钙热解与分子筛在线催化不仅可以实现低碳烯烃的最大富集，而且可以联产化工原料芳香烃，促进了生物质的进一步高值化利用。本项目研究取得了丰硕的成果，共发表论文21篇，其中SCI收录论文16篇，EI收录论文4篇；申请国家发明专利5项，其中授权发明专利1项，项目的研究成果将有利于探索出一条高值转化可再生生物质制备低碳烯烃的新途径。