生物质热解油选择性催化/吸附协同强化重整耦合机制与定向调控规律

Catalytic reforming of bio-oil is one of the most promising routes for large-scale hydrogen production from biomass in future. The project focuses on the preparation and structure-activity relationship of efficient nanocatalysts, selective catalytic/adsorption and transfer/reaction coupling mechanism, directional control behavior of bio-oil enhanced reforming. This project is proposed to establish a novel method for hydrogen generation via bio-oil efficient reforming over core-shell difunctional nanocatalysts. The research would be accomplished through the following steps: 1) to establish the preparation methods of core-shell difunctional Ni@CeO2-MxOy/CaO nanocatalysts and explore modification mechanism of catalysts performance enhancement by using the plasma and coating method; 2) to study the structure-activity relationship of the nanocatalysts and clarify their catalysis/adsorption difunctional mechanism; 3) to explore the competition and synergy mechanism of the key processes during bio-oil reforming and delve into the coupling mechanism of multiphase flow, heat and mass transfer and catalytic reactions; 4) to explore the mechanism of bio-oil selective catalytic/adsorptive enhanced reforming under the interaction of transfer processes enhancement and catalytic reactions. The corresponding global reaction network and mathematical model are established to reveal the directional control behavior for hydrogen production. The successful accomplishment of this project could enrich and improve the existing theoretical system of hydrogen production via bio-oil catalytic reforming and afford the theoretical horizon and technological support for the effective transformation and high-valued utilization of bio-oil.

生物油催化重整制氢技术是未来实现生物质大规模经济制取氢气的主要路线之一，具有良好的开发利用潜力。本项目围绕生物油重整制氢中高效纳米催化剂的制备与构效关系、选择性催化/吸附及传递/反应协同强化重整耦合机制、定向调控规律的研究目标，构建双功能核壳型纳米催化剂Ni@CeO2-MxOy/CaO体系，揭示等离子体协同包覆法改性增强催化剂性能的机理，获得催化剂的构效关系规律及其催化/吸收双功能的发挥和耦合作用机制；确定核壳双功能纳米催化剂作用下生物油催化重整制氢关键过程竞争和协同作用规律以及多相流动、热质传递与催化反应的耦合机制，建立生物油催化重整制氢的整体反应网络和数学模型，揭示过程传递强化与反应耦合协同的生物油选择性催化/吸附强化重整制氢机理。本项目的完成将进一步丰富和完善生物油催化重整制氢基础理论体系，为生物油高效转化及高值化利用提供理论基础和技术支撑。

生物质热解油蒸汽催化重整制氢技术是实现生物质大规模经济制取氢气的路线之一，具有良好的开发利用潜力。本项目开展了生物质固体热载体法热解产物分布与特性研究，进行了生物油的制备，确定生物油化学组成分布特征。进行了生物油组分蒸汽重整制氢研究，确定了主要气相组分的释放规律，分析了重整温度、水碳比、重时空速、催化剂化学组成、结构和性质等因素对原料转化率、氢气和主要副产物产率与选择性的影响规律，探明了催化剂的化学组成、结构、性质与其反应活性和抗积碳性能之间的关系，揭示催化剂构效关系规律和催化作用发挥机理。在T=800℃、S/C=3、WHSV=5h-1的最佳操作条件下，在镍负载量为15%的Ni/ZnO催化剂中添加25%的CeO2，可使醋酸重整的氢气产率从51.0%提高到74.0%。CO产率从35.7%降低到33.2%，H2/CO比从2.9提高到4.5。随着CZMR的增加，H2、CO和潜在H2产率服从高斯正态分布。建立了H2、CO和潜在H2产率与Ni负载量的指数函数关系式。当CZMR从0增加到1/3时，H2产率从57.8%增加到69.4%，增长率为20.1%。此外，当CZMR从1/3增加到3时，H2产率降低了37.6%。当镍含量从0%增加到15%时，H2的产率从20.6%增加到73.5%。此外，当镍含量从15%增加到25%时，氢气产率仅增加了5.8%。当CZMR为1/3，载镍量为15%时，H2和CO的选择性分别高达91.6%和42.3%。研究了反应过程中多相流动和转化反应耦合特性，阐明了生物油催化重整的触发机理及积碳行为规律，揭示了生物油催化重整制氢反应机理。生物油催化重整反应的开始是由于氧原子吸附在催化剂表面的氧空位上，导致O-H键断裂。在氧空位的作用下，C-H键也会断裂生成氢气，但伴随的碳化物是催化剂失活的主要原因。本项目已发表SCI论文14篇，EI论文1篇，其中SCI一区5篇、二区5篇，申请国家发明专利4项，其中授权发明专利3项，获得了农业农村部中华农业科技二等奖、全国商业科技进步一等奖和淄博市科技进步二等奖等科技奖励。