基于氧解耦的煤与生物质直接接触式化学链共气化机理研究

Oxygen is seperated from air by oxygen uncoupling of transition metal oxide.The Cu-based composite oxygen carriers with oxygen carrying ability and catalytic property were prepared for direct contact chemical looping coal and biomass co-gasification. In this proposal,the oxygen release reaction kinetics of oxygen carrier is investigated. The nucleation and growth characteristics of the product layer on the surface of oxygen carrier in the oxygen release process is analyzed. By introducing transition metal or rare earth ions, the formation process of the product layer is controlled to accelerate the oxygen release rate. Based on the micro-pore structure evolution laws of oxygen carrier during oxygen carrier circulation process has been mastered. By adding inert carriers, the pore structure of oxygen carrier is optimized, and the cycle stability of oxygen carrier is improved. The depolymerization pathways of coal and biomass are studied in the gasification reactor.The mechanism of absorption and transformation of coal coke, biomass coke and depolymerized materials over the oxygen carrier are investigated. The coke deposition and coke removal processes are explored. The microscopic mechanism and control strategies of chemical looping coal and biomass co-gasification are discovered. This proposal can provide the basic theory and data for the following study of chemical looping solid fuel gasification. It can also offer previous information for the basic research and application of oxygen carrier design,coal/biomass catalytic gasification and other related fields.

基于过渡金属氧化物氧解耦方法分离空气中的氧气，合成兼有载氧功能和催化作用的Cu基复合载氧体，用以驱动煤与生物质直接接触式化学链共气化反应。研究载氧体在CO2气氛中的释氧动力学，分析释氧过程中载氧体表面产物层的成核与生长特性；通过引入少量过渡金属和稀土离子，控制表面产物层形成过程，加快释氧反应速率；在掌握循环过程中载氧体微观结构演变规律的基础上，向载氧体中添加惰性载体物质，优化载氧体孔隙结构，以改善载氧体循环反应稳定性；研究煤与生物质在气化反应器中的解聚途径，分析煤焦、生物质焦及解聚物在载氧体表面的吸附和转化机制，探索载氧体表面的积炭/消炭过程，明晰煤与生物质化学链共气化的微观机理和反应历程调控策略。本项目预期为固体燃料化学链气化方法的后续研究提供基础理论和数据，对载氧体设计和煤/生物质催化气化机理等相关领域的基础研究具有一定的借鉴意义。

基于过渡金属氧化物氧解耦方法分离空气中的氧气，合成兼有载氧功能和催化作用的Cu基复合载氧体，用以驱动煤与生物质直接接触式化学链共气化反应。明晰了载氧体在CO2气氛中的释氧动力学，发现所有Cu基载氧体的释氧均可以用二维成核与核生长反应模型来表示，机理函数表达式为G(α) =[–ln(1–α)]1/2。通过引入过渡金属Co、Fe、Ni等和稀土离子Ce、Y和Zr，发现释氧反应速率加快。向载氧体中添加惰性载体物质Ce、Y和Zr，提高了载氧体循环反应稳定性。研究了煤与生物质在气化反应器中共气化，发现发现在煤和稻壳的水蒸气气化和化学链气化反应中，H2具有最高的生成速率与产量。在煤和稻壳的化学链气化与共气化中，5%Co3O4/CuO相比与5%NiO/CuO具有更好的反应性能和更佳的气化效果。煤、稻壳的化学链气化相比其水蒸气气化具有更高的H2、CO产量，煤与稻壳的水蒸气共气化在H2和CO的产量上有着较好的协同作用。在化学链共气化中，H2与CO的产量与协同作用都要高于水蒸气共气化，其中H2产量增长了15.38%，CO产量增长了38.89%。同时，共气化比单独气化表现出了更高的碳转化率。