尖晶石载氧体驱动煤化学链气化制合成气多尺度研究

Chemical looping gasification of coal can produce syngas by oxygen uncoupling of oxygen carrier. In this proposal, the nanoscle spinel crystal grain, the microscale oxygen carrier particle and the macroscale fluidized bed reactor are studied by a multiscale mechod. The nucleation and growth characteristics of the product layer on the surface of oxygen carrier in the oxygen uncoupling process is analyzed. The formation and collapse of active site are uncovered. By introducing other metal 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 particle during the circulation process, the pore structure of oxygen carrier particle is optimized, and cycle stability of oxygen carrier particle is improved by adding inert carriers. The mechanism of absorption, decomposition and transformation of depolymerized materials from coal over the spinel oxygen carrier are investigated. The microscopic reaction pathways of chemical looping gasification of coal are discovered. The preparation method of oxygen carrier which has high efficiency and long service life can be obtained. The useful design solutions of fluidized bed can be proposed for chemical looping of coal. This proposal can provide the basic theory and data for the following study of chemical looping gasification of coal. It can also offer previous information for the basic research and application of oxygen carrier design,coal catalytic gasification and other related fields.

煤化学链气化技术利用载氧体的氧解耦作用驱动煤气化制取合成气。拟采用多尺度方法，以纳尺度尖晶石晶粒、微尺度的载氧体颗粒和宏尺度的流化床反应器为研究对象。分析氧解耦过程中尖晶石表面产物层的成核动力学与生长特性，揭示其表面活性位的产生和湮灭机制。通过外来金属离子的引入，控制尖晶石表面固体产物层形成过程，提高尖晶石的释氧速率。在掌握循环过程中尖晶石载氧体颗粒微观结构演变规律的基础上，添加惰性载体物质，优化尖晶石载氧体颗粒孔隙结构，改善颗粒的循环稳定性。研究煤解聚物在尖晶石载氧体表面的吸附、分解和转化过程，明晰煤化学链气化的微观反应历程。本项目预期可获得高效长寿命尖晶石载氧体颗粒的制备方法，得到适用于煤化学链气化的流化床设计方案。项目成果可为煤化学链气化方法的后续研究提供基础理论和数据，对化学链空气分离和煤催化气化等相关领域的基础研究具有一定的借鉴意义。

本项目着眼于纳尺度晶粒、微尺度颗粒和宏尺度流化床，分析了CuFe2O4、NiFe2O4等尖晶石在氧解耦过程中表面产物层的成核动力学与生长特性，发现了尖晶石表面缺陷的产生和湮灭机制。通过碱金属和碱土离子的引入，改变了尖晶石表面固体产物层的结构，提高了尖晶石的释氧速率。添加惰性物质改善了颗粒的循环稳定性。提出了C、CO等小分子在载氧体表面的吸附、分解和转化等微观反应历程。本项目获得了高效长寿命尖晶石载氧体颗粒的制备方法，得到了适用于煤化学链气化的流化床设计方案。项目成果可为煤化学链气化方法的后续研究提供基础理论和数据，对化学链空气分离和煤催化气化等相关领域的基础研究具有一定的借鉴意义。本项目经过4年的研究实施，已经顺利地完成了相应的研究目标和内容，其研究结果在国内外发表论文32篇，其中SCI论文25篇。