化工学报2023，Vol.74Issue(10)：4252-4266,15.DOI:10.11949/0438-1157.20230747
镍基载氧体化学链燃烧过程中宁夏QH和YCW煤分子结构演化特征及对比分析
Molecular structure evolution characteristics and comparative analysis of Ningxia QH and YCW coal with nickel based oxygen carriers during chemical looping combustion
摘要
Abstract
Chemical looping combustion(CLC)is an important research orientation of clean energy processing and efficient conversion in the period of profound global changes.The reaction between solid fuels such as coal and oxygen carriers are one of the core scientific issues in CLC research.However,the evolution rules and the transformation mechanism are still unclear,especially the microscale description of the molecular structure evolution and functional group transformation of coal and other macromolecular solids in the fuel reactor from the atomic and molecular scale is lacking.Based on the macromolecular structure of coal and ReaxFF MD simulation,we study the chemical looping combustion process of Ningxia QH and YCW coal and nickel oxide oxygen carrier.Through the CLC process analysis of QH-NiO and YCW-NiO systems,the rules of total energy,total molecular number,product distribution and gas conversion are obtained.Based on the ReaxFF MD simulation process,the dynamic evolution process of coal macromolecular structure in CLC process is directly obtained.As the CLC reaction progresses,the macromolecular structure of coal gradually dissociates due to the breaking of old bonds and the generation of new bonds,resulting in various intermediate products,small molecules such as COx and H2O.The regulation and mechanism of quantity and rate of oxygen release from oxygen carrier during CLC in QH-NiO and YCW-NiO systems are revealed.The results show that compared with QH coal,YCW coal has lower metamorphism and higher reactivity.Therefore,the YCW-NiO system has lower total potential energy,generates more molecular fragments and more non-hydrocarbon gas,which can attribute to the oxygen carrier release lattice oxygen earlier.With the progress of CLC reaction,the oxygen vacancy formed on oxygen carrier surface leads to the migration and release of lattice oxygen in the secondary outer and inner lattice to the surface.关键词
分子模拟/介尺度/反应/化学链燃烧/煤分子结构/载氧体Key words
molecular simulation/mesoscale/reaction/chemical looping combustion/coal molecular structure/oxygen carrier分类
化学工程引用本文复制引用
张金鹏,王强,王艳美,严舒,吴建波,张慧,白红存..镍基载氧体化学链燃烧过程中宁夏QH和YCW煤分子结构演化特征及对比分析[J].化工学报,2023,74(10):4252-4266,15.基金项目
国家自然科学基金项目(52006110) （52006110）
宁夏自然科学基金项目(2022AAC01001) （2022AAC01001）
