摘要
固体化学链燃烧伴生大量灰分,与载氧体共同流化,两者存在复杂的相互作用.同时,灰成分与载氧体形成稳定骨架所需惰性添加剂类似,具有影响载氧体骨架及活性的潜力.针对这一特性,提出了采用生物质灰原位形成似长石结构强化载氧体颗粒骨架的方法,研究了含K、Ca油菜秸秆灰对载氧体的影响,分析其活性与骨架变化.采用机械二次混烧的方法改性载氧体,通过小型流化床实验系统和热重分析仪分别研究反应过程、整体颗粒、单颗粒的宏观特性,结合XRF、SEM-EDS、XRD、PSD分析强化机理.结果表明:灰分的加入未降低反应活性,但却有效减小了颗粒磨损率、增大了留存粒径的分布范围.对比XRD和SEM-EDS结果,发现灰改性载氧体的表面原位生成似长石结构(KNa_(3)(AlSiO_(4))_(4)),并存在丰富的撕裂棱和准解理裂纹,保护和强化了载氧体骨架.
A large amount of ash is the by-product of solid chemical looping combustion,which is co-fluidized with oxygen carriers(OCs),with the occurrence of complex interactions.At the same time,ash composition is similar to that of the inert additives used in oxygen carrier preparation to form a stable skeleton,which has the potential to affect the activity of oxygen carrier and skeleton.In view of this characteristic,the effect of rape straw ash containing K and Ca on oxygen carriers was studied,the changes in activity and skeleton were analyzed,and a structure strengthening method for OCs skeleton through in-situ feldspar-like formation was proposed.The OCs were modified by the method of mechanical secondary mixed firing.The reaction process and the macroscopic characteristics of monolithic particles and single particles were studied by the bench fluidized bed and thermogravimetric analyzer,and the strengthening mechanism was analyzed in combination with the results of XRF,SEMEDS,XRD and PSD.The results show that the addition of ash does not reduce the reactivity but effectively re-duces the particle attrition rate and increases the particle size distribution range.The XRD and SEM-EDS results show that the feldspar-like structure(KNa_(3)(AlSiO_(4))_(4))is in-situ generated on the surface of the ash modified oxygen carrier,and that there exist abundant tearing edges and quasi cleavage cracks,which protects and strengthens the skeleton of OCs.
作者
刘方
张曦
杨丽
陈文斌
亢炜燎
Liu Fang;Zhang Xi;Yang Li;Chen Wenbin;Kang Weiliao(School of Low-Carbon Energy and Power Engineering,China University of Mining and Technology,Xuzhou 221116,China)
出处
《燃烧科学与技术》
CAS
CSCD
北大核心
2022年第5期498-506,共9页
Journal of Combustion Science and Technology
基金
国家自然科学基金资助项目(52176143)
国家重点研发计划资助项目(2018YFE0111100).
关键词
化学链燃烧
载氧体
生物质灰
颗粒磨损
增韧方法
chemical looping combustion
oxygen carrier
biomass ash
particle attrition
toughening method
作者简介
刘方(1984-),男,博士,教授,fang.liu@cumt.edu.cn;通信作者:杨丽,女,博士,副教授,li.yang@cumt.edu.cn.
