Experimental study on the activation of coal gasification fly ash from industrial CFB gasifiers  

作　　者：Qiyao Yang Xiaobin Qi Qinggang Lyu Zhiping Zhu 

机构地区：[1]North China Electric Power University,Beijing 102206,China [2]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [3]Shanxi Key Laboratory of Coal Flexible Combustion and Thermal Conversion,Datong 037000,China [4]University of Chinese Academy of Sciences,Beijing 100049,China [5]Shanxi Engineering Research Center of Coal Clean,Efficient Combustion and Gasification,Datong 037000,China

出　　处：《Chinese Journal of Chemical Engineering》2024年第1期8-18,共11页中国化学工程学报（英文版）

基　　金：financially supported by the Special Research Assistant Fund Project of Chinese Academy of Sciences.

摘　　要：Coal gasification fly ash(CGFA)is an industrial solid waste from the coal circulating fluidized bed(CFB)gasification process,and it needs to be effectively disposed to achieve sustainable development of the environment.To realize the application of CGFA as a precursor of porous carbon materials,the physicochemical properties of three kinds of CGFA from industrial CFB gasifiers are analyzed.Then,the activation potential of CGFA is acquired via steam activation experiments in a tube furnace reactor.Finally,the fluidization activation technology of CGFA is practiced in a bench-scale CFB test rig,and its advantages are highlighted.The results show that CGFA is characterized by a high carbon content in the range of 54.06%–74.09%,an ultrafine particle size(d50:16.3–26.1 μm),and a relatively developed pore structure(specific surface area SSA:139.29–551.97 m^(2)·g^(-1)).The proportion of micropores in CGFA increases gradually with the coal rank.Steam activation experiments show that the pore development of CGFA mainly includes three stages:initial pore development,dynamic equilibrium between micropores and mesopores and pore collapse.The SSA of lignite fly ash(LFA),subbituminous fly ash(SBFA)and anthracite fly ash(AFA)is maximally increased by 105%,13%and 72%after steam activation;the order of the largest carbon reaction rate and decomposition ratio of steam among the three kinds of CGFA is SBFA>LFA>AFA.As the ratio of oxygen to carbon during the fluidization activation of LFA is from 0.09 to 0.19,the carbon conversion ratio increases from 14.4%to 26.8%and the cold gas efficiency increases from 6.8%to 10.2%.The SSA of LFA increases by up to 53.9%during the fluidization activation process,which is mainly due to the mesoporous development.Relative to steam activation in a tube furnace reactor,fluidization activation takes an extremely short time(seconds)to achieve the same activation effect.It is expected to further improve the activation effect of LFA by regulating the carbon conversion ratio range of 27%–35%to

关 键 词：Circulating fluidized bed Coal gasification fly ash Steam activation Pore structure evolution Fluidization activation 

分 类 号：X701[环境科学与工程—环境工程]