Gasification of Anthracite in a Pilot-Scale CFB Gasifier and Pore Structure Evolution of Gasification Fly Ash during Steam Activation  

作　　者：QI Xiaobin YANG Qiyao ZHAN Yueping SONG Weijian ZHU Zhiping LYU Qinggang 

机构地区：[1]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China [3]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Journal of Thermal Science》2023年第5期1899-1911,共13页热科学学报（英文版）

基　　金：financially supported by the Special Research Assistant Project,Chinese Academy of Sciences。

摘　　要：The poor-reactivity anthracite urgently needs more ways for large-scale and high-quality utilization.Due to the advantage of good fuel adaptability,the circulating fluidized bed(CFB)gasification technology has the potential of high-quality utilization of anthracite.In this paper,one kind of anthracite from Shanxi province,China,was employed to be gasified in a pilot-scale CFB gasifier.It is found that at the operating temperature of 1049℃and oxygen concentration of 60.75%,the gas with a concentration of combustibles of 66%and a low heating value of 7.93 MJ/m^(3)(at about 25℃and 101.325 kPa)was produced in the CFB gasification process.However,the overall gasification efficiency was not desired because a large amount of gasification fly ash(GFA)escaped and its yield was up to 22%.In this case,the cold gas efficiency was below 48%and the carbon conversion ratio was only 62%.Further analysis reveals that the GFA was featured with a developed pore structure and the specific surface area(S_(BET))reached 277 m^(2)/g.This indicates such GFA has a potential to use as activated carbon(AC)or AC precursor.Basis on this,steam activation experiments of the GFA produced were conducted to investigate the activation characteristics of GFA and thereby to determine its activation potential.Experimental results indicate that increasing temperature sharply accelerated the activation process,while did not impair the maximum activation effect.After activation,the S_(BET)of GFA maximumly increased by 63%,reaching452 m^(2)/g.With the progress of activation,the pore structure of GFA presents a three-stage evolution process:development,dynamic balance,and collapse.Such a process can be divided and quantified according to the carbon loss.In order to achieve an optimal activation of GFA,the carbon loss shall be controlled at~15%.This work provides a new scheme for high-quality utilization of anthracite.

关 键 词：ANTHRACITE CFB gasification fly ash GASIFICATION steam activation 

分 类 号：TQ546[化学工程—煤化学工程]