不同气氛下褐煤气化特性实验研究进展——新型反应器  

Research Progress on Characteristics of Lignite Gasification in Different Atmospheres:Novel Reactor

作　　者：程相龙 郭晋菊 辛坤涵 陈英赞 任海波 马名杰[2] 张海永[3] CHENG Xianglong;GUO Jinju;XIN Kunhan;CHEN Yingzan;REN Haibo;MA Mingjie;ZHANG Haiyong(School of Materials and Chemical Engineering,Henan University of Urban Construction,467036 Pingdingshan,China;School of Materials and Chemical Engineering,Henan Polytechnic University,Jiaozuo,454150 Henan,China;School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),100083 Beijing,China)

机构地区：[1]河南城建学院材料与化工学院,河南平顶山467036 [2]河南理工大学材料科学与工程学院,河南焦作454150 [3]中国矿业大学(北京)化学与环境工程学院,北京100083

出　　处：《煤炭转化》2022年第1期90-100,共11页Coal Conversion

基　　金：国家自然科学基金资助项目(21506251);河南省科技攻关计划项目(202102310238).

摘　　要：丝网、一段或二段式固定床-流化床、燃烧-气化双床及套管反应器等是为褐煤气化过程中某些气化特性(如负压快速热解等)而开发的新型反应器。针对这些新型反应器及其对褐煤气化的研究结果进行总结,分析和讨论了负压快速热解(10000℃/s)特点、半焦与挥发分相互作用、碱金属和碱土金属(AAEMs)的催化作用及粒径对气化影响的双面性(促进/抑制作用)等方面的研究进展。分析认为:挥发分与半焦相互作用对气化过程具有抑制作用,主要由于挥发分重整产生的自由基促使半焦结构缩合,芳香度增大,反应性降低;如何将该抑制作用最小化,是开发新型流化床反应器的切入点;只有吸附在焦炭颗粒表面的高活性的AAEMs可以与半焦官能团等发生离子交换,改变碳颗粒表面的电荷分布,形成活性位,才具有催化作用;然而,煤灰中AAEMs在气化过程中演变复杂,如何将其分解开来,在接近真实气化条件下研究AAEMs的催化作用值得关注;粒径对褐煤气化的影响具有双面性,可以从反应速控步、颗粒孔隙特征及表面化学结构(如官能团等)等方面进行深入研究。Lignite gasification is a high-efficiency clean technology,which has attracted much attentions from both research community and industry.Wire-mesh,primary or secondary fixed-fluidized bed,combustion gasification double bed and casing reactor are new reactors developed for meeting specific requirements of some gasification characteristics(such as negative pressure rapid pyrolysis)in the process of the lignite gasification,which have attracted growing attentions.This paper summarizes these new reactors and their research results on the lignite gasification,and discusses the research progress in the characteristics of the negative pressure rapid pyrolysis(10000℃/s),char and volatile interaction,catalysis of alkali metals and alkaline earth metals(AAEMs),and the double effect(promotion/inhibition effect)of the particle size on the gasification.It is concluded that char and volatile interactions found in the fixed-fluidized bed inhibit the gasification,because the free radical produced by the volatile reforming causes the condensation of the chemical structure and the reactivity decrease in the char.The research for answering how to minimize the inhibition offers the guidance for developing new fluidized bed reactors.Besides,only the highly active AAEMs adsorbed on the char surface could exchange the ions with the functional group,thereby changing the charge distribution and yielding the active position and thus the catalysis on the char surface.However,the evolution of the coal-ash-associated AAEMs in the gasification process is complicated,and how to decompose it and the catalytic effect of AAEMs under the actual conditions of the gasification is worth future studying.In addition,the double effect of the particle size on the brown coal gasification should be deeply studied from the aspects of the reaction rate control step,particle pore characteristics and surface chemical structure(such as functional groups).

关 键 词：褐煤气化 气氛 反应器 丝网 AAEMs 粒径 

分 类 号：TQ545[化学工程—煤化学工程]