煤催化加氢气化研究进展  

Research progress on the technology of coal catalytic hydrogasification

作　　者：严帅 夏梓洪[1] 陈彩霞[1] 曲旋[2] 毕继诚[2] YAN Shuai;XIA Zihong;CHEN Caixia;QU Xuan;BI Jicheng(School of Resources and Environmental Engineering,East China University of Science and Technology,Shanghai 200237,China;State Key Laboratory of Coal Conversion,Institute of Coal Chemistry of Chinese Academy of Sciences,Taiyuan 030001,China)

机构地区：[1]华东理工大学资源与环境工程学院,上海200237 [2]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001

出　　处：《洁净煤技术》2021年第1期60-72,共13页Clean Coal Technology

基　　金：煤转化国家重点实验室开放基金资助项目(J19-20-202);国家自然科学基金-联合基金资助项目(U1703253);国家自然科学基金-青年基金资助项目(21908062)。

摘　　要：煤加氢气化制天然气技术具有工艺路径短、热效率高等优点,其应用基础研究备受关注。但煤中存在部分致密的芳香碳结构,加氢反应性较差,即使在苛刻的反应条件下(~1 000℃、~7 MPa H_2),仍难以转化。通过引入催化剂,进行煤催化加氢气化可在温和的反应条件下实现煤的碳转化率和CH_4收率的同步提高。论述了碱金属(K、Na等)、碱土金属(Ca)和过渡金属(Fe、Co、Ni等)催化剂对模型碳加氢气化的催化作用原理。探讨了反应温度、氢气压力、和碳结构对C-H_2催化反应的影响规律,分析了适用于原煤催化加氢气化的最佳催化剂及工艺条件,并从CH_4和轻质液体焦油等产物生成规律、煤中碳结构随着反应进行的衍变过程等角度,讨论了催化剂分别对煤加氢热解和热解半焦加氢气化的催化作用行为。提出了煤催化加氢气化联产CH_4和轻质液体焦油技术从基础走向应用的进一步研究建议。现有研究结果表明,过渡金属与碱土金属组成的二元催化剂(Fe/Co/Ni-Ca)对煤加氢气化的活性较高。过渡金属元素在反应过程中主要提供C-H_2反应所需的活性氢,并削弱C—C键的键能;碱土金属元素Ca主要促进Fe/Co/Ni的分散,防止其发生硫中毒失活,并增强Fe/Co/Ni与碳之间的相互作用。温度升高一方面为化学键断裂过程提供了更高能量,加速C-H_2反应,另一方面促进催化剂在煤结构中扩散,提升催化剂的供氢和断键效率。升高压力促进了活性氢的供应,同时CH_4浓度得到稀释,反应向生成CH_4的方向移动。以5%Co-1%Ca为催化剂,在850℃、3 MPa H_2反应条件下,30 min内可同时达到90.0%的碳转化率和77.3%的CH_4收率。Co-Ca催化剂在煤加氢热解过程中具有催化解聚和催化加氢的作用,提高焦油和CH_4收率,同时催化剂在煤加氢热解过程中对煤结构产生催化活化作用,使得生成的半焦具有较高的气化活性。煤催化加氢气化的The technology of coal hydrogasification to natural gas has the advantages of short process and high thermal efficiency.The basic research of its application has attracted much attention.However,coal structure contains large quantities of inert carbon and the hydrogenation reactivity is poor,which are hard to be converted although harsh reaction conditions(~1000℃,~7 MPa)are applied.The reactivity of coal can be improved by adding desirable catalysts,and The carbon conversion and CH 4 yield under mild conditions can be increased simultaneously by coal catalytic hydrogasification(CCHG).The catalytic mechanism of alkali metal(K,Na,et al.),alkaline earth metal(Ca),and transition metals(Fe,Co,Ni,et al.)on hydrogasification of model carbon was reviewed.The effects of temperature,H 2 pressure and carbon structure on C-H 2 catalytic reaction process were discussed.On these bases,the optimal catalyst and process conditions for the catalytic hydrogasification of raw coal were proposed.Moreover,the catalytic behavior of catalysts on hydropyrolysis of coal and hydrogasification of pyrolyzed coal char were analyzed,in terms of formation of CH 4 and light hydrocarbon liquids(HCL)and the evolution process of carbon structure in coal with the reaction.Finally,further research suggestions for co-production of CH 4 and HCL from CCHG were put forward from an application perspective.The existing research results indicate that the use of iron-group metals with calcium salts(Fe/Co/Ni-Ca)as bimetallistic catalysts hasprofound catalytic performance on hydrogasifification.Transition metals mainly provide active hydrogen for C-H 2 reaction and decrease the energy for the fracture of C—C bonds.Ca mainly promotes the dispersion of transition metals and prevents its deactivation by sulfur poisoning,and enhances catalyst-carbon interaction.On the one hand,higher temperature provides higher energy for fracturing chemical bonds in coal,and accelerates the C-H 2 reaction.On the other hand,higher temperature facilitates the diffusion of the c

关 键 词：煤 催化加氢气化 甲烷 轻质液体焦油 碳结构 

分 类 号：TQ546[化学工程—煤化学工程]