褐煤超临界水气化制甲烷的催化剂比较研究  

STUDY ON CATALYSTS FOR METHANE PRODUCTION FROM LIGNITE GASIFICATION IN SUPERCRITICAL WATER

作　　者：夏凤高[1,2] 田森林[1] 谷俊杰[1] 宁平[1] 王奕雪[1] 关清卿[1] 

机构地区：[1]昆明理工大学环境科学与工程学院,昆明硕士生650093 [2]昆昭通市环境监测站,云南昭通657000

出　　处：《煤炭转化》2013年第4期24-28,共5页Coal Conversion

基　　金：国家教育部博士点基金资助项目(20105314110009);云南省高端科技人才引进计划项目(210C110)

摘　　要：运用超临界水气化技术,在间歇式高温高压反应釜内,分析对比了KOH,K2CO3,Na2CO3和Ca(OH)2四种碱性催化剂及ZnCl2,FeCl3,CuCl2和AlCl3四种金属氯化物催化剂对褐煤在超临界水中气化反应制取CH4的影响.研究表明,反应条件为550℃,25MPa,水煤比10∶1,KOH与煤的质量比为20%,停留时间20min时,CH4产量由高到低的顺序为:KOH>K2CO3>ZnCl2>Na2CO3>AlCl3>Ca(OH)2>不加催化剂>FeCl3>CuCl2.实验发现,ZnCl2对CH4产量有促进作用,其主要原因为ZnCl2具有能促进中间产物降解生成酸,有利于酸催化反应,从而能更好地促进气化反应的进行.而KOH催化效率最高(110.2mL/g daf coal),比不添加催化剂时增加了1倍多,其主要原理为KOH在超临界水中的自由基反应及碱性金属对水气置换反应的促进作用.For the production of CH4,supercritical water gasification of lignite was investigated in a high temperature and pressure batch autoclave.The influences of four basic catalysts （KOH,K2CO3,Na2CO3 and Ca（OH）2） and four metal chloride catalysts （ZnCl2,FeCl3,CuCl2and AlCl3） were discussed.The reaction condition was 550 ℃,25 MPa,10 ∶ 1 mass ratio of H2O to lignite,20％ mass ratio of KOH to lignite,20 min residence time.The results show that the effect of catalysts on yield of CH4 from high to low order is KOH＞K2CO3 ＞ZnCl2 ＞Na2CO3 ＞ AlCl3＞Ca（OH）2＞no catalyst＞FeCl3＞CuCl2.It was found that ZnCl2 can promote the yield of CH4,which can be explained that intermediate products can be degraded to acid by ZnCl2 which is good for acid catalyzed reaction and can promote the gasification reaction better.Compared with no catalyst addition,the addition of FeCl3 and CuCl2 turns to lower yield of CH4.And catalytic efficiency of KOH is the highest.Yield of CH4 is 110.2 mL/（g daf coal） which is almost double to that of no catalyst addition when KOH was added.The main mechanism is the free radical reaction and promoting of basic metal to the water-gas shift reaction in supercritical water.

关 键 词：褐煤 超临界水 气化 甲烷 催化剂 

分 类 号：TQ541[化学工程—煤化学工程] TQ426