基于产品导向的胜利褐煤中温催化热解特性研究

Product-oriented catalytic pyrolysis characteristics of Shengli lignite at intermediate temperature

为解决鲁奇炉出口煤气焦油含量高、气化效率低,阻碍热解产物的清洁利用,造成后续系统水处理成本高等问题。以降低焦油收率、提升煤气产量、提高煤炭转化率为导向,以胜利褐煤为研究对象,在固定床常压热解反应器及600℃条件下开展了胜利褐煤二元复合催化热解实验研究,考察了由K2CO3、Ca(NO3)2、CaO和Fe(NO3)3四种单组分催化剂所制备的二元复合催化剂的种类和配比对热解产物收率和热解转化率的影响,揭示了胜利褐煤中温催化热解特性。研究结果表明:添加5%配比为1∶1的K/Ca催化剂时,煤气收率提升最显著,由无催化剂时的8.46%升至14.88%,突出表现为H2和CO的收率有显著提升;焦油收率相对原煤热解降低了62.4%,其中沥青质降低了82.09%,芳香烃提高了21.69%。这表明添加催化剂可以降低焦油收率,提升煤气品质,实现热解产品的定向转化。

In order to solve the problems of high tar content of gas at the outlet of Lurgi furnace and low gasification efficiency,which hinder the clean utilization of pyrolysis products,and cause high cost of water treatment in the post-system. To reduce the yield of tar,increase gas output and coal conversion rate,Shengli lignite was taken as the research object,the binary composite catalytic pyrolysis experiment of Shengli lignite was carried out in a fixed bed atmospheric pyrolysis reactor and at600℃,the effects of the type and ration of binary composite catalysts prepared by four single component catalysts,K2 CO3,Ca( NO3)2,Ca O and Fe( NO3)3,on the pyrolysis product yield and pyrolysis conversion were investigated to reveal the catalytic pyrolysis characteristics of Shengli lignite at intermediate temperature. The results show that the gas yield increases most significantly when adding 5% K/Ca catalyst with 1 ∶ 1 ratio,from 8. 46%( non-catalyst) to 14. 88%,showing a major improvement of H2 and CO yield. The tar yield decreased 62. 4% compared with the pyrolysis of raw coal,in which asphaltene decreased 82. 09% and aromatic hydrocarbon increased 21. 69%,indicating that the addition of catalyst can reduce the yield of tar,improve the quality of gas and realize the directional conversion of pyrolysis products.