煤的多段加氢热解过程及机理分析  

Process Analysis and Mechanism of Multi-stage Hydropyrolysis of Coal

作　　者：李文[1] 王娜[1] 李保庆[1] 

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,太原030001

出　　处：《高等学校化学学报》2002年第9期1767-1771,共5页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金 (批准号 :2 993 60 90 )资助

摘　　要：通过对不同停留方式加氢热解过程产物的详细分析 ,探讨了煤多段加氢热解过程的机理 .结果表明 ,不同停留方式对热解产物的分布及性质有重要的影响 ,并使氢气的有效利用率相差很大 .停留温度应选在煤热解产生自由基最多的温度范围 (3 5 0～ 5 0 0℃ ) ;于 3 5 0℃停留段在挥发组分大量逸出的过程中产生丰富的孔隙 ,有利于后续加氢反应的进行 ;低温下的停留过程使气相中的氢优先与煤中的含氧官能团结合而生成酚类 ,从而避免了在更高温度下生成水 ;加氢热解半焦中化学官能团的断裂主要与热解温度有关 ,停留过程只是通过稳定热解产生的自由基和较重热解产物的进一步加氢而改变产物的分布和组成 .The mechanism of multi\|stage hydropyrolysis of coal was probed through detailed analysis of products of hydropyrolysis with different holding methods. The results showed that the holding method significantly affects the product distributions, thus making an apparent difference in hydrogen utilization efficiency. The holding temperature should be about 350\_500 ℃ during which more free radicals are produced rapidly. Pore\|riched structures are formed at the holding stage at 350 ℃ due to the evolution of large amount of volatiles, which is favorable to the subsequent hydrogenation reaction. The holding at a low temperature favors the reaction of hydrogen with oxygen\|containing groups, leading to the formation of phenol and avoiding the formation of water at a high temperature. The cleavage of chemical bonds in the char is mainly dependent on the pyrolysis temperature. The effect of holding stage is to change the distribution and components of products via stabilizing the free radicals and hydrogenating the heavier products.

关 键 词：煤 多段加氢热解 过程分析 热解机理 产物组成 产物分布 

分 类 号：TQ536[化学工程—煤化学工程] O643.1[理学—物理化学]