Abstract:

China's coking coal resources are scarce and unevenly distributed. However, the low-grade coal in China is rich in reserves, low in price, and has the characteristics of low ash and low sulfur, near-zero caking index. Catalytic hydrogenation is an effective method to improve the caking property of low-grade coal. In this paper, the catalytic hydrogenation of long-flame coal was carried out, and elemental analysis, infrared analysis, electron paramagnetic resonance analysis, and reaction hydrogen consumption calculation were performed for the raw coal and modified coal to study the role of catalyst and the hydrogen transport mechanism. The results indicated that the caking property of long-flame coal was significantly enhanced, which could partially replace coking coal in the coking process. Hydrogenation can remove part of the oxygen-containing functional groups and alkyl side chains in the long-flame coal, and reduce the degree of crosslinking of coal molecules. The main function of the catalyst is to activate hydrogen, and secondly to promote the depolymerization of coal molecules and promote the hydrogen transport of tetralin to coal. In the presence of a catalyst, the dominant hydrogen transport path of the catalytic hydrogenation reaction is directly from hydrogen to coal molecules instead of from hydrogen donor solvent to coal.

Key words: low-rank coal, catalysis, hydrogen transport, solvent extraction, radical

摘要：

我国炼焦煤资源短缺且分布不均匀，而低阶煤储量丰富，价格低廉，具有低灰、低硫等特点，但其黏结性几近为零。催化加氢增黏是一种有效提高低阶煤黏结性的方法。本文通过对长焰煤进行催化加氢增黏，对原煤及增黏煤进行元素分析、红外分析、电子顺磁共振分析和反应中氢耗计算研究催化加氢增黏反应中催化剂及氢传递机理。结果表明：长焰煤黏结性显著增强，在炼焦过程中可部分替代炼焦煤使用；加氢增黏可以去除长焰煤中部分含氧官能团及烷基侧链，降低煤分子的交联程度；催化剂主要作用是活化氢气，其次可以促进煤分子解聚并且促进四氢萘到煤的氢传递。当催化剂存在时，催化加氢增黏反应氢传递路径主要是从氢气直接至煤分子，而不是通过供氢溶剂至煤分子。

关键词: 低阶煤, 催化（作用）, 氢传递, 溶剂萃取, 自由基