低阶煤热解挥发分热催化重整研究进展

Research progress in catalytic reforming of low rank coal pyrolysis volatiles

低阶煤清洁高效利用是我国的重大战略需求之一。在煤热转化技术中,煤热解挥发分催化重整可将复杂热解产品定向轻质化制备化学品,具有广泛应用前景。改变工艺条件是提高热解转化率和产品收率的重要手段,优化反应器设计以及开发高活性和稳定性催化剂是该技术发展的重要方向。本文首先介绍了低阶煤及其挥发分的催化重整方式,在此基础上综述了温度、气氛、停留时间等反应条件的影响以及固定床和流化床反应器应用的策略和挑战,然后对金属类、炭基和沸石类催化剂的后处理及原位控制等改性方法与作用原理进行了分析,阐述了热解挥发分的催化裂解机理。此外,指出了煤热解挥发分催化重整技术在工业化生产中的瓶颈,明确了挥发分中低碳烃类与大分子化合物的催化转化路径对煤热解过程中二次反应定向调控的关键作用,深入探究了催化剂中酸催化质子化作用对催化剂失活机制的影响。

The clean and efficient utilization of low rank coal is one of the important strategic needs of China.Among coal thermal conversion technologies,catalytic reforming of coal pyrolysis volatile has high efficiency and wide application prospect.Changing process conditions is an important way to increase pyrolysis conversion and product yield.Optimizing reactor design and developing catalysts with high activity and stability are the important development directions of this technology.This paper firstly introduced the catalytic reforming method of low rank coal and its volatiles,on the basis of which the influence of process parameters such as temperature,atmosphere,and residence time,as well as the strategies and challenges for the application of fixed-bed and fluidized-bed reactors,were reviewed.Then,the modification methods of metal catalysts,carbon-based catalysts and zeolite catalysts and the action principles of their post-treatment and in-situ control were analyzed.The catalytic cracking mechanism of pyrolytic volatiles was summarized.The paper also pointed out the bottlenecks of the catalytic reforming of coal pyrolysis volatiles in industrialized production.The key role of the catalytic conversion path of volatile low carbon hydrocarbons and macromolecular compounds in the directional regulation of secondary reactions during coal pyrolysis was identified,and the influence of acid-catalyzed protonation on the deactivation mechanism of catalysts was deeply explored.