超临界流体改质煤焦油研究进展

Progress on application of supercritical fluids to upgrade coal tar

中国是一个多煤少油的国家,煤制油技术在我国有着广泛的应用前景。由于超临界流体对有机物有较好的溶解性,因此越来越多地应用到煤焦油深加工过程中。本文总结了超临界流体改质煤焦油过程中,操作参数对煤焦油轻质化的影响和强化改质方法,重点分析了超临界水和超临界甲醇,超临界水改质煤焦油主要体现在物理上的溶解和分散作用,而超临界甲醇除此之外,有一定的供氢能力,可以为反应提供氢,但是供氢能力有限。因此,本文又讨论了添加催化剂、自由基引发剂、加氢等手段强化超临界流体改质煤焦油。在此基础上对超临界流体改质煤焦油进行了展望,将超临界流体的萃取和超临界改质耦合在一起,充分发挥超临界流体优越性;选择新的超临界流体、催化剂等促进煤焦油轻质化。

Given the backdrop of China’s coal-rich but oil and gas-short condition, the utilization rate of coal is not high. Developing the coal-to-liquid(CTL) technologies has a great potential for coal applications. Because supercritical fluids(SCF) have high solubility for a variety of organic compounds,they have been widely used to upgrade coal tar. This paper summarized the effect of operating parameters on the process of supercritical fluid upgrading coal tar, and the reaction mechanism, with a focuson the analysis of supercritical water(SCW) and supercritical methanol(SC-MeOH). Previous studies found that the SCW and SC-MeOH could modify coal tar mainly through the physical dissolution and dispersion.The SC-MeOH can also produce hydrogen but its capacity of supplying hydrogen is limited. Therefore,the addition of catalysts, free radical initiators, and hydrogenation were discussed to enhance supercritical coal tar upgrading process. Future research may focus on the combination of SCF extraction and reaction,developing and applying new types of SCF and catalysts.