煤直接液化工艺过程中的结焦现象是制约该技术工业应用的瓶颈。结焦的化学本质是高温缺氢环境中自由基的生成速率与加氢速率的不匹配。煤直接液化过程中起决定作用的是短寿命的活性自由基，但是目前缺少相关的检测手段。本项目拟通过9,10-二氢菲捕获活性自由基，实现活性自由基的定性和定量表征，进而研究煤直接液化结焦过程中自由基的生成规律、供氢溶剂对自由基的供氢规律、自由基的耦合反应规律。焦及其前驱物的加氢转化可以抑制结焦，前提是其结构中含有可断裂的共价键。本项目通过焦及其前驱物在供氢溶剂中的加氢转化率表征其反应活性，通过活性自由基量计算其结构中的可断裂共价键量，进而获得焦及其前驱物的结构和加氢反应活性随反应条件的变化规律。通过本项目的实施可以揭示煤直接液化过程中的自由基反应与结焦规律的关系以及焦形成过程中的可断裂共价键变化规律和焦的反应特性这两个关键科学问题，为解决煤直接液化过程的结焦问题提供理论支撑。

Coking is a bottleneck restricting the large-scale industrial application of the direct coal liquefaction (DCL) technology. The chemical essence of coking is that the rate of free radicals generation does not match the rate of free radical hydrogenation in a high temperature and hydrogen-deficient environment. Active free radicals with short lifetime play a decisive role in the DCL process, however, at present the understanding of active radical reaction in DCL process is very limited because of the lack of detection methods. Therefore, this project intends to trap active free radicals by 9,10-dihydrophenanthrene to achieve the qualitative and quantitative characterization of these radicals, and further study the generation of free radicals, the hydrogenation of free radicals by hydrogen donor solvent, and the coupling of free radicals in the coking process of DCL. Hydrogenation of coke and its precursors can inhibit coking on the premise that there are cleavable covalent bonds in the structure. To understand the variation of structure and hydrogenation activity of coke and its precursors with reaction conditions, the hydrogenation conversion of coke and its precursors that react with hydrogen donor solvents is used to characterize their reactivity, and the amount of cleavable covalent bonds in their structures are calculated by the amount of active free radicals. This project will reveal two key scientific problems including the relationship between the free radical reaction and coking behavior in the DCL process, and the variation of cleavable covalent bond and reactivity in the process of coke formation, which will provides theoretical support for solving the coking problem in DCL.