Abstract: To understand the nature of DCL process and identify challenges in chemical engineering，this paper analyzes DCL technology in a view of rates balance between generation of free radical fragments through pyrolysis of coal structure and hydrogenation of the free radical fragments to products. The rate balance of these two fundamental reaction steps governs the performance of key equipments，such as the slurry preheater，the liquefaction reactor，as well as the high temperature separator.

摘要： 从对煤直接液化的化学本质的分析入手，讨论了煤直接液化技术发展的化学脉络及所面临的化学工程挑战。作者认为，煤直接液化技术的化学本质是煤大分子结构在热场中裂解产生自由基碎片的速率和自由基碎片加氢的速率的匹配，这两个速率的差异决定了煤浆预热、煤液化反应，甚至高温条件下产物分离等过程的特征，决定了油收率、系统中物料结焦、物料输送等行为。