煤直接液化残渣与低变质烟煤制备气化用水煤浆的基础研究

The liquefaction residue is an important by-product in direct coal liquefaction and its utilization affects the economic efficiency of the whole liquefaction process. Using coal direct liquefaction residue and low rank bituminous to prepare coal water slurry for gasification will lower the hydrogen consumption and the operation cost of liquefaction process. In this work, the effects of the properties of residue, the heavy component, mineral matters and the liquefaction catalyst in residue on the slurryability and fluidity of the residue water slurry are investigated. The low rank bituminous coal is added into liquefaction residue to prepare coal water slurry, and the effects of the structure and properties of the coal on the slurryability of the liquefaction residue are studied. Furthermore, the cokeability of the coal/residue water slurry at high temperature with a flash heating rate is studied. And the method improving the cokeability of the slurry will be explored. At last, the gasification reactivity of the coal/residue water slurry at high temperature is investigated. Meanwhile, the behavior of mineral matters in coal and catalyst in the residue under high temperature gasification and its effects on the slurry gasification reactivity is studied. Through the result of this work, basic data and theoretical direction will be provided for the preparation of the slurry from liquefaction residue and low rank bituminous coal and its gasification utilization.

液化残渣是煤直接液化过程中重要的副产物，其高效利用关系到整个煤直接液化过程的经济性。将煤直接液化残渣与低变质烟煤共制水煤浆后进行气化，可以补充煤直接液化过程中的氢耗，进一步降低操作成本。本项目研究液化残渣制备水渣浆的成浆性，考察液化残渣性质及其中的重质组分、矿物质和催化剂对其成浆性及流变性的影响。将液化残渣与低变质烟煤共制水煤浆，考察低变质烟煤的物理结构与化学组成对液化残渣成浆性和气化特性的影响；并针对水煤/渣浆在高温下快速加热下的结焦可能性，探讨改善和缓解的方法。最后在研究水煤/渣浆在高温下的气化反应性的同时，考察液化残渣中矿物质及催化剂在高温气化条件下的熔融特性及对气化反应性的影响。通过本项目的研究可以为煤直接液化残渣和低变质烟煤制备水煤/渣浆及其气化利用提供基础数据和理论指导。

本项目针对直接液化工艺副产的大量液化残渣的高效气化利用，提出低阶煤与液化残渣共制水煤渣浆后气化制氢方案，以弥补直接液化过程的氢耗，提高过程的经济性。深入研究了液化残渣单独成浆的优化条件及相关机制，获得了影响液化残渣和低阶煤成浆性的关键因素；揭示了液化残渣中矿物质对其成浆特性的影响机制；同时为充分利用液化残渣中的重质组分，研究了低温热解回收重质组分后的残渣焦的成浆特性，为液化残渣的高值化利用提供了思路；以上工作为制备高浓度且具有良好流体性质的气化用水渣浆提供了理论支撑。基于液化残渣产量不足及重质组分含量高粘结性强的特点，研究了低阶煤与液化残渣共制气化用水煤浆特性及两者在共热解过程中的相互作用，获得了两者共制浆过程中的匹配机制及在共热解过程中的协同效应。另外，针对液化残渣灰中铁含量较高的特点，深入研究了液化残渣灰在高温气化条件下的演化规律及铁价态的分布及调控，获得了液化残渣气化过程中的灰化学特性，为其大规模气化利用提供了理论指导。