煤制乙二醇关键单元技术与低碳集成工艺的研究进展

我国乙二醇对外依存度居高不下，而富煤少油的资源特性使得我国煤制乙二醇技术具有较好的成本与原料优势，发展迅速。本文综述了国内外煤制乙二醇技术的技术现状和发展趋势，重点介绍了煤气化、草酸二甲酯合成和乙二醇合成与精制等关键单元技术的技术特征、工艺流程和技术进展，并分析了相关单元对整个煤制乙二醇系统技术经济性能的影响。针对现有煤制乙二醇技术存在能耗高、质能效率低和CO₂排放大的问题，着重讨论了集成CO₂高效利用的煤与富氢资源联供制乙二醇集成工艺的进展，包括耦合焦炉气、页岩气和绿氢等资源的新工艺等。以焦炉气为例，集成不同重整技术的新工艺使得传统工艺的碳效率和?效率分别提升了23.35%~39.17%和4.25%~10.12%，生产成本降低了8.73%~19.88%，内部收益率提高了3.6%~9.6%。因此，集成富氢资源与CO₂高效利用的煤制乙二醇创新工艺是该行业向高效-经济-清洁可持续发展的重要方向。

Progress in key unit technologies and low-carbon integrated processes of coal to ethylene glycol process

The consistently high dependency on importing ethylene glycol and the resource characteristics of rich coal and less oil of China make coal-to-ethylene glycol technology have better cost and raw material advantages and develop rapidly. The present situation and development trend of coal-to-ethylene glycol technology at home and abroad are summarized, and the technical characteristics, flowsheet and technological progress of key unit technologies such as coal gasification, dimethyl oxalate synthesis and ethylene glycol synthesis and refining units are emphatically introduced. The influence of the relevant units on the technical and economic performance of the whole coal-to-ethylene glycol system is analyzed. Aiming at the problems of high energy consumption, low mass and energy efficiency and large CO₂ emission in the existing technology of coal-to-ethylene glycol, it focuses on the development of the novel process for the production of ethylene glycol from coal and hydrogen-rich resources that integrates the efficient utilization of CO₂, including the novel processes that couple with coke oven gas, shale gas and green hydrogen resources. Taking coke oven gas as an example, compared with the traditional process, the novel processes integrating different reforming technologies can improve carbon efficiency and exergy efficiency by 23.35%—39.17% and 4.25%—10.12%, reduce production cost by 8.73%—19.88%, and increase internal rate of return by 3.6%—9.6%, respectively. Therefore, the coal to ethylene glycol process integrated with the effective utilization of coke oven gas, shale gas and green hydrogen is the promising direction for the efficient, economic, and clean development of this industry.