碳中和约束下的煤化工产业展望

“多煤少油贫气”的能源资源禀赋,决定了煤炭在我国能源结构中的压舱石和兜底保障作用。二氧化碳的双重性、能源低碳化利用特征和未来低碳电气化时代的煤炭定位,又决定了大力发展煤化工产业的必要性,煤化工产业是推动煤炭清洁高效低碳能源化、高值原料化利用最有潜力的发展途径。我国现代煤化工产业在相关技术和装备取得长足进步的同时,也存在发展战略定位不清晰、理论基础薄弱、关键核心技术内在不足与缺失、终端产品低值化和同质化、碳排放以及水资源供需矛盾等问题。作为煤炭清洁高效低碳高值化利用的有效途径,碳中和约束下的煤化工产业应对现有存续和未来新建煤化工项目分类施策。现有存续煤基发电和煤化工企业要通过技术改造和升级转型,最大化盘活现有煤化工资产,充分利用现有资源,实现低碳化高质量发展。新增煤化工项目应依据煤炭特性和碳排放“双控”要求,坚持燃料和原料并重,合理遴选最适宜的技术,优势特色产业要坚持绿色低碳高值化可持续发展。按照煤化工产业二氧化碳排放特性,积极研发和推广应用二氧化碳高效原料化和工质化利用技术,从末端破解煤化工产业碳排放难题。最终达到煤炭资源最大化利用、低成本合理有效实施绿色碳减排。

基于化学族组成的煤化学研究体系构建及其应用

针对170多年来按照物理相似性、以显微组分为基础的传统煤化学研究方法普适性差和近70 a来借助现代分析仪器和量子化学计算得到的煤大分子结构模型无法解析煤结构和反应性的关联性的核心科学问题,提出表征可溶化程度的相对抽提率概念,构建了基于环己酮和CS_(2)-NMP复合溶剂分步抽提煤的普适性可溶化体系,按照化学相似性将煤中有机物分为饱和分、芳香分,胶质、沥青质、碳青质和焦质6个化学族组分,开展不同变质程度煤化学族组分的物理化学结构、组成及其不同热解条件下的热解行为、热解特性、反应机理与动力学研究;提出煤热解反应主体由热离解的自由基主导的新观点,构建了普适性的煤热解自由基调控机理及其强化机制,并按照煤化学族组分的基元反应产生初始自由基、自由基调控和自由基复合3个阶段的反应机理合理有效地解析了煤等离子热解制乙炔过程反应历程与机理以及产物中乙炔选择性高达80%以上的现象、低阶煤快速热解提质实现焦油收率最大化的适宜条件等工业现象,从而形成了基于化学族组成的现代煤化学研究方法,实现了从分子水平识别、表征和描述煤的组成和物理与化学结构参数、煤中各种化学键和有害组分的存在形态,进而利用煤的化学族组成从分子水平研究煤转化过程的反应历程、反应机理和反应动力学,揭示各种煤在反应性方面的相似之处,提高煤转化过程效率、降低污染排放,为煤炭资源的高效清洁转化与利用提供借鉴。

Effect of Structural Parameters on the Performance of NS High-efficiency Composite TraysⅠ.The Effect of Aperture and Opening Ratio on NS High-efficiency Composite Trays

In this paper,the structure and characteristics of the NS high-efficiency composite trays based on the doublelayer aperture jet sieve plate and compositely structured packing were investigated.The effect of aperture and opening ratio of plate on the fluid dynamics of the NS high-efficiency composite trays,such as the dry tray pressure drop,the wet tray pressure drop,the entrainment,the froth height,the leakage and mass transfer characteristics,were investigated.As a result, the low pressure drop,the high efficiency and the high capacity are the main advantages of the NS high-efficiency composite trays compared to other types of trays.According to this study,small aperture is useful for reducing the pressure drop and entrainment with a high mass transfer efficiency;while large aperture can achieve high capacity and efficiency in a broader operating range at the same pressure drop and entrainment.

Status and Suggestion for Modern Coal Chemical Industry and Coal Clean Technology

Coal is fossil fuel abundant and widespread all over the world. It is a vital resource for energy security in our country, because the supply is stable. In this paper, the important role of coal played in the total primary energy supply was described, and the status of modern coal chemical industry and clean coal technologies was analyzed. Based on the scientific research experiences of author, strategy and suggestion for Chinese development were proposed according to the regulation of scientific panning. In China, there are more social benefits and strategic meaning for developing the coal high-efficiency utilization technology. Considering of the general situation of our countries, these technologies with the features of can be industrialized, advanced, applicative, mature and feasible should be developed preferentially. The high-expend, low economic effectiveness and behindhand technologies should be abandoned. So, the development of coal clean technology in China should meet the natural resources, restrictive condition and elements of our countries industry situations. Based on these analysis, the most important technologies and fundamental researches should be prior developed in China.

“十四五”期间现代煤化工发展的几点思考

经过多年发展,我国现代煤化工产业已经取得长足进步。一是总体规模在全球前列。截至2019年,我国煤制油产能921万t/a,煤制烯烃产能1 362万t/a,煤制乙二醇产能为478万t/a,煤制气产能为51.05亿m^3/a。二是示范或生产装置运行水平不断提高。采用具有国内自主知识产权技术建成的400万t/a煤间接液化示范项目、百万吨级煤直接液化示范项目和数十套50万~60万t/a煤制烯烃(MTO)项目实现了安全稳定长周期运行,物耗、能耗、水耗和"三废"排放量不断降低,产品差异化水平有所提升。