水热改性对褐煤下游应用影响的研究进展

Research progress on effect of hydrothermal treatment dewatering of lignite on downstream applications

褐煤已成为我国东北和蒙东地区重要的能源保障,但高含水量、高氧含量及低热值限制了其高效清洁利用,造成了极大的资源浪费。水热改性(HTD)是一种典型的非蒸发式高效脱水脱氧技术且对下游应用具有很好的促进作用,在节能降碳和下游高效清洁利用等方面具有优势,是一种非常有潜力的褐煤提质技术,需要继续了解其研究现状。系统性总结了水热改性对下游褐煤应用(包括热解、浮选、燃烧、水煤浆制备等)的影响机理和技术进展,分析了水热改性对褐煤下游应用的技术优势。水热改性不仅提高了提质煤水煤浆的成浆浓度,而且提升了热解油气资源产率和浮选效率,同时也有利于煤液化长周期的稳定运行。由于褐煤提质产业本身内驱力不足、水热过程连续化设备研发投入力度不够、存在环境污染和市场盈利空间低等问题,导致褐煤水热改性提质在半工业化、工业化方面进步缓慢。褐煤脱水提质在“双碳”目标和新的历史时期下仍有其重要的历史使命,这需要国家给予褐煤提质产业顶层设计,引导科研机构、人员、企业转变“谈褐煤提质色变”的观念,持续投入研发力度,解决设备连续化以及有机废水处理等方面的问题。基于上述观点,提出了以褐煤提质为基础的多联产技术开发的发展方向(如水热提质脱水脱氧+水煤浆制备+水煤浆气化现代煤化工和水热提质脱水脱氧+热解提油+气流床气化现代煤化工等),为我国褐煤清洁高效利用提供参考。

Lignite has become an important energy security in the northeast and eastern Inner Mongolia region of China,but high moisture,high oxygen content and low calorific value limit its efficient and clean utilization.Hydrothermal treatment dewatering(HTD)is a typical non-evaporative dewatering technology prompting the downstream utilization of lignite,which needs to continue summarizing and understanding its research progress.The progress and mecha-nism on the influences of HTD on the downstream application of lignite,such as pyrolysis,flota-tion,combustion and preparation of coal water slurry,were systematically summarized.HTD not only increases the concentration of coal water slurry,and the yield of oil and gas in the process of pyrolysis,but also improves the flotation efficiency,and meanwhile enhances the long-term stable operation of coal liquefaction.However,the application of HTD technology for lig-nite is subject to the problem of the in sufficient of inner motivation,the in sufficient research and development of continuous equipment,environmental pollution and low profit margin in the market,which hinders the technological progress in industrialization and semi-industrialization application.HTD of lignite still has an important historical mission for the“dual carbon”goal in the new historical period.This requires the state to provide top-level design for the lignite upgra-ding industry,guiding research institutions,researchers and enterprises to change their mindset of being afraid to talk about lignite upgrading.At the same time,it needs to continuously invest the research and development on the equipment continuity and organic wastewater treatment.Based on the above viewpoints,the development direction of poly-generation technology based on lignite upgrading is proposed,such as HTD+preparation of coal water slurry+water coal slurry gasification and HTD+pyrolysis+entrained flow gasification,which provides the refer-ence for the clean and efficient utilization of lignite in China.