Resource property and exploitation concepts with green and low-carbon of tar-rich coal as coal-based oil and gas
WANG Shuangming,SHI Qingmin,WANG Shengquan,SHEN Yanjun,SUN Qiang,CAI Yue
黄河中上游是国家大型煤炭基地集中分布区，也是我国富油煤的主要生产区。受我国“缺油、少气、相对富煤”资源禀赋特点的制约，煤炭安全绿色开采，清洁低碳利用已成为保障国家能源安全的重大需求。实现黄河流域富油煤开发与生态环境保护协调发展，对缓解我国油气供应紧张、保障能源战略安全具有重要的科学价值和现实意义。富油煤是集煤油气属性为一体的煤炭资源，其油气潜力、特殊性、关键地质问题亟需研究，绿色低碳化开发技术亟待探索。① 富油煤主要赋存于中低阶煤类中，主要特点是富含较多富氢结构;在隔绝空气加热时，可生成油、气和半焦。半焦主要成分为固定碳，与无烟煤相近;气体的主要成分是CH4，H2，CO等，可以作为燃料气和原料气;油为煤焦油，类似于重质石油，可通过前处理、加氢精制和加氢催化裂化工艺等达到清洁燃料油标准;② 富氢结构是富油煤具有油气资源属性的物质基础，研究富氢结构的岩石学、沉积学特征及变化规律，分析富氢结构物质来源、沉积转化、变质演化、聚集规律及地质驱动机制，是构建富油煤预测模式与评价理论的基础;③ 梯级利用和原位热解是富油煤绿色低炭开发的重要途径。富油煤地面热解-气化一体化、热解-化工-发电一体化技术可以实现清洁高效利用，井下原位热解有望破解清洁低炭利用的难题。其中，矿井式原位热解技术通过井巷工程布置方式，利用井下巷道开展煤层分割、保温封闭，通过煤层原位加热实现井下热解生产油气;钻孔式原位热解技术通过注热孔加热和油气抽采孔回收油气，也可借助人工辅助造缝，实现加热回收油气。将富油煤作为煤基油气资源管理和开发，是新时代煤炭工业高质量发展的重要取向。
The middle reaches of the Yellow River is an important coal rich area and the main production area of tar-rich coal.Restricted by the resource endowment characteristics that is lack of oil,less gas and relatively rich coal,it is a significant requirement for the basic guarantee for domestic energy supply security to utilize coal with the green mining,clean and low-carbon development.Realizing the coordinated development of tar-rich coal exploitation in the Yellow River Basin and eco-environmental protection is great significant to alleviate the shortage of oil and gas supply and ensure the energy strategic security in China.As a kind of coal-based oil and gas resource,the scientific connotation,particularity and key geological problems of tar-rich coal are needed to be further illustration,and the green and low-carbon development technology needs to be studied.① Tar-rich coal is occurrence in low and middle rank of coal,with generate oil,gases and semi-coke by pyrolysis.And the major characteristic is with more hydrogen-rich structure.The main composition of the semi-coke is fixed carbon,which is similar to anthracite;The gases are mainly CH4,H2,CO and hydrocarbon gases,which are considered as fuels and chemical materials;The oil is coal tar that is similar to heavy oil,which can convert to the standard clean fuel through pretreatment,hydrofining and hydrocracking.② The hydrogen-rich structure is the vital basis for tar-rich coal as coal-based oil and gas.The fundamental principle to establish the prediction model and evaluation theory of tar-rich coal is investigating the petrological and sedimentological characteristics and control laws of hydrogen-rich structure,and analyzing the mechanism of the coal-forming origin,deposition and transformation,coalification,accumulation and geological control.③ Cascade utilization and in-situ pyrolysis are important pathways to realize green and low-carbon development of tar-rich coal.The pyrolysis-gasification integration and the pyrolysis-chemical-power on the ground can realize the clean and efficient utilization of the tar-rich coal.The underground in-situ pyrolysis is expected to overcome the problem of clean and low-carbon utilization of tar-rich coal.For instance,underground in-situ pyrolysis technology uses the underground roadway to carry out coal seam segmentation,thermal insulation and sealing,and realize the underground pyrolysis and tar recovery through the in-situ heating of coal seam;The borehole in-situ pyrolysis technology can achieve heating tar recovery by injecting heat from the hot injection hole and collecting tar from the extraction hole.T artificial cracking is needed as an ancillary technique.Exploiting and managing the tar-rich coal as the coal-based oil and gas is an important direction of high quality development of coal industry in a new era.
tar-rich coal;coal-based oil and gas;hydrogen-rich structure;tar yield;low-carbon exploitation