State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University

The control of carbon emissions has already become a great social strategic problem in China which must besolved at present and in the future. It is imperative to carry out safe, efficient, and low-carbon utilizations in the coal industryunder the target of achieving carbon emission peak. Tar-rich coal is abundant in western China. It is mostly combustedfor power generation, which results in the wastage of valuable resources and serious environmental pollution. Thein-situ pyrolysis process of tar-rich coal provides a new method for generating oil from coal. This method is to produce oilwithout mining coal while alleviating damage and pollution to geological formations. Compared with traditional coal miningmethods, it can reduce the size of goaf section and minimize the damage to rock structure. As a new coal-to-oil route,the in-situ pyrolysis of oil-rich coal is still at an initial stage for research, for which there are still few carbon emission evaluations from the perspective of the full life cycle analysis. Based on the carbon emission accounting method widelyadopted, the life cycle analysis (LCA) is employed to analyze the carbon dioxide emission in the whole process of an insitutar-rich coal pyrolysis project, including coal seam modification, in-situ heating, product processing, product transportationand terminal consumption. A lateral comparison of greenhouse gas inventory with indirect coal liquefaction anddirect coal liquefaction is also carried out. At the same time, the greenhouse gas emission from the in-situ pyrolysis of tarrichcoal is analyzed systematically. The results show that it is necessary to adopt low-carbon energy in the development ofin-situ pyrolysis of oil-rich coal. With power grid as the energy source, the LCA carbon emission of in-situ pyrolysis isabout 2.234 5 t CO2 for each tonne of coal treated, while with wind power as the energy source, merely 0.608 6 t CO2. Thein-situ pyrolysis of tar-rich coal has an obvious advantage in carbon emission reduction over indirect or direct coal liquefactionprocess. To reduce carbon emissions effectively, several mitigation measures need to be combined, including promotingenergy efficiency, optimizing heat sources, and increasing the proportion of clean energy.

华能集团总部科技课题能源安全技术专题资助项目(HNKJ20-H87)

薛香玉，王长安，邓磊，等. 基于全生命周期的富油煤原位热解碳排放[J]. 煤炭学报，2023，48(4)：1773−1781

XUE Xiangyu，WANG Chang’an，DENG Lei，et al. Carbon emissions from in-situ pyrolysis of tar-rich coal based on full life cycle analysis method[J]. Journal of China Coal Society，2023，48(4)：1773−1781