Wang Lijuan, Lu Yingxin, Chen Guojun, Xue Lianhua, Zhang Zhongning, Wang Shuan, Gao Jian
Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Key Laboratory of Petroleum Resources, Gansu Province, Lanzhou 730000, China.
ACS Omega. 2024 Apr 2;9(15):17491-17505. doi: 10.1021/acsomega.4c00435. eCollection 2024 Apr 16.
Geological bodies are important sources of greenhouse gas (GHG) emissions. Organic-rich oil shale in sedimentary basins is a good gas source rock, the GHG in which will be released into the atmosphere during crushing to affect climate change. Quantitative calculations of GHG emissions during oil shale crushing were carried out on oil shales from the Yaojie (YJ) and Fushun (FS) mining areas in China. Organic geochemistry, X-ray diffraction, and pore structure analysis experiments, as well as the relationship between storage time and GHG emissions, were analyzed to investigate the main controlling factors of GHG release in different types of oil shales. The results showed that the CH and CO released from the YJ oil shale were 0.002-0.145 mL/g and 0.011-0.054 mL/g, respectively; the CH and CO released from the FS oil shale were 0.0001-0.0008 mL/g and 0.002-0.045 mL/g, respectively. Residual CH release was closely related to total organic carbon (TOC) and maturity: the CH released from the organic-rich and mature YJ oil shale was much higher than that of the FS oil shale, which is relatively organic-lean and immature. The control factors of the released CO vary in different regions: CO released from the YJ oil shale was somewhat affected by the TOC, while that released from the FS oil shale was mainly controlled by carbonate minerals and their contributing pores. The results of pore structure and organic maceral analyses indicated that both organic and inorganic pores of the YJ oil shale are occupied by asphaltenes, forming a key gas preservation mechanism of residual CH and CO as solutes dissolved in asphaltenes. In addition, CO has a greater absorptive capacity than CH and is therefore more difficult to release during the same crushing time. As oil shale is stored for longer periods, residual CH will be preferentially released to the atmosphere, while residual CO will be released in large quantities during crushing.
地质体是温室气体（GHG）排放的重要来源。沉积盆地中富含有机质的油页岩是一种良好的气源岩，其所含的温室气体在破碎过程中会释放到大气中，从而影响气候变化。对中国窑街（YJ）和抚顺（FS）矿区的油页岩进行了油页岩破碎过程中温室气体排放的定量计算。通过有机地球化学、X射线衍射和孔隙结构分析实验，以及储存时间与温室气体排放之间的关系分析，研究了不同类型油页岩中温室气体释放的主要控制因素。结果表明，YJ油页岩释放的CH和CO分别为0.002 - 0.145 mL/g和0.011 - 0.054 mL/g；FS油页岩释放的CH和CO分别为0.0001 - 0.0008 mL/g和0.002 - 0.045 mL/g。残余CH的释放与总有机碳（TOC）和成熟度密切相关：富含有机质且成熟的YJ油页岩释放的CH远高于相对贫有机质且不成熟的FS油页岩。不同地区释放CO的控制因素各不相同：YJ油页岩释放的CO在一定程度上受TOC影响，而FS油页岩释放的CO主要受碳酸盐矿物及其贡献孔隙的控制。孔隙结构和有机显微组分分析结果表明，YJ油页岩的有机孔和无机孔均被沥青质占据，形成了残余CH和CO作为溶解在沥青质中的溶质的关键气体保存机制。此外，CO的吸附能力比CH更强，因此在相同的破碎时间内更难释放。随着油页岩储存时间的延长，残余CH将优先释放到大气中，而残余CO将在破碎过程中大量释放。
