Yang Qinchuan, Guo Mingyi, Guo Wei
College of Construction Engineering, Jilin University, Changchun 130021, China.
National-Local Joint Engineering Laboratory of In-situ Conversion, Drilling and Exploitation Technology for Oil Shale, Jilin University, Changchun 130021, China.
ACS Omega. 2021 Sep 7;6(37):23988-23997. doi: 10.1021/acsomega.1c03098. eCollection 2021 Sep 21.
Low-temperature co-current oxidizing pyrolysis, which can achieve high recovery of hydrocarbons without significant oil loss, has great potential to reduce the huge external energy required for oil shale conversion. However, this promising method is far from being fully understood, especially the unknown competing mechanism of different types of inorganic minerals in promoting or inhibiting hydrocarbon generation. In this study, the raw Huadian oil shale (HD-R), its carbonate-free (HD-C-F), and carbonate-silicate-free (HD-CS-F) samples obtained through acid treatment are used to investigate the effects of associated minerals on the oil shale co-current oxidizing pyrolysis. The results of shale oil yields of HD-R, HD-C-F, and HD-CS-F were 41.53, 22.38, and 33.97%, respectively, indicating that silicates inhibited, while carbonates catalyzed the formation of shale oil during the co-current oxidizing pyrolysis. Meanwhile, silicates increase the alkane content and decrease the alkene content in shale oil via promoting the combination of hydrogen radicals and alkyl radicals. On the contrary, alkali metals and alkaline earth metals in carbonates inhibit the binding activity of hydrogen radicals and alkyl radicals, concurrently enhancing the release of hydrogen-free radicals of alkyl radicals to form more alkenes. The removal of carbonates could enhance the conversion of organic carbon into hydrocarbons, and the silicates will strengthen the conversion process. It is hoped that this experiment can further enrich and perfect the basic theory of oil shale pyrolysis and provide a reliable reference for the pretreatment of oil shale conversion.
低温并流氧化热解能够在不造成显著油损失的情况下实现高烃类回收率，在减少油页岩转化所需的巨大外部能量方面具有巨大潜力。然而，这种有前景的方法远未被完全理解，尤其是不同类型无机矿物在促进或抑制烃生成方面未知的竞争机制。在本研究中，通过酸处理获得的桦甸油页岩原样（HD-R）、无碳酸盐样（HD-C-F）和无碳酸盐-硅酸盐样（HD-CS-F）被用于研究伴生矿物对油页岩并流氧化热解的影响。HD-R、HD-C-F和HD-CS-F的页岩油产率结果分别为41.53%、22.38%和33.97%，表明在并流氧化热解过程中，硅酸盐起到抑制作用，而碳酸盐起到催化页岩油形成的作用。同时，硅酸盐通过促进氢自由基与烷基自由基的结合，增加了页岩油中的烷烃含量并降低了烯烃含量。相反，碳酸盐中的碱金属和碱土金属抑制了氢自由基与烷基自由基的结合活性，同时增强了烷基自由基释放无氢自由基以形成更多烯烃的能力。去除碳酸盐可以提高有机碳向烃类的转化，而硅酸盐会强化这一转化过程。希望该实验能够进一步丰富和完善油页岩热解的基础理论，并为油页岩转化的预处理提供可靠参考。
