Energy & Environment
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2022
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IF 3.154
Fei Liu,Weiguang Shi,Tianbao Liu,Wei Li,Liang Sun,Xiangbin Liu,Changming Zhao,Benxian Li,Sunhua Deng,Zhaohui Dong,Chengwu Xu,Xiaofei Fu,Xiuling Yan
Oil shale kerogen is a kind of composite nature of fossil energy polymer. Kerogen pyrolysis is a feasible and alternative strategy to produce fossil fuels from shales. However, the disadvantages including the high energy consumption, the high cost, and the low hydrocarbon conversion, significantly hinder the development and utilization of unconventional hydrocarbon resources. Herein, the hexagonal crystal structural layered double hydroxides (LDHs) with the Ni/Fe ratio of 5.64:2.36 is proposed as pyrolysis catalyst to improve the catalytic efficiency, the selectivity of target hydrocarbons, and lower the temperature for the process of kerogen pyrolysis. As a result, needle-like nanoscale NiFe-LDHs are prepared successfully to perform the fast thermal upgrading of Balikun oil shale kerogen. The catalytic pyrolysis performance has been observed that the temperature for maximum conversion (Tmax) is 401.18 °C, presenting a Tmax reduction of 37.84 °C, the yield of shale oil is increased by 7.83 wt%. And during 350°C– 400°C, a progressive increment of 147.67%, 230.86%, and 310.61% is obtained corresponding to the content of C1-C5, C6-C14, and C14 + hydrocarbons, respectively. This finding enriches the catalyst candidates for kerogen pyrolysis and provides new insights into industrial applications of in-situ pyrolysis technology for oil shale recovery processes.
研究领域:
能源化学
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石油工程
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材料科学
✓ 已验证
DOI
高影响因子
Carbon Resources Conversion
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2019
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IF 0
Qian Wang,Yucui Hou,Weize Wu,Yupeng Wang,Qing Liu,Shuhang Ren
The structural characteristics of oil shale are important to its application. In this work, a deep insight into the structural characteristics of Yilan oil shale kerogen (YLK) was studied using alkali-oxygen oxidation at different times and ruthenium ion catalyzed oxidation (RICO). The results indicate that YLK is gradually converted to humic acids (HAs), water-soluble acids (WSAs), carboxylic acids (CAs), CO 2 and H 2 O. 13 C NMR analyses of YLK, residues and HAs indicate that C–O bonds, especially C ar –O bonds of YLK, are easily cleaved. The condensed aromatic rings and long alkyl chains are difficult to be oxidized during the oxidation process. With increasing oxidation time, the molar fraction of aromatic bridgehead carbon ( X b ) of YLK and the residues increases from 0.174 to 0.201, and that of HAs increases from 0.225 to 0.267. The result indicates that the aromatic structures of YLK are composed of 1-ring aromatic clusters (26.5%), 2-ring aromatic clusters (67.1%) and 3 or more-ring aromatic clusters (6.4%). Also, the average methylene chain ( C n ) of YLK and the residues increases from 2.0 to 5.1, and that of HAs increases from 1.3 to 2.7, indicating that the alkyl chain length is not average but has a distribution. 2.5% methylene carbons exist as long n -alkyl chains in the alkyl side chains groups (SCGs) on the aromatic rings in YLK. The carbon number of SCGs ranges from 5 to 22, and C 15 and C 17 are predominant. 3.8% methylene carbons exist as alkyl bridges linkages (BLs) connecting aromatic rings in YLK. The carbon number of BLs connecting aromatic rings ranges from 6 to 19, and C 8 is predominant. Because of the existence of above long n -alkyl chains, 93.7% methylene carbons in YLK exist as alkyl chains with an average length of 1.84.
研究领域:
地质学
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化学
✓ 已验证
产品关联
DOI
Frontiers in Earth Science
·
2022
·
IF 3.661
Huang Xiaowei,Jin Zhijun,Liu Quanyou,Meng Qingqiang,Zhu Dongya,Wang Lu,Liu Jiayi,Zhang Panpan,Wang Jingbin
There is increasingly valued attention on whether the matter and energy carried in the deep fluids can significantly change the hydrocarbon (HC) generation of low-mature source rocks. Previous studies suggest that the upward movement of deep fluids to sedimentary basins will change the HC generation evolution mode of low-mature source rocks, and the matter and energy carried by the fluid will transform the evolution process as transient events. However, there is a lack of quantitative evaluation of the specific changes of gaseous HC generation in the process of modification. In this study, the effect of deep fluids on HC generation and evolution of low maturity source rocks were quantitatively studied through simulation experiments of the gold tube closed system. We quantitatively selected hydrogen and catalysts (ZnCl2 and MoS2) to conduct catalytic hydrogenation of kerogen and explore the quantitative effects of deep fluids on HC generation in low-mature source rocks. Through the experimental results, it is found that catalytic hydrogenation has significant changes in a HC generation transformation of organic matter (OM). With the increase of catalytic hydrogenation reaction intensity, the maximum gaseous HC generation yield is 3.16–3.24 times that of the control groups without hydrogenation. In the relatively low-temperature stage (<400°C), the competitive hydrogenation effect occurs and the drying coefficient is high. After the high-temperature stage, a large amount of hydrogen participates in the reaction, which significantly promotes the increase of gaseous HCs and decreases the drying coefficient. ZnCl2 or MoS2 can change the relative content ratio of isomerism and isomorphism of butane and pentane, suggesting that cationic catalysis plays a greater role. In the reaction process, OM plays the most important role in the contribution to HC generation, exogenous hydrogen is more likely to participate in HC generation reaction than water and has the potential contribution to HC generation in Fischer-Tropsch synthesis (FFT) under catalytic conditions. The results of this study effectively verify that exogenous hydrogen and metal elements in deep fluids significantly modify the thermal evolution of low-mature source rocks, and enhance the HC generation potential in the high-temperature stage.
研究领域:
地质化学
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能源地质学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2025
·
IF 6.9
Tianbao Liu,Weiguang Shi,Wei Li,Benxian Li,Xiaofei Fu,Zhiyong Chang,Sunhua Deng
Low to medium maturity shale oil, an essential energy source, faces challenges due to traditional pyrolysis methods, which are characterized by high energy consumption, low yield, and poor selectivity. Moreover, the inefficiencies in in-situ heat injection underscore the necessity for effective catalysts and improved heat transfer mechanisms involving water vapor. This study aims to elucidate the heat transfer enhancement and catalytic synergy of NiFe-layered double hydroxides (NiFe-LDH) in improving the in-situ pyrolysis efficiency of medium–low maturity oil shale via steam pyrolysis. Analyses conducted using GC–MS, Raman spectroscopy, and 13 C NMR demonstrated that the incorporation of NiFe-LDH with water vapor significantly enhances kerogen pyrolysis. This process increases the yields of alcohols, alkanes, and olefins by 1.32, 1.21, and 1.81 times, respectively, and it reduces the temperature needed to produce oil from kerogen. The catalyst helps turn aromatics into alcohols, olefins, and alkanes while breaking down residues into short-chain alkanes. It does this by weakening C–H bonds and removing hydrogen from methyl groups, ultimately reducing the energy required for heat injection by 38.17 %. Thermal and kinetic studies reveal that NiFe-LDH increases kerogen thermal diffusivity by 75.5 % and decreases specific heat capacity by 28.1 %, while elucidating the kinetic mechanism for a 59 °C elevation in the initial temperature of the main pyrolysis stage (increasing 6.1 times prefactor). A nucleation-reaction-order-geometric contraction multi-mechanism coupling model is established. This work proposes a novel “catalyst-water vapor pyrolysis-kerogen oxidation” synergistic enhancement theory, refining the multi-scale coupling mechanisms of heat/mass/chemical reactions during in-situ oil shale pyrolysis.
研究领域:
能源工程
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化学工程
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石油地质学
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材料科学
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催化
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热分析
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF COAL GEOLOGY
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2022
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IF 6.3
Yanan Yang,Ningning Zhong,Jia Wu,Yueyang Pan
Under hot, deep-basin conditions, hydrogen-to-carbon ratios of residual kerogen are low. Whether ubiquitous water in sedimentary environments contributes hydrogen directly to hydrocarbon gas formation through organic-inorganic interactions is, therefore, critical for natural gas generation. Accordingly, we conducted laboratory experiments on immature to overmature kerogens at 300–600°C and 700 bar to examine the chemical interactions between kerogens and fluid under varying redox states and hydrothermal conditions. Mineral buffers, comprised of magnetite-hematite, nickel‑nickel oxide, cobalt‑cobalt oxide, and molybdenum‑molybdenum trioxide, were added to the experiments to control the redox state of the fluid from geologically reasonable to generally excessive values. The kerogens and mineral buffers were spatially isolated using double-capsule techniques to prevent contact catalysis. Our results indicated that chemical interactions between kerogens and water depended strongly on the kerogen thermal maturity and fluid redox state. The chemical interactions of overmature kerogens with reducing water were stronger than those of immature kerogens, which could be ascribed to the weaker competitive transfer of hydrogen from organics to organics than from water to organics. Unexpectedly high amounts of hydrocarbon gas were generated by incorporating water-derived hydrogen in the pyrolysis of overmature kerogens, and the yields increased under low to high reducing fluid conditions for a given temperature. Along with the increasing thermal maturity, residual kerogen eventually became ineffective for hydrocarbon gas generation through reduction reactions. Demethylation, bridge bond cleavage reaction, aromatic structure ring opening reactions in residual kerogen and subsequent redox reaction of intermediate products with reducing fluids is evidenced as the possible reaction mechanisms. The produced hydrocarbon gas under f H 2 level of oilfield water is characterized by high dryness (99 mol%) and more-enriched 13 C in CH 4 compared with precursors. Natural gas deep within the Sichuan and Appalachian basins with similar characteristics suggests that our simulated organic–inorganic interactions could occur widely under natural conditions. Consequently, a potentially prolific source of natural gas may be formed by the overmature source rocks in the deep basin and fluid redox should be considered for gas potential evaluation of overmature source rocks.
研究领域:
地质学
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地球化学
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石油工程
·
实验岩石学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）