Article
Engineering, Environmental
Xinran Yu, Jing Li, Zhangxin Chen, Keliu Wu, Linyang Zhang, Sheng Yang, Gang Hui, Min Yang
Summary: Gas adsorption in kerogen can induce swelling, and a theoretical model is proposed to calculate excess adsorption isotherms coupling swelling. Results show stronger affinities of C2H6 and CO2 than CH4, but larger C2H6 size leads to smaller maximum adsorption amounts. A linear relationship between volumetric strain and adsorption amount is found for CH4, C2H6, and CO2 separately.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Energy & Fuels
Clement Afagwu, Saad Al-Afnan, Shirish Patil, Jaber Aljaberi, Mohamed A. Mahmoud, Jun Li
Summary: Diffusion tortuosity is an important parameter for calculating effective gas transport coefficients in porous media. This study used molecular simulation to build a realistic kerogen structure and investigate the impact of adsorption on diffusion tortuosity in organic shale materials. The results showed that methane molecules follow tortuous pathways in kerogen, and the adsorption effect further increases the tortuosity.
Article
Energy & Fuels
Yufan Zhang, Dexiang Li, Gongming Xin, Shaoran Ren
Summary: By using the CuO-CeO2 catalyst, the CO-selective catalytic reduction reaction can convert NO and CO into exhaust gas, CO2, and N-2. The displacement efficiency of CO2 + N-2 is higher than that of CO + NO, suggesting potential application in enhancing shale gas recovery. The scheme provides a feasible guide to NO x treatment and the utilization of exhaust gas from FCC units.
Article
Biochemistry & Molecular Biology
Arshad Raza, Mohamed Mahmoud, Saad Alafnan, Muhammad Arif, Guenther Glatz
Summary: We conducted molecular dynamics simulation to investigate the adsorption behavior of hydrogen, carbon dioxide, and methane on type II kerogens with varying thermal maturities. The adsorption capacity was found to be positively correlated with pressure and negatively correlated with temperature. The adsorption capacity depended on specific functional groups and effective pore volume, which in turn related to the maturity and carbon content of the kerogen.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Energy & Fuels
Jian Wu, Pengyu Huang, Federico Maggi, Luming Shen
Summary: This study investigates the effect of kerogen deformation on methane transport through simulation, and finds that sorption-induced swelling significantly reduces methane mass flux. Additionally, the study also shows that the influence of diffusion and viscous flow changes with different pressures.
Article
Chemistry, Multidisciplinary
Xiaoyu Zhang, Jian Cheng, Tianhe Kang, Xianxian Zhou, Liankun Zhang
Summary: The study found that the wettability of the coal surface changed after electrochemical modification, leading to changes in methane adsorption/desorption and water movement in coal reservoirs. The results showed that electrochemical modification reduced the saturated adsorption amount of CH4 and decreased the coal-water contact angle, mainly affecting coal wettability by altering functional groups and pore structures.
Review
Energy & Fuels
Hongwei Zhang, Do Yoon Moh, Xin Wang, Rui Qiao
Summary: This paper reviews the use of molecular dynamics simulations to study shale gas recovery at the nanoscale. The design and simulation protocols of the systems used to study gas recovery are discussed, followed by a review of gas recovery in scenarios involving single-component gas, multicomponent gas, and multiphase flows. Emphasis is placed on works exploring and elucidating new pore-scale phenomena, as well as guiding and validating new pore-scale continuum models.
Article
Energy & Fuels
Junsheng Fei, Min Wang, Jinbu Li, Chen Zhao, Xin Wang, Lianbin Zhang, Changqi Yu, Ying Li, Shangde Dong
Summary: Based on molecular dynamics (MD) simulation, the adsorption and absorption of shale oil in a type II kerogen slit were calculated, and the influences of temperature, pressure, and pore diameter on the occurrence of shale oil were discussed. The results showed that temperature had opposite effects on the distribution of shale oil in adsorption and absorption, while pressure and pore diameter had minimal influence. Under aqueous conditions, the absorption of shale oil was blocked once water clusters formed. The evolution of the ratio of free-adsorbed-absorbed oil at different temperatures and pressures was also established, providing a new method for detecting the occurrence and mobility evaluation of shale oil under reservoir conditions.
Article
Energy & Fuels
Saad Alafnan
Summary: This study investigates the adsorption-desorption hysteresis of methane in shale through molecular simulation and reveals that adsorption causes structural changes and swelling in the organic matter, which may serve as a potential mechanism for hysteresis. The observed hysteresis leads to 10-30% uncertainty in the interpretation of recoverable adsorbed gas.
Article
Energy & Fuels
Wei Li, Lee A. Stevens, Clement N. Uguna, Christopher H. Vane, Will Meredith, Ling Tang, Qianwen Li, Colin E. Snape
Summary: Moisture in shales can negatively impact gas adsorption and pore structure under reservoir conditions, affecting methane adsorption capacity. The presence of water reduces the micropores volume, blocks micropore necks, and results in reduced accessible pores for gas transport, leading to significant decreases in surface area and pore volume. Failure to consider moisture levels can lead to overestimation of the total gas in place for shale formations.
INTERNATIONAL JOURNAL OF COAL GEOLOGY
(2021)
Article
Energy & Fuels
Wenning Zhou, Jiadan Zhu, Haobo Wang, Debin Kong
Summary: This study investigates the transport diffusion mechanisms and behaviors of a CO2/CH4 mixture in shale nanopores using simulation methods. The results show different diffusion mechanisms for gas molecules near the surface and middle area of the nanopores. The adsorption and diffusion characteristics of CO2/CH4 are influenced by temperature, pressure, and pore size. Surface diffusion of CH4 is weakened in the presence of CO2, and larger pore size leads to stronger diffusion of CH4 over CO2.
Article
Chemistry, Physical
Shan Yuan, Hong-Ze Gang, Yi-Fan Liu, Lei Zhou, Muhammad Irfan, Shi-Zhong Yang, Bo-Zhong Mu
Summary: In this study, simulations were conducted to investigate the behavior of CO2 and CH4 adsorption and diffusion on kerogen models with different maturity. It was found that CO2 has a higher adsorption capacity compared to CH4, and this capacity increases with maturity. Furthermore, the addition of water reduces the adsorption and diffusion coefficients of both gases but increases the selectivity of CO2 over CH4. These findings suggest that injecting CO2 into shale gas and oil formations can enhance energy recovery.
MOLECULAR SIMULATION
(2023)
Article
Energy & Fuels
Liang Huang, Zhengfu Ning, Hao Lin, Wen Zhou, Lu Wang, Jie Zou, Hao Xu
Summary: High-pressure sorption isotherms were measured on shales from Sichuan Basin, China for CH4, C2H6, and their mixtures using a volumetric method. The temperature had a more notable effect on the binary excess sorption isotherms compared to gas composition. C2H6 showed stronger affinity than CH4, with its effect more significant at high pressures and less significant at low pressures.
Article
Chemistry, Multidisciplinary
Elshad Aslanov, Saad Alafnan, Mohamed Mahmoud, Abdulazeez Abdulraheem
Summary: This study investigates the mechanical behavior of kerogen and its influencing factors by forming kerogen structures using three-dimensional macromolecules. The results show that kerogen exhibits elastomer-like mechanical behavior regardless of the maturity level, and its behavior is sensitive to the type of fluid contained within the structure.
Article
Energy & Fuels
Zhongqi Mu, Zhengfu Ning, Fangtao Lyu, Bei Liu
Summary: This study investigates the adsorption behavior of deep shale gas in pores using molecular modeling techniques and simulation methods. The results show that shale gas is adsorbed as strong monolayers in pores, and the Langmuir equation is applicable for adsorption over a wide range of pressures. The interactions between gas and different types of pores vary.