Effects of moisture, salinity and ethane on the competitive adsorption mechanisms of CH4/CO2 with applications to coalbed reservoirs: A molecular simulation study

Li, Jiawei; Wang, Yuzhu; Chen, Zhixi; Rahman, Sheik S.

doi:10.1016/j.jngse.2021.104151

Cited by 20 publications

(14 citation statements)

References 70 publications

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“…According to the plots, the gas uptake of CO 2 and CH 4 increases with increasing bulk gas pressure and decreases with increasing temperature, which is consistent with previous observations. − At high temperatures, the enhanced kinetic energy of the gas molecules causes them to overcome the attractive interactions between the adsorbate and adsorbent and consequently reduces their stability on the surface of the MOF structure. On the opposite side, increasing the pressure promotes gas adsorption because much stronger interactions between the adsorbent and gas molecules are established through external force at high pressures . In the low-pressure area of isotherms, the adsorption rate is more significant than that in the high-pressure region owing to the availability of many free adsorption sites at the early stage of adsorption .…”

Section: Resultssupporting

confidence: 90%

“…On the opposite side, increasing the pressure promotes gas adsorption because much stronger interactions between the adsorbent and gas molecules are established through external force at high pressures. 111 In the low-pressure area of isotherms, the adsorption rate is more significant than that in the high-pressure region owing to the availability of many free adsorption sites at the early stage of adsorption. 112 In the case of pure gases, greater amounts of CO 2 are adsorbed at low pressures, and with increasing the pressure, the adsorbed amounts of both gases increase.…”

Section: Adsorption Behaviors Of Ch 4 and Co 2 On Mut-11mentioning

confidence: 99%

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Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Parsaei

Akhbari

Kawata

2023

Crystal Growth & Design

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Natural gas purification and biogas recovery require efficient separation of CO2 from CH4, as CH4 is increasingly being recognized as a promising substitute for petroleum due to its environmentally sustainable nature, abundance in natural resources, and economic benefits. In the present work, a 3D Cd-based metal–organic framework, [Cd2(DBrTPA)2(DMF)3] (MUT-11) 2,5-[dibromoterephthalic acid (DBrTPA) and dimethyl formamide (DMF)] was synthesized using a combination of different synthetic methods and fully characterized via several techniques. Additionally, a variety of organic solvents were employed to perform the solvent stability test. The MUT-11 structure was subjected to Grand Canonical Monte Carlo and molecular dynamics simulations to study the adsorption characteristics of CO2 and CH4 gases in both pure and binary states. The results acquired through the simulation-based analysis revealed that the adsorption of CO2 is dominant in all pressure and temperature conditions.

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Section: Resultssupporting

confidence: 90%

Section: Adsorption Behaviors Of Ch 4 and Co 2 On Mut-11mentioning

confidence: 99%

Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Parsaei

Akhbari

Kawata

2023

Crystal Growth & Design

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“…Moreover, the surface area increases gradually with the decrease of particle size class. The surface area of coal particles with a particle size smaller than 0.075 mm is the most significant (Dai et al, 2021;Li et al, 2021). The results show that the adsorption capacity is also related to excessive pore volume, micropore volume, and specific surface area.…”

Section: Figurementioning

confidence: 94%

“…Dai analyzed the molecular dynamics method of methane and carbon dioxide's absorption and diffusion properties at different burial depths and found the competitive adsorption relationship between methane and carbon dioxide (Dai et al, 2021). Li believes that the adsorption mechanism of CH 4 and the competitive adsorption process between CH 4 and CO 2 still need to be explored in the coal seam at the microscope level, especially the water that hinders the adsorption isotherm of CH 4 , and the salinity reduces the adsorption capacity of CH 4 (Li et al, 2021). I proposed that when the injection pressure is not higher than the initial reservoir pressure, the deformation of the coal matrix is mainly desorbed by CH 4 .…”

Section: Introductionmentioning

confidence: 99%

Study on key influencing factors of competitive adsorption of coalbed methane by carbon dioxide displacement

et al. 2022

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The extraction of coal bed methane (CBM) by injecting CO2 into deeply buried unmined coal seams in competition with CH4 adsorption to provide a clean fuel is known as enhanced coal bed methane recovery (ECBM) and has proven to be an effective technological strategy to address global warming. The study of the interaction of coal with CO2 and CH4 under multi-physical field conditions is particularly necessary. In this work, a series of experiments were conducted on a home-made test system to investigate the competing sorption patterns of high and medium ash coal samples subjected to variables such as gas pressure, temperature, nodulation and lateral limit constraints. The results show that there is a sorption isotherm relationship between coal samples and exposure time. The adsorption capacity sorption of CH4/CO2 varied considerably for different ash coal samples. As the CO2 pressure increased from 2.3 to 5.5 MPa, the strain on the coal samples increased from 0.082 to 0.4%. The deformation in the vertical laminae direction is always greater than that in the parallel laminae direction. A correlation coefficient K exists between 1 and 2, and there is an internal expansion pattern in the adsorption deformation of coal. This paper can contribute to the improvement of ECBM efficiency.

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“…Many studies have observed that the adsorption isotherm decreases with temperature and increases with pressure for pure CH 4 and CO 2 . − High temperature provides gas molecules with more energy and promotes intramolecular interactions; therefore, gas molecules could escape from the adsorbent surface, leading to a decreased isotherm. In contrast, high pressure would strengthen the interactions between the adsorbent and the gas molecules, and increasing uptake is obtained with pressure.…”

Section: Introductionmentioning

confidence: 99%

Insights into the Molecular Competitive Adsorption Mechanism of CH₄/CO₂ in a Kerogen Matrix in the Presence of Moisture, Salinity, and Ethane

Wang

Chen

et al. 2021

Langmuir

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Carbon dioxide (CO 2 ) injection in shale and coal seam gas reservoirs has become one of the most popular ways to promote methane (CH 4 ) production. However, geological factors affecting the CO 2 enhanced gas recovery (CO 2 -EGR) projects have not been studied in great depth, including underground moisture, subsurface water salinity, and other gases accompanying CH 4 . Thus, a hybrid methodology of molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulation is employed to reveal the gas adsorption and displacement mechanisms at a fundamental molecular level. This study generates a type II-D kerogen matrix as the adsorbent. The simulation environment includes 0−5 wt % moisture content, 0−6 mol/L NaCl saline, and 0− 5 wt % C 2 H 6 for up to 30 MPa at 308, 338, and 368 K. The impressions of moisture, C 2 H 6 , and salinity on gas adsorption and competitive adsorption characteristics are analyzed and discussed. On the basis of the simulation results, the preloaded H 2 O molecules negatively influence CH 4 adsorption, leading to a 44.9% reduction at 5 wt % moisture content. Additionally, 6 mol/L NaCl within 5 wt % moisture content exhibits a further 9.8% reduction on the basis of the moisture effect. C 2 H 6 presents a more noticeable negative impact, of which 5 wt % results in a 73.2% reduction in CH 4 adsorption. Moreover, the competitive process indicator, preferential selectivity S CO 2 /CH 4 , is analyzed and discussed in the presence of the mentioned factors. Moisture positively influences S CO 2 /CH 4 , salinity promotes S CO 2 /CH 4 , and C 2 H 6 develops S CO 2 /CH 4 . These factors would encourage the displacement processes of CH 4 by CO 2 injection. This study provides essential information for better gas resource estimation and gas recovery improvement in unconventional systems.

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Effects of moisture, salinity and ethane on the competitive adsorption mechanisms of CH4/CO2 with applications to coalbed reservoirs: A molecular simulation study

Cited by 20 publications

References 70 publications

Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Study on key influencing factors of competitive adsorption of coalbed methane by carbon dioxide displacement

Insights into the Molecular Competitive Adsorption Mechanism of CH₄/CO₂ in a Kerogen Matrix in the Presence of Moisture, Salinity, and Ethane

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Effects of moisture, salinity and ethane on the competitive adsorption mechanisms of CH4/CO2 with applications to coalbed reservoirs: A molecular simulation study

Cited by 20 publications

References 70 publications

Computational Simulation of CO2/CH4 Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Computational Simulation of CO2/CH4 Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Study on key influencing factors of competitive adsorption of coalbed methane by carbon dioxide displacement

Insights into the Molecular Competitive Adsorption Mechanism of CH4/CO2 in a Kerogen Matrix in the Presence of Moisture, Salinity, and Ethane

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Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Computational Simulation of CO₂/CH₄ Separation on a Three-Dimensional Cd-Based Metal–Organic Framework

Insights into the Molecular Competitive Adsorption Mechanism of CH₄/CO₂ in a Kerogen Matrix in the Presence of Moisture, Salinity, and Ethane