scholarly journals Pore system and gas adsorption potential of lacustrine Yanchang Mudstone, Ordos Basin, China

2022 ◽  
Vol 8 ◽  
pp. 571-581
Author(s):  
Shutong Li ◽  
Yang Wang ◽  
Ximeng Wang ◽  
Ruiliang Guo
Keyword(s):  
Gas Adsorption ◽  
Ordos Basin ◽  
Adsorption Potential ◽  
Pore System

scholarly journals Roles of adsorption potential and surface free energy on pure CH4 and CO2 adsorption under different temperatures

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 747-755
Author(s):  
Tong-Qiang Xia ◽  
Jing-Yu Meng ◽  
You-Pai Wang ◽  
Jian-Hong Kang ◽  
Hong-Yun Ren
Keyword(s):  
Free Energy ◽  
Adsorption Capacity ◽  
Surface Free Energy ◽  
Gas Adsorption ◽  
Reduction Rate ◽  
Adsorption Potential ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Static Volumetric Method ◽  
C 50

To fill the knowledge of adsorption characteristics of CH4 and CO2 associated with equilibrium and thermodynamics, adsorption equilibrium tests of pure gas on a coal were conducted under the different temperatures (35 ?C, 50 ?C, and 65?C by the static volumetric method. The equilibrium data were well matched by the SLD-PR model. The influence of some significant factors including temperature, pressure, adsorption potential and surface free energy on gas adsorption capacity were discussed. The results showed that the higher temperature (gas pressure) corresponds to the smaller (larger) adsorption capacity and the larger adsorption potential is, the smaller adsorption capacity is. Taking CH4 as adsorbent, the modified Langmuir equation can well match the SLD-PR model. However, when the adsorption medium is CO2, modified Freundlich equation is better. Using the two modified equations, we study further the relationship among the variation of surface free energy, its reduction rate and gas adsorption capacity. It can be concluded the larger the gas adsorption capacity is, the greater the reduction of surface free energy is, and the smaller the reduction rate of surface free energy is.

scholarly journals Application of adsorption potential theory in prediction of CO2 and CH4 adsorption on carbon molecular sieves

2018 ◽  
Vol 36 (9-10) ◽  
pp. 1669-1686
Author(s):  
Xue Song ◽  
Li’ao Wang ◽  
Yifu Li ◽  
Yunmin Zeng ◽  
Xinyuan Zhan ◽  
...  
Keyword(s):  
Potential Theory ◽  
Molecular Sieves ◽  
Gas Adsorption ◽  
Characteristic Curve ◽  
Empirical Method ◽  
Adsorption Potential ◽  
Adsorption Characteristic ◽  
Carbon Molecular Sieves ◽  
Adsorbed Phase ◽  
Adsorption Potential Theory

The adsorption of CO2 and CH4 on carbon molecular sieves was studied based on the adsorption potential theory, which is widely used in gas adsorption on microporous adsorbents. The methods to obtain the adsorption density in the adsorbed phase, including Ozawa’s method and the empirical method, and the methods to calculate the virtual saturation vapor pressure, including Dubinin’s method and Amankwah’s method, were discussed. A functional exponential form proposed in this study could describe the adsorption characteristic curve better than the cubic polynomial and logarithmic function used in the previous literature. A new model, which expresses the correlation of adsorbed amount, temperature, and pressure, was proposed and verified experimentally. The model provides a reliable way to predict the adsorption isotherms of CO2 and CH4 on carbon molecular sieves at different temperatures according to the data measured at a certain temperature and to select a proper kind of carbon molecular sieve in CO2/CH4 separation.

Nanopore Surfaces Control the Shale Gas Adsorption via Roughness and Layer-Accumulated Adsorption Potential: A Molecular Dynamics Study

2021 ◽  
Vol 35 (6) ◽  
pp. 4893-4900
Author(s):  
Kai Gao ◽  
Guang-Jun Guo ◽  
Mingmin Zhang ◽  
Zhengcai Zhang ◽  
Bo Peng
Keyword(s):  
Molecular Dynamics ◽  
Shale Gas ◽  
Gas Adsorption ◽  
Adsorption Potential

scholarly journals Investigation into the Pore Structure and Multifractal Characteristics of Shale Reservoirs through N2 Adsorption: An Application in the Triassic Yanchang Formation, Ordos Basin, China

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Zhikai Liang ◽  
Zhenxue Jiang ◽  
Zhuo Li ◽  
Fenglin Gao ◽  
Xiaoqing Liu
Keyword(s):  
Organic Matter ◽  
Pore Structure ◽  
Mineral Content ◽  
Gas Adsorption ◽  
Ordos Basin ◽  
Total Pore Volume ◽  
Silty Mudstone ◽  
Nitrogen Gas ◽  
Rock Composition ◽  
Yanchang Formation

To understand the pore structure and heterogeneity of pore size distribution (PSD) is essential for revealing fluid mechanics and evaluating the utilization of unconventional resources. In this study, there are multiple shale examples collected from the Chang 7 section in the Ordos Basin for the investigation was conducted on the basis of various experiments on total organic carbon (TOC), X-ray diffraction (XRD), and nitrogen gas adsorption, through scanning electron microscopy (SEM) and multifractal method. The multifractal characteristic parameters, including the width of singularity spectra ( Δ α ), Hurst exponent ( H ), D 1 / D 0 , and nitrogen gas adsorption, were used to find out about the characteristics of pore development and to quantify the complexity and heterogeneity of pore structure. Depending on the exact mineral composition, the Yanchang Formation of Chang 7 shales is classified into either silty mudstone (SM) or muddy siltstone lithofacies (MS). According to the investigative results, the Chang 7 lacustrine shale features a complex pore system with the pores ranging from 1.5 to 10 nm in diameter. Besides, mesopores contribute significantly to the total pore volume (TPV) and total surface area (TSA). As for TPV and TSA of the SM lithofacies in the samples under investigation, they are nearly 1.09–1.78 and 0.80–1.72 times greater as compared to the MS lithofacies samples. The dominant types of reservoir spaces include organic matter (OM) pore and interparticle pore which are related to inorganic minerals. The value of Δ α is higher for MS lithofacies than for SM lithofacies, indicating a greater heterogeneity of PSD in the MS lithofacies. The pore structure of MS lithofacies is determined mainly by TOC and siliceous mineral content, whereas the influencing factors for SM lithofacies are TOC and clay mineral content. There is a significant relationship between multifractal parameters and pore structure parameters for both SM and MS lithofacies. The TOC of SM and MS lithofacies exhibits a close correlation with Δ α , suggesting that the pores in organic matter are dominated by those nanopores with a complex and heterogeneous pore structure. The rock composition of the lithofacies can affect Δ α to a varying extent, which means that the minerals have an evident impact on the heterogeneity of MS and SM lithofacies.

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