Molecular simulation of N2 and CO2 injection into a coal model containing adsorbed methane at different temperatures

Energy ◽  
2021 ◽  
Vol 219 ◽  
pp. 119686
Author(s):  
Yang Bai ◽  
Hai-Fei Lin ◽  
Shu-Gang Li ◽  
Min Yan ◽  
Hang Long
Keyword(s):  
Molecular Simulation ◽  
Co2 Injection ◽  
Different Temperatures ◽  
Adsorbed Methane

scholarly journals Modified Dual-Site Langmuir Adsorption Equilibrium Models from A GCMC Molecular Simulation

2020 ◽  
Vol 10 (4) ◽  
pp. 1311
Author(s):  
Junchao Wang ◽  
Yongjie Wei ◽  
Zhengfei Ma
Keyword(s):  
Molecular Simulation ◽  
Adsorption Energy ◽  
Pressure Swing Adsorption ◽  
Adsorption Equilibrium ◽  
Equilibrium Data ◽  
Different Temperatures ◽  
Adsorption Energies ◽  
Pressure Swing ◽  
Adsorption Equilibrium Data ◽  
Dual Site

In the modern industrial separation process, the pressure swing adsorption technology is widely used to separate and purify gases due to its low energy consumption, low cost, convenience, reliability, and environmental benignity. The basic elements of the design and application of the pressure swing adsorption process are adsorption isotherms at different temperatures for adsorbents. The dual-site Langmuir (DSL) adsorption equilibrium model is the mostly used model; however, this model is based on the assumption that the adsorption energy on the surface of an adsorbent is uniform and remains unchanged. Here, a grand canonical Monte Carlo (GCMC) molecular simulation was used to calculate the CO2 adsorption equilibrium on MIL-101 (Cr) at 298 K. MIL-101 (Cr) was chosen, as it has more a general pore structure with three different pores. The calculation results showed that the adsorption energies with different adsorption pressures fitted a normal distribution and the relationship of the average adsorption energies, E with pressures had a linear form described as: E = aP + c. With this relationship, the parameter b = k·exp(E/RT) in the DSL model was modified to b = k·exp((aP + c)/RT), and the modified DSL model (M-DSL) was used to correlate the adsorption equilibrium data on CO2-MIL-101 (Cr), C2H4-HHPAC, CH4-BPL, and CO2-H-Mordenite, showing better correlations than those of the DSL model. We also extended the parameter qm in the M-DSL model with the equation qm = k1 + k2T to adsorption equilibrium data for different temperatures. The obtained model (M-TDSL) was checked with the abovementioned adsorption equilibrium systems. The fitting results also indicated that the M-TDSL model could be used to improve the correlation of adsorption equilibrium data for different temperatures. The linear relationship between the average adsorption energy and adsorption pressure could be further tested in other adsorption equilibrium models to determine its universality.

IMPACT OF WATER AND CO2 ON THE MECHANICAL PROPERTIES OF LOW PERMEABLE ROCKS

2021 ◽  
Vol 7 (2) ◽  
pp. 130-146
Author(s):  
Anatolii A. KISLITSYN ◽  
Nikita V. Lipatov
Keyword(s):  
Mechanical Properties ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Strength Properties ◽  
Pore Fluid ◽  
Co2 Injection ◽  
Core Samples ◽  
Different Temperatures ◽  
Confining Pressures ◽  
Temporary Decrease

This article features experiments on triaxial compression of low-permeable dolomite samples with different confining pressures (2-20 MPa), different pore fluids (dry air, water, CO2), and different temperatures (25-150 °C). The authors have studied the effect of confining pressure, pore fluid and temperature on the strength properties of the studied samples. The results show an increase in the strength with grwoing confining pressure. When the confining pressure increases from 2 to 20 MPa, the compressive strength increases from 86 to 370 MPa. Temperature has a significant effect on rock strength under low confining pressure conditions. With the increasing confining pressure reaching 15 MPa, increasing temperature has little effect on the strength of dolomite samples. Under an effective confining pressure of 5 MPa, the temperature weakening occurs on the dolomite specimens when the temperature exceeds 90 °C. During compression, liquid diffusion occurs in the specimens. Higher water viscosity can cause a temporary decrease in effective confining pressure, which can increase the strength of the rock. More prominent fractures are observed in the samples, and more fluid is injected under CO2 injection conditions, which may be useful for increasing the permeability of the geothermal reservoir. Two groups of experiments have been performed on the samples in this study: the first group of experiments investigated the effect of confining pressure on the fracture stress of core samples, without pore fluid injection; the second group of experiments investigated the effect of water or CO2 and temperature on the mechanical properties of core samples.

The Effect of Salinity on In-Situ Generated CO2 Gas: Simulations and Experiments

2006 ◽  
Author(s):  
Onur Coskun ◽  
Reid Grigg ◽  
Robert Svec ◽  
Sayavur I. Bakhtiyarov ◽  
Dennis Siginer
Keyword(s):  
Oil Recovery ◽  
Co2 Injection ◽  
Chemical Additives ◽  
Co2 Solubility ◽  
Gas Generation ◽  
Co2 Gas ◽  
Different Temperatures ◽  
Carbon Dioxide Co2 ◽  
Brine Concentration

Carbon dioxide (CO2) injection has been used as a commercial process for enhanced oil recovery (EOR) since the 1970's. Recently, a new in-situ CO2 gas generation technology has been developed but not well studied. We conducted experiments to observe the dynamics of the system with different temperatures, injection sequences of chemical agents, chemical additives, and behavior of CO2 generation with respect to these varying factors and comparison of the actual CO2 pressure with the calculated values. Experiments on generation of CO2 gas as a result of reactions of gas forming and gas yielding solutions were carried out. It is shown that the injection sequence of the chemicals affects the reaction characteristics, but the total amount of CO2 gas generated does not vary significantly. Regardless of the injected solution (either gas forming or gas yielding) the maximum attainable pressures are less than the calculated pressures as a result of chemical equilibrium in the system; so this difference should be considered while calculating the size of the slug in the field applications. The brine concentration has an impact on CO2 solubility in water and so on CO2 pressure. Because of this impact, brine concentration of formation water should be considered in addition to the brine which is introduced to the system by the reaction.

Molecular simulation of benzene adsorption on different activated carbon under different temperatures

2020 ◽  
Vol 302 ◽  
pp. 110220 ◽  
Author(s):  
Shi Li ◽  
Kunli Song ◽  
Dongfeng Zhao ◽  
John Rwiza Rugarabamu ◽  
Rui Diao ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Molecular Simulation ◽  
Benzene Adsorption ◽  
Different Temperatures

Molecular simulation of the enthalpies of argon (1) + methane (2) at different temperatures and pressures

1993 ◽  
Vol 221 (2) ◽  
pp. 163-170 ◽  
Author(s):  
Ming-Xue Guo ◽  
Yi-Gui Li ◽  
Wen-Chuan Wang ◽  
Huan-Zhang Lu
Keyword(s):  
Molecular Simulation ◽  
Different Temperatures
Sign in / Sign up

Export Citation Format

Share Document