Investigation of the Interaction of Polar Molecules on Graphite Surface: Prediction of Isosteric Heat of Adsorption at Zero Surface Coverage

The adsorption of CO2 and CO2/CH4 mixtures on kaolinite was calculated by grand canonical Monte Carlo (GCMC) simulations with different temperatures (283.15, 293.15, and 313.15 K) up to 40 MPa. The simulation results show that the adsorption amount of CO2 followed the Langmuir model and decreased with an increasing temperature. The excess adsorption of CO2 increased with an increasing pressure until the pressure reached 3 MPa and then decreased at different temperatures. The S C O 2 / C H 4 decreased logarithmically with increasing pressure, and the S C O 2 / C H 4 was lower with a higher temperature at the same pressure. The interaction energy between CO2 and kaolinite was much higher than that between CH4 and kaolinite at the same pressure. The interaction energy between the adsorbent and adsorbate was dominant, and that between CO2 and CO2 and between CH4 and CH4 accounted for less than 20% of the total interaction energy. The isothermal adsorption heat of CO2 was higher than that of CH4, indicating that the affinity of kaolinite to CO2 was higher than that of CH4. The strong adsorption sites of carbon dioxide on kaolinite were hydrogen, oxygen, and silicon atoms, respectively. CO2 was not only physically adsorbed on kaolinite, but also exhibited chemical adsorption. In gas-bearing reservoirs, a CO2 injection to displace CH4 and enhance CO2 sequestration and enhanced gas recovery (CS-EGR) should be implemented at a low temperature.

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“…The van der Waals energy and electrostatic energy together constitute the total interaction energy [18,34].…”

Section: Interaction Potential Modelmentioning

confidence: 99%

Effect of Pressure and Temperature on CO2/CH4 Competitive Adsorption on Kaolinite by Monte Carlo Simulations

et al. 2020

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“…Firstly, the graphite structure is considered as simple layers of lattice with parallel slit-shaped pore model [14]. The total interaction potential between graphite and polar molecules (such as water, methanol and ethanol) and nonpolar molecules [10] contributions are more than 90%.…”

Section: Discussionmentioning

confidence: 99%

“…at higher pressure is complicated due to the presence of intermolecular interactions along the adsorbates. The modelling of has been studied by molecular simulations for many commonly applied adsorbent and adsorbate pairs [13,14].…”

Section: Figure 13 the Schematic Formalism Of Adsorption Isosteric Heatmentioning

confidence: 99%

Thermodynamic study of isosteric heat at zero coverage : applications to adsorption cooling and desalination

Wang¹

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The production of cooling and drinkable water represents major and essential needs for the mankind. Vapor compression cooling and desalination systems are mainly driven by electricity, produced by burning fossil fuels, which contributes to the global warming (GW) because of the encountered direct CO 2-emissions. The refrigerants used in vapor compression systems possess high global warming potential (GWP), resulting in an indirect contribution to the GW and, consequently, to the severe consequences on the worldwide climate. Recovering the waste heat generated upon burning fossil fuels to provide both cooling and fresh water demands through the application of adsorption assisted cooling and desalination cycle may remarkably contribute in mitigating the bad consequences of the GW. At present, the bulky size of adsorption chiller and desalination systems obstructs its practical application. The size of an adsorption bed depends on the quality of the porous adsorbents. Therefore, the present thesis aims to develop a thermodynamic framework for calculating the interaction potentials between the adsorbate and the adsorbent pore structures, from which the isosteric heat at zero coverage is formulated as a function of pore width and volume. The proposed modelling provides necessary information for the design of adsorbent materials. The proposed interaction potential model includes the Lennard Jones (LJ) Potential with the inclusion of electrostatic and induction potential. The model is first applied to the graphite surface, in which the electrostatic and induction potentials are obtained to be very small compared to the LJ potential. The maximum isosteric heat is found in the super micro-pore regions. On the other hand, the Reverse Monte Carlo (RMC) and molecular dynamics methods are applied to understand the silica structure for water adsorption. For water interaction with silica gel, the electrostatic interaction is found to be high. For water adsorption on CHA and AFI 4.4 Summary of Chapter 4 ..

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“…As compared with the parent MOF-801 structure, water molecule transfer inside the "methyl functional group-blocked pores" result in higher Lennard-Jones (LJ) potential, electrostatic potential, the induction interaction as well as the high order interactions. Furthermore, the lateral attraction force between adsorbed water molecules is also increased within methyl functional group-blocked pore walls, especially at higher pressure [161].…”

Section: Functional Mof-801 (Zr) Plus Watermentioning

confidence: 99%

“…The universal force field (12-6 Lennard-Jones bonding + Coulomb potential) used to study the adsorbentadsorbate interactions could only reveal 85-90% of the total binding energy [161].…”

Section: Modelling and Simulationmentioning

confidence: 99%

Synthesisation, characterisation and water adsorption on novel functional metal organic frameworks for heat transformation process

Han¹

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Referring to the present situation of the global climate condition, the reduction of the energy consumption is always of great importance in combatting the grave situation of enhanced global warming potential (GWP). Adsorption-assisted heat transformation (AHT) systems such as chillers, heat pumps and desalination can predominantly help us to reduce the global warming.Therefore, the adsorption devices should be improved with the use of highly efficient adsorbents.

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Investigation of the Interaction of Polar Molecules on Graphite Surface: Prediction of Isosteric Heat of Adsorption at Zero Surface Coverage

Cited by 21 publications

References 41 publications

Effect of Pressure and Temperature on CO2/CH4 Competitive Adsorption on Kaolinite by Monte Carlo Simulations

Effect of Pressure and Temperature on CO2/CH4 Competitive Adsorption on Kaolinite by Monte Carlo Simulations

Thermodynamic study of isosteric heat at zero coverage : applications to adsorption cooling and desalination

Synthesisation, characterisation and water adsorption on novel functional metal organic frameworks for heat transformation process

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