Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces
The knowledge of the isosteric heats (Qsto) is essential to design porous adsorbents for calculating the performances of adsorption-assisted cooling, separation and gas storage systems. This paper presents a thermodynamic framework to calculate the interaction potentials and isosteric heats for wate...
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sg-ntu-dr.10356-1427292020-06-29T07:02:37Z Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces Fan, Wu Chakraborty, Anutosh Leong, Kai Choong School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Isosteric Heat of Adsorption Pore Width The knowledge of the isosteric heats (Qsto) is essential to design porous adsorbents for calculating the performances of adsorption-assisted cooling, separation and gas storage systems. This paper presents a thermodynamic framework to calculate the interaction potentials and isosteric heats for water adsorption on SiO2 structures. Here both Lennard Jones (LJ) and electrostatic potentials are considered. It is found that (i) Qsto varies from 1.37 eV (∼131 kJ/mol) to 0.54 eV (∼52 kJ/mol) for the adsorption of one water molecule on various pore sizes of SiO2 structure, and (ii) Qsto depends on the pore size (H). Qsto is found to be very high in the super-micro-pore regions. The density functional theory (DFT) is applied to calculate Qsto for the adsorption of water on silica. Here water-water interactions are not considered. Later Qsto for five types of silica gels are obtained from experimentally-measured isotherms data at low pressures (up to 0.15 kPa) and wide range of temperatures. The simulation result agrees well with the experimental data. MOE (Min. of Education, S’pore) 2020-06-29T07:02:37Z 2020-06-29T07:02:37Z 2018 Journal Article Fan, W., Chakraborty, A., & Leong, K. C. (2018). Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces. Applied Thermal Engineering, 141, 134-142. doi:10.1016/j.applthermaleng.2018.05.096 1359-4311 https://hdl.handle.net/10356/142729 10.1016/j.applthermaleng.2018.05.096 2-s2.0-85048504253 141 134 142 en Applied Thermal Engineering © 2018 Elsevier Ltd. All rights reserved. |
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Engineering::Mechanical engineering Isosteric Heat of Adsorption Pore Width Fan, Wu Chakraborty, Anutosh Leong, Kai Choong Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
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The knowledge of the isosteric heats (Qsto) is essential to design porous adsorbents for calculating the performances of adsorption-assisted cooling, separation and gas storage systems. This paper presents a thermodynamic framework to calculate the interaction potentials and isosteric heats for water adsorption on SiO2 structures. Here both Lennard Jones (LJ) and electrostatic potentials are considered. It is found that (i) Qsto varies from 1.37 eV (∼131 kJ/mol) to 0.54 eV (∼52 kJ/mol) for the adsorption of one water molecule on various pore sizes of SiO2 structure, and (ii) Qsto depends on the pore size (H). Qsto is found to be very high in the super-micro-pore regions. The density functional theory (DFT) is applied to calculate Qsto for the adsorption of water on silica. Here water-water interactions are not considered. Later Qsto for five types of silica gels are obtained from experimentally-measured isotherms data at low pressures (up to 0.15 kPa) and wide range of temperatures. The simulation result agrees well with the experimental data. |
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School of Mechanical and Aerospace Engineering |
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School of Mechanical and Aerospace Engineering Fan, Wu Chakraborty, Anutosh Leong, Kai Choong |
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Article |
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Fan, Wu Chakraborty, Anutosh Leong, Kai Choong |
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Fan, Wu |
title |
Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
title_short |
Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
title_full |
Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
title_fullStr |
Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
title_full_unstemmed |
Theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
title_sort |
theoretical and experimental investigations of isosteric heats for water adsorption on silica gel surfaces |
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2020 |
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https://hdl.handle.net/10356/142729 |
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