Theoretical insight of physical adsorption for a single component adsorbent+adsorbate system: II. The Henry region.
The Henry coefficients of a single component adsorbent + adsorbate system are calculated from experimentally measured adsorption isotherm data, from which the heat of adsorption at zero coverage is evaluated. The first part of the papers relates to the development of thermodynamic property surfaces for a single-component adsorbent+adsorbate system (Chakraborty, A.; Saha, B. B.; Ng, K. C.; Koyama, S.; Srinivasan, K. Langmuir 2009, 25, 2204). A thermodynamic framework is presented to capture the relationship between the specific surface area (Ai) and the energy factor, and the surface structural and the surface energy heterogeneity distribution factors are analyzed. Using the outlined approach, the maximum possible amount of adsorbate uptake has been evaluated and compared with experimental data. It is found that the adsorbents with higher specific surface areas tend to possess lower heat of adsorption (DeltaH degrees) at the Henry regime. In this paper, we have established the definitive relation between Ai and DeltaH degrees for (i) carbonaceous materials, metal organic frameworks (MOFs), carbon nanotubes, zeolites+hydrogen, and (ii) activated carbons+methane systems. The proposed theoretical framework of Ai and DeltaH degrees provides valuable guides for researchers in developing advanced porous adsorbents for methane and hydrogen uptake.
Chakraborty
Anutosh
A
Department of Mechanical Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Singapore.
Saha
Bidyut Baran
BB
Ng
Kim Choon
KC
Koyama
Shigeru
S
Srinivasan
Kandadai
K