The equilibrium adsorption isotherm has a crucial effect on various characteristics of the solid adsorbent (e.g., pore volume, bulk density, surface area, pore geometry). A historical paradox exists in conventional estimation of adsorption isotherm parameters. Traditionally, the total amount of adsorb material (total adsorption isotherm) has been considered equivalent to the local adsorption isotherm. This assumption is only valid when the corresponding pore size or energy distribution (PSD or ED) of the porous adsorbent can be successfully represented with the Dirac_x000D_ delta function. In practice, the actual PSD (or ED) is far from such assumption, and the traditional method for prediction of local adsorption isotherm parameters leads to serious errors. Up to now, the powerful combination of inverse theory and linear regularization technique has drastically failed when used for extraction of PSD from real adsorption data. For this reason, all previous researches used synthetic data because they were not able to extract proper PSD from the measured total adsorption isotherm with unrealistic parameters of local adsorption isotherm. We propose a novel approach that can successfully provide the correct values of local adsorption isotherm parameters without any a priori and unrealistic assumptions. Two distinct methods are suggested and several illustrative (synthetic and real experimental) examples are presented to clearly demonstrate the effectiveness of the newly proposed methods on computing the correct values of local adsorption isotherm parameters. The so-called Iterative and Optima methods’ impressive performances on extraction of correct PSD are validated using several experimental data sets.

Adsorption Isotherm Pore Size Distribution Parameters Estimation Iterative Method Optima Method

Guntuka S, National University of Singapore, M.Sc. Thesis (2006)
Shahsavand A, Shahrak MN, Colloids Surf.. A., 378, 1 (2011)
Shahsavand A, Shahrak MN, Chem. Eng. J., 171(1), 69 (2011)
Malek A, Farooq S, AIChE J., 42, 11 (1996)
Langmuir I, J. Am. Chem. Soc., 38, 11 (1916)
De Boer JH, The Dynamical Character of Adsorption, Second Ed., Oxford University Press, London (1968)
Myers AL, Prausnitz JM, AIChE J., 11, 1 (1965)
Dubinin MM, Chem. Rev., 60, 235 (1960)
Ruthven DM, Principles of Adsorption and Adsorption Processes, Wiley, New York (1984)
Foo KY, Hameed BH, Chem. Eng. J., 156(1), 2 (2010)
Press WH, Teukolsky SA, Vetterling WT, Flannery BP, Numerical recipes in FORTRAN: The art of scientific computing, Cambridge University Press (1992)
Do DD, Adsorption Analysis: Equilibria and Kinetics, Imperial College Press, London (1998)
Solcova O, Matejova L, Schneider P, Appl. Catal. A: Gen., 313(2), 167 (2006)
Merz PH, J. Comp. Phys., 38, 64 (1980)
House WA, Jaroniec M, Brauer P, Fink P, Thin. Solid. Films, 87, 323 (1982)
Bhatia SK, Chem. Eng. Sci., 53, 18 (1998)
Gun’koa VM, Do DD, Colloids Surf., A., 193, 71 (2001)
Keller J, Staudt R, Gas adsorption equilibria: Experimental methods and adsorption isotherms, Springer Science Press, U.S. (2005)