Determination of Adsorption-Induced Deformation of Microporous Carbons due to Adsorption of a Binary Gas Mixture by Monte Carlo simulation

LOPEZ, RAÚL H.; CORNETTE V.; DELGADO MONS, RODRIGO

Congreso; Statphys 2019; 2019

Gas adsorption in porous solids is known to induce elastic deformation, and this is well-documented in the literature. In microporous materials such as carbons and zeolites, the induced strain is usually very small, of the order of 10-3. However, this implies large internal stresses on the order of megapascals. Although mechanical properties of microporous carbons are critically important for various technological applications, such as characterization of porous materials, equilibrium separation of fluid mixtures by porous sieves, and so on; the basic mechanisms of deformation during the adsorption-desorption processes are still not completely understood.Considering the thermodynamic grand potential for more than one adsorbate in an isothermal system, we generalize the model of adsorption-induced deformation of microporous carbons developed by Kowalczyk et al. [1]We report a comprehensive study of the effects of adsorption-induced deformation of carbonaceous amorphous porous materials due to adsorption of carbon dioxide, methane, and their mixtures. The adsorption process is simulated by using the Grand Canonical Monte Carlo (GCMC) method and the calculations are then used to analyze experimental isotherms for the pure gases and mixtures with a different molar fraction in the gas phase. The pore size distribution determined from an experimental isotherm is used for predicting the adsorption-induced deformation of both pure gases and their mixtures. The volumetric strain predictions from the GCMC method are compared against relevant experiments with good agreement found in the cases of pure gases. [1]P. Kowalczyk, A. Ciach, and A. V. Neimark, ?Adsorption-induced deformation of microporous carbons: Pore size distribution effect,? Langmuir, vol. 24, no. 13, pp. 6603?6608, 2008.