Adsorption-Induced Deformation of Microporous Carbons: Pore Size Distribution Effect due to Adsorption of a Binary Gas Mixture

V. CORNETTE; J.C.A DE OLIVEIRA; D.C.S ACEVEDO; R.H. LÓPEZ

Río de Janeiro

Conferencia; CARBON 2013; 2013

Gas adsorption in porous solids is known to induce elastic deformation, andthis is well-documented in the literature. In microporous materials such as carbonsand zeolites the induced strain is usually very small, of the order of 10-3,[1] andthis effect has thus often been neglected in the past discussions and modelingstudies of adsorption experiments. However, this implies large internal stresses onthe order of megapascals[2]. Although mechanical properties of microporouscarbons are critically important for various technological applications, such ascharacterization of porous materials, equilibrium separation of fluid mixtures byporous sieves, and so on[3], [4], the basic mechanisms of deformation during theadsorption desorption processes are still not completely understood. Kowalczyk etal. [5?7] in particular showed that deformation effect caused by argon, carbondioxide and methane adsorption in micropores may be highly sensitive to themicropore size distribution of the material under investigation and the kind ofadsorbate applied. However, not many works have been devoted to analysis thesolvation or disjoining pressure as applied to adsorption of a binary gas mixture.Recently, Brochard et al. [8] simulated the competitive adsorption of carbondioxide and methane in CS1000 (a realistic model for microporous coal) andconcluded that the competitive adsorption of the two fluids in the coal microporesis responsible for the differential swelling phenomenon, a major problem for fieldapplication of enhanced coal bed methane recovery (ECBM).Furthermore the adsorptive separation of gases is an important process in manyindustrial and environmental applications. In particular, the separation of CO2 fromCO2-CH4 mixtures is a fundamental problem in natural gas and biogaspurification/upgrading in energy generation applications [9], [10].References[2] M. Colligan, P. M. Forster, A. K. Cheetham, Y. Lee, T. Vogt, and J. A. Hriljac, J. of the American Chemical Society, vol. 126, no. 38, pp. 12015?12022, 2004.[3] S. J. Gregg and K. S. W. Sing, London: Academic Press, 1982.[4] H. Mash and F. Rodríguez-Reinoso, Activated Carbon. Oxford: Elsevier Ltd, 2006.[5] P. Kowalczyk, A. Ciach, and A. V. Neimark, Langmuir, vol. 24, no. 13, pp. 6603?8, Jun. 2008.[6] P. Kowalczyk, S. Furmaniak, P. a. Gauden, and A. P. Terzyk, The Journal of Physical Chemistry C, vol. 114, no. 11, pp. 5126?5133, Mar. 2010.[7] P. Kowalczyk, S. Furmaniak, P. A. Gauden, and A. P. Terzyk, J. of Physical Chemistry C, vol. 116, no. 2, pp. 1740?1747, 2012.[8] L. Brochard, M. Vandamme, R. J.-M. Pellenq, and T. Fen-Chong, Langmuir, vol. 28, no. 5, pp. 2659?70, Feb. 2012.[9] R. Babarao, Z. Hu, J. Jiang, S. Chempath, and S. I. Sandler, Langmuir, vol. 23, no. 2, pp. 659?666, 2007.[10] Y.-S. Bae, K. L. Mulfort, H. Frost, P. Ryan, S. Punnathanam, L. J. Broadbelt, J. T. Hupp, and R. Q. Snurr, Langmuir, vol. 24, no. 16, pp. 8592?8598, 2008.