Easily tunable parameterization of a force field for gas adsorption on FAU zeolites
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Easily tunable parameterization of a force field for gas adsorption on FAU zeolites Victor A. M. Gomes • Juliana A. Coelho • Hugo R. Peixoto • Sebastia˜o M. P. Lucena
Received: 4 July 2014 / Revised: 20 December 2014 / Accepted: 23 December 2014 Ó Springer Science+Business Media New York 2014
Abstract Considering the great economic and environmental interests in the capture and separation of CO2 and the wide availability of faujasites zeolites (FAU), we propose a set of parameters based on classical force fields that has good transferability among Na-FAU sieves and CO2. In addition to CO2, the parameterization strategy was tested for H2S, O2, N2 and CH4 gases. For these gases, the force field adequately predicts the adsorption isotherms at low pressure. The force field was also tested for N2 in the FAU framework with different monovalent and divalent cations, resulting in quantitative agreement for monovalent cations and qualitative agreement for divalent cations. The good tradeoff between the reliability and ease of implementation will enable rapid evaluation of the adsorption properties of gaseous mixtures of industrial relevance. The reasoning of the re-parameterization strategy is also discussed in detail. Keywords Molecular simulation Adsorption Carbon dioxide Light gases and faujasite
1 Introduction In recent years, there has been great demand to facilitate the use of adsorption processes for CO2 capture (Su and Lu
Electronic supplementary material The online version of this article (doi:10.1007/s10450-014-9647-3) contains supplementary material, which is available to authorized users. V. A. M. Gomes J. A. Coelho H. R. Peixoto S. M. P. Lucena (&) Grupo de Pesquisa em Separac¸o˜es por Adsorc¸a˜o – GPSA, Dept. Engenharia Quı´mica, Universidade Federal do Ceara´, Campus do Pici, Bl. 709, Fortaleza, CE 60455-760, Brazil e-mail: [email protected]
2012; Bae et al. 2013; First et al. 2014) and the separation of toxic gases (Kumar et al. 2011; Tagliabue et al. 2012; Sun et al. 2014). On one hand, carbon dioxide, coming from several sources, is associated with methane (natural gas, shale gas, biogas), nitrogen (gas burning) or toxic gases, making it difficult to select materials and to design adsorption industrial units (PSA, TSA). On the other hand, zeolites based in sodalite units dominate the molecular sieve market. The LTA-type is the most frequently used zeolite, and the FAU-type zeolite is the second most used zeolite (Cejka et al. 2007). Experimental isotherms for FAU crystals in low-pressure conditions were performed with CO2 (Walton et al. 2006; Hyun and Danner 1982; Cavenati et al. 2004; Kim et al. 1994), N2 (Jayaraman et al. 2002; Cavenati et al. 2004; Llewellyn et al. 2005; Kim et al. 1994), CH4 (Cavenati et al. 2004; Pillai et al. 2010; Silva et al. 2012), O2 (Jayaraman et al. 2002) and H2S (Cruz et al. 2005). Despite the great interest of the scientific community on the subject, multicomponent experimental isotherms at low pressures in pure crystals remain scarce (Kim et al. 1994). Thi
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