New Nano-Structured Hybrid Materials-based Polyoxometalate for CH4/H2 Separation: A Computational Study

Abstract

Global climate change is one of the most serious and formidable challenges in the world. After carbon dioxide that is well-known as the most important greenhouse gas, methane has been ranked the second. On the other hand, high-pressure separation of binary mixture of CH4 and H2 is relevant to hydrogen purification which absolutly play a vital role in many industrial processes. Thus, methane separation poses a big challenge that could be faced via various techniques such as adsorption. In this paper the capability of some of the recently synthesized structures of a new class of nano-porous materials, known as inorganic-organic hybrids based-Polyoxometalate (POM), have been examined for capturing methane from hydrogen stream. Grand Canonical Monte Carlo (GCMC) simulation has been used to predict pure methane and hydrogen and also their binary isotherms as well as CH4 selectivity calculations over H2 at two different concentrations of CH4/H2 mixture of 50/50 and 10/90. In addition, Ideal Adsorption Solution Theory (IAST) has been employed for the binary isotherms predictions and the results are compared with those of GCMC. The obtained results present that POMs could be introduced as a promising candidates for CH4/H2 separation in comparison with other conventional adsorbents such as Metal-Organic Frameworks (MOFs) and Covalent-Organic Frameworks (COFs) materials.