High Pressures Gas Adsorption in Porous Media and Polymeric Membrane Materials

Abstract—

The current state and future development of the energy industry dictate the need to use natural gas as a more environmentally friendly fossil fuel and to make a smooth transition to hydrogen energy. In this regard, adsorption at elevated pressures (>10 MPa) has been actively studied in recent decades to solve problems such as the extraction of natural gas from deep underground deposits and its further membrane purification, as well as the selection of adsorbents for the accumulation of methane and hydrogen. However, the correct determination of adsorption values at elevated pressures faces a number of problems that are not typical for moderate pressures. The main difficulties here are the correct determination of the skeletal volume of the adsorbent and the volume of the adsorbate. In the case of amorphous adsorbents, the swelling of the sample induced by sorption and its compressibility must also be taken into account. This review discusses recent advances in the description of gas adsorption at high pressures in porous media and membrane polymeric materials, including the specific conditions of contact with supercritical carbon dioxide. The paper also gives brief descriptions of the adsorption values used (net, excess, and absolute adsorption), as well as experimental methods for measuring adsorption at high pressures.