(292d) Adsorption and phase behaviour of CO2 and CH4  in hierarchically organized      nanoporous materials over a wide range of temperatures and pressures

Adsorption of CO₂ in porous materials plays an important role in different applications. Among them are CO2-capture from flue gas and other industrial waste streams as well as upgrading natural gas and biogas for pipeline transport. Understanding the fundamental adsorption mechanisms and phase behaviour of the adsorptive in the pore system can help to identify critical adsorbent properties that influence process performance. Within this context, the adsorption and phase behaviour of mainly CO₂ but also CH₄ in hierarchically structured nanoporous materials (e.g, hierarchical zeolites) and ordered mesoporous materials (e.g., CMK carbons, KIT-6 silica) was studied over a wide range of temperatures (subcritical and supercritical) and pressures using volumetric and gravimetric techniques. An accurate textural characterization (e.g., pore volume/size distribution, pore network characteristics) of the adsorbent materials was obtained by advanced gas adsorption studies coupled with the application of methods such as non-local density functional theory (NLDFT) and molecular simulation. This allows for an in-depth correlation of the CO₂ and CH₄ adsorption behaviour with the surface- and pore characteristics. Our results lead to a better understanding of how confined geometry effects contribute to the adsorption and phase behaviour of CO₂ and CH₄ in hierarchically structured nanoporous materials. These insights allow one to explore important aspects related to applications such as gas storage and filtration/purification processes.