Abstract
A significant number of industrially relevant separation processes involves the removal of carbon dioxide (CO2), as the purification of natural gas (CO2/CH4 separation). In this scenario, the development of new adsorbents with a real technological future for CO2 separation, i.e with a high separation efficiency, good mechanical properties and easy to handle, is of primary importance. In the present work, novel composite monolithic aerogels containing the UTSA-16 metal organic framework as the active phase and porous crystalline polymers (namely syndiotactic polystyrene and polyphenyloxide) as binders were successfully synthesized and fully characterized. The adsorption capacity of such novel aerogels towards CO2 and CH4 was tested at low pressure and variable temperature, allowing the evaluation of their CO2/CH4 selectivity. Microcalorimetric experiments provided the CO2 interaction energy and disclosed possible deformation-relaxation phenomena involving the polymeric matrix during gas adsorption. The new composites retain a very high CO2 adsorption capacity compared to the pristine UTSA-16 (around 75% at 298 K and 1 bar) and have excellent CO2 capture performances in comparison to other types of supported/printed MOFs reported in the literature. The outstanding adsorption properties and the possibility to obtain monoliths with the desired size and shape and good mechanical stability make these new composites very good candidates for efficient CO2/CH4 separation processes.
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•Novel composite monolithic aerogels containing UTSA-16 as the active phase.•The aerogels have the desired shape and maintain good mechanical properties.•The new composites exhibit a very high CO2 adsorption capacity.•The composite aerogels retain the 77% of the adsorption capacity of pure MOF.