Use of monolithic silicon carbide aerogel as a reusable support for development of regenerable CO2 adsorbent

Abstract

Monolithic silicon carbide aerogel (MSiCA) was firstly used as a reusable support to develop a novel CO₂ adsorbent, i.e. amine functionalized monolithic silicon carbide aerogel (AFMSiCA). Used or exhausted AFMSiCA was separated, treated and re-functionalized by amine to form RF-MSiCA. CO₂ capture performance of the resulting adsorbents was investigated in a 1% CO₂ flow stream. The results revealed that CO₂ adsorption capacities of AFMSiCA at different temperatures ranging from 25 to 75 °C showed little change, indicating that the resulting adsorbent is well-adapted to temperature. The adsorption rate is affected by the combined effect of CO₂ adsorption and desorption. Benefiting from the highly unique properties of the aerogel (e.g. high surface area and large pore volume), MSiCA-based adsorbents are dynamic in their CO₂ adsorption process. MSiCA could be readily recovered and reused at least 12 times without significant loss of CO₂ adsorption performance. The resulting adsorbents presented good stability during cyclic adsorption–regeneration tests. MSiCA is exceptional in practical application for CO₂ capture due to its excellent reusability and the regenerability of its amine functionalized counterparts.