Feasibility of MOF-based carbon capture from indoor spaces as air revitalization system

Abstract

Conventional air-conditioning systems, for providing thermal comfort and acceptable indoor air quality, are energy intensive, especially for spaces located in hot and humid climates. This is attributed to the energy needed to offset the latent and sensible loads of the ambient air, which is typically achieved using a solid desiccant integrated with a vapor compression cooling. Air revitalization system (ARS) is proposed as an alternative solution to remove excess H2O and CO2 sequentially from the recirculated air using solid adsorbents such as silica gel for H2O and metal-organic frameworks (MOFs) for CO2. In this work, the feasibility of MOFs-based ARS is investigated by predicting its operational performance cost and compare it to the conventional system. Accordingly, mathematical models were developed for the adsorption beds and the indoor space and integrated to genetic algorithm. The integrated model was used to properly size and optimize the system for a classroom and a residential house located in the Qatari climate. The simulation results showed that the ARS decreased the fresh air intake by 91% and 71%, for the classroom and house, respectively, leading to savings of 30% and 24% as well as payback periods of 5 and 2 years compared to the conventional system.