Isobutane adsorption with carrier gas recirculation at different relative humidities using activated carbon fiber cloth and electrothermal regeneration

Abstract

An improved gas recovery system (GRS) using activated-carbon fiber-cloth (ACFC), electrothermal swing adsorption (ESA), and carrier gas recirculation was shown to capture and recover >99% isobutane while reducing N2, H2O, and energy consumption. ACFC-15 was selected as the adsorbent after a trade-off of adsorption capacity and cost. Carrier gas recirculation was used for the first time to conserve N2 and H2O at relative humidity (RH) up to 80% while recovering volatile organic compound (VOC) (i.e., isobutane). When RH is 24% and 77%, overall energy (EOverall) consumed with recirculation decreases by 2.5% and 26% compared to without recirculation, respectively. Recommendations are provided to reduce the gap of energy consumption of the GRS with recirculation based on idealized and experimental conditions. Unique contributions and importance of this work are demonstrating that carrier gas recovery and reuse can be used to better conserve N2, H2O, and energy; analyzing specific energy consumption values; and proposing improvements of such a system to let the GRS with recirculation operate closer to idealized conditions.