Adsorption isotherms and kinetics of activated carbon/Difluoroethane adsorption pair: Theory and experiments

This study introduces a new adsorbent/refrigerant pair to be used in adsorption cooling applications. Adsorption isotherms and kinetics of Difluoroethane (HFC-152a) onto highly porous activated carbon Maxsorb III at temperatures ranging from 25 to 75°C have been investigated. Experimental data of adsorption uptake have been fitted with Dubinin-Astakhov (D-A) and Tóth equations. D-A equation is found to be more suitable than Tóth equation for fitting the adsorption uptake. Experimental results showed that Maxsorb III can adsorb up to 1.3 kg of HFC-152a per kg of adsorbent. Experimental data of adsorption kinetics have been fitted with linear driving force (LDF) and Fickian diffusion (FD) models. Both LDF and FD models are found to be able to simulate the adsorption kinetics of the proposed pair. Isosteric heat of adsorption has been estimated considering the real gas case. Pressure-temperature-concentration (P-T-C) diagram of the pair has been also presented.