Studying Isotherm, Kinetics, and Thermodynamic Parameters of Heat-Stable Acetate Salt Adsorption from Amine Solution by Anion Ion-Exchange Resin

The formation of heat-stable salts (HSS), such as acetate, formate, oxalate, and thiosulfate, in gas-sweetening units creates various issues, including corrosion, high foaming, and reduced unit efficiency. This research aims to investigate eliminating heat-stable salts using an anion-exchange resin. The findings indicated that removing approximately ۸۵% of acetate anion salt from an amine solution at a solution-to-resin ratio of ۳۰ was feasible. Two adsorption models, Langmuir and Freundlich, were employed to analyze the equilibrium adsorption of acetate anion salt. The results indicated that the Langmuir adsorption isotherm aligned more closely with the data obtained from the acetate anion ion exchange process with the resin. Furthermore, it was determined that the maximum adsorption capacity for acetate onto the resin was ۱۵ mg/g at a temperature of ۲۵ °C. The impact of contact time during adsorption was examined using quasi-first-order and quasi-second-order kinetic models and an intra-particle model. The results indicated that the quasi-first-order kinetic model provided the best fit to the data, and equilibrium adsorption was achieved after approximately ۷۰ min. Thermodynamic parameters were also investigated, revealing a ΔH value of –۱۲.۷۳۷۰ kJ/mol, indicating an exothermic adsorption process. Based on the studies, utilizing the selected resin appears to be a suitable option for removing heat-stable salts.

کلیدواژه ها:

ion-exchange resin ، heat stable salts (HSS) ، adsorption equilibrium isotherms ، Kinetics ، thermodynamic parameters