Kinetics studies of CO2 adsorption and desorption on waste ion-exchange resin-based activated carbon

Abstract

This paper is first to investigate the kinetics of CO2 adsorption and desorption on waste ion-exchange resin-based activated carbons by the isothermal thermal analysis method. Not only the application of isothermal thermal analysis is expanded, but also a new method for study the kinetics of CO2 adsorption and desorption is provided in this paper. CO2 adsorption kinetics following Avrami-Eroféev model is A3/2 on chemically activated carbon (CA) and physically activated carbon (PA). The values of activation energy (E) of CA and PA are negative, and the absolute values of activation energy (E) reduce with the increase of CO2 concentration. Desorption kinetics also follow Avrami-Eroféev model, and CA is A3/2 while PA is A1. The values of activation energy are positive, which is opposite to adsorption. CO2 adsorption and desorption processes are similar to the nucleation and growth of the crystal, which starts from a point, then spreads to the surrounding.