Kinetic study and breakthrough analysis of the hybrid physical/chemical CO2 adsorption/desorption behavior of a magnetite-based sorbent

Abstract

The CO2 adsorption and desorption kinetics of a magnetite-based sorbent, CB-FM, obtained coating a low-cost carbon black (CB) with magnetite fine particles (FM), has been systematically and thoroughly investigated for the first time under post-combustion capture operating conditions. Experimental data of CO2 uptake (18–150 °C) and extent of CO2 desorption (200–260 °C) have been fitted to different apparent kinetic models, namely pseudo-first-order, pseudo-second-order and Avrami’s fractional-order kinetic models. The mechanism of CO2 adsorption on CB-FM in terms of controlling mass transfer resistances, interparticle diffusion, intraparticle diffusion and Boyd’s film-diffusion models has been also investigated. Finally, a two-constants deactivation model has been adopted to simulate the dynamic breakthrough curves.