Search

Some graphene-based adsorbents such as mesoporous graphene oxide/TiO 2 nanocomposite, thermally treated graphene nanosheets, holey graphene frameworks and 3-D graphene-based porous adsorbent have recently been introduced as promising adsorbents for post-combustion CO 2 capture while, their CO 2 adsorption kinetics and mechanisms have not sufficiently been reported by the scholars. To begin, in this study, CO 2 capture kinetics of these adsorbents are investigated by different adsorption kinetic models including pseudo-first order model, pseudo-second order model, Avrami model, and the fractal-like exponential kinetic model. Subsequently, the Eyring and Arrhenius equations are used to determine the activation parameters related to the CO 2 adsorption on these adsorbents. Furthermore, a mechanism is proposed to describe the negative activation energy assessed for CO 2 adsorption on the studied adsorbents. Eventually, the rate-limiting kinetic models including interparticle diffusion model, intraparticle diffusion model and Boyd’s film diffusion model are applied to determine CO 2 capture mechanisms on the mentioned graphene-based adsorbents. [ABSTRACT FROM AUTHOR]