Kinetics Studies of CO₂ Adsorption/Desorption on Amine-Functionalized Multiwalled Carbon Nanotubes

Abstract

The adsorption/desorption kinetics of carbon dioxide on tetraethylenepentamine (TEPA) impregnated industrial grade multiwalled carbon nanotubes (IG-MWCNTs) was investigated to obtain insight into the underlying mechanisms on the fixed bed. After evaluating four kinetic models for CO 2 adsorption at various adsorption temperatures, CO 2 partial pressure, and amine loadings, it was found that Avrami's fractional-order kinetic model provided the best fitting for the adsorption behavior of CO 2 . In order to find the optimal regeneration method, three desorption methods were evaluated for the regeneration of solid sorbents. The activation energy E a of CO 2 adsorption/desorption was calculated from Arrhenius equation and used to evaluate the performance of the adsorbent. The E a decreased with increasing CO 2 concentration, indicating that CO 2 adsorption of amine-functionalized IG-MWCNTs is possibly intraparticle controlled. Meanwhile, because of the energy input of a vacuum pump, E a for the vacuum swing regeneration method was less than that for temperature swing regeneration.

Kinetics of CO2 adsorption on cherry stone-based carbons in CO2/CH4 separations

“…The increase in the mass transfer coefficient with the rise in the concentration of CO 2 in the feed is reflected in the significantly steeper concentration profiles (depicted in Figures 1-3). The trend observed agrees well with the data reported in the literature [57].…”

Desorption Kinetics and Mechanisms of CO2 on Amine-Based Mesoporous Silica Materials

“…The values of n A for the desorption process are in the range of 0.459-0.507 for physical desorption and 0.366-0.391 for chemical desorption. Liu et al [33] also obtained the n A of the desorption process in the range of 0.768-0.935. The E a values are 15.86 kJ/mol and 57.15 kJ/mol for CO 2 physical desorption and chemical desorption, respectively.…”

“…Serna-Guerrero et al [21] and Liu et al [33] used this model to study the adsorption process of CO 2 onto amine-based adsorbents. This model can be described as Equation (6):…”

“…Liu et al [33] obtained the n A of the desorption process in the range of 0.768-0.935 and assumed it is associated with the desorption of physical desorption first and then chemical desorption. However, physical desorption and chemical desorption are concurrent.…”

The impact of surface chemistry and texture on the CO2 uptake capacity of graphene oxide

“…Materials such as zeolites [6,7], metal-organic frameworks (MOFs) [8,9] and some carbon allotropes [10][11][12] are characterized by their high surface area and regular pore structure [13], two properties that favor gas uptake. In Industry, microporous carbons, most commonly in the activated form, are one of the workhorse materials for physical gas adsorption.…”