CO2 adsorption on oxygen enriched porous carbon monoliths: Kinetics, isotherm and thermodynamic studies

The present study reports the use of nanocasted carbon monoliths (CMs) as adsorbents synthesized by using furfuryl alcohol as carbon precursor and silica monoliths (SM) as a template for CO2 capture. The oxygen content decreases from 18.92 to 14.38% with increase of carbonization temperature from 550 to 950 degrees C. BET surface area and total pore volume of CM carbonized at 950 degrees C was found to be maximum i.e. 1225 m(2) g(-1) and 1.26 cm(3) g(-1), respectively with the presence of a large number of micropores and mesopores. Performance evolution of the CMs was done thermogravimetrically at different adsorption temperatures and CO2 concentrations and found that, CM-950 shows the highest CO2 capacity (1.6 mmol g(-1)) which is approximately three times higher than SM (0.52 mmol g(-1)). The CMs exhibit stable CO2 uptake capacities (>= 1 mmol g(-1)) with easy regenerability over multiple adsorption desorption cycles. Furthermore, fractional order kinetic model provided the best description over all adsorption temperatures and CO2 concentrations. Heterogeneous nature of the carbon surface was confirmed from the Temkin isotherm fit and isosteric heat of adsorption (Q(st)) values. (C) 2017 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.