Comparative Studies on CO2 Adsorption Isotherms by Solid Adsorbents

Abstract

The present study provides the necessary thermodynamic data required for the design of CO2 based adsorption systems using the activated carbon (Norit type RB3 steam activated rod) and zeolite 5A (Si/Al = 1.33). In this work, the CO2 adsorption isotherms of activated carbon and Zeolite 5A are studied at different temperatures (298, 308, 318 and 338 K) and pressures (0-30 bar) using a Sievert's type experimental setup. Experimental data of CO2 adsorption isotherms on adsorbents are modelled using Langmuir and Freundlich isotherm models. The coefficient of correlation and normalized standard deviation are estimated, which revealed that the Freundlich isotherm model is well suited to the experimental data of CO2 adsorption isotherms than Langmuir model. The thermodynamic parameters are estimated and these parameters indicated that the adsorption process is spontaneous, exothermic and physisorption in nature. Isosteric heat of adsorption and limiting heat of adsorption are calculated using the Clausius-Clapeyron and van't Hoff equations respectively. © 2018 Elsevier Ltd.