Linear Driving Force Model in Carbon Dioxide Capture by Adsorption

Abstract

In this work, experimental data of CO2 capture by adsorption was determined gravimetrically, at 30 °C and pressures up to 40 bar, and in a fixed bed unit at 20 bar, using NaY as adsorbent. Langmuir, Sips and Tóth isotherm models were used to correlate the equilibrium data. Sips and Tóth models were best fitted allowing estimate the maximum CO2 adsorbed amount. The breakthrough curve was modeled using Linear Driving Force (LDF) and Thomas models. The LDF model represented better the CO2 breakthrough curve than Thomas model. The mass transfer resistance in NaY micropores can be assumed as the limiting step for CO2 adsorption in fixed bed, since the intraparticle mass transfer coefficient of LDF model was smaller than the experimental overall volumetric mass transfer coefficient, although external film resistance is not negligible.