Equilibrium and Absorption Kinetics of Carbon Dioxide by Solid Supported Amine Sorbent

The equilibrium and conversion-time data on the absorption of carbon dioxide (CO2) with amine-based solid sorbent were analyzed over the range of 303-373 K. Data on CO2 loading on amine based solid sorbent at these temperatures and CO2 partial pressure between 10 and 760 mm Hg obtained from volumetric adsorption apparatus were fitted to a simple equilibrium model to generate the different parameters (including equilibrium constant) in the model. Using these constants, a correlation was obtained to define equilibrium constant and maximum CO2 loading as a function of temperature. In this study, a shrinking core model (SCM) was applied to elucidate the relative importance of pore diffusion and surface chemical reaction in controlling the rate of reaction. Application of SCM to the data suggested a surface reaction-controlled mechanism for the temperature of up to 40 degrees C and pore-diffusion mechanism at higher temperature. Published 2011 American Institute of Chemical Engineers AIChE J, 57: 3153-3159, 2011