Experimental and modeling study of CO2 capture by phase change blend of triethylenetetramine-ethanol solvent

Abstract

Post combustion Carbon capture based on chemical absorption is the best-known technology to reduce CO2. Recently, attention has been paid to biphasic solvents due to their excellent potential in reducing energy consumption. This study investigated carbon dioxide absorption by biphasic non-aqueous triethylenetetramine (TETA)-ethanol solvent in a T-shaped microchannel. Effect of four parameters including: concentration of TETA (4–8 wt%), liquid flow (2–5 ml/min), inlet CO2 concentration (5–20 vol%) and gas flow (100–175 ml/min) have been examined. Mass transfer characteristics has been assessed by investigation of absorption percentage, molar flux and overall mass transfer coefficient. The results show that increasing the concentration of amine diminishes all three responses by increasing the solution viscosity. As a result, it decreases the penetration of CO2 in the solution and the rate of absorption.Furthermore, the TETA-ethanol phase change solvent has been compared with aqueous monoethanolamine (MEA). The results of this comparison indicated that the efficiency of CO2 absorption and mass transfer coefficient, for TETA-ethanol biphasic solvent are higher than MEA solvent, respectively. Finally, the dimensionless Damköhler number (Da) was utilized in the new correlation to predict KLa for CO2 absorption into TETA-Ethanol solution with acceptable accuracy.