Exploiting an Alternative CO2 Absorption Process by Efficient Solvent Mixture

Abstract

CO2 capture greatly helps with greenhouse gas mitigation. Chemical and physical absorption can control CO2 emission, but these methods are costly. To reduce the cost, an efficient solvent mixture of tetramethylammonium hydroxide (TAMH), tetramethylene sulfone (TMS), and ethylene glycol (EG) is assessed. Gas–liquid equilibrium, reaction kinetics, and mass transfer models are developed and validated by experiments. Henry’s constant, reaction kinetics, and mass transfer coefficients between CO2 and TAMH-TMS-EG are identified. CO2 loading and mass transfer coefficient are, respectively, obtained as 0.55 mol/molTAMH and 4.02kmol/m2/s/kPa, which are on average 25% and 34% higher than the typical MEA process. The theoretical energy consumption amount for desorption of TAMH-TMS-EG-CO2 solutions is identified as 1.11 GJ/t to 1.34GJ/t. Minimum mass transfer resistance is determined at 40% to 80% TMS fraction. A temperature bulge shift and improvement in the interface characteristics enhance mass transfer due to uni...