Assessment of mass transfer intensification potential for a CO2 capture process using three-phase fluidized bed

Abstract

In order to assess the post-combustion CO2 capture intensification potential, a detailed mathematical model was developed for a three-phase fluidized bed. As solvents, various aqueous solutions were used e.g. NaOH and MEA with and without glycerol addition. An innovative mass transfer equipment is presented, a three-phase gas-solid-liquid fluidized bed absorber, in which the bed of low-density inert solid particles is fluidized by the counter current flow of gas as a continuous phase and liquid as a dispersed phase. Experimental data from a pilot plant was used to validate the developed model. The hydrodynamic parameters determined were the followings: fluidized bed expansion ratio, liquid holdup and bed pressure. The most important efficiency parameter, the effective mass transfer area, was assessed. The results show that by using a three-phase fluidization column, the mass transfer parameters exhibit significant increases (8–10 times) in comparison to conventional packed beds. In addition, introducing glycerol to NaOH and MEA solutions was investigated as a potential method to further improve the overall CO2 absorption performance. As the results show, the glycerol addition intensifies the CO2 absorption process by about 10 %.