Model study of CO2 absorption in aqueous amine solution enhanced by nanoparticles

An investigation for the enhancement of nanoparticles (TiO2, MgO, SiO2) on the mass transfer for CO2 absorption was presented through both the experiment method and a 3-D unsteady model. The effects of nanoparticle loadings, nanoparticle diameters, nanoparticle species, solution species, experimental temperature and the CO2 initial volume fraction on the CO2 absorption were investigated in this paper. Considering the chemical reaction between gas and solution, a 3-D unsteady model was developed to study the mass transfer for CO2 absorption enhanced by nanoparticles in monoethanolamine (MEA) solution. Based on the analysis of zwitterion mechanism in the process of chemical reaction between MEA and CO2, it was shown that the rate of chemical reaction is proportional to the concentration of CO2 due to the large MEA concentration and the zero-order reaction in the liquid membrane. Further, the differential equation of mass transfer in three dimensions was set up, which is related to the rate of chemical reaction and the random distribution ofnanoparticles. The random distribution of nanoparticles in a fluid element was determined by Monte Carlo method. In addition, the absorption experiments of CO2 in MEA solution using the bubbling reactor were carried out, which could also verify the correctness of the developed model. (C) 2017 Elsevier Ltd. All rights reserved.