Modeling of Carbon Dioxide Separation by Aqueous Ammonia Solution in a Hollow‐Fiber Membrane Contactor

Abstract CO2 separation from gaseous mixtures in a hollow‐fiber membrane contactor (HFMC) with conventional solvents has a high energy cost. Aqueous ammonia is an industrial solvent candidate that provides better features. A mass transfer model was developed to investigate the effect of operating parameters on the separation performance of an HFMC using aqueous ammonia for CO2 removal. The governing equations were solved numerically. The influence of the liquid flow rate, liquid concentration, and gas flow rate on CO2 removal was studied at different CO2 inlet concentrations. The liquid flow rate had a slight effect on the CO2 concentration at the shell exit, while the CO2 removal significantly changed with variation of the gas flow rate. Moreover, the proposed model can predict CO2 removal as well as axial and radial CO2 concentration profiles in the HFMC as a function of the main operating parameters.