Mass Transfer Simulation of Caffeine Extraction by Subcritical CO2 in a Hollow-Fiber Membrane Contactor

A 2-dimentional mass-transfer model was developed to describe the solvent extraction of caffeine by subcritical CO2 through a hollow-fiber membrane contactor. The proposed model was based on the conservation equation for the concentration of caffeine in both aqueous and solvent phases as well as membrane. The model equations were solved by numerical method based on finite element. The model findings were verified through comparison with experimental data from the literature. The effects of contactor configurations, membrane characteristics, and operational conditions on the extraction of caffeine were investigated. The results indicated that the developed model well predicts the general behavior of caffeine extraction versus process variables.