Mass transfer performance and correlation for CO2 absorption into aqueous 1-Dimethylamino-2-propanol (1DMA2P) solution in a PTFE hollow fiber membrane contactor

Abstract

1-Dimethylamino-2-propanol (1DMA2P), a tertiary amine, has been regarded as the promising absorbent with relative higher reaction rate and high capacity for CO2 capture. The CO2 absorption into aqueous 1-Dimethylamino-2-propanol (1DMA2P) solution in the polytetrafluoroethene (PTFE) hollow fiber membrane contactor (HFMC) was firstly studied experimentally in the present work. The CO2 absorption performance in terms of the CO2 absorption flux was comprehensively investigated by considering a series of operating parameters, including liquid velocity, gas velocity, liquid phase temperature, CO2 partial pressure, initial lean CO2 loading in the liquid phase, amine concentration and flow orientations. The experimental results indicated increasing liquid velocity can significantly enhance CO2 absorption performance over a reasonable range of liquid velocities while similar trends were observed by increasing gas velocity, liquid temperature, CO2 partial pressure and amine concentration properly. By contrast, there was a severe loss of CO2 absorption flux with increase in lean CO2 loading. Counter-current flow achieved the improvement of CO2 absorption performance compared to co-current flow. Besides, to predict the CO2 absorption performance at various operating parameters, satisfactory correlations of KG and JCO₂ were proposed for the 1DMA2P-CO2 system.