Organic-inorganic composite membrane-based transport membrane condenser: Performance of waste recovery from hot gas mixture of CO2 and water vapor

Abstract

Recovering the waste heat from the stripped gas (i.e., the gas mixture of CO2 and water vapor) using the transport membrane condenser is an effective approach to reduce the regeneration heat consumption in CO2 chemical absorption process. To decrease the capital expenditure of transport membrane condenser, this study prepared an inexpensive organic–inorganic composite membrane through adding the hydroxylated boron nitride (BN-OH) into the polyvinylidene fluoride (PVDF) during membrane preparation via nonsolvent induced phase separation. Then the composite membrane was placed in a membrane cell as the transport membrane condenser to recovery the waste heat of simulated stripped gas. The results showed that when compared to the single PVDF membrane, the addition of BN-OH improves the pore uniformity, thermal conductivity, and porosity of membrane. Among all the prepared composite membranes, the composite membrane adding 5 wt% nano-sized BN-OH particles exhibits the best waste heat recovery performance. Furthermore, a decrease in the membrane thickness in addition to an increase in polyvinylpyrrolidone dosage during membrane preparation enhances the waste heat recovery performance, however deteriorates the mechanical strength of membrane. Moreover, the organic–inorganic composite membrane prepared in this study demonstrated a good stability of waste heat recovery performance during a long-term operation, showing a potential in the rich solvent-split modified carbon capture process to achieve a low capital expenditure and a high waste heat recovery performance.