Integration of membrane contactors and catalytic solvent regeneration for efficient carbon dioxide capture

To develop an energy-efficient and available carbon dioxide (CO 2 ) capture technique with amine-based solvents and membrane contactors (MCs), an innovative technological route was proposed to remove CO 2 from industrial flue gas by coupling MCs with catalyst-aided solvent regeneration (MC-CR). A laboratory-scale experimental setup with ceramic membrane module was then designed and built to accurately estimate the performance of the MC-CR route, using aqueous monoethanolamine (MEA) and powder metatitanic acid [TiO(OH) 2 ] as the solvent and catalyst, respectively. The results indicated that the nanofluid effect of the catalyst reduced the mass transfer resistance and promoted a concentration change in the liquid film , resulting in a high CO 2 absorption rate.The surface acidic sites of TiO(OH) 2 boosted the process of proton transfer in the solvent, thus facilitating the decomposition of carbamate. The CO 2 capture efficiency increased by 9.48% and the energy consumption of solvent regeneration considerably decreased by 40.8% at dosage of 2 wt% TiO(OH) 2 . In addition, matched pressure regulation for gas–liquid flow in the MCs effectively avoided membrane fouling and wetting after 180 min continuous operation. Industrial-scale simulation indicated that the MC-CR route achieved a low capture cost at $46.7/t CO 2 , a decrease of 28% compared with the cost of the traditional route. This study established the groundwork for developing MC technology as an effective approach for low-cost industrial CO 2 capture.