Direct CO 2 mineralization using seawater reverse osmosis brine facilitated by hollow fiber membrane contactor

Abstract

The urgent demand for sustainable water management has given rise to widespread seawater desalination, leading to significant brine waste and a substantial carbon footprint resulting from extensive energy consumption. To address this challenge, we propose the utilization of hollow fiber membrane contactors (HFMCs) for direct CO 2 mineralization. By mimicking lotus leaf surfaces, HFMs are successfully modified to possess superhydrophobic and antifouling properties, resulting in enhanced operational stability, as evidenced by a marginal 3.5 % flux decline after 10 days. Moreover, HFMCs incorporating these modified membranes achieve remarkable CO 2 removal (up to 94 %) and selective mineral carbonation of Ca 2 + and Mg 2 + through staged pH swing. A techno-economic analysis highlights the superiority of our system compared to traditional amine scrubbing, with a 35 % reduction in CO 2 capture costs and the generation of valuable products. This innovative application of HFMCs presents a promising solution for CO 2 management, transforming seawater reverse osmosis brine into a valuable resource.