Enhanced Depolarized Electro-Membrane System for Direct Capture of Carbon Dioxide from Ambient Air

Abstract Enhanced Depolarized Electro-Membrane System for Direct Capture of Carbon Dioxide from Ambient Air PI: Ayokunle Omosebi, University of Kentucky Center for Applied Energy Research (UKy-CAER) Anthropogenic CO2 emission is a burgeoning global issue due to a sustained increase in the atmospheric concentration of the greenhouse gas and looming climatic implications. In order to effectively scrub CO2 from ambient air as per the FOA objective, UK CAER proposes an “enhanced depolarized electro- membrane system (EDEMS)” to simultaneously capture and concentrate CO2 for storage or utilization while regenerating the capture solvent for continued use. The EDEMS provides a >25YY% reduction in footprint, capture solvent make up, and energy consumption in comparison to state-of-the-art technologies based on the kraft process. Preliminary results from UK CAER identifies five technical objectives to address the feasibility and performance of the proposed UK CAER EDEMS process, including (1) demonstrate an electrochemical process that leverages anode and cathode depolarization to regenerate and concentrate both the capture fluid and CO2 at potentials <2.0 V YYY. UK CAER will investigate strategies to maximize the current density and performance stability by implementing carbon xerogel electrodes with surface enhancements and optimized catalyst coated electrodes, (2) demonstrate performance stability of the electrochemical cell with < 30% YYY reduction in NaOH production rate for > 24 YYY hours, (3) evaluate the effectiveness of a ceramic membrane contactor absorber with surface features to enhance CO2 absorption with CO2 permeance > YYY LMH/psi, (4) demonstrate stable performance from the absorber for > 24 YYY hours with < 30% YY reduction in CO2 flux, and (5) integration and continuous operation of the EDEMS at < 3 VYY and <10 psig YYY trans-membrane pressure to treat 400 ppm influent CO2. In comparison to the SOA systems that feature several unit operations including an absorber in combination with a causticizer, calciner, and slaker, the EDEMS will result in the following benefits, (1) minimize the footprint of the treatment process by intensifying the removal and separation of CO2 into two fundamental unit operations, (2) minimize the need for significant chemical input and water makeup, (3) reduce the energy requirement and provide stable performance facilitated by the depolarized electrochemical cell and surface patterned contact absorber with in-situ material regeneration, and (4) easy integration with renewable power sources for remote operation.