Energy-efficient direct air capture combining an impeller-based scrubber and anion exchange membrane electrolysis

[Geoengineering News]

https://www.sciencedirect.com/science/article/abs/pii/S1385894725120329

Authors: Sunghyeon Han, Jongmin Jin, Hui Song, Jong-In Han

24 November 2025

https://doi.org/10.1016/j.cej.2025.171186

Highlights

•Integrated system for CO2 capture and absorbent regeneration was developed.

•The impeller-based scrubber was optimized using a mesh sheet through CFD simulation.

•A CO2 removal efficiency of 84.1 % was achieved at L/G ratio of 2.

•The Electrochemical regeneration process obtained a low energy consumption of 4.28 GJ/t-CO2

Abstract

Direct air capture (DAC) is a technology developed to remove carbon dioxide (CO2) directly from the atmosphere. One of the most critical barriers to the commercialization of DAC is the high energy consumption. To address this rather fundamental and critical challenge, this study aims to develop an energy-efficient DAC system that integrates an exceptionally capable impeller-based scrubber for CO2 absorption with a high-performing electrochemical cell for absorbent regeneration. Computational fluid dynamics (CFD) simulations were employed to optimize the impeller design, and the results were experimentally validated. For the electrochemical cell, a strategy to minimize resistance and energy consumption was proposed. The integration of the impeller-based scrubber with the electrochemical cell enabled stable operation of the continuous process. The integrated system demonstrated a total energy consumption of 6.94 GJel/t-CO2 captured, representing a significant improvement over conventional DAC systems, which typically consume 7.5–12 GJ/t-CO2. This study successfully demonstrates the potential of an integrated DAC system, comprising an impeller-based scrubber and an electrochemical cell, as energy-efficient solution for atmospheric CO2 removal.

Source: ScienceDirect