Research progress on solid acid catalysts for enhanced CO2 desorption from alkanolamine solutions in the past five years
The escalating global demand for carbon reduction has positioned chemical absorption using alkanolamine solvents as the predominant post-combustion CO2 capture technology, owing to its high absorption efficiency and process maturity. However, the regeneration of CO2-rich solvents is energy-intensive, with the desorption step accounting for 40.0%–60.0% of total energy consumption. Traditional amine-based methods suffer from high energy penalties, solvent degradation, and equipment corrosion, limiting scalability. Catalytic CO2 desorption, employing solid acid catalysts (SACs), has emerged to address these challenges by lowering the activation energy for CO2 release, enhancing reaction kinetics, and enabling efficient regeneration at lower temperatures (110–130 °C reduced). This review systematically examines research from the past five years on key catalyst materials, focusing on structure-activity relationships, synergistic mechanisms of Lewis acid, Brønsted acid, and basic sites, and their influence on desorption pathways. It highlights that SACs not only improve desorption dynamics but also facilitate catalyst recovery, avoiding adverse effects on absorption. The paper analyzes current scientific and technological challenges, including catalyst stability, selectivity, and scale-up, and provides an outlook on industrial application in low-cost carbon capture. Key findings indicate that catalysts such as metal-organic frameworks (MOFs), heteropolyacids, and waste-derived materials can reduce regeneration energy by up to 30%–40% while maintaining high desorption efficiency. The review underscores the potential of catalytic regeneration to significantly lower operational costs and enhance the viability of amine-based CO2 capture in industrial settings.