Key Takeaways & Executive Findings
- •• • Catalytic desorption with solid acid catalysts reduces regeneration energy consumption by 40.0%–60.0% of total system energy, with potential savings of 30%–40% in desorption energy, as demonstrated by MOF-derived catalysts (e.g., Ce-MOF) achieving energy-efficient amine regeneration. • • Solid acid catalysts lower the desorption temperature from 110–130 °C to below 100 °C, enabling operation at atmospheric pressure and reducing equipment investment and operational costs. • • Synergistic acid sites (Lewis and Brønsted) in catalysts like heteropolyacid-modified Ce-MOFs enhance C–N bond cleavage, improving CO2 desorption rates by up to 50% compared to non-catalytic systems. • • Catalyst recovery and reusability are critical; studies show that catalysts like waste red mud and aluminum-modified diatomite maintain >90% activity after multiple cycles, ensuring economic viability.
Abstract
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.
1. Introduction
The chemical absorption of CO2 using alkanolamine solvents remains the most mature post-combustion capture technology, yet its commercial deployment is hindered by the high energy penalty of solvent regeneration. The desorption step alone consumes 40%–60% of total plant energy, primarily due to the strong C–N bonds in carbamate species and the need to maintain temperatures of 110–130 °C. This thermal demand leads to excessive steam consumption, solvent degradation, and equipment corrosion, making the process economically prohibitive at scale. While process optimizations such as heat integration and novel solvents have been explored, they often involve trade-offs between absorption capacity and regeneration energy.
Catalytic CO2 desorption using solid acid catalysts offers a direct intervention at the molecular level. By providing Lewis and Brønsted acid sites, these catalysts facilitate proton transfer and destabilize the carbamate, lowering the activation energy for CO2 release. This enables efficient regeneration at reduced temperatures, potentially below 100 °C, and at atmospheric pressure. Moreover, the heterogeneous nature of solid catalysts allows for easy separation and reuse, mitigating solvent contamination issues. This review synthesizes recent advances in catalyst design, focusing on structure-activity relationships and mechanistic insights, to evaluate the feasibility of this technology for industrial deployment.
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TAN Zhan, ZHANG Xiaowen, HE Huiling, ZHANG Zhiyang, LIU Yuxiang, MAO Jiayu, YOU Kuiyi, LUO Hean (2026). Research progress on solid acid catalysts for enhanced CO2 desorption from alkanolamine solutions in the past five years. Journal of Fuel Chemistry and Technology. https://doi.org/10.3724/2097-213X.2026.JFCT.0001
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Frequently Asked Questions
What is the maximum reduction in regeneration energy achieved with solid acid catalysts, and what are the underlying mechanisms?
Studies report up to 30–40% reduction in regeneration energy compared to non-catalytic processes. For instance, MOF-derived catalysts with synergistic acid sites lower the desorption temperature from 110–130 °C to below 100 °C, reducing steam requirements. The mechanism involves Lewis acid sites polarizing C–N bonds and Brønsted acid sites donating protons, facilitating carbamate decomposition.
How do solid acid catalysts affect solvent degradation and equipment corrosion in amine-based systems?
By enabling lower regeneration temperatures, solid acid catalysts reduce thermal degradation of amines, which typically occurs above 120 °C. Additionally, the heterogeneous nature of catalysts allows for easy separation, preventing accumulation of corrosive species. However, long-term stability of catalysts under acidic and high-temperature conditions must be validated.
What are the scalability challenges for catalytic desorption from laboratory to industrial scale?
Key challenges include maintaining catalyst activity and stability in continuous flow reactors, ensuring uniform dispersion in viscous amine solutions, and developing cost-effective catalyst regeneration methods. Pilot-scale studies are needed to assess mass transfer limitations and pressure drop in packed columns.
Can solid acid catalysts be integrated into existing amine scrubbing plants without major modifications?
Yes, catalysts can be added to the rich solvent stream before the desorber or packed into the desorber column. However, reactor design must accommodate catalyst particle size and potential fouling. Retrofitting may require adjustments to heat exchanger networks to optimize low-temperature operation.
What is the cost comparison between catalytic and non-catalytic regeneration, including catalyst replacement and disposal?
Catalytic regeneration reduces energy costs by 30–40%, which can offset catalyst expenses. For example, waste-derived catalysts like red mud are low-cost, while MOF-based catalysts are more expensive but offer higher activity. Life-cycle assessments indicate net cost savings of 15–25% when considering energy savings and reduced solvent makeup.
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