Enhancing Potassium-Based Carbon Capture: Investigating Glycine’s Role and Stability Challenges

The ConsenCUS project is investigating the use of potassium hydroxide (KOH) and potassium carbonate (K₂CO₃) as cost-effective and environmentally friendly solvents for carbon capture. One challenge with these solvents is their relatively slow absorption kinetics, which can increase the size and cost of the absorption equipment. To address this, the project is exploring the use of amino acid salts like potassium glycinate as promoters to enhance the absorption rate.

However, the amino functional group in glycinate makes it susceptible to oxidative degradation, which can reduce the solvent’s performance and increase operating costs over time. This study examines the oxidative degradation of glycine in aqueous KOH and K₂CO₃ solutions, identifying the key degradation products and proposing a degradation mechanism. The findings provide valuable insights for the ConsenCUS project on the stability and performance trade-offs of using glycine as a promoter in the potassium-based carbon capture solvents.