Enhancing Post-Combustion CO2 Capture in Power Plant – A Catalytic Approach

Improved solvent reaction kinetics and carbon capacity continue to be a major research interest for the scrubbing of CO2 in post-combustion processes. The DOE has set a new target for post-combustion CO2 capture of less than a 35% increase in the cost of electricity, while capturing at least 90% of the CO2 released during the combustion of fossil fuels in existing coal-fired power plants. In order to meet the DOE target, it will be necessary to promote the CO2 absorption rate in aqueous capture solutions. This work will discuss the use of catalysts to promote the reaction rate. Some current research efforts are targeted at developing new solvents or enhancing the absorption capabilities of some of the solvents already in use such as amine-based, ammonium-based, and alkali-carbonates. The use of catalytic additives in these solvents is one approach to promoting CO2 capture.

In this work, we describe the synthesis, characterization, and use of low cost non-toxic additives such as zeolites for CO2 capture rate enhancement. Ion-exchange reactions and metal impregnation were carried out on these additives to improve their catalytic properties. Results have shown that some zeolites provide catalytic enhancement in CO2 scrubbing when added to aqueous ammonium-based solutions.