Effect of support material on the performance of K2CO3-based pellets for cyclic CO2 capture

The K2CO3-based sorbent is promising for CO2 capture from the flue gas of fossil-fuel-fired power plant. In this work, various support/binder materials were utilized to prepare K2CO3-based sorbent pellets by an extrusion method, and their mechanical strength and CO2 capture performance were studied with different techniques. Results show that both the type of support/binder used and the content of K2CO3 have significant impact on the performance of the sorbents for CO2 capture. Among the sorbents prepared, K2CO3/Al2O3 exhibited the highest CO2 capture capacity of 71mg-CO2/g-sorbent, while K2CO3/clay demonstrated a much better compressive strength (25.2MPa), resistance to attrition and an interesting phenomenon of increased CO2 capture capacity with the number of cycles. It was also found that the support/binder material affects the physical properties of the pellets significantly.