Enhanced K2CO3 utilization efficiency of K2CO3/Al2O3 adsorbents using a large-scale production spray agglomeration synthesis

The decarbonization of K2CO3-based adsorbents presents significant potential for widespread applications in the fields of CO2 capture and carbon emission reduction. However, conventional synthesis methods employed in the early stages, such as simple impregnation and sol-gel techniques, encounter numerous challenges when it comes to industrial scaling-up. Therefore, there is an urgent need for a technology that can facilitate large-scale production. The scalable spray agglomeration technique is a promising technology, but its applicability in synthesizing K2CO3-based adsorbents still requires further validation. In this study, K2CO3/Al2O3 adsorbents with 40 wt % loading were synthesized using conventional impregnation, dry mixing, and spray agglomeration. Surprisingly, the adsorbents synthesized by dry mixing exhibited a modest CO2 adsorption capacity of only 0.7 mmol/g. Conversely, the K2CO3 utilization efficiency of K2CO3/Al2O3 adsorbents synthesized via spray agglomeration reached 86 %, despite a slightly lower CO2 adsorption capacity compared to conventional impregnation (lower by 0.69 mmol/g). Further investigation into the effect of different K2CO3 loadings (10 wt% to 50 wt%) on the K2CO3/Al2O3 adsorbents synthesized by spray agglomeration. It revealed that an optimal K2CO3 loading of 30 wt % resulted in the highest CO2 adsorption capacity, reaching 1.89 mmol/g. The CO2 adsorption test was conducted at a constant reaction temperature of 60 degrees C using simulated flue gas comprising 10 % CO2, 10 % H2O and a balance of N2. It is worth noting that excessive K2CO3 loading led to an undesirable pore structure in the adsorbents. The load-optimized K2CO3/Al2O3 adsorbents, synthesized via spray agglomeration, offer a straightforward synthesis process and demonstrate immense potential for application. This research provides novel insights and directions for the development of efficient K2CO3-based adsorbents.