Inexpensive calcium-modified potassium carbonate sorbent for CO2 capture from flue gas: Improved SO2 resistance, enhanced capacity and stability

Many sorbents have been studied for their CO2 sorption capacities with CO2 and N2 mixture. In reality, flue gases contain SO2. This research was designed to develop and evaluates an inexpensive and robust CO2 sorbent for actual flue gas. Ca(OH)2, CaO and CaCO3 were explored to serve as additives of K2CO3/γ-Al2O3 for CO2 capture. The three additives were characterized using different methods including thermal gravimetric, X-ray diffraction analyses and so on. It was found that Ca(OH)2 is the best additive of K2CO3/γ-Al2O3 for CO2 capture. The performances of K2CO3/Ca(OH)2/γ-Al2O3 were evaluated with a fluidized bed reactor under different conditions including the presence of SO2. Experimental results show that introduction of Ca(OH)2 made K2CO3/Ca(OH)2/γ-Al2O3 not only more capable in adsorbing CO2 but also more robust within SO2-containing flue gas. Thus the research work provides useful information for further development and subsequent commercialization of K2CO3/Ca(OH)2/γ-Al2O3 in coal-fired power plants.