(688g) Effect of Zirconia Doping On Calcium Oxide On Stability and Performance During the Extended Operating Cycles

Growing energy demand and subsequent CO₂ production call for highly efficient CO₂ capture process, which is benign to the environment. Flame synthesized doped Calcium-based novel refractory sorbents have shown excellent performance in CO₂ adsorption. In our previous studies we incorporated several metals (Co, Si, Ti, Cr, Hf, W, Y, La, Ce, Zr) into calcium oxide lattice to improve stability of the sorbent during the CO₂ adsorption experiments. Among these dopants, Zirconia doped CaO with molar ratio of 10:3 showed enormous adsorption stability during 100 cycles of operation. We reported that formation of orthorhombic structured CaZrO₃ in CaO-Zr sorbent is responsible for the observed stability. This impressive relationship between CaO and Zr has become the interest of our research in present study. Therefore the present study focuses on the Ca-Zr system and obtains the optimum combination during extended carbonation-decarbonation operation cycles in the presence of highly concentrated CO₂. Various molar ratios of Ca: Zr were synthesized using flame technique. The sorbents were characterized by BET, XRD, SEM and TEM techniques and analyzed using TGA. The sorbent with optimum molar ratio exhibited huge stability up to 1000 carbonation-decarbonation cycles with considerable molar conversion. Our analysis showed that increase in quantity of CaZrO₃ in the sorbent improves the resistance to sintering. The optimal sorbent were tested under severe condition of high temperature. These interesting findings will be discussed in the presentation.