(484c) Effect of Alumina Doping On Structure and Stability of CaO Based Sorbents for High Temperature CO2 Capture

Gunugunuri, K. R., University of Cincinnati
Smirniotis, P., University of Cincinnati
Qullin, S., University of Cincinnati

In an age where environmental concerns have become increasingly prevalent, efficient and carbon neutral methods for satisfying the global energy demand have become necessities. Increasing levels of greenhouse gases are widely regarded as a key factor in the shifts observed in global climate patterns. In this study, we reported that Flame synthesized doped Calcium-based novel refractory sorbents have shown excellent performance in CO2 adsorption. In our previous studies we incorporated several metals (Hf, W, Y, La, and Al) into calcium oxide lattice to improve stability of the sorbent during the CO2 adsorption experiments. Among these dopants, Alumina doped CaO with molar ratio of 10:3 showed very high adsorption stability during 100 cycles of operation and better adsorption capacity than Ca/Zr sorbents (our previous best system). We reported that the formation of perovskite type of structure in CaO-Al sorbent is responsible for the observed stability. The present study mainly focuses on the Ca-Al system and obtains the optimum combination during extended carbonation-decarbonation operation cycles in the presence of highly concentrated CO2. Various molar ratios of Ca: Al were synthesized using flame spray pyrolysis technique. The sorbents were characterized by BET, XRD, SEM and TEM techniques and analyzed using TGA. The optimal sorbent were tested under severe condition of high temperature. These interesting findings will be discussed in the presentation.