Materials for Energy, Efficiency and Sustainability: TechConnect Briefs 2016Materials for Energy, Efficiency and Sustainability TechConnect Briefs 2016

Materials for Solar Technologies Chapter 2

Sustained Solar Fuel Production in Multiple Thermochemical Cycles Using Sol-Gel Derived Ferrite Nanopowders

R. Bhosale, P. Sutar, A. Kumar, F. AlMomani, I. Alxneit, J. Scheffe
Qatar University, Qatar

pp. 31 - 34

Keywords: solar fuel, ferrite, sol-gel, thermochemical cycles

According to the recent studies, it is expected that the global energy requirement will increase from 14 TW to 30 TW by the year 2050. Currently, fossil fuels are the major energy source utilized for the fulfillment of the energy requirement. Due to the excessive utilization of fossil fuels, the concentration of greenhouse gases in the atmosphere is increasing day by day and hence there is a pressing need to develop technologies to produce carbon free renewable fuels. The liberated CO2 can be re-energized into CO via ferrite based thermochemical looping process using concentrated solar energy. The CO produced via solar thermochemical CO2-splitting can be combined with H2 derived from ferrite based solar thermochemical water-splitting process to produce solar syngas which can be further processed to liquid fuels such as Methanol, Diesel, and Kerosene via the Fischer-Tropsch process. The current research trends in solar thermochemical community are focused towards high and constant levels of solar fuel production in multiple cycles and it is believed that non-volatile mixed metal oxides such as ferrites will significantly improve the production of solar fuels. This investigation reports the synthesis of a variety of ferrites using propylene oxide assisted sol-gel method. To synthesize different ferrites, respective metal precursors were dissolved in ethanol with the help of a sonic bath and a predetermined amount of propylene oxide was added to this solution for the formation of ferrite gel. As-synthesized gels were dried and heated upto different temperature in air. Obtained calcined powder was characterized using various analytical techniques such as powder X-ray diffraction, BET surface area analysis, scanning (SEM) & transmission electron microscopy (TEM), and Inductively coupled plasma spectrometer (ICP). Synthesized ferrite nanopowders were further examined for their solar fuel production ability by performing multiple thermal reduction (inert atmosphere) and oxidation (in presence of H2O/CO2) cycles in a high-temperature thermogravimetric analyzer (TGA). The ferrite powder was thermally reduced at 1400oC while the oxidation was performed at different temperatures. O2 and H2/CO release was further monitored by gas chromatography. The results obtained indicate that the sol-gel derived ferrites produced high and constant levels of H2/CO as compared to previously reported metal oxides in multiple thermochemical cycles as. The results related to synthesis, characterization and thermochemical conversion of H2O/CO2 into solar fuels will be presented in detail.