Abstract:
To overcome the carbon dioxide effects on the environment, chemical looping processes
are considered a novel way of burning carbonaceous fuel in which CO2 can be inherently separated. Chemical looping combustion (CLC) is a promising technology to separate CO2 from power plants that contains two reactor beds, a fuel reactor, and an air reactor. Solid oxygen carriers move cyclically between these interconnected reactors for the transfer of oxygen from the air to fuel without any contact between them. Ilmenite
(FeTiO3), is an attractive and low-cost promising oxygen carrier material for CLC. This project aims to study the structural and thermodynamic properties of ilmenite
through several characterizations to investigate the feasibility of using ilmenite as an
oxygen carrier in chemical-looping combustion. Ilmenite show low reactivity towards
fuel in CLC. Cerium due to its catalytic properties was used as an additive in ilmenite to
enhance its reactivity and oxygen transport capacity. Preparation of material was done by
the Solid-state reaction method. The thermogravimetric analysis (TGA) technique was
used to investigate the redox cycle behavior, OTC, fractional oxidation, and fractional
reduction of mass of ilmenite at a temperature of 900℃. Oxygen transfer capacity (OTC)
of ilmenite increased from 0.53% to 1.41% with a gradual increase in the amount of ceria. The structural properties are studied with the help of XRD and obtained a cubic fluorite structure for both Cerium oxide and iron titanium oxide. The identification peak of
ilmenite was observed at 413cm-1 , 403cm-1, and 395cm-1 wavelengths, and cerium oxide shows the peaks at second order bands are observed through Raman Spectra of the synthesized material. The vibratory characteristics are studied through FTIR spectroscopy. The peak at 657cm-1 may show the stretching vibrations of Fe-O and Ti-O. The characteristic band of Ce-O vibrations considers being a shoulder peak at 810cm-1
wave number. Some stretching bands of C-O and O-H are also observed. SEM analysis
confirms the formation of the pores on the ilmenite surface due to cerium oxide diffusion
and iron ions migration from bulk to the particle surface. Similarly, confirmation of
elemental composition was done by EDX.
