The use of ilmenite as oxygen carrier with kerosene in a 300W CLC laboratory reactor with continuous circulation
Poster (konferens), 2012
Heavy oil residues are intermediate products from oil refineries. Some of those residues can be blended with lighter oil fractions to produce fuel oils, while others are waste products. Heavy oil residues are highly viscous at ambient temperature and contain high amounts of impurities such as sulfur, up to 6 wt-%, and metals, up to 1000 ppm. Using such fuel in a stationary combustion process with separation of CO2, namely chemical-looping combustion, might be an interesting option. The use of kerosene is an intermediate step in the upscaling of the process.
An ilmenite oxygen carrier was tested in a laboratory scale chemical-looping reactor with a design thermal capacity of 300 W. Ilmenite is a mineral iron-titanium oxide, which has been used extensively as an oxygen carrier in CLC. Two different kinds of fuels were used, a sulfur-free kerosene and one that contained 0.57 mass-% sulfur. Both fuels were continuously evaporated and directly fed into the chemical-looping reactor. Experiments were conducted for 50 h with the sulfur-free kerosene and for 30 h with the sulfurous kerosene. CO2 yields above 99% were achieved with both types of fuel. It seems that a significant and lasting improvement in the oxygen carrier’s reactivity was achieved by using sulfurous kerosene. No evidence of sulfur was found on the particles’ surface.