关键词: 化学链燃烧, 机械混合法, 铁基载氧体, 积炭

Abstract: The iron-based oxygen carriers with Al₂O₃ as an inert prepared by mechanical mixing were studied on thermal gravimetric analyzer(TGA).Through the thermograms reduced by CH₄,it was found that there was severe carbon deposition which even caused the mass curve to increase during reduction process. The concentration of reducing gas had a strong effect on the reaction rate as well as the degree of carbon deposition. At the same mass loss, higher concentration of the gas fuel tends to lead higher reaction rate while less carbon deposition. In addition, as the newly-generated carbon can be oxidized when introduced O₂, the amount of CO₂ during oxidation process can be applied to compare the level of carbon formation. With the redox cycles increased, the reaction was almost stable while the formation of carbon had a slightly downward tendency. Through analysis of the products with carbon deposition by X-ray diffraction and scanning electron microscope, there was Fe₃C generated and the other part of C existed on the carrier in the form of carbon filaments.

Key words: chemical-looping combustion, mechanical mixing, Fe-based carrier, carbon deposition