Performance of a Victorian brown coal and iron ore during chemical looping combustion in a 10Â kWth alternating fluidized bed

This paper presents the performance of Victorian Yallourn coal during chemical looping combustion with iron ore in a 10 kWth alternating fluidized bed reactor. CO2 was used as the gasification agent and fluidization gas. The effect of reaction temperature, fuel type and number of redox cycles were investigated. The NOx emission from the system was determined. The used oxygen carrier particles were characterized using SEM, EDS, XRD, and surface area analyser. It was found that the optimum condition for CO2 yield and carbon conversion was obtained at a temperature of 900 °C. Under this condition with the present reactor configuration, the average carbon conversion and CO2 yield over six cycles were found to be 92.2% and 82.9% respectively. Although Yallourn ash has high amounts of iron and silica, no ash deposition was detected on the oxygen carrier particles. The NOx concentration was found to be 25 ppm. Results from the carbon balance showed that about 1% was present in the solid phase; about 6.8% was unaccounted for and possibly elutriated out of the reactor. While favourable results were obtained for this configuration, the use of circulating fluidized bed reactors and an improved cyclone separation system would increase the carbon conversion and CO2 yield.