Chemical-looping combustion of solid fuels in a 10 kW reactor system using natural minerals as oxygen carrier

Chemical-looping combustion (CLC) is an unmixed combustion concept where fuel and combustion air are kept separate by means of an oxygen carrier, and the CO2 capture is inherently achieved. This work presents findings from a continuously operated 10 kW pilot for solid fuels. Using petcoke as fuel, the following oxygen carriers are compared: (a) ilmenite, (b) ilmenite + lime, (c) manganese ore, and (d) manganese ore + lime. Compared to ilmenite, the use of manganese ore as oxygen carrier greatly enhanced the rate of gasification. By adding lime particles to the Mn ore, performance improved further. The addition of lime to ilmenite had a small beneficial effect on gas conversion and char gasification rate.