Chemical-looping combustion and chemical-looping with oxygen uncoupling of kerosene with Mn- and Cu-based oxygen carriers in a circulating fluidized-bed 300 W laboratory reactor

The fuel conversion properties of two oxygen carriers, based on manganese- and copper-oxide, were investigated with sulfur-free kerosene in a chemical-looping reactor with continuous particle circulation. An injection system was used, in which kerosene was evaporated, mixed with superheated steam and fed directly into the chemical-looping reactor. The manganese-based oxygen carrier M4MZ-1200 was composed of 40 wt.% Mn3O4 and 60 wt.% MgO–ZrO2 and was used for chemical-looping combustion (CLC) experiments for 17 h. The copper-based oxygen carrier C2Z-1050 was composed of 20 wt.% CuO and 80 wt.% ZrO2 and was used for 45 h with fuel addition. With M4MZ-1200 oxygen carrier, 83–99.3% of the fuel carbon was converted to CO2 at temperatures between 800 °C and 950 °C and fuel flows equivalent to 144–462 Wth. With C2Z-1050 oxygen carrier, 99.99% CO2 yield was achieved at 900 °C and 144 Wth fuel equivalent. The particles were analyzed before and after the experiments using XRD, SEM, BET surface area and particle size distribution. Whereas nearly the whole batch of M4MZ-1200 particles was disintegrated after the experiments, only about 5% of the C2Z-1050 particles turned to fines. This is the first time that combustion of liquid fuel using CLOU is demonstrated in a continuous unit.