Chemical looping combustion of waste-derived fuel at 150 kW pilot-scale: Fuel conversion behavior and CO2 capture

To reduce emissions from waste management, chemical looping combustion can be applied to waste-to-energy processes for carbon capture. This study presents experimental results testing chemical looping combustion of waste-derived fuel at pilot-scale (150 kW th ) using ilmenite as oxygen carrier. For comparison, tests with biomass were conducted under similar conditions. Six operating periods were analyzed focusing on hydrodynamics, gas-phase composition including heavier hydrocarbons such as benzene, carbon distribution, and energy recovery. Additionally, the performance indicators oxygen demand and carbon capture efficiency are determined. The results demonstrate the technical feasibility of chemical looping combustion with waste as fuel. Stable operation was achieved in all cases, including a modified configuration for simplified scale-up without a secondary circulation pathway coupling the bottom of both reactors. While reactor hydrodynamics remained consistent, disabling the bottom-loop led to lower temperatures and significantly reduced fuel conversion. Compared to biomass, waste yielded less residual carbon monoxide and hydrogen and higher concentrations of heavier hydrocarbons like ethylene and benzene in the fuel reactor off-gas, particularly at lower temperatures. Carbon slip was similar for both fuels with capture efficiencies ranging from 92 % to 96 %. Oxygen demands were determined above 30 % with slightly lower values observed for waste compared to biomass. Up to 60 % of the fuel chemical energy remained in combustible off-gas species, indicating substantial incomplete conversion but also potential for gasification-oriented applications. This highlights the need for further optimization of reactor design, oxygen carrier materials, and operating conditions before large-scale deployment in future waste management systems.