Combustion and gasification kinetics of pyrolysis chars from waste and biomass

Abstract The combustion and gasification of chars from medium temperature pyrolysis of municipal waste, electronic scrap, wood and straw has been investigated in view to potential technical applications. Reaction rate measurements with oxygen and carbon dioxide have been carried out at lower temperatures in the chemical regime, using a thermobalance, a differential flow reactor and a fluidised bed of sand. These chars from waste and biomass belong to the most reactive technical carbon materials. The major reason is the porous and highly disordered carbon structure, catalysts play a minor role. In char incineration tests in a small rotary kiln facility, complete burnout could be attained in 1h at temperatures down to ≈600°C. Use of oxygen-enriched air improves burnout and drastically reduces the flue gas volume and the specific emissions per ton of waste.