Air gasification of mixed plastic wastes using a two-stage gasifier for the production of producer gas with low tar and a high caloric value

Air gasification was conducted with a fraction of mixed plastic wastes in a newly developed two-stage gasifier. In this work, the influence of the reaction parameters, such as equivalence ratio, upper-reactor temperature and feed size, on the producer gas composition and tar removal were investigated. In addition, the effects of activated carbon and dolomite were also examined. At an equivalence ratio of 0.21, a very clean producer gas was obtained with a LHV of 13.44 MJ/Nm³. Activated carbon had a better tar removal efficiency than dolomite. The amount of additive had significant effects on the tar removal efficiency and hydrogen production. When 640 g of activated carbon was applied, the total tar production was about 2.5 times less and H₂ production two times higher than without activated carbon.