Gasification characteristics of waste plastics (SRF) in a bubbling fluidized bed: Effects of temperature and equivalence ratio

Abstract

This study investigates air gasification properties of SRF with high content of residual mixed waste plastic in a 1 kg/h lab scale bubbling fluidized bed gasifier. Gasifier internal diameter is 0.114 m and its height is 1 m. Silica sand particles with a mean diameter of 400 μm is used as the bed material. During the gasification experiments the effect of bed temperature is determined in the range of 600–900 °C and the effect of air-to-fuel equivalence ratio (ER) is investigated in the range of 0.15–0.30. Gas analysis is conducted using a non-dispersive infrared analyzer and gas chromatograph. As the operating temperature and ER increases, the gas yield increases, and tar yield decreases. The yield of CO, CH4, H2, and C2H2 in the gas product increases with temperature, whereas those of CO2, C2–C3 hydrocarbons decreases. The increase in ER decreases the concentrations of CO, CH4, H2, and C2–C3 hydrocarbons and increases the CO2 in the gas product. H2/CO ratio substantially increases with rising temperature and decreases with rising ER. Carbon conversion efficiency (CCE) and cold gas efficiency reach peak at 800 °C and ER of 0.25.