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

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.