Microwave-assisted fluidized bed reactor pyrolysis of polypropylene plastic for pyrolysis gas production towards a sustainable development

Conversion of plastic wastes into value added fuels is a good way for sustainable development. In this study, microwave-assisted fluidized bed reactor pyrolysis of polypropylene plastic for pyrolysis gas production was experimentally investigated, and the effects of pyrolysis temperature (700, 800, 900, 1000 and 1100 °C), fluidizing velocity (1.18, 2.36, 3.54, 4.72 and 5.90 × 10^-3 m/s) and microwave power (600, 700, 800, 900 and 1000 W) on the pyrolysis gas products were analyzed. The results showed that when the pyrolysis temperature increased from 700 °C to 900 °C, the pyrolysis gas yield was increased from 65.2 wt% to 76.1 wt%, and then decreased to 60.7 wt% at 1100 °C. The pyrolysis gas yield was increased from 60.2 wt% to 76.1 wt% and then decreased to 42.0 wt% as the fluidizing velocity increased from 1.18 × 10^-3 m/s to 5.90 × 10^-3 m/s. The pyrolysis gas yield was increased from 52.2 wt% to 76.1 wt% and then decreased to 68.9 wt% as the microwave power increased from 600 W to 1000 W. An optimal pyrolysis gas yield of 76.1 wt% was obtained when the pyrolysis temperature was 900 °C, fluidizing velocity was 2.36 × 10^-3 m/s and microwave power was 800 W, and the pyrolysis gas was rich in C₃H₆ (68.6 wt%), CH₄ (15.5 wt%), and C₃H₈ (7.1 wt%) with a higher heating value of 51.8 MJ/m³. The pyrolysis gas produced with high heating value and abundant propylene has great potentials in applications, i.e., fuel cells.