A comparative study on pyrolysis of bundle and fluffy shapes of waste packaging plastics

The pyrolysis of waste packaging plastic was performed in a semi-batch reactor to study the effect of the shape of reactant on the compositions of pyrolysis oils under N-2 gas inflow conditions. Bundle and fluffy shapes of reactants were pyrolyzed at 400 degrees C for 90 min at N-2 inflow rates from 0 to 300 mL/min. The yields of pyrolysis oils were between 67.7 and 76.1% under the reaction conditions, and diesel-like middle oil (C-11-C-22) was mainly produced with mass fractions over 64%. The main oil product was mostly composed of n-paraffin and n-olefin compounds, and its mass fraction was considerably influenced by the reactant shape and the N-2 flow rate. The pyrolysis of the fluff reactant exhibited higher middle oil fractions with higher fraction ratios of n-paraffins to n-olefins than the bundle reactant. This study suggests that the compositions of pyrolysis oil could be controlled by the reactant shape and the N-2 inflow, which will provide important information for improving the quality of oil products in a large-scale of pyrolysis processes, and for developing a continuous pyrolysis system because the fluffy shape of reactant is more suitable for continuous feeding.