(620f) Evaluation of Pyrolysis Wax As a Solvent in Polyolefin Pyrolysis Processing

A lack of recycling techniques has led to plastic pollution becoming one of the world's biggest environmental crises. Plastic fast pyrolysis is a recycling technology that aims to turn waste plastic into virgin resin, although some challenges do remain. In this study, pyrolysis wax, a by-product of the plastic pyrolysis process, was evaluated as a solvent for plastic waste . The viscosity of a 1:1 ratio mixture pyrolysis wax with HDPE and LDPE at 220, 240, and 260°C were measured. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were performed at three different weight percentages of the samples (25, 50, and 75 wt%) to determine the solubility and characterize the thermal behavior of HDPE/pyrolysis wax, LDPE/pyrolysis wax, and PP/pyrolysis wax mixtures. A unique semi-batch pyrolysis pilot plant, including a dissolution tank and a tubular pyrolysis reactor, was used to demonstrate the application of the pyrolysis wax solvent. In addition, the pyrolysis products from conversion of the 1:1 HDPE/pyrolysis wax ratio were similar the product distribution from pyrolysis of the 1:1 HDPE/paraffin wax mixture ratio at 600 °C. According to the results, plastic waste and pyrolysis wax are soluble at 240°C up to 75 wt%. In comparison to polyolefin/paraffin wax, the polyolefin/pyrolysis wax mixture exhibits a lower viscosity. Furthermore, the pilot plant experiment, with its semi-batch system involving a dissolution tank, verifies the feasibility of using pyrolysis wax as a viscosity-reducing strategy prior to pyrolysis.