Design of a 1000 g Laboratory-Scale Plastic Pyrolyzer System for Converting Polyethylene Terephthalate (PET) to Derived Oil

Abstract

This study presents the design and material selection of a 1000 g pyrolysis system for converting waste Polyethylene Terephthalate (PET) bottles into diesel fuel. The volume, height, wall thickness, the flat-end thickness of the top of the pyrolysis reactor, and the thickness of the insulation material were designed as 3,376,800 mm³, 220 mm, 2.13 mm, 4.49 mm, and 3 mm respectively. The system is designed to operate at a maximum temperature of 400 ℃, based on the vaporization temperature of diesel being within 300–360 ℃.

The material balance of the 1000 g of PET plastic feedstock was based on 38.89 wt% liquid fuel, 52.13 wt% gas, and 8.91 wt% char yields, while the power rating of the heating element was designed as 682.6 kJ. The safety analysis associated with high-temperature processing, gas handling, and high-pressure systems was accounted for in the design and mitigated through the implementation of safety protocols.

The reactor was designed to be operationally safe, with a total cost of fabrication and safety analysis estimated at four hundred and forty-five thousand naira (₦445,000) only. This pyrolysis system demonstrates a promising approach for the conversion of waste PET plastics to a valuable fuel, gas, and char.