Low-Density Polyethylene Plastic Waste to Liquid Fuel Using Pyrolysis Method: An Effect of Temperatures on the Oil Yields Physicochemical Properties

Abstract

Pyrolysis has been recognized as the most effective way to convert waste for producing alternative fuels through thermal degradation at elevated temperatures. In this work, pyrolysis was applied to convert plastic wastes into oil yields. The physical and chemical properties of the obtained oil yields were analysed to find out whether their existence can be ascertained as the availability of standard fuel. This study was conducted in a real pilot plant using samples of low-density polyethylene plastic waste. The pyrolysis temperature varied at 200 °C, 250 °C, 300 °C, 350 °C, and 400 °C for two hours with a heating rate of 10 °C/min. Physically, the pyrolysis resulted in an oil yield similar to commercial fuel oils, having a light-yellow colour in all various pyrolysis temperatures. Gas Chromatography-Mass Spectrometry analysis showed the change in hydrocarbon chain and chemical molecular structures, thus influencing its physical properties. The increase in hydrocarbon chain length and in cyclic molecules and alkyl compounds as the temperatures increased led to the increase in density, viscosity, flashpoint, and octane number within the range of standard commercial oil fuels. Even though there was an increase in calorific values, these values were still under the commercial standard oil values. However, this can be tolerated by providing any oil-yield refined treatments.