Prototype Co-Pyrolysis of Used Lubricant Oil and Mixed Plastic Waste to Produce a Diesel-Like Fuel

Natacha Phetyim,Sommai Pivsa-Art

doi:10.3390/en11112973

Abstract

The co-pyrolysis of used lubricant oil blended with plastic waste, namely high-density polyethylene (HDPE), polypropylene (PP), and polystyrene (PS), to produce a diesel-like fuel was studied. The proportions of the raw materials were optimized using laboratory scale pyrolysis at atmospheric pressure at a final temperature of 450 °C without a catalyst. The ratios of used lubricant oil (Oil) and plastic waste (Oil:HDPE:PP:PS) investigated were 50:30:20:0, 50:30:0:20, 50:0:30:20, and 50:30:10:10 by weight. It was found that the oil produced using an Oil:HDPE:PP:PS ratio of 50:30:20:0 exhibited most of the properties of standard diesel oil as specified by the Ministry of Energy (Thailand), except for its flash point, which was lower than the standard. Therefore, this proportion was utilized for the scaled-up testing in the co-pyrolysis prototype (10 kg/day). Three reactor temperature ranges (less than 400 °C, 400–425 °C, and 425–450 °C) were studied, and the properties of the oil products were analysed. The oil products produced at 400–425 °C exhibited diesel-like fuel properties.

Highlights

Pyrolysis is an environmentally friendly method to recover hydrocarbon materials due to its good capacity and lower environmental impact
The aim of this work is to apply a two-stage methodology for a prototype co-pyrolysis process for used lubricant oil blended with mixed waste plastics (HDPE, PP, and PS)
The co-pyrolysis of waste oil blended with three types of plastic waste were carried out under nitrogen gas at atmospheric pressure on a lab-scale

Summary

Introduction

Pyrolysis is an environmentally friendly method to recover hydrocarbon materials due to its good capacity and lower environmental impact. Only 8.4 million tons were disposed of by appropriate methods, i.e., landfilling or incineration. About 7.09 million tons of MSW were disposed of through dumping on the ground or in the water, or by combustion in open air [1]. In Thailand, hazardous mixed scrap waste comprising used lubricant oil, car batteries, and fluorescent tubes has been found throughout the country. For the pyrolysis of plastic waste, the co-existing hazardous waste must be sorted out. Used lubricant oil with low hazardous material content can be thermally decomposed to small hydrocarbons. During the pyrolysis reactions of mixed plastic waste, PE and PP are converted into a mixture of paraffins and olefins, while PS is converted into aromatic monomers [2]

Objectives

Results

Conclusion