Distribution and characteristics of pyrolysis products from automobile shredder residue using an experimental semi-batch reactor

Abstract

Automobile shredder residue (ASR) generated by end-of-life vehicles, comprises more than 20% of a new vehicle by weight. Significant amounts of polymers in ASR, such as Poly Propylene (PP), Poly Ethylene (PE), Acrylonitrile Butadiene Styrene (ABS), Ethylene Propylene Ethylidene Nobomene (EPDM), rubber, Polyethylene Terephthalate (PET), Poly Amide (PA), and Poly Vinyl Chloride (PVC), can be used as energy or chemical sources, whereas other components, such as tires, rubber, glass, wood, sand/dust, and heavy metals inhibit the recycling of ASR. In many countries, landfill use of ASR is regulated, so landfill costs have increased, as has inappropriate disposal; sending ASR to landfills will be needed to be regulated in Korea. Pyrolysis has been suggested as an economically feasible recycling and recovery technique for ASR in Korea and other advanced countries. Before such technology is implemented, the characteristics of pyrolyzed products should be investigated. Shredded samples from the facility were collected, and calorific value, elemental analysis, and leaching tests were performed to determine ASR characteristics. Pyrolysis experiments were conducted at five different temperatures, 400, 500, 600, 700, and 800 °C, and the product distributions of gas, tar, and char were investigated. The optimal temperature for ASR pyrolysis, in terms of yield efficiency, was found to be 600 °C. The mean calorific value was also found to be higher in this case; thus, ASR can be treated as an auxiliary fuel. During pyrolysis, there were high ignition losses of light and heavy fluff, due to the presence of organic materials. The leaching concentrations of all tested heavy metals were found to be within the Korean guideline values. In terms of carbon number distributions, pyrolysis of ASR at 600 °C was optimal. For further utilization of pyrolysis products as fuel, the characteristics of char, oil, and gas were investigated with an experimental batch reactor.