Production and droplet combustion characteristics of waste tire pyrolysis oil

This work aims to study the pyrolysis of scrap tires as an end-to-end process, from its production to the combustion characteristics of the tire pyrolysis liquid (TPL) obtained. The TPL was produced in a continuous auger reactor (150 kWth) and its combustion characteristics were acquired through a drop tube facility, where the TPL burning behavior was compared to that of conventional heating oil (FO). The evaluated combustion characteristics included droplet and flame size evolution, burning rates, soot shell morphology, microexplosion occurrence and soot analysis. When compared to FO, TPL displayed considerably lower burning rates, although the consistent occurrence of microexplosions effectively shortened the TPL droplets lifetimes below those of FO. TPL also presented smaller flames and a higher propensity to soot. A TPL-FO blend of interest for heating applications (with only 5% of TPL due to its high sulfur content), was also tested, showing identical results to those of neat FO for all the studied combustion characteristics. The reported results are thought to provide valuable experimental data regarding the combustion behavior of a well characterized tire pyrolysis oil, which could also be used as the fuel-specific input data required for the simulation of realistic spray flames. •A Tire Pyrolysis Liquid (TPL) was produced and subsequently characterized.•Single droplet combustion tests were performed to extract its combustion behavior.•TPL had lower burning rates and higher soot yield than conventional heating oil.•Occurrence of microexplosions for TPL effectively reduced its conversion time.•The examined TPL-heating oil mixture behaved identically as heating oil.