Activation of Anthracite Combustion Using Pyrolysis Oil from Thermal Conversion of Waste Car Tires

Abstract

The ignition and combustion of anthracite modified by the addition of pyrolysis oil obtained during thermal processing of waste car tires (WCTs) had been studied. The mass fraction of WCT pyrolysis oil was varied in the range from 5 to 30 wt %. The additive was applied by the drop impregnation method. Ignition and combustion of obtained samples were carried out in a combustion chamber at temperatures of the heating medium Tg=600–800 °C. The gas-phase combustion products were analyzed using an in-line gas analyzer. The application of WCT pyrolysis oil as a combustion modifier contributed to an increase in the reactivity of anthracite, which was expressed in a decrease in the minimum ignition temperature (by 23–104 °C) and a reduction in the ignition delay time. The high-speed video recording indicated that the combustion of both initial and modified with 5 wt % pyrolysis oil anthracite samples was realized in oxidation mode. For samples with more than 10 wt % pyrolysis oil additive, the formation of a visible flame was observed near the sample surface. With an increase in the mass fraction of the additive, the rate of combustion front propagation was increased. The application of WCT pyrolysis oil as a combustion modifier also contributed to the reduction or even the almost complete elimination of unburnt carbon content in the ash residue formed after anthracite combustion.