An Alternative Fuel for Lime Industry: Evaluation the Pyrolysis of the Scrap Tires

Abstract

Scrap tire is considered an environmental concern with inadequate final disposal. A good alternative can be to use the tire as an energy source. Pyrolysis is a thermal process that can transform the rubber portion of used tires into oil, gas and pyrolytic carbon. This type of carbon can be converted into carbon black (CB). The lime industry that demands great amount of energy could be one of the ways to take advantage the scrap tires adequately as energy source. This work aimed to study the operational conditions of the pyrolysis process as well as investigating the possibility to use the pyrolysis products from used tires as industrial fuel. A batch pilot-scale pyrolysis unit was built. Temperatures from 400 to 600oC and relative pressures from 0 to -500 mmHg were investigated in order to evaluate product distribution and quality. Experimental results showed that as the reactor temperature was increased the pyrolytic carbon yield remained constant with a mean of 39.8 wt % and the pyrolytic oil yield reached a maximum value of 45.1 wt % at 500 °C. It is also possible to show that the pyrolytic oil can be used as liquid fuels because of its high heating value (40-42 MJ/kg), excellent viscosity (1.6-3.7 cS), and reasonable sulfur content (0.97-1.54wt %). In addition, chemical and physical characterization was made in order to compare the pyrolytic carbon and oil with currently fuels used in Brazilian lime industries (wood charcoal and coke of petroleum).