Producing of qualified oil and carbon black from waste tyres and pet bottles in a newly designed pyrolysis reactor

Abstract

Waste tyre and waste polyethylene terephthalate (PET) bottles are major environmental problems. In this study, by using newly designed simple and efficient pyrolysis reactor, a five-stage decomposition (200, 300, 400, 500 and 600 °C) and pre-condensation with cooler motor (− 20, − 10, 0, + 10 and + 20 °C) followed by a final condensation were applied to waste tyre and waste PET bottles. In the pyrolysis process, liquid (pyrolytic oil) and solid (carbon black) products were obtained from only waste tyres. Waste PET gasified in the decomposition steps, but pyrolytic oil could not be obtained because it tended to freeze during condensations. Intermediate temperature and cooling steps were tried by making an optimum design for the amount/efficiency of the pyrolytic oil obtained from waste tyre, and the combination giving the best result (about 50–60% for yield and 43.1 MJ kg−1 for the highest calorific value) was determined to be 500 °C and + 20 °C as decomposition and condensation temperatures, respectively. Compared to the literature, it was produced a highly productive pyrolytic oil at lower temperatures. The physical and chemical properties of this oil were in accordance with national and international standards in terms of the fundamental parameters. The net calorific value of the carbon black produced was in the range of 6337–7308 kcal kg−1 (26.5–30.6 MJ kg−1).