Chemical decomposition of waste tires and evaluation of the obtained products

In the preliminary experiments carried out with H2SO4 solutions with different concentrations (%96, %80 ve %60) and different H2SO4/AL (g/g) (30.67; 18.4;15.34; 12.27; 7.36 ) ratios for the chemical degradation of waste rubber (AL) samples, swelling and gelation conditions were examined by time control. After about 20 minutes at 96% H2SO4 and 12.27 H2SO4/AL (g/g), the sample swelled and geled homogeneously. Experiments with different H2SO4/AL (g/g) ratios of H2SO4 solutions with 80% and 60% concentration showed no swelling and gelation events in AL samples, however AL samples were found to form skeleton in solution. Experimental studies were carried out at different ambient temperatures (110 °C,130 °C,140 °C,150°C,200 °C) with a constant 12.27 ratio of H2SO4/AL (g/g) and the swelling and gelation states of AL samples were re-examined by controlling the time and temperature. Experimental studies carried out at 150 °C and 200 °C showed that some of the AL samples had skeletal structure properties. In the experimental studies carried out in the second stage; The ratio of 12.27 H2SO4/AL (g/g), 140 °C ambient temperature and 20 minutes gelling time were maintained constant. The gelled sample in the 96% H2SO4 solution was added slowly to at different ratios NaOH/CH3OH (g/mL) solutions (0.025; 0.037; 0.05; 0.057; 0.066) prepared in the room conditions and the gel structure precipitated to the liquid phase separation. After the decomposotion reactions were completed, the liquid phase and the gel phase were separated by filtration. The dried solid phase samples were milled and, after grinding, activation procedures were carried out using different chemicals. Some of the activated samples were subjected to carbonization (temperature 550 ºC, heating rate 10 ºC/min, nitrogen flow rate 5 mL/min and duration 3 hours). The obtained carbon based products were characterized by proximate and elemental analysis, BET, FT-IR, XRD, TGA-DTA and SEM analyzes. According to the results of analysis of obtained carbon based solid product; the similarity of solid products to carbon-based materials such as carbon black, activated carbon, graphite, CNT, etc. has been compaired.