Oil recovery from scrap tires by low-temperature supercritical decomposition with toluene and cyclohexane

Hydrocarbon oils with molecular weight below 300 were obtained from automotive tire by supercritical decomposition with toluene and cyclohexane. Experiments were carried out at various temperatures (523.15, 573.15, and 623.15 Ei) and pressures (5, 10, and 15 MPa) for 25 g sample tires. For each solvent, the sample tire was completely decomposed within an hour at 623.15 K and 10 h-MPa. By measurement of the weight of residual solids and TGA analysis after each decomposition reaction, the percent decomposition and the decomposition characteristics were evaluated with respect to temperature and pressure. Also, by GC-MS analysis of decomposed oil, the major components of oil and their molecular weight were confirmed. Based on the results, the advantage and shortcomings of using each solvent are discussed.