Some physical and heavy metal analysis of waste tire derived oil produced by a locally fabricated reactor

Abstract

The amount of waste generated in the modern world is constantly on the increase due to world`s urbanization, industrialization and population increase, thus there is a need to recycle these wastes especially non-biodegradable types. The aim and objective of this research was to produce bio-oil, bio-char, and bio-gas from waste tire using a fixed batch pyrolysis reactor, determine yield at three different temperatures of 400, 550 and 750 °C, determine the calorific value, flash and fire points, cloud and pour points, ash content, moisture content as well as concentration of Zn, Cd, Fe, Cr, Cu, and Pb in the produced bio-oil as well as in the original tire sample. The result shows that the char, oil and gas yields at the three different temperatures analysed for were 62, 24, 14; 48, 36.2, 15.8; and 42, 40, 18 respectively all in weight percent. The char and oil yield was determined by weight measurement, while that of gas was determine by mass balancing. The caloric value of the oil produced was found to be 64.44 KJ/kg, the flash and fire points were found to be 67 and 85 °C while the cloud and pour points were found to be 16 and -3 °C. The ash content and moisture content were found to be 0.04 and 8.18 in weight percent. The heavy metal concentration of the original tire sample was found to be 0.605 Cu, 0.170 Pb, 1.019 Zn, 0.777 Cr, 0.077 Cd and 0.447 Fe while the bio-oil produced contains 0.065 Cu, 0.090 Pb, 0.144 Zn, 2.121Cr, 0.006 Cd and 0.010 Fe all in ppm. This result shows that the rector used has a maximum oil yield of 40% w at 750 °C, and that the oil produced showed decrease in heavy metal concentration when compared to that present in the original tire sample and other petroleum products. Further studies should be conducted to extrapolate the reactor since it produced oil with high thermal stability and caloric value with low ash content and also decreased the heavy metal composition of the oil produced. The heavy metal concentration of other toxic metal should be analysed to further examine its public health risk.