EFFECTS OF HEAT REGIME ON LIQUOR PRODUCTION OF PYROLYSED WASTE WATER

Abstract

The dwindling of fossil fuels and environmental degradation across the globe calls for the development of alternative fuels from renewable resources. Therefore, this research aims to evaluate the pyrolysis of tyres in a fluidized bed reactor to provide a high material value with the potential of various industrial use. Discarded waste tyres were collected from auto mechanic shops and shredded. The particles were pyrolyzed at 400 °C, 500 °C, and 600 °C in the absence of oxygen in a fluidized bed reactor. During the experiment, the temperature of the system and the yield of the oil were monitored while the properties of the obtained pyrolytic oil, which includes the density, viscosity, and calorific values were determined using standard methods. The result shows that the internal temperature of the reactor increased progressively to a maximum point (preset temperature) of inflection. Subsequently, the temperature inside the reactor was varied and finalized with a constant temperature until the end of the process; three types of products (liquid oil, solid, and gas) were observed during the pyrolytic process. The maximum yield of pyrolytic oil (350 ml) was found at 600 °C. Meanwhile, the oil yield at 500 °C was not significantly (P<0.05) different from 600 °C. The density, viscosity and calorific value of pyrolytic oil ranges from 852.05 ± 2.19kg/m³ - 9 41.75 ± 2.37 kg/m³, 3.95 ± 0.07 mm²/s - 4.50 ± 2.37 mm²/s, and 35.65 ± 0.63 MJ/kg - 40.45 ± 0.78 MJ/kg, respectively. The calorific value of the pyrolytic oil slightly decreased with an increase in the temperature of the pyrolysis process considered in this study, although all the pyrolytic oil obtained at different heat regimes shows high similarity with conventional diesel fuel. The developed linear model for predicting the properties and yield of the pyrolytic oil as a function of temperature show that the heat regime explained about 74.0%, 49.0%, 91.7%, and 15.0% of the variation in the yield, density, kinematic viscosity and calorific value of the pyrolytic oil, respectively. The FT-IR results of all three oils follow a similar trend with the viii identification of some bands, which indicate the presence of OH group (3600 -3150 cm-1), secondary amines (3500 - 3100 cm-1) and CH group (3007 cm-1), and the gas chromatography, coupled with a mass spectrometer. Furthermore, the results showed the presence of eighty (80), eighty-seven (87), and eighty-one (81) compounds for treatment at 400 °C, 500°C, and 600°C, respectively. These revealed that the increased temperature affected pyrolytic oil composition as some of the compound formed at 500 °C was degraded at a higher temperature of 600 °C, which justifies the higher energy potential (calorific value) recorded for the pyrolytic oil obtained at 500 °C. Therefore, the waste tyre should be pyrolyzed at 500 °C of heat regime for optimal pyrolytic oil production on a small or large scale.