Pyrolysis of Scrap Tires and Production of Fuel for Diesel Engine

Around the world, people are suffering the continuous increase in hydrocarbon fuel prices and are astonishingly following the fuel crisis. Due to this matter, there are initiatives to replace diesel fuel and gasoline with new alternatives which their resources are renewable and environmentally friendly. Daily increase in fuel consumption and the adoption of stringent emission norms, are motivated some researchers to find new alternative fuels for internal combustion engine. Many substituted fuels like Alcohol, Biodiesel, LPG, CNG have been already commercialized in the transport sector. Recently, the oil from pyrolysis of scrap tires has been interested to some engineers as fuel oil. With respect to production of 1.5 billions of scrap tires worldwide, and the fact that 50- percent of them are not possible to be properly recycled, and are inevitably accumulated in the environment have been forced researches to find alternative fuels from scrap tires. Following the inventions of tire pyrolysis processes under vacuum and also flow of nitrogen gas and production of tire pyrolysis oil (TPO), some initiatives for its utilization as fuel for diesel engine has been commenced. First, a researcher in 2008 used TPO as fuel in an internal combustion engine. He tried to compare the motor performance and its exhaust gases with those a common diesel engine. Then, another researcher in 2011 was blended TPO with different percentage of diesel fuel and used the mixtures as fuel for a diesel motor. He also investigated the motor performance and its exhaust emissions in the way as previous researcher. As the amount of polluting emissions for the mixtures of TPO and different percentage of diesel fuel are higher than those for pure diesel fuel, so we have endeavored to investigate the effect of adding ethanol to the mixture of TPO plus diesel fuel. Therefore, 10%, 15% and 20% of TPO were blended with diesel fuel and the mixtures were used as fuel in a single cylinder diesel motor. At the same time, the performance of motor and its exhaust emissions were analyzed. Then, with addition of 5%, 10% and 15% ethanol to the above fuel mixtures of TPO and diesel fuel, the same investigation and analysis have been carried out on motor and its emissions. The results show addition of ethanol to the blended mixture of TPO and diesel fuel lead to better burning of the mixture reducing its carbon monoxide (CO) and unburnt hydrocarbons (HC).