Non-Conventional fuels from thermocatalytic pyrolysis of waste tube rubber using SiO2 as catalyst

Large quantities of used rubber material, mostly from vehicle scrap tires and tube rubbers, are discarded every year, causing environmental problems of great concern and representing a tough challenge for waste management bodies around the world. Various ways to remediate the issues have been proposed and applied from time to time. Pyrolysis offers a promising solution to convert waste tires into potential fuels and chemicals. Thermo-catalytic pyrolysis is a well-established process that aims for material, energy or chemical product recovery. The demand and need for the use of materials like scrap tubes and rubbers for producing useful products is a valuable consideration for this kind of waste that in turn may minimize the dependency on natural resources. Inner tube rubber, which is mainly made of isobutylene-isoprene, poses a hazard to the environment. However, there is also an opportunity to turn this waste product into a valuable energy source. In the current study optimization of parameters such as temperature, time and catalyst weight for catalytic pyrolysis of isobutylene-isoprene rubber into liquid fuel in the presence of Silicon Dioxide (SiO₂) as catalyst is reported. A maximum rubber conversion into oils was obtained at optimized conditions of 350 °C temperature, 1.5 g of catalyst (SiO₂) for an hour heating time. The obtained pyrolyzed products were subjected to several physical and chemical tests. Reported results confirm the presence of 30 % of aliphatic hydrocarbons, 25 % polar hydrocarbons and 40 % aromatic hydrocarbons. The distillation data indicates that oil obtained is a mixture of aromatic and olefinic hydrocarbons as that of diesel and may be used as an alternative fuel.