Influence of oily wastes on the pyrolysis of scrap tire

The co-pyrolysis of scrap tires with oily wastes from ships (bilge water oil and oily sludge) was studied to investigate the effect of oily wastes on the pyrolysis of scrap tire. Co-pyrolysis experiments were carried out in a fixed bed reactor in the absence and the presence of catalyst at 500 °C. The catalysts used in the pyrolysis were a commercial refinery catalyst and an industrial by-product containing iron. The fuel characteristics and chemical compositions of pyrolysis products were characterized by means of chromatographic, spectroscopic and standard ASTM methods. Although, the oily wastes did not affect the product yields from the pyrolysis of scrap tire, they improved the fuel characteristics of scrap tire derived oils. The fuel characteristics of co-pyrolysis oils (except flash point and sulfur content) had similar fuel characteristic with the commercial diesel. It was also found that the amounts of metal impurities in all pyrolytic oils were smaller than 0.3 ppm, which was a significantly low amount compared with those in the original oily wastes. Gross calorific values of pyrolysis gases were found to be in the range of 20.4–26.4 MJ Nm−3. It was concluded that co-pyrolysis of scrap tire with oily wastes could be an environmentally friendly way for the conversion of disposable and hazardous wastes such as scrap tires, bilge water oil and oily sludge into fuels.