Fuel production from pyrolysis of natural and synthetic rubbers

Pyrolysis of rubber wastes is an efficient thermo-chemical means of generating high-value energy and fuels. In this work, a variety of technological tools were employed to characterise the pyrolysis of natural and synthetic rubbers, which included three tyres (natural rubber tyre, pneumatic tyre and synthetic rubber tyre) and one natural rubber mat. The composition of gas products was determined by gas chromatography (GC). H₂ and CO were the major gases released from the pyrolysis process although the evolution rates of gas species differed for the four samples. The organic compounds contained in the resulting pyrolysis oils were analysed by gas chromatography–mass spectrometry (GC–MS), and the results confirmed the existence of large amounts of hydrocarbons and nitrogen-containing compounds as well as some sulphur-containing compounds. The raw rubbers and solid char products were analysed by Fourier transform-infrared (FT-IR) spectrometry to determine the change in functional groups, which indicated the loss of organics after pyrolysis at different temperatures. Distinct mass and heat change behaviour of the selected rubber samples was also detected through thermogravimetric analysis and computer aided thermal analysis, respectively. The pyrolysis behaviour and fuel product properties of the rubbers were compared in this work. The obtained data will provide important reference information for energy and fuel generation from rubber pyrolysis.