Pyro-gas analysis of fixed bed reactor end of life tyres (ELTs) pyrolysis: A comparative study

Pyrolysis of end of life tyres (ELTs) present a promising alternative to their incineration or classical product recovery using mechanical means. It can produce light hydrocarbons (HCs) and other valuable chemicals as part of the pyro-gas stream it generates. In this work, two grades of tyres namely a fresh (virgin) one and a waste disposed ELTs, were used as a feedstock to analyse their pyro-gas constituents. There wasn't much difference in the maximum conversion rate between both tyre grades where the fresh tyres had an estimated 15.17% con-version and the ELTs was 13.45% conversion (both at 800 degrees C). The difference herein was attributed to release of free radicals prior to subjecting the samples to pyrolysis due to their history. The analysis of the pyro-gas samples showed a large make of light hydrocarbon (HC) products, namely methane (CH4/C1), ethane (C2H6/C2), ethylene (C2H4), propane (C3H8/C3), propylene (C3H6), n-butane (C4H10), butadiene compounds, carbon mono and di-oxide (CO,CO2). Light HCs mimciking natural gas were more abundant in the case of ELTs were C1 was estimated as 14.53% at 500 degrees C and 16.73% at 800 degrees C. C2 was also estimated higher than the fresh tyres where a 11.78% at 500 degrees C was noted and 7.67% at 800 degrees C. It can be recommended that future integration plans in oil and gas ventures, namely refinery and petrochemical complexes, are to start taking responsible measures towards the environment by substituting part of their operations with sustainable feedstock such as ELTs.

Automated summary

Pyrolysis of end of life tyres is a promising alternative to incineration or classical product recovery. The analysis showed that there was not much difference in the maximum conversion rate between different tyre grades, and the difference was attributed to the release of free radicals. The pyro-gas from the pyrolysis of end of life tyres contained abundant light hydrocarbon products, which could be utilized in oil and gas ventures.