Alternative fuels, such as biomass and refuse derived fuels tend to play an increasingly important role in the European energy industry. Co-firing fuels derived from non-hazardous waste streams may contribute to cover the future demand on co-incineration capacities, due to the implementation of the 2000/76 EC landfill Directive. However, their combustion behaviour has not yet been fully investigated, because of the difficulty to define representative fuel characteristics simulating accurately all the fuel fractions. In the present study, refuse derived fuel behaviour was investigated by thermogravimetry under pyrolysis and combustion conditions. A non-isothermal thermogravimetric analyser (TA Q600) operated at ambient pressure was used for both the pyrolysis and combustion experiments. The devolatilisation of the waste samples was investigated at the temperature range of 30cC to 1000°C at the constant heating rate of 20°C/min and for particle sizes between 150-250לחי. Combustion tests were realized under the same heating conditions. The independent parallel, first order, reactions model was elaborated for the kinetic analysis of the pyrolysis results. The thermal degradation of the refuse derived fuel samples was modeled assuming four parallel reactions corresponding to the devolatilisation of cellulose, hemicellulose, lignin and plastics. Increased activation energies were calculated for the plastics fraction. Lignin presented the lowest contribution in die pyrolysis of the samples. Slightly increased combustion reactivities were found for the waste fuel samples compared to lignite. It is concluded that waste recovered fuels can be used in existing combustion facilities either alone or in combination with coal and future investigations should focus on the operational behaviour of large-scale facilities when exploiting these waste species.
Keywords : thermogravimetry, refuse derived fuel, devolatilisation