TGA and macro-TGA characterisation of biomass fuels and fuel mixtures

The thermal behaviour of selected biomass fuels and mixtures as wood, demolition wood, coffee waste and glossy paper was investigated using a thermogravimetric analyzer (TGA) and a macro-thermobalance (macro-TGA). A kinetic model, involving first-order independent parallel reactions, was applied to results obtained from pyrolysis TGA experiments. The pyrolysis rate was considered as the sum of the main biomass pseudo-components, namely cellulose, hemicellulose and lignin. Additionally, the thermal behaviour of the same fuels was investigated at combustion conditions in the TGA, including ignition behaviour. The thermogravimetric analysis showed that each single fuel had pyrolysis and combustion characteristics based on its own main pseudo-components (hemicellulose, cellulose and lignin). The pyrolysis and combustion characteristics of selected fuel mixtures and the gas composition analysis from macro-TGA experiments showed respectively quantitative and qualitative summative behaviour based on the single fuels.