Pyrolysis and Combustion Energetic Characterization of Coal-Biomass Fuel Blends

A simultaneous thermogravimetric analyzer (STA) and a microscale combustion calorimeter (MCC) were used to investigate the energetic properties of coal, biomass and mixture samples. The STA was used to measure the gravimetric and energetic response of a pyrolyzing sample under inert atmosphere. A pyrolysis mathematical model was used to calculate the heat of pyrolysis of samples from the STA data. The MCC was used to quantify the dynamic heat output from the combustion of the gases produced during the pyrolysis process. The measurement of heat output as a function of temperature was used to calculate the heat of combustion of fuels. It was found that the co-pyrolysis of coal and biomass fuel mixtures exhibited a weighted additive gravimetric and energetic behavior, both from pyrolysis and combustion aspects. It was further validated and concluded that the weighted sum prediction for the heat of pyrolysis and heat of combustion for the coal-biomass fuel mixtures must be conducted on the basis of their individual volatile mass contributions, and not on the basis of initial fuel mixture proportion.