Effect of the carbon oxidation state of biomass compounds on the relationship between GCV and carbon content

The gross calorific value of biomass is an important parameter for its applications for energy purposes. It represents the enthalpy of the complete combustion of a fuel, including the latent heat of water formed by the process. Several mathematical relationships are proposed in the literature to calculate the gross calorific value (GCV) of biomass fuels, using some characteristics as proximate analysis, ultimate analysis and chemical composition analysis. All these formulae were obtained by a mere application of statistical data elaboration, in some cases collected from literature and not from direct experimental analysis. In this study an investigation on the relationships between the chemical composition of the biomass compounds and their GCVs has been carried out. More than 650 biomass samples have been analyzed to develop four mathematical relationships between GCV and carbon content, considering the average oxidation state (Cox) of the biomass compounds.

► The average carbon oxidation state (Cox) of the biomass influences the GCV.
► Different types of biomass are characterized by different Cox values.
► The study shows the possibility to decrease the GCV prevision errors over the 50%.