Numerous mathematical equations have been created based on data from physical or chemical compositions, proximate or ultimate analysis, and structural analysis of fuel, including combustible elements (i.e., C and H). Elemental composition-based mathematical models are the most reported, with Dulong's equation being among the first available to calculate the calorific value of coal or biomass. However, elemental analysis is expensive and tedious and needs skilled workers to carry out the analysis. It is difficult to make accurately an ultimate analysis of a fuel sample.
Acknowledgments
This study was financially supported by the Scientific Research Project (BAP in Turkish initials) of Selcuk University.