Prediction of the Higher Heats of Combustion of Plant Raw Materials Based on the Ultimate Analysis Data

Abstract—The relationships of the data of proximate (moisture content, ash content, volatile matter, and fixed carbon) and elemental (carbon, hydrogen, nitrogen, sulfur, and oxygen contents) analyses of various plant raw materials (362 samples) for the production of biogas, charcoal, and torrefied biomass with their higher heat of combustion were analyzed. The closest correlation was found between the carbon and oxygen contents of the organic matter of plant raw materials (R² = 0.898). Mathematical relationships were developed for predicting the higher heat of combustion of plant raw materials with high accuracy (R² > 0.849) based on the carbon and oxygen contents and atomic ratios between carbon and oxygen.