Higher heating value prediction of hydrochar from sugarcane leaf and giant leucaena wood during hydrothermal carbonization process

Higher heating value (HHV) is an important property of fuels because it can be used to calculate their required quantity for generating heat in thermal processes. In this work, the HHV of sugarcane leaf and giant leucaena wood after treatment via hydrothermal carbonization (HTC) under various conditions were measured. The HTC was performed with biomass to water weight ratio of 1:0 - 1:25, 156 - 273°C for 9.5 - 110 min. The empirical correlations based on ultimate and proximate analysis were proposed for predicting HHV of sugarcane leaf and giant leucaena wood during the HTC process. The multiple linear and nonlinear regression methods were used to develop the correlation. The nonlinear correlation was better than the linear correlation for predicting HHV of hydrochar based on ultimate analysis, while the linear correlation was better than the nonlinear equation for predicting HHV of hydrochar based on proximate analysis. Types of biomass feedstock, HTC operating conditions, compositions of hydrochar and scopes of ultimate and proximate variable affected to the accuracy for using the HHV correlation prediction. The aim of creating the correlation was to accurately predict the HHV of hydrochar obtained at different HTC conditions by using ultimate and proximate analysis data, saving experimental costs, and providing a theoretical basis for modeling hydrochar combustion and hydrothermal carbonization processes. • HHV equations of hydrochar from sugarcane leaf and giant leucaena were developed. • Hydrochar was derived from various conditions of HTC process designed using DOE. • HHV prediction models were developed based on ultimate and proximate compositions. • The developed HHV equations were more accurate than the previous correlations.