Estimation of Higher Heating Value of Torrefied Palm Oil Wastes from Proximate Analysis

In Malaysia, palm oil wastes are identified as the potential biomass for renewable energy sources. Usually the higher heating value (HHV) is essential for energy analysis and can be estimated using bomb calorimeter but this method usually is time consuming with possibilities of experimental errors. Thus many correlations have been established to predict the HHV based on the proximate analysis. However, most of the correlations only take into account the HHV of raw biomass. No attempts have been made on estimating HHV of torrefied biomass using model correlation. Therefore, the objective of this study is to propose new correlation based on proximate analysis which is applicable for raw and torrefied palm oil wastes. The HHV and proximate analysis of raw and torrefied palm oil wastes at different torrefaction temperature ranges from 240 to 330°C are measured experimentally for model correlation. In addition the HHV and proximate analysis of raw and torrefied palm oil wastes from published literature are included in order to enhance the reliability of model correlation. Based on the model correlation, low average absolute error (AAE) of 5.37% and low average bias error (ABE) of -1.00% are obtained indicating the estimated model correlation is suitable and reliable to estimate the HHV of raw and torrefied palm oil wastes from proximate analysis.