TORREFACTION OF PALM KERNEL SHELL AND RICE HUSK FOR ENHANCED SOLID FUEL ENERGY PERFORMANCE

Abstract

The present study investigated the effect of torrefaction on the characteristics of rice husk (RH) and palm kernel shell (PKS) under varying conditions, specifically temperatures ranging from 200-300 °C and residence times between 35-60 mins in an inert environment. The results showed that higher temperatures and longer residence times increased the fixed carbon content, ash content, and moisture content of the biomass, all of which improved the torrefied biomass's high heating value (HHV). The optimum HHV achieved for the torrefied PKS was 22.89 MJ/kg, which was 17.3% higher than 18.93 MJ/kg for RH at 300 0C, 60 minutes. This treatment also resulted in subsequent reductions in O/C ratio of PKS and RH by 42.1% and 40% respectivey, from 1.14 to 0.66 and 0.94 to 0.54, and H/C ratio from 1.45 to 0.84 and 1.13 to 0.84 PKS rand RH espectively. The torrefied PKS showed more enhancement than RH under the same condition. The energy yield and mass yield decrease with an increase in the torrefaction temperature and residence time. The FTIR spectra showed a progressive loss of hydroxyl, carbonyl and C–O functionalities and the appearance of aromatic C=C bonds, indicating the formation of the biochar. Thus, this research presented torrefaction as a promising approach to the enhancement of biomass characteristic and torrefied solid fuel as competitive alternatives to traditional biomass resources in the biofuel industry, thereby promoting sustainable energy practices.