Effect of Reaction Temperature on Properties of Torrefied Kenaf

Torrefaction is a thermal treatment method used to achieve solid-phase biofuel. Raw biomass generally have low heating value and high moisture content; thus, these characteristics should be enhanced before using it as a fuel. In this study, herbaceous biomass kenaf was torrefied at 220, 260, 300, and 340 °C under nitrogen atmosphere for 30 min to investigate the effect of temperature on its properties. The properties of torrefied kenaf were classified into two groups: physical properties such as mass and energy yields, moisture content, and proximate analysis and chemical properties such as functional groups and chemical compositions of sugars and lignin. The mass and energy yield of torrefied kenaf decreased as the reaction temperature increased. In addition, an increase in carbon content and a rapid decrease in oxygen content were observed in torrefied kenaf, which indicated the degradation of compounds such as hemicellulose and cellulose. Elemental analysis, proximate analysis, thermal analysis, Fourier transform infrared spectroscopy, and chemical composition analysis were performed to further investigate the characteristics of torrefied kenaf.