Torrecfaction of Oil Palm Biomass

Torrecfaction is a mild thermal treatment of organic by-products such as oil palm biomass. It is a thermochemical treatment of biomass at 200-320 °C under atmospheric pressure in the absence of oxygen or air. It can selectively modify a number of the properties of the biomass to make it an environmentally-friendly fuel for domestic or industrial uses. Torrefaction has been found to be effective in improving the energy density and the shelf life of biomass. During torrefaction, various permanent gases and condensable having high oxygen content are formed mainly due to hemicellulos degradation. Consequently, the final solid product composes mainly of cellulose and lignin and is characterized by increased brittleness, hydrophobicity, microbial degradation resistance and energy density. The thermal treatment not only destructs the fibrous structure and tenacity of biomass but also increases the calorific value. Torrefaction devolatilizes the biomass partly leading to a decrease in mass but the initial energy content of the torrefied biomass is mainly preserved in the solid product so the energy density of biomass becomes higher than the original biomass.