Product characteristics from the torrefaction of oil palm fiber pellets in inert and oxidative atmospheres

The aim of this work was to study the characteristics of solid and liquid products from the torrefaction of oil palm fiber pellets (OPFP) in inert and oxidative environments. The torrefaction temperature and O2 concentration in the carrier gas were in the ranges of 275-350 °C and 0-10 vol%, respectively, while the torrefaction duration was 30 min. The oxidative torrefaction of OPFP at 275 °C drastically intensified the HHV of the biomass when compared to the non-oxidative torrefaction. OPFP torrefied at 300 °C is recommended to upgrade the biomass, irrespective of the atmosphere. The HHV of condensed liquid was between 10.1 and 13.2 MJ kg−1, and was promoted to 23.2-28.7 MJ kg−1 following dewatering. This accounts for 92-139% improvement in the calorific value of the liquid. This reveals that the recovery of condensed liquid with dewatering is able to enhance the energy efficiency of a torrefaction system.