Palm bunch (PB) is waste biomass from palm oil production and has good potential as a
renewable energy resource. However, PB has poor fuel properties. The main problems result from the
high moisture and volatile organic content of the material and the low fixed carbon content. These
properties contribute to the low calorific values of PB. Nevertheless, techniques exist that improve the fuel
quality of biomass and the most suitable is thermochemical treatment by torrefaction, a procedure that is
carried out in a temperature range from 200 to 320o
C in the absence of oxygen. This research applied response surface methodology (RSM) based on central composite design (CCD) to study the influence of
operational factors affecting the torrefaction process. The investigated parameters included temperature
(200–320o
C) and time (5–50 min) of torrefaction and the response variables were moisture content (MC),
volatile organic content (VC), ash content (AC), fixed carbon content (FC) and heating value (HV). By
improving these fuel properties, this research aims to enhance the fuel quality of the biomass. The
statistical results showed that both temperature and time significantly influenced the qualities of torrefied
PB. MC and VC were reduced by 90.22% (wet basis, w.b.) and 31.26% (w.b.), respectively and FC and
HV were increased by 1,363.2% (w.b.) and 26.69% (w.b.), respectively. In conclusion, torrefaction has
the potential to be an efficient technique for improving the fuel properties of PB.