For a ton of fresh fruit bunch (FFB) of oil palm the following residues are generated
at the mill; 0.87 m3 of waste water (biogas 434.3 MJ per m3 of wastewater), 0.28 ton of
empty fruit bunch (4.6 MJ/kg), 0.12 ton of pressed fiber (9.6 MJ/kg) and 0.08 ton of
kernel shell (17.4 MJ/kg) [12–14]. In conclusion, each ton of FFB gives residue
equivalent to 4.2 MJ of heat. The milling process for a ton of FFB requires 20–25 kWh
electricity and steam of 0.73 ton (2.5 bar) [15], which requires total primary energy of
2.2 MJ. Thus, surplus energy from the mill is 2 MJ for each ton of FFB being
processed. With the production of 5.3!106 ton of FFB a year, the energy potential
from the palm oil mills is 10.6!106 MJ. In addition, biomass from the oil palm
replantation is 80.4 t/ha [16] or 1250!103 MJ/ha. Considering 3–4% of the planting