Page 137 - Materials Chemistry, Second Edition

Life Cycle Assessment of Biodiesel from Palm Oil 123

Table 4 Emissions of heavy Heavy metal type Emissions, mg/kg FFB
metals from the production of
1 kg FFB Arsenic 0.0285
Cadmium 0.05429
Chromium 1.26857
Cobalt 0.00571
Copper 0.0.331429
Mercury 0.000857
Molybdenum 0.002857
Nickel 0.145714
Lead 0.057143
Selenium 0.011429
Zinc 1.96286

The harvests of FFB, irrigation, etc., are done manually, some requiring the use
of trucks and other machinery which utilizes fossil fuel. This can also result in
greenhouse gas emissions contributing to high climate change effect. Land use/
conversion effect was highest (98.51 %) for the plantation stage due to heavy land
use. It is recommended that, new oil palm plantations should be cultivation on
degraded land in order to reduce land conversion/use effects. On a percentage
score with transportations impacts inclusive, the plantation stage alone contributed
approximately 7 % of the total environmental impacts from the whole production
stages (Fig. 15). On the basis of human health, ecosystem depletion, and resource
use, the plantation stage had a percent contribution of 13.10, 7.26, and 1.70 %,
respectively.

5.3 Emissions Associated with the Palm Oil Mill

The most significant impact categories in the oil milling stage are carcinogens,
respiratory organics, respiratory inorganics, and ozone layer depletion with percent
shares of 30.83, 41.44, 55.02, and 55.51 % with transportations excluded (Fig. 13).
The major parameters resulting in high potentials of these impact categories are
the POME and the boiler ash. POME is the wastewater generated from the clar-
ification and other processing steps in the mill. This is normally treated in open
ponds in order to reduce its biological oxygen demand. The EFB in this chapter is
considered to be used for fuel production within the mill hence no emissions from
dumping sites resulting in climate change effect. Climate change potential is
insignificant due to the use of renewable fuels from PPF to EFB in the mill. The
boiler ash also contributes to emissions into the soil. In this chapter, most of the
wastes within the mill were considered to be recycled or treated before they were
released into the environment.