Page 116 - Materials Chemistry, Second Edition

102 K. T. Lee and C. Ofori-Boateng

Air FFB
Water Emissions
S
BOILER STERILIZER
Landfills
EFB
Fibre and kernel
STRIPPER
Mulch
S DIGESTER
Shells & fibre
Pressed cake & nuts
SCREW PRESS
SEPARATOR
Pressed liquor
VIBRATING SCREEN
DRYER
Oil
CLARIFIER
NUT CRACKER
Sludge Oil
DESILTER PURIFIER CYCLONE
Nuts
SEPARATOR PURIFIER
HYDROCYCLONE
Sludge CPO
DRYER

Palm kernel
Fig. 3 Flow diagram of palm oil milling processes S represents steam

plant (ETP). The CPO produced is then stored and transported later to oil refinery.
The palm kernel nuts are also cracked to separate the kernel from the shells. The
oil palm fiber and kernel shells from the PKC plant are used as fuel in the boiler
which generates steam for the oil milling processes.

2.2.1 Environmental Impacts Associated with CPO Production

The palm oil mill produces solid wastes such as palm pressed fiber (PPF), palm
kernel shells (PKS), decanter cake, EFB, ash which are often damped without
proper management or treatment. The EFB are also dumped in landfills or used as
mulch in the oil palm plantation whose emissions also contribute to GWP. Due to
some other problems associated with the use of EFB as mulch (including long
decomposition period, high distribution and transportation cost), they can be used
as fuel though it has a very small calorific value of 5 MJ/kg (Budiharjo 2010).