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INTERDISCIPLINARY JOURNAL OF CONTEMPORARY RESEARCH IN BUSINESS
8. HISTORY OF OIL EXTRACTION
Over the years, human beings have found that fats and oil can be extracted from nuts and
seeds by heat , solvent and pressure. Extraction involves the removal of the constituent
component from its source which of paramount importance to the individual involved.
Early small-scale systems converted various seeds, nuts ,and fruits into liquid and solid
components for both food and non food uses. The advancement of processing technology of
recovering oil have been primarily driven by economics and productivity. After thousands
of years of practices with stone mills and several centuries of simple hydraulic or lever
presses , the continuous mechanical presses became reality during the early 1900s. Not until
1930s did extraction solvent became available which greatly enhance the recovery of oils
from oil bearing seeds or materials(P.J Wan, P.J Wakelyn, 2004).
Generally, oil extraction from palm kernel can either be by mechanical also known as
expeller method or by solvent extraction also known as chemical method. With the
advancement the technology of vegetable oil processing industries, other extraction methods
have been discovered over the years to enhance oil extraction from palm kernel. the
following oil extraction methods shall be reviewed in this project topic:
� Mechanical extraction
� Solvent extraction
� Supercritical fluid extraction technology
� Traditional extraction method
� Liquefied gas extraction technology
� Gas assisted mechanical extraction technology
� Enzyme assisted extraction
� Aqueous extraction technology
8. MECHANICAL EXTRACTION/EXPRESSION(EXPELLER) METHOD
Mechanical expression is the oldest method used for oil extraction from seeds. The seeds are
placed between permeable barriers and mechanical pressure is increased by reducing the
volume available for the seeds. This way oil is squeezed from the seeds. In practice, this
operation can take two shapes: a hydraulic, uni-axial press or a screw press (also called
extruder or expeller). The advantages of a screw press compared to a hydraulic press are its
slightly higher yield and its continuous mode of operation. Mechanical expression results in
high quality oil, but has a relatively low yield. Generally it is only used for smaller capacity
plants, speciality products or as a prepress operation in a large scale solvent extraction
plant.This extraction method involves size reduction operation, surface area and
extractability increase operation. Mechanical extraction processes are suitable for both
small- and large- scale capacity operations. The three basic steps in mechanical oil
extraction method are:
� Kernel pre -treatment
� Screw- pressing
� Oil clarification
COPY RIGHT © 2011 Institute of Interdisciplinary Business Research 65
JANUARY 2011
VOL 2, NO 9