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INTERDISCIPLINARY JOURNAL OF CONTEMPORARY RESEARCH IN BUSINESS
9.1 CHARACTERISTICS OF EXTRACTION SOLVENT
� Ability to dissolve triglyceride at low temperature.
� It must be non toxic to plant workers and to animals and humans when meal is used
for food or as feed.
� The solvent must be easily recovered from the meal and the oil.
� Non flammability or flammability within a narrow temperature range of explosion to
reduce the hazard of fire and explosion.
� It should be stable to heat , light and water.
� The solvent must be re-useable and must withstand high temperatures.
9.2 ADVANTAGES OF SOLVENT EXTRACTION METHOD
� The oil is almost completely recovered (about 98.5% oil recovery).
� The oil and meal are recovered , undamaged by heat.
9.3 LIMITATIONS OF SOLVENT EXTRACTION METHOD
� High capital cost for extraction equipment.
� Emission criteria pollutant that is volatile organic compound (VOC) into the
environment/atmosphere.
� The hazard of explosion by flammable solvent.
10. SUPERCRITICAL FLUID EXTRACTION TECHNOLOGY
SFE is the process of separating one component (the extractant) from another (the matrix)
using supercritical fluids as the extracting solvent. Extraction is usually from a solid
matrix, but can also be from liquids.
SCF technology has been examined as an alternative technique for the conventional oil
and oilseed processing methods for more than two decades. Carbon (iv) oxide has been
suggested as a replacement for n-hexane or toluene in desolventization. In their
supercritical state, carbon (iv) oxide and water can be used in many extraction and has
been recorganised as earth compatible solvents.(Arain and Adschiri,1999.) The
supercritical carbon dioxide (SC-CO2) technique, which utilizes carbon dioxide above its
critical pressure (7.3 MPa) and temperature (31°C) as solvent, has been the choice for the
majority of edible applications. The unique advantage of SC-CO2 is the easy removal of
solvent from the extract. Palm kernel oil has a good solubility in supercritical carbon
(iv)oxide at high pressure(>30MPa) and temperatures(>350K). Thus extraction of palm
kernel oil requires relatively high temperatures and pressures for separation of oil from
kernel as palm kernel is hard and compact; and has an intricate honey combed pericarp
(Hassan etal,2000; Rahman etal,2001; Zaidul etal, 2003; Zaidul etal, 2006).
The flow rates of co2 has a large effects on the mass transfer of the extraction which can
be divided into
� Solubility controlled region and
� Diffusion controlled region.
A lower solvent flow rates improves the extraction performance, particularly in the
solubility controlled region and decreases the total solvent mass required to extract a
given oil. At lower pressure, the oil yield directly proportional to the amount of the
COPY RIGHT © 2011 Institute of Interdisciplinary Business Research 69
JANUARY 2011
VOL 2, NO 9