Extraction other-wise called
leaching is the preferential solution of one or more constituents of a solid
mixture by contact with a liquid solvent.
This unit operation, one of the oldest in the chemical industries, here
been given many names, depending to some extent upon the technique used for
carrying it out extraction of oil form groundnut seeds can be carried out using
any of the two solid-liquid extraction methods namely: mechanical extraction
method or the used of solvent other- wise called mass-transfer method. The
yield of the second method is higher but contains more impurities than the
first method and it requires another unit operation (distillation) in purity it
better.

The success of an extraction and the technique to be used
will vary frequently depending upon any prior treatment which may be given to
he solid. In some instance small
particles of the soluble material are completely surrounded by a matrix of
insoluble matter. The solvent must then
diffuse into the mass, and the resulting solution must diffuse out before a
separation can result. Crushing and
grinding of such solids will greatly alliterate the leaching action, since then
the soluble portions are made more accessible to the solvent.

Seeds like groundnut seeds and other vegetable seeds are
cellular in structure, and the natural products to be leached form this
material are usually found inside the cells. if the cell walls remain intact
upon exposure to a suitable solvent, the leaching involves osmotic passage of
the solute through the cell walls. This
may be slow, but in is impractical and sometime undesirable to grind the
material small enough to release the contents of individual cells.

Oil constitutes a well-defined class of neutral organic
substance, which are essential constituents of all forms of plant and animal
life. They are soluble in other and
organic solvents but not in water.
Commercial oils are however from a relatively few member of the plant
and animal kingdom available forms. They are primary a product of agriculture
although these is also a considerably production from uncultivated tropical
plants and from mature animals. Oil can be grouped into edible and non-edible
depending on the amount of unspecified matters and impurities. Owing to the
fact that the use of oil from crop seed as a major raw materials has increased
in recent yeses their has been the need for extended and numerous research
works based on the extraction of these oil.
Form its seeds as economically efficiently as possible.

The only possible way of obtaining large quality of oil
from oil being vegetable or plant materials is by extraction and this could
best be achieve using leading process. This process can be accomplished by a
variety of ways but as might be expected its efficiency depends to an extant an
obtaining intimate contact between the liquid solvent and the solid containing
he solute. Leaching reduces the oil
content in the residue to about 0.5-1.5 percent as compared.

With about 5-9 percent by mechanical process. The types of
solvent available for leaching include 17-hexane, petroleum ether benzene ethyl
ether etc which are high petroleum fractions.
The choice of a solvent for extraction is a function of its volatility
and relative volatility for easy separation by distillation.

Groundnut oil is used primary in homes for cooking and
also as an industrial raw material for other usefully products.

1.2     SCOPE
AIMS/ OBJECTIVES FO THE PROJECT

The scope of this research project is to extract oil from
groundnut seeds and compare the yields obtained using different solvents and to
standard.

Also the project is aimed at characterizing the extracted
oil by determining the physical and chemical properties of the oil.