Preparation
of Seeds
The
processing of seeds for oil extraction involves the following
steps:
- Seeds
are passed through cleaners to remove all foreign matters like
mud bolls, stem, pods etc.
- Seeds
are passed through Magnetic separators to remove metallic impurities
- Pre-cleaned
seeds are passed through de-stoner, where heavy stones are removed
- Clean
seeds are passed through 2 pairs of cracker rolls to crack the
seeds into 6-8 pieces
- Cracked
seeds are stored in the Tempering bin after adding 1-3% moisture
for tempering
- Materials
are cooked and conditioned with open steam at 80-90c to make
it suitable for making flakes
- Tempered
seeds are passed through high speed rolls under 50 bar pressure
to produce flakes
- Flakes
are passed through extruders under pressure with open steam
to produce pellets. This operation makes most of the oil bearing
cells rupture and makes oil extraction easier.Refining of Vegetable
Crude Oil
Extraction
of oil from seeds
The
pellets are fed into the extractor at the solvent extraction plant
for oil extraction along with solvent hexane, where extraction process
takes place in several stages. At the end hexane and vegetable oil
mixture, called miscella, is taken in the distillation section.
Here solvent hexane is recovered from crude oil and recycled for
further extraction process. Crude oil so obtained is stored in crude
oil tanks for processing.
Treatment
of Extracted
Meal
The de-oiled spent meal is taken in DTDC vessel, where the material
is desolventised, toasted, dried and cooled, in this process, maximum
recovery of solvent, uniform toasting to achieve the desired urease
activity level, optimum steam consumption, low power consumption
design feature are taken care.
The
Process
Refining
of Vegetable Crude Oil
The
following operations are carried out to convert vegetable crude
oil into refining vegetable oil fit for human consumption:
-
Degumming of Vegetable Oil
The crude oil is treated with hot water to remove hydratable
phosphates which upon drying becomes food grade Lecithin
- Removal
of free fatty acids
Measure excess caustic soda is added in the degummed oil along
with phosphoric acid to remove unwanted free fatty acids and
non hydratable phosphatites. The neutral oil so obtained is
then washed with hot water to remove traces of soap and finally
dried
- Bleaching
Neutral oil is treated with measured quantity of bleaching earths
at bleacher under vacuum to remove all colouriferous matters
and peroxides
- Deodorization
Bleached oil is deodourized at high temperatures and very low
vacuum to remove odoureferous compounds including low molecular
weight free fatty acids and thermo bleachable materials. The
by product recovered at this stage is fatty acid which is rich
in Vitamin E
- Waste
water treatment
Process water generated during the refinery operation containing
oil and grease being major objectionable components are sent
to the water treatment plant where the water quality is brought
to acceptable limits of BOD, COD, suspended solids and oil &
grease.
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