step by step process description of cotton seed oil with pictures and pfd

2. COTTON
It is a soft, fluffy staple fiber that grows in
a boll, or protective capsule, around the seeds
of cotton plants. The fiber is almost
pure cellulose . This fiber is used for making
clothes and many more

3. COTTON SEED OIL
It Is a cooking oil extracted from the seeds of cotton plants of
various species, mainly Gossypium hirsutum and Gossypium
herbaceum, that are grown for cotton fiber, animal feed, and
oil.
COTTON SEED has a similar structure to other oilseeds such
as sunflower seed, having an oil-bearing kernel surrounded by a
hard outer hull; in processing, the oil is extracted from the
kernel.

4. CONTINUED….
Cottonseed has been divided into three parts;
Meat (Kernels)
Hull (outer hard covering of seed)
Lint ( soft white fibers)

5. PROPERTIES
• Cottonseed oil has a mild taste
• Crude cottonseed oil has a dark reddish-brown color
because of the presence of highly colored material. After
processing, it typically has a rich golden yellow color that is
lighter than peanut and corn oils but darker than soybean,
sunflower
• Its fatty acid profile generally consists of 70% unsaturated
fatty acids (18% monounsaturated, and 52%
polyunsaturated), 26% saturated fatty acids.

6. CONTINUED…
• It’s density ranges from 0.917 g/cm3 to 0.933 g/cm3.
• Cottonseed oil is among the most unsaturated oils.
• It is used as insecticide
• Cottonseed oil has a smoke point of about (232 °C)
SMOKE POINT:
• The smoke point refers to the temperature at which a
cooking fat or oil begins to break down. The substance
smokes or burns, and gives food an unpleasant taste.

7. APPLICATIONS
 Cottonseed oil has traditionally been used in foods, As a
cooking oil. it is used for frying in both commercial and
home cooking
 It is significantly less expensive than olive oil or canola oil
 Cottonseed oil is a good choice where oil with good stability
is needed
 Also used as salad oil

8. COTTON SEED PREPARATION
Most oilseeds require some degree of cleaning and preparation
before the oil is separated from the solid portion of the seed .
So preparation process are:
Cleaning
Delinting
Dehulling
Separation
Flaking
Cooking
Oil extraction

9. CLEANING
 When the cottonseeds are removed from storage for
extraction, dirt and other trash must be removed
 Several seed-cleaning systems are used, which are all based
on some type of screening.
 Trash that is lighter or smaller than the seeds will be
aspirated in pneumatic systems or sifted out mechanically.
The larger pieces of trash are screened out and magnets are
used to remove ferrous metal

10. DELINTING
This step is unique to cottonseed among all the oilseeds. The
cellulose linter fibers must be removed from the seeds because
leaving them on the seed would lower the yield of oil due to
absorption of the oil by the cellulose fibers.
1. Chemicals, such as sulfuric acid, have been used to remove
the linters
2. The other method to remove lint is by passing the cotton
seed into linters(machines similar to cotton gins which
operates on saw and rib principle).each series of linters
removes lint of different length which is designated for first
cut and second cut lint.

11. CONTINUED…

12. DEHULLING AND SEPARATION
Once the lint is removed, the hulls are separated from the seeds.
Hulls that are allowed to remain with the kernels absorb oil during
extraction and lower the quality of the meal produced by lowering
the protein level.
DEHULLING IS THE PROCESS OF REMOVING THE HULLS FROM BEANS AND
OTHER SEEDS.
Two types of hullers are used
Bar huller(consist of bars)
Knife huller(consists of knifes)

13. CONTINUED…
• Studded cylinder that rotates within another cylinder having
similar knives protruding from its interior.
• The hulls are cut as the seeds pass around the inner cylinder.
• The seeds are fed between the rolls and then cut by the
grooves and the difference in speed between the two rolls.
• The hulls and uncut seeds are removed from the kernels by
screening.
• Hulls are aspirated so that the seeds may be returned to the
huller.
• Hull is used in animal feeds.

15. FLAKING
 After hulling, the meats or kernel are reduced in size or flaked
to facilitate oil removal.
 Meats are rolled into thin flakes (.25 to .35 mm thick) to make
them easily permeable to steam in the cooking operation
 Cottonseeds may be flaked by passing between two rolls
mounted side-by-side.
The ultimate thickness of the flake is determined by the method
of extraction used.

16. COOKING
Cooking process is necessary for some important reasons:
 To rupture the oil glands
 Cell walls are broken down allowing the oil to escape
 To precipitates the phosphatides
 To detoxify the gossypol
 To coagulate proteins
 Oil viscosity is reduced
GOSSYPOL is a natural phenol derived from the cotton plant. It is a
yellow pigment. It also causes low potassium levels and thus causes temporary
paralysis . It can cause also cancer.

17. CONTINUED…
 They are cooked in horizontal cookers at 110◦C for 20
min.
 These horizontal cookers are generally integrated with
the expellers.
 Stack cookers are used for additional heating capacity.
In stack cookers moisture is frequently raised to 12% to 14%
and then reduced to 5% to 7% in it.

18. Oil extraction may be a single or combination of various method:
1) Expression in expeller
2) Solvent extraction
a) Direct solvent extraction
b) Pre-press solvent extraction
Solvent extraction has assumed importance in virtually all vegetable oil recovery
plants ,alone or in combination with pre-pressing.

19. EXPRESSION
 Mostly pre-pressed in mechanical screw presses
 Heavy perforated barrel.
 Exerting a pressure up to 11.7 to 13.8 MPa.
 About 3–4% oil remains in the cake that results from screw
pressing .
 These screw presses are displaced by hydraulic press.
 The filter cloths and spent cake were manually removed
from the hydraulic press.
 The residual oil in spent cake was approximately 10%.

20. SCREW PRESS HYDRAULIC PRESS
A disadvantage of the screw press method compared with the now outdated
hydraulic pressing was the tendency of screw-pressed cottonseed oil to have
higher color due to the lower moisture content of the cooked meats

21. SOLVENT EXTRACTION
 Solvent hexane is used.
 Hexane is sprayed onto flakes.
 Hexane dissolving the oil is known as
miscella.
 This miscella is firstly filter.
 After that this miscella is send to
evaporator.
 And than send to stripping tower.

23. CONTINUED
Solvent extraction recovers up to 98% of the cotton seed
oil , compared with 90% to 93% from screw press
expression alone

25. THE CRUDE OIL IS FURTHER PROCESSED BY SOME PROCESSES.
THESE PROCESSES ARE NECESSARY IN EVERY OIL INDUSTRY
TO GET REFINED OIL ,WHICH IS USEABLE FOR OUR
REQUIREMENTS .

26. RIFINING
 The usual processing of vegetable oils involves four steps:
(1)Degumming/Steam Refining
(2) Absorptive Bleaching
(3) Hydrogenation
(4) Deodorization.
 These are usually batch operations, although a few continuous
processes are in operation.
 The oils are degummed by the coagulation with small amount
(0.05%) of Conc. Phosphoric Acid.
 In Alkali Refining ,the free fatty acids are neutralized with an
excess of 0.1% NaOH solution and the mixture is then heated to
75 ⁰ C to break any emulsion formed.
 The gums and soaps are removed by centrifugation and the free
fatty acids are removed by “ACIDULATION”.

27. BLEACHING
Bleaching is accomplished by the use of absorptive
BENTONITE CLAYS for edible oils, and alternatively by
chemical reaction for non edible ones.
The bleached oil, if it is to be used as salad oil, is then
subjected to a winterizing treatment which removes any
material that with solidify out at refrigerator
temperature.
This is accomplished by cooling to about 5 ⁰ C and
filtering out any solidified material.

28. HYDROGENATION
 The conversion of various unsaturated radicals of fatty glycerides
into more highly or completely saturated glycerides by the
addition of hydrogen in the presence of catalyst.
 Soybean , cottonseed converted by partial hydrogenation into
fats of composition more suitable for margarine and other edible
purposes. Taste and odor is also make better.
 The amount of hydrogen is related to degree of reduction of
unsaturation required. Measured by decrease in iodine number.
 Theoretical quantity is 0.95 m3 per metric ton of oil to reduce
iodine number one unit.
 Degree of hydrogenation is controlled by refractrometer to
indicate the physical.

30. MANUFACTURING OF HYDROGEN AND
CATALYST
 The hydrogen for hydrogenation is prepared by hydrocarbon-
steam process.
 The gaseous sulfur compound like hydrogen sulfide and sulfur
dioxide are strong catalyst poisons even in trace amounts.
 The hydrogen gas should be pure from taste producing
substances.
 Cylindrical ,tall closed vessel are charged with catalyst and
unsaturated oil.
 The charge is heated at high temperature 240 degree Celsius,
but 190 degree Celsius is a more common temperature.
 Normal operating pressures are 200 to 700 Kpa gage. At 150
degree Celsius the nickel format begins reduction.

31. CONTINUED…
 Temperature is held maximum for 1 hour and then cooled.
 During reduction and cooling period, hydrogen is bubbled
through the oil.
 Upon completion the charge is pumped directly to the
converter or formed into blocks, flakes, or granules for later
use.
 Condition can be changed to permit hydrogenation of both
mono- and poly unsaturated fatty acids simultaneously.
Selective and direct hydrogenation can be used.

32. DEODARIZATION
 Deodorization is accompanied by blowing superheated
steam through the oil.
 Under high vacuum of 138 to 800 pa and 210 to 275
degree Celsius.
 Odor causing and color producing pigments are also
removed.
 Deleterious oxidation is prevented under nitrogen
atmosphere.