Transcript INTRODUCTRY TO CHEMICAL ENGINEERING

INTRODUCTRY TO CHEMICAL
ENGINEERING
EXTRACTION
Extraction is one of the most useful and
widely used chemical seperation methods.
There are two types of extraction process:
•Solid – Liquid Extraction
•Liquid – Liquid Extraction
Solid – Liquid Extraction
Leaching generally refers to the removal
of a substance from a solid via a liquid
extraction media. The desired component
diffuses into the solvent from its natural
solid form.
Some usage examples:
Examples of leaching include the
removal of sugar from sugar beets with
hot water and the removal of nickel
salts or gold from their natural solid
beds with sulfuric acid solutions.
Types of Equipments
There are many different types of equipment used for
leaching. Most of these pieces of equipment fall into
one of two categories:
• Percolation....."Liquid Added to Solids“
The solvent is contacted with the solid in a
continuous or batch method. This method is popular
for in-place ore leaching or large scale "heap"
leaching. Popular for extreme amounts of solids.
• Dispersed Solids....."Solids Added to Liquid“
The solids are usually crushed into small pieces before
being contacted with solvents. This is a popular
leaching method when an especially high recovery rate
can economically justify the typically higher operating
cost (Ex/ gold extraction)
Figure for Leaching
Liquid – Liquid Extraction
Liquid extraction (or solvent extraction) refers to
an operation in which the components of a liquid
mixture are separated by contacting it with a suitable
insoluble liquid solvent which preferentially dissolves
one or more components.
In this operation, the separation of the components
depends upon the unequal distribution of the
components between the immiscible liquids. The feed
solution represents one phase and the solvent to be
used to effect separation represents the second
phase. The mass transfer of the solute liquid takes
place from the feed solution to the solvent phase.
Basic Steps
Typical liquid-liquid extraction operations
utilize the differences in the solubilities of
the components of a liquid mixture. The basic
steps involved include:
1. Contacting the feed with the extraction
solvent.
2. Separation of the resulting phases, and
3. Removal/recovery of solvent from each
phase.
Some Basic Steps & Extractor Design
Typical liquid-liquid
extraction operations
utilize the differences in
the solubilities of the
components of a liquid
mixture. The basic steps
involved include:
1. Contacting the feed with
the extraction solvent.
2. Separation of the
resulting phases
3. Removal/recovery of
solvent from each phase.
LET’S START TO EXTRACT
SOME OIL!!!
OILSEED
PROCESSING
Removing tough
outer shells
DECORTICATION
Improve the
surface area
Removing
dust,sand etc.
SEED CLEANING
Getting your seeds
into useful sizes
Clean some mess out
Selecting the best
system for type of oil
SIZE
REDUCTION
ROLLING
CONDITIONING
Need some oil?
EXTRACTION
Getting pure oil
REFINING
PREPERATION OF OIL
EXTRACTION
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Oilseed processing
Decortication
Seed cleaning
Size reduction
Rolling
Conditioning
• Oilseed processing
Various small-scale techniques are available to enable
people in rural areas to process their own oilseeds
locally. Careful consideration is needed to select the
system that will best suit the local circumstances.
These circumstances include the scale of operation
required, the availability of a power source, and a
number of other factors.
• Decortication
Some oilseeds have a hard outer shell which must be
removed before processing. This process is called
decortication. Palm kernel is an example of a seed
that must be decorticated prior to processing. The
extraction of oil from other oilseeds which can be
processed without decorticating them first, such as
sunflower, may be aided by removing a proportion of
the hulls before processing.
• Seed cleaning
It is essential to winnow and sieve oilseeds, prior to
expelling, to remove as much dirt, dust, sand and
small stones as possible. The presence of sand results
in high wear on critical components of expellers such
as cages, wormshafts and chokes. Using clean oilseed
for expelling will greatly increase the time that the
expeller can be used before replacement parts are
needed.
• Size reduction
Generally, small oilseeds (such as sesame or rapeseed)
can be processed directly, while larger seeds (such as
copra or shea nuts) need to be ground before
processing. At the domestic level, grinding is usually
carried out with a pestle and mortar (Plate I) while
larger quantities may be ground in a village maize mill
(Plate II). Hand-operated meat mincing machines can
also be used in certain circumstances. The most
common type of powered mill used for small-scale
operations is the hammer mill.
• Rolling
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Rolling a seed generally results in an improvement in
oil extraction by increasing the surface area of the
seed while at the same time retaining channels for
the flow of oil. The flakes should be very fine and
preferably thinner than 0.1 mm. Rolling before
processing in a bridge press is said to increase oil
yields by 10% for palm kernel, groundnut and
sunflower.
Conditioning
Oilseeds are nearly always conditioned before largescale expelling. Small-scale expellers minimize the
need for pre-treatment by using a relatively fast
wormshaft speed which shears the oilseed as it
passes through the expeller and produces frictional
heating within the expeller barrel. This assists oil
expulsion by raising the temperature of the oilseed.
VEGETABLE OIL EXTRACTION
• The "modern" way of processing vegetable oil is by chemical
extraction, using solvent extracts, which produces higher yields
and is quicker and less expensive. The most common solvent is
petroleum-derived hexane. This technique is used for most of
the "newer" industrial oils such as soybean and corn oils.
• Another way is physical extraction, which does not use solvent
extracts. It is made the "traditional" way using several
different types of mechanical extraction. This method is
typically used to produce the more traditional oils (e.g., olive),
and it is preferred by most "health-food" customers in the USA
and in Europe. Expeller-pressed extraction is one type, and
there are two other types that are both oil presses: the screw
press and the ram press. Oil seed presses are commonly used in
developing countries, among people for whom other extraction
methods would be prohibitively expensive. The amount of oil
extracted using these methods varies widely.
Wet extraction methods:
In wet extraction methods water is
used to extract oil from oilseeds. The
distinction should be made between wet
methods and water-assisted methods of
oil extraction.
Wet extraction methods involve the
use of a relatively large amount of
water so that the oilseed is suspended
in the water and the extracted oil
floats on the surface.
WATER-ASSISTED METHODS
Involve the addition of a small
quantity of water to the oilseed before
the oil is extracted by manual kneading.
These methods are discussed later.
They are not classified as wet methods
because all the water used is absorbed
by the oilseed and no separate water
layer is apparent.
HOT WATER FLOTATION (HWF)
METHOD
The hot water flotation (HOOF) method of edible oil
extraction is traditionally used in the rural areas of many
developing countries. Usually, decorticated oilseed is used.
The oilseed kernels are heated and ground by pounding in a
pestle and mortar. The ground seed is then suspended in
boiling water and boiled for at least 30 min. Liberated oil
floats to the surface. Further quantities of water are
sometimes added after boiling to replace that lost by
evaporation, and to encourage the oil to float to the
surface. The oil is carefully scooped from the surface of
the water using a shallow dish and is then heated over a
fire to remove residual moisture.
• The advantage of the HWF method over other small-
scale oilseed processing techniques, such as those using
expellers or ghanis, is its simplicity. The equipment
required (pestle and mortar, boiling pans, etc.) is
readily available. However, oil yields tend to be low and
the process can be time consuming and arduous. This is
especially true if traditional pestle and mortar methods
are used to grind the oilseed kernel. If long boiling
times are used, fuel consumption will also be high.
• The above method may be applied to most oilseeds with
varying degrees of success. Sources of oil, such as
coconut and oil palm fruits, can be processed by
traditional methods which make use of the water
already present in the seed.
OIL EXTRACTION MACHINE
SOYBEAN MEALS’ STORAGE
OIL EXTRACTION PLANT
OIL EXPELLERS
Series of small scale oil expeller
These small scale screw type oil expeller are
advanced oil processing machinery,
characterized by their high oil output rate with
good quality, simple design, easy to use and
continuous operation. They can use for various
raw material, such as peanut, beans, rape and
cotton seeds, sesame, olive, sunflower, coconut,
grass seed etc
Oil expellers
Expellers are continuous in
operation and work by grinding and
pressing the raw material as it is
carried through a barrel by a helical
screw.The pressure inside the
barrel, and hence the yield of oil,
are adjusted using a ‘choke’ ring at
the outlet. The equipment has
higher production rates than similar
sized presses but is more expensive
to buy and operate.
PRESS TYPES OF THE OIL
EXTRACTION PROCESSES
These presses are used in the rolling stage of the oil
extraction. They help the extraction by widening the
extraction surface area.
• Manual presses
• Bridge-type Cage press
• The wedge press
• Scissor press
• The plank press
• Cage presses
• Curb presses
• Bridge press
• Hydraulic press
• Ram press
• Ghani
CURB PRESS
BRIDGE PRESS
SCISSOR PRESS
HYDRAULIC PRESS
RAM PRESS
POWER GHANI
INFORMATION ABOUT SOME
TYPES OF OILSEEDS
• COCONUTS
Coconuts grow in the
coastal areas of the
tropics.
Major producing
countries are: The
Philippines, Indonesia,
Malaysia, Sri Lanka,
India, C’ote d'Ivoire,
Mozambique, Tanzania,
and the Pacific Islands.
USAGE EXAMPLES OF COCONUT
• As a cooking oil and in the preparation
of oil and fat blends for the food
industry.
• Soap-making
GROUNDNUTS:
• The groundnut is an
annual plant.
• Varieties are grown
as two types, either
as a bushy bunch or
as a runner.
• Groundnuts grow in
tropical and
subtropical regions,
and in warm parts of
temperate regions.
USAGE EXAMPLES OF GROUNDNUTS
• Using a diesel-powered CeCoCo H54
expeller
OIL PALMS:
• The oil palm
requires a rainy
tropical climate
• begin to fruit
after 10 years
• do not give a full
crop for about 20
years
USAGE EXAMPLES OF OIL PALMS
• Used in commercial agriculture in the
production of palm oil.
RAPSEED &
MUSTERDSEED:
• Rape and mustard are
similar species and
for the purposes of
this manual can be
treated as one
oilseed. Rape is one
of the most widely
cultivated oilseed
crops
SUNFLOWER SEED:
• Sunflower is an
annual plant that
thrives in the
tropics at medium
and high elevations
and, under suitable
conditions, in
temperate climates.
SOYA:
• The soyabean, or
soybean, is an
annual, and with
the selection of
the appropriate
variety, can be
grown in a wide
range of
conditions
SOYBEAN (SOYABEAN) OILS
USAGE EXAMPLES OF SOYABEAN
• Widely used as a food crop
• Raw material in the manufacture of
'textured vegetable protein' used for
human consumption
TAKE LOOK AT OILSEEDS :)
MEANING OF SOME
OILSEEDS :))
• Palm : Palmiye
• Sesame: Susam
• Rapeseed: Kolza
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•
•
tohumu
Mustardseed:
Hardal tohumu
Linseed: Keten
tohumu
Cottonseed: pamuk
tohumu
• Soyabean: Soya
• Groundnut:
•
•
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yerfıstığı
Castorseed:
keneotu tohumu
Sunflower: ayçiçeği
Copra: kurutulmuş
hindistan cevizi
100
% OIL
90
80
70
60
50
40
30
20
10
0
PALM
SESAM E
RAPESEED
M USTARD
LINSEED COTTONSEED SOYABEAN PALM FRUIT GROUNDNUT CASTORSEED SUNFLOWER
COPRA
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