Solvent extraction, an innovative adaptation of existing crude oil refining technology, is being studied for its potential to upgrade used oils produced by small-scale oil treatment facilities. This report presents the design for a pilot-scale treatment plant using solvent extraction. This report presents the design and the needed information for a pilot scale solvent treatment plant. Observations and discussion regarding the project and the design assumptions are presented along with the design.

1. The Techniques used in
processing of Edible Quality
of crude Rice Bran oil in a
Small-Scale Industry
Submitted by
Alif Hossain
IMTH-3rd Sem.
1060005
2010-2015
1

2. DECLARATION
I, Mr. Alif Hossain hereby declare that this project is the
record of authentic work carried out by me during the
period from 26th December to 4th of January and has not
been submitted to any other University or Institution for
the award of any degree/diploma etc.
Signature
Name of the student
Date-
2

3. Abstract of The Project
Solvent extraction, an innovative adaptation of existing
crude oil refining technology, is being studied for its
potential to upgrade used oils produced by small-scale oil
treatment facilities. This report presents the design for a
pilot-scale treatment plant using solvent extraction.
This report presents the design and the needed
information for a pilot scale solvent treatment plant.
Observations and discussion regarding the project and the
design assumptions are presented along with the design.
3

4. FINAL REPORT
Table of Content Page
Introduction 7
Enzyme in Rice Bran 11
Study of Unit Operators 13
 Bran unloading Area 13
 Preparatory Section 14
 Solvent Extraction
20
Plant
 Boiler Section 26
Other Project Detail 29
Further Development of 31
the Plant
Reference 32
4

5. Introduction
Rice oil, also called rice bran oil, has been used extensively in use in
Asian countries such as Japan, Korea, China, Taiwan, Thailand and
Pakistan. It is the preferred oil in Japan for its subtle flavor and odor.
Rice Bran is the brown layer of brown rice. It is the most nutritious part
of rice. Rice bran is rich in Vitamin E and Oryzanol, which are natural
substances that helps reduce blood cholesterol and fight against free
radicals. Rice oil is a minor constituent of rough rice when compared
with the carbohydrate and protein content. Two major classes of lipids
are present: (1) Those internal within the endosperm and (2) those
associated with the bran. The internal lipids contribute to the nutritional,
functional, and sensory qualities of rice.
More recently, interest in rice oil escalated with its identification as a
“health oil”. Rice oil is a minor constituent of rough rice when compared
with the carbohydrate and protein content. Attempts at further
development of rice oil production have not been successful because of
high capital requirement to construct an oil extraction plant and refining
facility and limited availability of stabilized rice bran. Rice bran is the
main source of rice oil. The majority of available bran continues to be
used for animal feeds without being extracted for the oil. The food
industry uses minor quantities of stabilized rice bran as a source of
dietary fiber, protein, and desirable oil.
Crude rice bran oil is the raw material of refined rice bran oil
manufacturing. In animal feed industry, crude rice bran oil is a better
source of energy when compared to animal fats because it is high in
metabolizable energy. It contains essential fatty acids for animals and
helps reduce heat of digestion. The typical composition of crude rice
bran oil is 81.3-84.3% triglycerides, 2-3% diglycerides, 5-6%
monoglycerides, 2-3% free fatty acids, 0.3% waxes, 0.8% glycolipids,
1.6% phospholipids, 4% unsaponifiables. In comparison with other
vegetable oils, crude rice bran oil tends to contain higher levels of non- 5

6. triglyceride components, most of which are removed during further
refining processes.
Crude Rice Bran Oil Parameters:
Parameter Values
Grade Crude Rice Bran Oil
Color 30 units measured in a 1/4' cell
Flash point 1000C
Free fatty acid % 4% - 20%
Moisture and insoluble 0.50%
Refractive index at 40' C 1.46 - 1.47
Specific gravity at 30' C 0.91 - 0.92
Iodine value 85 – 105
Acid value 50 max
Unsaponifiable matter %
4.0% max
by mass
Type Crude
This project is comprised of depth study of unit operations,
monitoring, measurement and
6

7. Name of Project : Pancham Marketiers Pvt. Ltd.
(Centrilized crude bran oil refining
unit)
Address of the Unit
a) Village : Chandipur
b) P.O. : Badnagra Via Gazole
c) P.S. : Gazole
d) District : Malda(West Bengal)
Capacity Utilization : 1st year- 65%
2nd year- 73%
3rd year- 87%
Man power requirements/
Employment Potential
: General Manager - 1
Account - 3
Office Staff - 7
Total Nos. - 11
Chemist - 2
Machine Operator - 6
Maintenance Staff - 2
Boiler Operator - 3
Skilled Workers - 12
7

8. Unskilled Workers - 80
Total Nos.- 105
8

9. ENZYMES IN RICE BRAN
Rice bran contains active enzymes. Germ and the outer layers of the
caryopsis have higher enzyme activities. Some enzymes that are present
include a-amylase, b-amylase, ascorbic acid oxidase, catalase,
cytochrome oxidase, dehydrogenase, deoxyribonuclease, esterase, flavin
oxidase, a and b-glycosidase, invertase, lecithinase, lipase, lipoxygenase,
pectinase, peroxidase, phosphatase, phytase, proteinase and succinate
dehydrogenase.
Particularly lipase, but also lipoxygenase and peroxidase, are probably
most important commercially because they affect the keeping quality
and shelf life of rice bran.
Lipase promotes the hydrolysis
of the oil in the bran into
glycerol and free fatty acids
(FFA). In the intact grain, the
lipases are localized in the
testa-cross layer of the rice
grains while the oil is in the
aleurone and subaleurone
layers and in the germ. The
germ, where 60% of the lipase
occurs, is similarly
compartmentalized. The rate of
FFA formation is highly
dependent on environmental
conditions. Formation of 5–7%
free fatty acids per day has
been reported. Up to 70% FFA
has been reported for a single month of bran storage. Rice bran oil
contains 2–4% FFA at the time of milling. Less than 5% FFA is
desirable for producing rice bran oil because high FFA results in high
refining losses.
9

10. Lipase has a molecular weight of about 40,000 Da and an isoelectric
point (pI) of 8.56. It is activated by calcium and inhibited by heavy
metals. The optimum pH is 7.5–8.0, and the optimum temperature is
37oC. It is inactivated by heating at 60oC for 15 minutes. A second rice
bran lipase has a pI of 9.1 and an optimum temperature of 27oC. It has a
high specificity for triacylglycerols having short-chain fatty acids. The
enzyme, lipoxygenase, is associated with the oxidation of the
polyunsaturated fatty acids (PUFA). The carbonyl products from the
degradation, particularly hexanal, have been implicated in the stale
flavor of rice. Lipoxygenase activity is highest in the germ fraction.
Three forms of lipoxygenase have been isolated differing in pH
optimum and specificity.
10

11. Study of Unit Operators
The factory comprises of various units doing different sets of
processes. These are listed below. All of them are interlinked with
each other. The interrelationships of these units are shown in the
Figure-1.
Area 1 : Bran Unloading Area
Area 2 : Preparatory section
Area 3 : Solvent Extraction Plant
Area 4 : Storage Section
Area 5 : Boiler Section
A General Process Flow Diagram of Rice Bran to Rice Bran Oil
Area 1: Bran unloading Area
The rice bran is brought from nearby areas (within 100-km radius) by
truck. The truck before entering the factory is weighed in the weighing 11

12. area along with the truck and then the weight of the truck is deducted to
calculate the amount of bran brought in. From there the truck proceeds
to the unloading yard inside the factory. Out there workers do the job of
getting the bags of bran out by labor method and stocking it. Each and
every bag is inspected by a maintenance staff and samples collected for
testing. The samples are collected by punching a hole in the bag when it
is being unloaded and the sample is then collected. It receives around
120 tonnes of rice bran every day. The bran is generally of mixed type.
No specific type of bran for processing is available. The maximum
capacity of the plant is 200 T/day.
Area 2: Preparatory section
In this section the main stabilization of the bran takes place. These
include cooking, de-moisturizing, drying/cooling. In retained heating
methods (dry heat), a simple
hot air drying reduces the
moisture content to 3–4%.
The bran is kept dry in
moisture-proof containers, or
else the rehydrated bran will
regain its lipase activity. If the
bran is heated in the presence
of moisture, the lipase is
permanently denatured.
12

13. The types of retained-moisture heating methods include extrusion
cookers and sealed steam
heating/cooling conveyors.
Extrusion cooking results in
both lipase denaturation and
bran sterilization. When
pressure is released, part of
the superheated moisture
evaporates with little or no
drying being required.
Expanders or expellers are
also used to allow addition of moisture (wet heating) through steam and
preparation of pellets from the bran. The pellets help in handling and oil
extraction. Extrusion (dry heat) cookers are used for stabilization
because excess moisture is not added, eliminating the need for drying.
The heating of the bran occurs through conversion of mechanical energy
of the screw drive to heat the bran.
Temperatures used for stabilization vary from 100 to 140oC. The bran
is kept hot for 3–5
minutes after extrusion
to ensure lipase
inactivation. The hot
bran is then cooled
using ambient air.
According to the
research done, dry
extrusion was found
more suitable for
stabilizing bran to be
used as a food
ingredient. Wet heating
is more effective for
bran stabilization for oil
13

14. extraction than is dry heating. Lipase is inactivated in 3 minutes at
100oC.. Extrusion with steam injection andup to 10% added water
reduced the temperature required for lipase inactivation. Temperatures
are reduced to 100–120oC. Product may be held at 100oC for 1.5–3.0
minutes before drying to stable
moisture content. Bran expands
as it exits the extruder and
water flashes to steam. Porous
pellets helps in solvent
percolation during oil
extraction. Fines are collected
together as well.
Pelletizing of the bran improves percolation and minimizes fines in
the miscella. Pellets are 6–8
mm in diameter. Moistening
during palletizing reduces the
fines problem. Briefly cooked
(Parboiled) bran does not
produce the hard pellets found
for raw bran possibly because
of protein denaturation during
brief cooking. Parboiled bran
also presents problems with
sticking to dryer surfaces
resulting in self-ignition in the
dryer. Mixing before hand with raw bran lessens this problem.
14

15. Summary of Preparatory Stage in step wise
Rotary seiver- separates the bran from impurities like stone, nails,
sticks, etc
Elevator takes the bran to the top and brings down by gravity to the
cooking conveyor.
The cooking conveyor with
the help of steam cooks the
separated bran.
It is cooked to ease the load and
pressure of the machine.
The cooked bran
then comes to the
pelleting machine. The
15

16. pelleting machine comprises of the roller and the pin. The roller is a
bigger part of the machine which has the radius of about 2-3 feet and the
pin is about the size of a small bucket. These two sub-systems make up
the pelleting machine and turns the bran into pellet by rolling over one
another. There are two machines that make the pellet. Each has 5 rollers
and 5 pins in it.
The pellet is then led directly into the pellet cooler (A) which cools
the pellet. Ti cools in two way system: (i) Dry air (ii) Cool air. The one
with dry steam gives hot air,
avoiding the bran from
crumbling and becoming hard.
This machine is called radiator.
The moisture temperature is kept
at 1060C.
The second system which passes
the cool air s called Blower. It
passes cool air from the top f the tower so as to make it harder.
 The radiator gives in moisture and the blower absorbs the
moisture. This leads to the hardening of the pellet.The pellet cooler
(B) comes into action now. It cools the pellet by normal method of
fanning. The fans are on top of the conveyor. It is a type of
conveyor cum fan cooling machine.
16

17. 17

18. Area 3: Solvent Extraction Plant
The unit has 150 T/D Solvent Extraction Plant. The DORB are
transferred to the SEP through a belt conveyor. In SEP there are three
major processes involved:
(i) Solvent Extraction
(ii) Desolventisaion, Toasting, Drying & Cooling (DT-DC)
(iii) Distillation
I Solvent Extraction
The pellets are fed through plug seal feed screw into the extractor.
The plug seal feed screw is sealed so as to avoid leakage of hexane
vapor of extractor. The extractor is of a slow moving conveyor. This
slow speed conveyor carries the pellets while hexane is continuously
poured at equal intervals from
the top in the extractor like a
mini waterfall. The extractor is
like a long steel cave. Pellets
are fed at the rate of 350 T/day
(i.e. 14.6 T/hr.). The hexane (in
circulation) is maintained at 1:1
proportion. The output from the
extraction is Miscella (mixture
of oil and hexane) and Wet De-
oiled cake (DOC). The
concentration of oil in the Miscella is 20-25% in case of pellets. The
hexane concentration in the Wet DOC is 25% in pellets. Temperature of
O
recirculated Miscella in the extractor is maintained at 55 –58 C.
The Miscella is sent for further processing like distillation, solvent
recovery whereas wet DOC or de-oiled mills is directly fed into
Desolventiser-Toaster-Dryer- Cooler (DT-DC).
18

19. II Desolventisation-Toasting- Drying-Cooling(DT-DC)
The objective of this process is to recover the hexane present in the
wet DOC and to reduce the lipase activity. The sizes of DT&DC are 3.2
& 4.0-m diameters respectively, placed one over the other called DTDC.
This is a vertical column
containing six compartments
in which wet DOC, containing
25-30% hexane, is fed. In
order to remove hexane, direct
as well as indirect steam is
used. Indirect steam is used
for raising the temperature
while direct steam is used for
blending. Out of six
compartments, two
compartments from the top
are for desolventisation.
Subsequently below it, two
compartments are for toasting,
fifth compartment is for
drying and the bottom
compartment is for cooling.
The temperature
st nd
maintained in the 1 and 2
compartment of the
o
Desolventiser is 90 C and
O
100 C respectively. In the
Toaster, temperature is raised
o st o nd
up to 105 C in the 1 compartment and 120 C in the 2 compartment.
After toasting, material flows to the drier compartment. Here it comes in
o
contact with hot air which as temperature around 100 – 120 C. The hot
air is carried out into the atmosphere through cyclone. From Drier,
19

20. material flows to the cooler compartment where closed air is used for
cooling the material. The cold air is let out into the atmosphere through
cyclone. The hot hexane
vapor containing steam is
freed from dust in cyclone
and then passed through
economizers (1 & 2) to
preheat the Miscella before
its evaporation.
The uncondensed hexane
vapor from the economizers
is passed through jet
condenser, where hexane
vapor is condensed by
direct contact with liquid
hexane. The uncondensed
hexane vapor from the jet
condenser then goes to
chiller condensers (2 nos.)
where it is absorbed by mineral oil in the absorber. The DOC from
DTDC is further screened in the DOC screen containing 3 mesh
vibrating screens, separate over sized DOC lumps and crush it in lump
crusher. Then the crushed lumps are mixed with screened DOC. Here,
moisture content and sand silica contents in the DOC are adjusted to
meet permissible limit (moisture 11.0% and Silica 2.0%). Finally, the
DOC is filled in the gunny bags and stacked in Godown.
II Distillation
The purpose of Distillation is to separate hexane from Miscella. The
Miscella is passed through economizer for pre-heating and to increase
the concentration of oil from 22% to 45%. The oil concentrated Miscella
is further processed in evaporator to increase the oil concentration up to
99%. In the economizers temperature of Miscella is raised up to 57 –
20

21. O O
58 C from 50 – 52 C. The economizers are maintained at 350 – 400
mm Hg vacuums. In the evaporator
temperature of Miscella is
O
increased up to 95 – 100 C. The
evaporated hexane vapor from
economizer and evaporator are
condensed in the condenser and
separated in the water solvent
separator. The recovered hexane is
further sent for circulation. The
traces of hexane present in the oil
after evaporator is removed in
stripper-cum-dryer where the
temperature and pressure is
O
maintained at 110 - 115 C and
about 600 mm. Hg vacuum
respectively. Crude oil is stored in crude
oil storage tanks.
During solvent extraction process, the
average hexane loss (from the monthly
hexane consumption figure) lies between
4.0 to 5.5 lit/T of bran processed. The
losses of hexane occur in the following
areas:
 Final DOC Hot air Discharge
 Traces in crude oil
 Traces in DOC
 Through final vent
 Through hot water
 Through leakage
 During plant break down & annual maintenance
21

22. 22

23. Area 4: Storage section
After the crude bran is extracted and the hexane is separated the bran
oil now is sent to the
large containers for
storing the bran.
While the liquefied
hexane is re-
circulated in the
extraction process.
The storage tanks
had the capacity of
storing around 100
tonnes of oil. The
factory had a total of
4 storage tanks, with
two of them in
working condition. The rest two were small of around 75 tonnes of
storage capacity or less and but were de-functioned.
23

24. Area 5: Boiler Section
A boiler is a closed vessel in which water or other fluid is heated.
The heated or vaporized fluid exits the boiler for use in various
processes or heating applications, including boiler-based power
generation, cooking, and sanitation.
The boiler played a very important part in the working of the factory.
It was the source of power as well as steam generator for the different
processes needed in the production of bran. The steam was used in the
preparatory section for dry heating and also in the SEP section. The
boiler used in the factory was a Husk-burned boiler. This boiler was
selected for the plant because for the easy availability of husk from the
area.
24

25. The boiler had a capacity range of 6000 kg/hr. with maximum
working pressure of 18.25 kg/cm2 and hydro test pressure shown was
27.38 kg/cm2. The main requirements for the working of the boiler were
three basic things: (1) Soft
Water (2) Husk (3)
Temperature -100oC. Small
amount of sand is also used
as a temperature balancer
in the furnace. The furnace
is the chamber where the
raw material along with the
temperature balancer is
inserted for generating
heat. It contains diagonally
placed tubes in it which
has a continuous running soft water through it. This soft water is
converted to steam from this chamber.
There are two safety valves in the boiler (drum). These valves are
used in case of emergency when excess of steam is produced and needs
to be expelled out. There number is two because in-case one does not
work out the other one is always there for emergency. The boiler or the
drum contains Safety valve, Pressure Gauge, Air Vent (attached with
Safety valve), Main Stock Valve which the operator can control and
check. The whole oiling section also has a feeder tank (softener plant)
which stores the soft water. To operate a boiler a person has to be
certified as minimum II class boiler (Needs a graduation certificate).
Three certification available: II class, I class and B.O.E. class (Boiler
Operating Engineer).
25

26. The boiler
has its own
in-built
cooling
system.
There are
three systems
for cooling
each for
different
parts of the
boiler.
 I.D. Fan- This cooling system chucks out the flow gas from the
boiler. Flow gas is the wasted gas that exists from chimney.
 F.D. Fan- It prepares the hot air. The hot air is used for heating
the sand faster. It serves as a dual purpose so it has two lines:
one leading to furnace (sand heating area) another to P.A. Fan.
 P.A. Fan-It also acts as in a dual way. It takes the F.D. fan air
and brings the husk faster into the furnace. It’s a type of blow-in
air system.
Its main features that it had:
 Top fuel feeding with independent fuel feeding fan.
 Bubbling Bed Combustion.
 Pressure part design validation by Finite Element Analysis.
 Bubbling Bed nozzle design by CFD Analysis.
26

27. OTHER PROJECT DETAILS
Power:
Required power is available from West Bengal State Electricity
Distribution Company Limited. The Total connected load for common
facility centre is 400 K.W.. The monthly electricity charge is Rs. 6 lakhs
at full capacity utilization.
Plant Capacity and Capacity Utilization:
The refinery section of common facility centre has a processing
capacity of 150 tonnes of extracted bran oil per day. Because of down
time and other various reasons, the capacity is not releasable and it is
assumed. The de-oiled rice bran is actually a by-product of solvent
extraction of rice bran. This de-oiled rice bran is sold to cattle feed
industries, so that value addition is ensured.
Study of Material Handling & House Keeping Practices:
While study and understanding about the working of the plant a study
was also carried out while in different sections to examine the present
work practices in the plant and identifying improvement opportunities in
the daily processing of the plant with the objective of waste elimination
and conservations of the study. The observations are mentioned in the
paragraphs below. Further, in order to achieve and demonstrate
continuous improvement in shop floor activities, an observation was
observed.
Observations on Material Handling Practices
Observations
1. Truck Movement and Parking area:
 Parking locations and addresses for rice bran filled trucks are
not specified results in parking of trucks in a random fashion
and improper movement of trucks in unloading area.
27

28.  The filled bags are stored and used as a platform where
workers are walking over the filled bags.
 Empty bags are thrown in the work area. Each empty bag still
contains 100-200 gms of rice bran and results in spilling of
bran in the entire work area. It results in significant amount
of rice ran spillage.
 Due to improper handling & holes in the bags significant
spillage of rice bran occurs.
 Workers tread over the spilled bran lying in the work area
resulting in deterioration of bran quality as well as unsafe
walking
2. Screening and Sieving Area:
 During sieving operation, the material directly thrown on the
ground and then pushed into the conveyor. These bags are
moved through the path, which is not optimum route.
 Workers walk on the slope with filled bags, which is not safe.
 The fallen bran on the truck is also cleaned and thrown
directly on the ground in the unloading area.
3. Preparatory Section:
 Spare parts i.e. rollers, chain & pulley block etc kept near
work centre, are not stored in a rational manner.
 Due to various reasons such as material sampling point are
kept in open condition/improper design of supporting plate,
processed material falls on the ground resulting in loss of
man-hours required to clean the material and charge in
feeder.
4. Solvent Extraction Plant:
 Many of meters are not on proper working conditions. Most
of them are either out of order or faulty ones.
28

29. FURTHER DEVELOPMENT OF
THE PLANT
The plant has enough experience now and should be now go for a
large scale production including the full processing of the bran oil. If it
is capable of getting proper technicians into its plant then the production
can increase up in large amount. Technical man power problems should
be taken care soon.
Boiler being the no 1 consumer of HSD, it has huge potential of
energy saving if we can explore and utilize a proper energy efficiency
measure. One of them is through condensate recovery system, using the
condensate to preheat boiler feed-water (6o C raise in feed water
temperature by condensate recovery corresponds to a 1% saving in fuel
consumption, in boiler), significant saving in fuel can be achieved.
29

30. REFERENCE
1. Thai Edible Oil Co., Ltd.
2. Frank T. Orthoefer study and writing on Rice Bran Oil.
3. Thammasaitn t. J. Sc. Tech..V ol. 8. No. 4. October-Decembe2003.
4. Peter Wan’s Peer Reviewed Journal on Solvent extraction,
Submitted to Inform.
5. Journal off Scientific & Industrial Research, Vol. 64, November
2005.
6. Agricultural Engineering Unit, International Rice Research
Institute.
7. Solvent Extraction Technology for Used Oil Treatment, ReTAP
Report, USA.
8. Food Industry-Phillip J. Wakelyn, NCC, USA and Peter J. Wan,
USDA, ARS, SRRC, USA.
9. George H., Andrews Engineering Associates, Inc., USA., Series of
Reprts resulting from overseas technical inquiries on factory.
10. Kalady Rice Millers Consortium Pvt. Ltd., Kerela, India,
Report onproposal for setting up a common facility centre under
Small Industries Cluster Development Programme Scheme.
11. Wikipedia, Rice Bran oil article.
30