Pilot Scale Rice Bran Industry


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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.

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Pilot Scale Rice Bran Industry

  1. 1. The Techniques used inprocessing 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. 2. DECLARATIONI, Mr. Alif Hossain hereby declare that this project is therecord of authentic work carried out by me during theperiod from 26th December to 4th of January and has notbeen submitted to any other University or Institution forthe award of any degree/diploma etc.SignatureName of the studentDate- 2
  3. 3. Abstract of The Project Solvent extraction, an innovative adaptation of existingcrude oil refining technology, is being studied for itspotential to upgrade used oils produced by small-scale oiltreatment facilities. This report presents the design for apilot-scale treatment plant using solvent extraction. This report presents the design and the neededinformation for a pilot scale solvent treatment plant.Observations and discussion regarding the project and thedesign assumptions are presented along with the design. 3
  4. 4. FINAL REPORTTable of Content PageIntroduction 7Enzyme in Rice Bran 11Study of Unit Operators 13  Bran unloading Area 13  Preparatory Section 14  Solvent Extraction 20 Plant  Boiler Section 26Other Project Detail 29Further Development of 31the PlantReference 32 4
  5. 5. Introduction Rice oil, also called rice bran oil, has been used extensively in use inAsian countries such as Japan, Korea, China, Taiwan, Thailand andPakistan. 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 partof rice. Rice bran is rich in Vitamin E and Oryzanol, which are naturalsubstances that helps reduce blood cholesterol and fight against freeradicals. Rice oil is a minor constituent of rough rice when comparedwith the carbohydrate and protein content. Two major classes of lipidsare present: (1) Those internal within the endosperm and (2) thoseassociated 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 comparedwith the carbohydrate and protein content. Attempts at furtherdevelopment of rice oil production have not been successful because ofhigh capital requirement to construct an oil extraction plant and refiningfacility and limited availability of stabilized rice bran. Rice bran is themain source of rice oil. The majority of available bran continues to beused for animal feeds without being extracted for the oil. The foodindustry uses minor quantities of stabilized rice bran as a source ofdietary fiber, protein, and desirable oil. Crude rice bran oil is the raw material of refined rice bran oilmanufacturing. In animal feed industry, crude rice bran oil is a bettersource of energy when compared to animal fats because it is high inmetabolizable energy. It contains essential fatty acids for animals andhelps reduce heat of digestion. The typical composition of crude ricebran 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 othervegetable oils, crude rice bran oil tends to contain higher levels of non- 5
  6. 6. triglyceride components, most of which are removed during furtherrefining 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. 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. 8. Unskilled Workers - 80Total Nos.- 105 8
  9. 9. ENZYMES IN RICE BRANRice bran contains active enzymes. Germ and the outer layers of thecaryopsis have higher enzyme activities. Some enzymes that are presentinclude a-amylase, b-amylase, ascorbic acid oxidase, catalase,cytochrome oxidase, dehydrogenase, deoxyribonuclease, esterase, flavinoxidase, a and b-glycosidase, invertase, lecithinase, lipase, lipoxygenase,pectinase, peroxidase, phosphatase, phytase, proteinase and succinatedehydrogenase.Particularly lipase, but also lipoxygenase and peroxidase, are probablymost 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% FFAhas been reported for a single month of bran storage. Rice bran oilcontains 2–4% FFA at the time of milling. Less than 5% FFA isdesirable for producing rice bran oil because high FFA results in highrefining losses. 9
  10. 10. Lipase has a molecular weight of about 40,000 Da and an isoelectricpoint (pI) of 8.56. It is activated by calcium and inhibited by heavymetals. The optimum pH is 7.5–8.0, and the optimum temperature is37oC. It is inactivated by heating at 60oC for 15 minutes. A second ricebran lipase has a pI of 9.1 and an optimum temperature of 27oC. It has ahigh specificity for triacylglycerols having short-chain fatty acids. Theenzyme, lipoxygenase, is associated with the oxidation of thepolyunsaturated fatty acids (PUFA). The carbonyl products from thedegradation, particularly hexanal, have been implicated in the staleflavor of rice. Lipoxygenase activity is highest in the germ fraction.Three forms of lipoxygenase have been isolated differing in pHoptimum and specificity. 10
  11. 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 OilArea 1: Bran unloading Area The rice bran is brought from nearby areas (within 100-km radius) bytruck. The truck before entering the factory is weighed in the weighing 11
  12. 12. area along with the truck and then the weight of the truck is deducted tocalculate the amount of bran brought in. From there the truck proceedsto the unloading yard inside the factory. Out there workers do the job ofgetting the bags of bran out by labor method and stocking it. Each andevery bag is inspected by a maintenance staff and samples collected fortesting. The samples are collected by punching a hole in the bag when itis being unloaded and the sample is then collected. It receives around120 tonnes of rice bran every day. The bran is generally of mixed type.No specific type of bran for processing is available. The maximumcapacity of the plant is 200 T/day.Area 2: Preparatory section In this section the main stabilization of the bran takes place. Theseinclude 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. 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 arealso used to allow addition of moisture (wet heating) through steam andpreparation of pellets from the bran. The pellets help in handling and oilextraction. Extrusion (dry heat) cookers are used for stabilizationbecause excess moisture is not added, eliminating the need for drying.The heating of the bran occurs through conversion of mechanical energyof 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. 14. extraction than is dry heating. Lipase is inactivated in 3 minutes at100oC.. Extrusion with steam injection andup to 10% added waterreduced the temperature required for lipase inactivation. Temperaturesare 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 inthe miscella. Pellets are 6–8mm in diameter. Moisteningduring palletizing reduces thefines problem. Briefly cooked(Parboiled) bran does notproduce the hard pellets foundfor raw bran possibly becauseof protein denaturation duringbrief cooking. Parboiled branalso presents problems withsticking to dryer surfacesresulting in self-ignition in thedryer. Mixing before hand with raw bran lessens this problem. 14
  15. 15. Summary of Preparatory Stage in step wise Rotary seiver- separates the bran from impurities like stone, nails,sticks, etcElevator takes the bran to the top and brings down by gravity to thecooking 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. 16. pelleting machine comprises of the roller and the pin. The roller is abigger part of the machine which has the radius of about 2-3 feet and thepin is about the size of a small bucket. These two sub-systems make upthe pelleting machine and turns the bran into pellet by rolling over oneanother. There are two machines that make the pellet. Each has 5 rollersand 5 pins in it. The pellet is then led directly into the pellet cooler (A) which coolsthe 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. Itpasses 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
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  18. 18. Area 3: Solvent Extraction Plant The unit has 150 T/D Solvent Extraction Plant. The DORB aretransferred to the SEP through a belt conveyor. In SEP there are threemajor processes involved: (i) Solvent Extraction (ii) Desolventisaion, Toasting, Drying & Cooling (DT-DC) (iii) DistillationI 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 hexanevapor of extractor. The extractor is of a slow moving conveyor. Thisslow 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). Theconcentration of oil in the Miscella is 20-25% in case of pellets. Thehexane concentration in the Wet DOC is 25% in pellets. Temperature of Orecirculated Miscella in the extractor is maintained at 55 –58 C. The Miscella is sent for further processing like distillation, solventrecovery whereas wet DOC or de-oiled mills is directly fed intoDesolventiser-Toaster-Dryer- Cooler (DT-DC). 18
  19. 19. II Desolventisation-Toasting- Drying-Cooling(DT-DC) The objective of this process is to recover the hexane present in thewet 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 ndup 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 ocontact with hot air which as temperature around 100 – 120 C. The hotair is carried out into the atmosphere through cyclone. From Drier, 19
  20. 20. material flows to the cooler compartment where closed air is used forcooling 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 fromDTDC is further screened in the DOC screen containing 3 meshvibrating screens, separate over sized DOC lumps and crush it in lumpcrusher. Then the crushed lumps are mixed with screened DOC. Here,moisture content and sand silica contents in the DOC are adjusted tomeet permissible limit (moisture 11.0% and Silica 2.0%). Finally, theDOC is filled in the gunny bags and stacked in Godown.II Distillation The purpose of Distillation is to separate hexane from Miscella. TheMiscella is passed through economizer for pre-heating and to increasethe concentration of oil from 22% to 45%. The oil concentrated Miscellais further processed in evaporator to increase the oil concentration up to99%. In the economizers temperature of Miscella is raised up to 57 – 20
  21. 21. O O58 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 vacuumrespectively. Crude oil is stored in crudeoil storage tanks. During solvent extraction process, theaverage hexane loss (from the monthlyhexane consumption figure) lies between4.0 to 5.5 lit/T of bran processed. Thelosses of hexane occur in the followingareas:  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
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  23. 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 inworking condition. The rest two were small of around 75 tonnes ofstorage capacity or less and but were de-functioned. 23
  24. 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 variousprocesses or heating applications, including boiler-based powergeneration, 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 differentprocesses needed in the production of bran. The steam was used in thepreparatory section for dry heating and also in the SEP section. Theboiler used in the factory was a Husk-burned boiler. This boiler wasselected for the plant because for the easy availability of husk from thearea. 24
  25. 25. The boiler had a capacity range of 6000 kg/hr. with maximumworking pressure of 18.25 kg/cm2 and hydro test pressure shown was27.38 kg/cm2. The main requirements for the working of the boiler werethree basic things: (1) SoftWater (2) Husk (3)Temperature -100oC. Smallamount of sand is also usedas a temperature balancerin the furnace. The furnaceis the chamber where theraw material along with thetemperature balancer isinserted for generatingheat. It contains diagonallyplaced tubes in it whichhas a continuous running soft water through it. This soft water isconverted to steam from this chamber. There are two safety valves in the boiler (drum). These valves areused in case of emergency when excess of steam is produced and needsto be expelled out. There number is two because in-case one does notwork out the other one is always there for emergency. The boiler or thedrum contains Safety valve, Pressure Gauge, Air Vent (attached withSafety valve), Main Stock Valve which the operator can control andcheck. The whole oiling section also has a feeder tank (softener plant)which stores the soft water. To operate a boiler a person has to becertified as minimum II class boiler (Needs a graduation certificate).Three certification available: II class, I class and B.O.E. class (BoilerOperating Engineer). 25
  26. 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. 27. OTHER PROJECT DETAILSPower: Required power is available from West Bengal State ElectricityDistribution Company Limited. The Total connected load for commonfacility centre is 400 K.W.. The monthly electricity charge is Rs. 6 lakhsat full capacity utilization.Plant Capacity and Capacity Utilization: The refinery section of common facility centre has a processingcapacity of 150 tonnes of extracted bran oil per day. Because of downtime and other various reasons, the capacity is not releasable and it isassumed. The de-oiled rice bran is actually a by-product of solventextraction of rice bran. This de-oiled rice bran is sold to cattle feedindustries, so that value addition is ensured.Study of Material Handling & House Keeping Practices:While study and understanding about the working of the plant a studywas also carried out while in different sections to examine the presentwork practices in the plant and identifying improvement opportunities inthe daily processing of the plant with the objective of waste eliminationand conservations of the study. The observations are mentioned in theparagraphs below. Further, in order to achieve and demonstratecontinuous improvement in shop floor activities, an observation wasobserved. 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. 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 walking2. 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. 29. FURTHER DEVELOPMENT OF THE PLANT The plant has enough experience now and should be now go for alarge scale production including the full processing of the bran oil. If itis capable of getting proper technicians into its plant then the productioncan increase up in large amount. Technical man power problems shouldbe taken care soon. Boiler being the no 1 consumer of HSD, it has huge potential ofenergy saving if we can explore and utilize a proper energy efficiencymeasure. One of them is through condensate recovery system, using thecondensate to preheat boiler feed-water (6o C raise in feed watertemperature by condensate recovery corresponds to a 1% saving in fuelconsumption, in boiler), significant saving in fuel can be achieved. 29
  30. 30. REFERENCE1. 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