Exp 2 Dry Fractionation of RBD

EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL 1.0

INTRODUCTION

The dry fractionation plant in Appendix l is used to separate the palm olein and palm stearin from the RBDPO produced by physical treatment. The RBDPO is passed through the further fractionation process to get various grade of palm olein and palm stearin. Usually, there are three types of olein are produced: (1) normal grade olein, (2) super grade olein and (3) olein with cloud point 7 - 8°e.

2.0

PROCESS DESCRIPTION

2.1

Crystallization Crystallization Process

Firstly, the RBDPO feed must pass the quality specification, color <2.6R and FFA< 0.075 is fed into the heat exchanger. The RBDPO feed is heated up by hot waters around 75°C. After that the oil is kept homogenized at about 70°C in homogenizes before the start of crystallization. The idea is to destroy any crystals present and to induce crystallization in a controlled manner in the crystallizer. After that, the oil is pumped to the crystallizer (Appendix 2). The crystallization system is a batch type and is equipped with special crystallizers operating alternatively. These crystallizers are made up of vertical cylindrical vessel full of thermo-regulated water which submerged barrels containing the oil to be fractionated: each of these barrels is fitted with a mechanical agitator. An automatic station controls the temperature in the various crystallizers. The crystallization process is carried out to remove the higher melting glycerides which cause liquid oils to become cloudy and more viscous at low temperature. There are 3 factors (temperature, time and agitation), have a fundamental importance on the formation and character of the crystal: 1. The lowering of temperature causes, because of supersaturating the higher melting component to separate from a solution. 2. Agitation facilitates the formation of small crystals. 3. Time with a gradual decrease in temperature and stillness, promotes the formation of longer crystals. 2.2

Filtration Process

After the crystallization process, the slurry from buffer tank passes through the filtration process for the t he physical ph ysical separation (Appendix 3) between RBD palm stearin and RBD palm olein. Presently, the membrane filter is used for this filtration. Another alternative for this purpose is by employing drum filter for separation. The membrane filter is pressure filter Bachelor in Biosystem Engineering Technology

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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL where the filter pack comprising alternatively plates and frames, or a series of chamber is compressed between one fixed and one movable cover or bulkhead. The filter media are located between each individual element. Cake will build up in the hollow space between the elements and fall out of the press when the filter pack is opened. Composition of the filter pack is by means of electrically driven hydraulic system (75 bar), which controls the entire mechanical parts of units, head plates, filter plates, plate shifting device with the built in panel board.

3.0

METHODOLOGY

3.1

Plant Description

The dry fractionation pilot plant is used to produce a liquid fraction (olein) and a solid fraction (stearin) from palm oil through crystallization and filtration. The pilot plant is designed for batch processing at a capacity of 12 kg/batch and comprises the following main components (refer to flow sheet R225P022 for tag number and description): 1. Crystallizer with agitator and cooling coil. 2. Filtration system with filtration pump and membrane filter press. 3. Olein discharge pump and stearin melting tank. 4. Chilled water system and hot water system. 3.2

Plant Operation

1. The following raw material, preheated to 45°C, is required: a) RBD palm oil in storage tank T704 2. The following utilities are required: a) Tap water for chilled water system and hot water system. b) Steam at 2 barg for stearin melting. c) Compressed air at 5 barg for control valve and cake squeezing. 3. Fill the chilled water tank with tap water and switch on the packaged chiller unit to produce chilled water at about 10°C. 4. Fill hot water tank TIl3 with tap water and switch on electrical heating element HTIl3 to produce hot water at about 90°C. Set the water temperature at temperature controller TIC 113. 5. Set the cooling program for crystallizer TIll at temperature controller TIC 111. 6. Start pump P704 (located at the storage tank area) and feed oil from the storage tank to crystallizer TIll. At high level HLAIIl, stop pump P704 and start mixer AG 111. Use the frequency inverter to adjust the mixer speed. 7. Starts pump PlIO and circulate water in the cooling coil of crystallizer TIll. Set the water temperature (80-85°C) at temperature controller TIC Ill. 8. Start pump P113 and feed hot water from hot water tank TIl3 to the cooling coil of Bachelor in Biosystem Engineering Technology

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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL crystallizer TIll to heat the oil to about 70°C. Maintain the oil at this temperature and under agitation for at least 10 min to melt and homogenize the oil. 9. At the end of the homogenizing time, start the cooling program at temperature controller TIC 111. Switch over pump P1l3 to the chilled water tank and feed chilled water to the cooling coil of crystallizer TIll to cool the oil according to the cooling program. 10. At the end of the cooling program as indicated by the end-of-cycle alarm, the oil in crystallizer TIll is ready for filtration. 11. Close filter FIll, start pump PIll and filter the oil through filter FIll. The liquid fraction (olein) flows into olein tank TI14 while the solid fraction (stearin) forms a cake in the filter chambers. The filter chambers are full when the feeding pressure reaches 2 barg. 12. Stops pump PIll and start squeezing the stearin cakes by feeding compressed air to filter FIll and inflating the rubber membranes. Olein trapped in the stearin cakes is squeezed out and flows into olein tank T 114 thus drying the stearin cakes. 13. After squeezing, release compressed air in the squeezing lines into the feed channel (core) of filter Fill to blow the feed channel (core) clear of oil. Open the pressure release valve of filter Fill to further reduce the internal pressure to zero (atmospheric). 14. When it is confirmed that there is zero pressure in the feed and squeezing lines, release the hydraulic closing pressure and open filter F5ll. Remove the stearin cakes from the filter chambers and drop them into stearin tank T1l5. Start steam flow to the internal heating coil of stearin tank TIl5 to melt the stearin cakes. 15. Repeat filtration (Steps 11 to 14) if there is still oil in crystallizer TIll. 16. When crystallizer TIll is empty, stop mixer AGlll, pump PlIO and pump P113. Switch off the packaged chiller unit and electrical heating element HTI13. Stop the temperature controllers. 17. Starts pump P114 and transfer the oil in olein tank TIl4 to the next processing stage. When olein tank TIl4 is empty, stop pump P114. 18. Open the drain valve of stearin tank TIl5 and transfer the oil to the next processing stage. Stop steam flow. 19. Empty the pipelines by opening the drain valve at the pump.

Bachelor in Biosystem Engineering Technology

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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL Set your recipes based on diagram below:

Table of data : Segment 1 Starting set (SSP1) in oC

point

Target set (TSP1) in oC

point

Segment 2

Segment 3

Time in minutes

3.3

Description

The quality parameters normally monitored for fractionation are Iodine Value (IV). By definition, iodine value is the number of centigrams of iodine absorbed per gram of sample. While the method provides good accuracy and precision when applied to normal fatty acids, analysts must be careful to follow procedures exactly, as small deviations in sample size, reagents and time of reaction will definitely affect the accuracy and precision of the method. IV represents the degree of saturation of an oil or fat. Lower IV means the oil is of high saturation and vice versa. Normally the IV for RBD paIm oil is 52 and IV for palm olein is 56. The efficiency of the plant is measured by the production yield. The yield is calculated as: Production Yield = Weight of olein produced Weight of RBDPO feed

x 100%


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL The yields for fractionation plant producing RBD palm olein from RBD palm oil normally between 78% to 80%. Many times in continuous running plant, the yield cannot be measured by weight basis.

4.0

ANALYSIS

4.1

Iodine Value Theory: The iodine value, IV expressed in grams per 100g of fats b y the equation:

Iodine Value, IV = Where, C is the concentration of the sodium thiosulphate solution (mol/L) V1 is the volume of sodium thiosulphate solution used for blank sample (ml) V2 is the volume of sodium thiosulphate solution used for the determination (ml) M is the mass of the test sample (g) Apparatus:  



Glass weighing scoops Conical flasks, 500 ml capacity fitted with ground glass stoppers and completely dry. Analytical balance

Reagents: 1. Potassium iodide (KI), 100 g/L not containing iodate. 2. Starch solution 

Mix 5g of soluble starch in 30 ml of water and add to 1000 ml of boiling water.

Boil for 3 min and allow to cool. 3. Sodium thiosulphate (Na 2S2O3.5H2O), standard volumetric solution, c = 0.1M 4. Solvent, prepared by mixing equal volumes of cyclohexane and glacial acetic acid. 5. Wijs reagent, containing iodine monochloride in acetic acid. 

Experimental procedures: 1. Melt the sample, if not already liquid and filter through two pieces of filter paper to remove any solid impurities and the last trace of moisture. 2. After filtration, allow the sample to achieve a temperature of 68oC – 71oC before weighing the sample. 3. Once the sample has achieved the temperature, immediately


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL weight the sample into a 500 mL flask. 4. According to the iodine value expected for the sample, weigh to the nearest 0.001g in a weighing scoop. The mass of test sample indicated in Table 1. Table 1: Mass of test sample Expected iodine value Mass of test sample (g/100g) (g)

< 1.5

15.00

Volume of solvent (ml) 25

1.5 – 2.5 2.5 – 5 5 – 20 20 – 50 50 – 100 100 – 150 150 - 200

10.00 3.00 1.00 0.40 0.20 0.13 0.10

25 20 20 20 20 20 20

5. Add the volume of solvent indicated in Table 1 on top of the sample and swirl to ensure the sample is completely dissolved. 6. Add 25 mL of Wijs reagents using the pipette into the flask containing the sample stopper the flask and swirl to ensure an intimate mixture. 7. Prepare a blank with solvent and reagent but omitting the test sample. 8. Immediately store the flasks in the dark room for the 1 hour at a temperature of 25oC. 9. Remove the flask from the storage and add 20 mL of potassium iodide (KI), followed and 150 ml of distilled water. 10. Titrate with standard sodium thiosulphate solution, adding it gradually and with constant and vigorous shaking. Continue the titration until the yellow color due to iodine has almost disappeared. 11. Add a few drops of starch indicator solution and continue the titration until the blue color just disappears after very vigorous shaking. 12. Prepare and conduct at least one blank determination with each group of samples simultaneously and similar in all aspect to the sample. 13. Take and analyze the sample of each 30 min running hours of fractionation plant.


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL Table of Data : Set your recipes based on diagram below:

Figure 1 Table 1: Data of experiment Segment 1 Starting set (SSP1) in oC

point

Target set (TSP1) in oC

point

Segment 2

Segment 3

Time in minutes

Weight of RBD Palm Oil feed

: ____________________ g

Weight of RBD Palm Olein

: ____________________ g

Weight of RBD Palm Stearin

: ____________________ g

Production Yield

: ____________________ %


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL Iodine value analysis Table 2: Result of iodine value for RBD Palm Oil feed RBD Palm Oil Feed

Volume of sodium thiosulphate solution used for blank sample, V1 (ml)

Volume of sodium thiosulphate solution used for the determination, V2 (ml)

Mass of test sample, M (g)

Iodine value

Sample 1 Sample 2 Sample 3 Average Table 3: Result of iodine value for RBD Palm Olein RBD Palm Olein




Iodine value

Sample 1 Sample 2 Sample 3 Average Table 4: Result of iodine value for RBD Palm Stearin RBD Palm Stearin




Iodine value

Sample 1 Sample 2 Sample 3 Average


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL

#Show sample of calculation for each analysis. Find the standard deviation of each data and present in the table.

5.0 Discussion 1. Explain the principle of crystallization in fractionation process. 2. Sketch your diagram based on Figure 1 and data in Table 1 and explain the overall process of fractionation. 3. Explain how temperature, agitation and time affect the yield of production for RBD Palm Olein and RBD Palm Stearin. 4. Compare and explain the result of the iodine value of RBD Palm Oil feed with RBD Palm Olein and RBD Palm Stearin. Justify your answer. 5. Compare and explain the result of iodine value of RPB Palm Olein and RBD Palm Stearin with the standard value of refinery qualit y (refer Appendix 1). 6. Comment on the production yield obtained in this experiment. 7. Discuss any possible errors and state any recommendation to improve the process.


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EXPERIMENT No.2 DRY FRACTIONATION of RBD OIL APPENDIX 1


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Exp 2 Dry Fractionation of RBD

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