JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 1.0
INTRODUCTION All crude fats and oil obtained after rendering, crushing or solvent extraction inevitably
contain variable amount of non tryglycerides, components such as fatty acids, mono and diglycerides, phospatides, sterols, tocopherols, hydrocarbons, pigment(gossypol,chlorophyll), vitamins(carotene), sterol glucosides and glycolipids. Physical refining was utilized as early as 1930 as a process for the preneutrallization of products with a high initial FFA content. In this th is case, preneutralization was followed by b y caustic refining. Later, it was found possible to physically refine lauric oils and tallow if the proper pretreatment was applied before steam distillation. Physical refining became a reality in the 1950s for processing palm oil, which typically contains high FFAs and low gum contents. The palm oil process subjected the crude feedstock first to pretreatment and then to deacidification. The pretreatment consisted of a degumming step and an earth bleaching step, which together remove certain nonvolatile impurities by filtration. Volatile and thermally labile components are removed during the conditions of steam distillation under vacuum, which originally gave the process its name na me of steam refining. However, for vegetable ve getable o ils, such as soybeans, that contain relatively low levels of FFA The traditional edible oil processing system consists of caustic neutralization, bleaching, and deodorization. Caustic neutralization of vegetable oils with high phosphatide contents delivers a soapstock that is a mixture of sodium salts of fatty acids, neutral oil, water, unused caustic, and other compounds resulting from the reactions of the caustic with various impurities in the oil. Disposal of this soapstock or the waste streams from soapstock processing systems has become increasingly inc reasingly more e xpensive. A second seco nd problem prob lem associated with chemical neutralization is the loss of neutral oil, which reduces the overall yield from the crude oil. Elimination of the caustic refining step is economically attractive, but it means that degumming or some other pretreatment process or system must assume all the functions of the alkali refining process, except for FFA removal
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JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 2.0
METHODOLOGY The experiment can be divided into 3 main parts: 1. Removal of free fatty acids, phospholipids and impurities. 2. Removal of pigments, oxidation products, metals and soup. 3. Removal of free fatty acids and fatty acids, mono & diglycerides, oxidation products, pigments and decomposition products.
The main objective of this experiment is to operate pilot scale experiment of refine, bleach and deodorize processing of crude palm oil. The experiment starts with identification of optimal parameter for degumming, bleaching and deodorization processes. The optimal parameter is identified in range as below: . Parameters
Degumming and
Deodorization(Range)
Bleaching(Range)
Temperature (oC)
80-110
220-260
Pressure (mmHg)
60-90
5-20
Contact time (minutes)
20-50
30-60
After the operating parameters have been identified, a pilot scale experiments facilities will be set up based on the operating parameter. There are two physical pilot will be used which are pre-treatment consists of degumming and bleaching stage and deodorization stage. The neutralization/the pre-treatment stage is done by using the portable container unit. Then analysis is done for the oil before and after the experiment.
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JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 2.1
Operating Parameter In this experiment, students need to identify the optimal operating parameters of refining
process. Based on the range of operating parameters given in the previous table process, students need to select different value of each trial.
Table 2.1: Operating parameter data sheet Parameters
Degumming
Bleaching
Deodorization
o
Temperature ( C) Pressure (mmHg) Contact time (min)
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 2.2
Crude Palm Oil Sample The crude palm oil (CPO) samples used in this research study were obtained from Kilang
Sawit Hutan Melintang Perak. The quality of the CPO sample is good which is the free fatty acid content of this sample is less than 2.5 % and the moisture content of the sample is about 0.15 %.
2.3
Phosphoric Acid and Bleaching Earth Bleaching earth used is neutral bleaching earth and phosphoric acid used is phosphoric
acid 85% concentrated. The dosage of bleaching earth is 1.0% - 3.0% by weight of oil and the phosphoric acid dosage is 0.5%- 2.0% by weight of oil depends on the FF A % at initial stage.
2.4
Degumming and Bleaching Experiment The degumming and bleaching experiment are set up according to the optimal parameter o
identified, which are ___ C, under vacuum of ___mmHg and contact time of ____ minutes. The equipment set up for this experiment is as shown in Figure 2.1 next page.
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JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL
Control panel
Stirrer rotor
Vacuum gauge
Bleaching Filter
Figure 2.1 Bleaching Unit 5
JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 2.4.1 Experimental Procedure for Degumming and Bleaching In this study, the CPO sample used for degumming and bleaching processes is 10000 gram ± 10 gram for each trial. The phosphoric acid used is about 0.1 % w/w and the
bleaching earth used is about 1 % w/w. Heating element for this experiment is silicon oil. The CPO is initially heated up to 65-90 oC using water bath. After heating up for 30 minutes, CPO will be transferred to main vessel body T 141 at Bleaching Pilot Plant Unit. The procedure must be doing through the hose given with initial vacuum condition in T141. Start stirrer and set the rotation speed accordingly with low rpm. Once the CPO has fully charged into the vessel, prepare the Phosphoric Acid (PA) with the calculated volume based on the theory given in the previous page. Transfer PA into T141 slowly through with the same inlet of CPO previously. Set the time of 30 minutes with constant speed of stirrer. The process can be done in atmospheric pressure. Once the degumming process completed, set the vacuum to ____ mmHg. At the same o
time, the mixture is heated up to 90 C by manipulating ball valve S141 BV 1555. Once the vacuum reading is consistent, prepare the bleaching agent based on the weight % provided. After achieve 30 minutes of degumming, slowly add bleaching powder through suction hose attached at small tank T 142 similar to CPO and PA charge in process. Let the temperature reach at desire state and reserve it for one hour or extra another 30 minutes. Stop the stirrer after that and check the filtration unit to ensure the tightness of thee filter frame. Run the filtration pump and same time bleed for 10 seconds to reduce vacuum condition. Open the bottom valve to allow the flow of mixture. The process may be sluggish due to small diameter of pipe and also the size of the filter cloth which is between 0.5-3.5 micronmeters. Collect the bleach oil in plastic pale and ready to transfer to deodorization pilot plant unit.
2.5
Deodorization Experiment The deodorization experiment is set up according to the optimal parameter identified,
which are ____ oC, under vacuum of ___ mmHg and contact time of _____ minutes. The equipment set up for this experiment is as shown in Figure 2.2 next page.
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL
Figure 2.2 Deodorization Unit
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 2.5.1 Experimental Procedure for Deodorization
After the oil has undergone degummed and bleached process, the oil is then will be prepared to deodorization process. Place a new filter bag in polishing filter F08I and close the filter. Start vacuum system V08I following the procedure outlined in the instruction manual and evacuate deodorizer D08I to a vacuum of about 6.7 mbar. Start pump P704 (located at the storage tank area) and feed oil from the storage tank to deodorizer D08I. At high level HLA08I, stops pump P704. Switch on electrical heating element HT08I. Set the deodorization temperature (normally 250°C) at temperature controller TIC08I. Use the metering valve to set the flowrate of sparging steam to deodorizer D08I (see Appendix 1). Maintain the oil in deodorizer D08I at the deodorization temperature and under steam sparging for the desired deodorization time. At the end of the deodorization time, switch off electrical heating element HT08I and stop temperature controller TIC08I. Start cooling water flow to the internal cooling coil of deodorizer D08I to cool down the oil to less than 90°C. Stop cooling water flow and the temperature controller, close the sparging steam valve and shut down vacuum system V08I. Open the vent valve of deodorizer D08I to break the vacuum. Starts pump P08I and discharge the oil to storage tank T082 through polishing filter F08. When deodorizer D08I is empty, stop pump P08I. Empty the pipelines by opening the drain valve at the pump.
3.0 Analysis The experiments for CPO and RBDPO qualities are conducted based on the standard method by MPOB. The following analysis should be done to determine the quality of oil (before and after the process): a) Free Fatty Acid (FFA) content b) Moisture content Sampling standard must be followed and data must be taken at least 3 trials. Data analysis should be conducted to find mean and median. For crude palm oil, sample should be taken from bottom, middle and top drum. The sample are mixed and taken for analysis.
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JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL For process oil, sample should be taken uniformity at sampling valve. Sample should be taken for the first time after processing.
3.1
Free Fatty Acids (FFA) Content Theory: Acidity or free fatty acid (FFA) in the palm oil is calculated as palmitic acid from the equation:
% Free Fatty Acid as palmitic acid =
. ××
Where, M is the molarity of standard NaOH or KOH solution V is the volume of the standard NaOH or KOH solution used (ml) m is the mass of the test sample (g) Apparatus: Burette, 25 ml capacity graduated in 0.05 ml subdivisions
Conical flasks, 250 ml and 500 ml
Hot plate, with magnetic stirrer and temperature control
Analytical balance
Reagents: 1. Standard potassium or sodium hydroxide, 0.1M Potassium or sodium hydroxide of approximate 0.1M should be standardized with potassium hydrogen phthalate.
Dry potassium hydrogen phthalate in an oven at 120oC for 2 hr and allow cooling in a desiccators before use. Weight 0.4g ± 0.02g to 0.1 mg accuracy of the potassium hydrogen phthalate directly into a conical flask. Add 50 ml of water and a few drop of phenolphthalein indicator. Place on a hot plate and swirl till the salt has completely dissolved and titrate with potassium or sodium hydroxide to the first appearance of a permanent pink color. Molarity of the alkali =
×
× .
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL
2. Phenolphathlein indicator solution, 1% in isopropanol (or in 95% ethanol) 3. Neutralized isopropanol
Place 50 ml isopropanol in a flask and bring the solution to the boil over hot plate. Add about 0.5 ml of phenolphthalein and neutralized by drop-wise addition of 0.1M potassium hydroxide or sodium hydroxide till a faint but permanent pink color is obtained.
Experimental procedures:
1. Prepare the sample for the analysis by melting the sample at 60 to 70 oC and thoroughly homogenize it before sampling. 2. Keep the sample in a clean and dry flask with stopper or screw cap to prevent contact with humidity. 3. Weigh 5 to 6 g of sample into a conical flask. 4. Add 50 ml of the neutralized solvent. o
5. Place the flask on the hot plate and regulate the temperature to about 40 C. 6. Shake the sample gently while titrating with standard alkali until the appearance of the first permanent pink color. The color must persist for 30 sec.
3.2
Moisture Content Theory:
The moisture content can be calculated by the equation below: % Moisture and volatile matter =
× 100%
Where, m
is the mass of the dish (g)
m b
is the mass of the dish and test sample (g)
md
is the mass of the dish and test sample after drying (g) 10
JAN 2015
EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL Apparatus:
Air oven
Analytical balance
Petri dishes
Desiccator
Experimental procedures:
1. Dry cleaned petri dishes in the oven at 103oC for at least 15 min and allow cooling in desiccators. Weigh the dish to the nearest 0.001g. 2. Weigh approximately 10g of the molten oil (test sample) to the nearest 0.001g into the dish. Return to the desiccators until the oil has thoroughly cooled. Weigh the dish plus the oil to the nearest 0.001g and place the dish in the middle shelf of the oven at 103oC for exactly 2.5h. 3. Remove the dish and allow it to cool to room temperature in the desiccators (30 to 45 min) before reweighing to the nearest 0.001g. 4. If the moisture exceeds 0.3%, continued drying (at 30 min interval) to constant weight is recommended. In this case, the difference between two successive weighing should not exceed 0.002g. Carry out two determinations of test portions taken from the same test sample.
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL Table of Data: Table 1: Result for analysis (CPO) Analysis
Crude Palm Oil (CPO) Sample 1
Sample 2
Sample 3
Average
Free Fatty Acid content (%) Moisture content (%)
Table 2: Result of analysis (RBDPO) Parameters
Refined Bleached Degummed Palm Oil (RBDPO) Sample 1
Sample 2
Sample 3
Average
Free Fatty Acid content (%) Moisture content (%)
Analysis
Find mean and standard deviation of each data.
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL 4.0 Discussion Compare the value of free fatty acid and moisture content of sample obtained with the standard value of refinery quality of RBDPO (refer Appendix 1).
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EXPERIMENT No: 1 PHYSICAL REFINING OF CRUDE PALM OIL APPENDIX 1 Table A1: Desired quality of pretreated and RBD Palm Oil
Table A2: Palm oil specification for Malaysia (taken from MPOB, 2002)
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