Physical refining technology of rice bran oil

1. Hydration degumming

In Physical refining of rice bran oil it is important to remove the colloid substances in the oil, as much as possible of colloidal substance can affect not only the quality of the products, and under the action of high temperature easy coking are attached to the packing surface to form oil dirties, affect the normal operation of equipment. In general, hydration degumming oil must be 30 mg/kg or less phosphorus content.

Will first hair oil to heat up to 80-85 ℃, add oil, concentration of 85% 0.3% of the amount of phosphoric acid, rapid mixing 30 min. Add the temperature is 90-95 ℃, 8% of the oil, the concentration of 5% salt solution slowly stir precipitation let stand for 2 h after 15 min, release oil foot.

2.Washing scrubbing

First will be degummed oil to heat up to 75-78 ℃, temperature is 90-95 ℃, 8% of the oil solution, concentration of 5% alum slowly stir precipitation let stand for 2 h after 15 min, release oil foot. Then the oil temperature rise to 75-78 ℃, the temperature is 90-95 ℃, 8% of the oil in the water slowly stir 15 min after precipitation let stand for 2 h, release oil foot. Set aside.

3.Dry

Dry before the degumming hydration degumming oil moisture must be below 0.5%.Hydration degumming oil drying is done in continuous packing desolventizing dehydrator, vacuum drying is 0.09 Mpa, the oil temperature 105-110 ℃.

4.Dry degumming

Dry oil heated to 85 ℃, by quantitative pump to join a concentration of 85% for the amount of consumption of phosphoric acid, 0.1% of the heavy oil, the knife mixer quickly after mixing with mixed reaction, into the leaf filter. Making use of waste clay after decolorizing filtration to remove residual phospholipids and metal ion impurities such as dry degummed oil. Generally, the dry process of 10 mg/kg or less phosphorus content of degummed oil.

5. Decoloration

70% of the dry degummed oil heated to 110 ℃, enter the bleaching tower decoloring.30% of the oil into the oil mixer and mixed with the clay soil, after mixing by vacuum suction decoloring bleaching tower. Bleaching tower of double-layer structure, the mixing of steam. Bleaching tower vacuum degree is 0.09 Mpa, the oil in the tower of decoloring decoloring time for 30 min, clay content with 2% advisable. If the decoloring effect is bad, can be used a soupcon of activated carbon.

6. Filtration

eaf filter operating pressure 0.2 0.3 Mpa, decoloring oil is entered into the vacuum bag filter decoloring oil store cans. Generally, decoloring oil of 5 mg/kg or less phosphorus content, colour and lustre is y, R6.If excessive phosphorus content must find out the reason for the next procedure.

7 .Deacidification

Oil - oil heat exchanger, the oil in the decolorization of the heater heating to 250-260 ℃ into acid tower acid.  Acid stripping tower for the structure of packing tower, the oil in the filler surface under gravity flow down from the top, and from the bottom into good contact with saturated steam stripping acid. Oil flow in the tower for 5 min, direct steam dosage is 2% of the heavy oil, the vacuum pressure pa 200 or less .Acid oil under the action of gravity flow delay decoloring cans.

8. Delay decoloring

Under the condition of high temperature and high vacuum, chlorophyll and carotenoid in acid oil heat-sensitive decompose pigment removal. Delay decoloring cans for horizontal tanks, the interior is divided into four, oil in the internal flow in sequence. Delay decoloring temperature is 240-245 ℃, the vacuum pabs 200 pa, or less time around 60 min.  Oil overflow to deodorization tower under gravity.

9.deordorization

Deodorization tower to packed tower structure., oil on the surface of packing from the top down under gravity flow, and from the bottom into good contact with saturated steam stripping deodorization. Oil flow in the tower time is about 15 to 20 min, deodorization temperature 230 ℃ or higher, about 1% of the amount of heavy oil steam directly, vacuum pressure pa 200 or less. From the bottom of the oil in the deodorization of oil - oil heat exchanger, the condenser cooling below 40 ℃.In general, deodorization oleic acid value of 0.2 or less mgKOH/g, colour and lustre Y20, R2 acid, the deodorization drew mixed fatty acid by the structure of packing tower after the capture flow to capture fatty acid circulation tank, mixed fatty acids in the is cooled to 60-70 ℃.The cooling of the mixed fatty acid by fatty acid circulation pump pumping capture top part of the instruments. Fatty acids in the filler surface flow from top to bottom, and high speed flow from bottom to the high temperature of mixed fatty acid gas contact heat exchange, the mixed fatty acid gas into a liquid, which was set down. Generally, the mixed fat cow values between 150-190 mgkoh/g.

10.Dewaxing

Plate heat exchanger and the oil in the deodorization of coolant heat exchange, the oil temperature down to 22 to 25 ℃ after pump into the crystallizing tank, stainless steel under the effect of mixing, the use of coil freezing liquid cycle makes it slowly cooled to 18 ℃ to form crystals. The crystallization time about 3 h. Crystallization pressure into crystal jar, under the condition of constant temperature 18 ℃ keep crystal 3 h filter, wax oil.

11.Degrease

Filter out of wax oil pump into the stainless steel degreasing tank, in a slow mixing with scraper device, the use of jacket coolant circulation slow cooling to 3 ℃.Under the condition of constant temperature 3 ℃ keep crystal 6 h filter defatted rice bran oil.

Project project indicators

Colour and lustre (133.4 slot) Y20 R1.8 smoke point (215 ℃)

Moisture and volatile matter 0.02 freezing test (0 ℃ 5.5 H) clarify \ transparent

Acid value, peroxide value (mgKOH/g) 0.15 (tendency for $4 / kg