Solvent extraction plant is a better way to extract oil from oil seeds, and after extracting, the oil residue rate in meal will be less than 1%. Solvent extraction method is very suitable for the oil seeds with low oil content rate.
Solvent Extraction is to use n-hexane to soak the oil cakes, then the oil in cakes will be dissolved in n-hexane, at last, pump the mixed oil, also called miscella. The n-hexane will be evaporated later from the miscella, then by condensing, it can be recycled and used over and over again.
And for the oil solvent extraction plant, the raw materials have two kinds:
1. The pressed oil cake from the oilseed pretreament &pre-pressing plant, such as the peanut cake, sunflower seed cake.
2. The oil seeds which have been pretreted, can be processing in oil solvent extraction plant directly, such as the soybean, the rice bran.
Different type of solvent extractor:
Below 20t/day, we use the small scale tank type extractor.
From 20t/day to 600t/day, we use the rotocel extractor.
Above 600t/day, we use the loop type extractor
The main machines used in the solvent extraction plant：
(1) Solvent pumps: continuously spray solvent to the rotary-type extractor
(2) Roary extractor: Spray and soak the pre-pressed cake with solvent so that oil fats can be dissolved in solvent(form miscella). After processing, you can get wet meal and miscella (mixed oil).
(3) DTDC: used to separate the solvent from the wet meal.
(4) Miscella tank 1st: pump the miscella (oil with solvent) in to the miscella 1st , and then add 10% saline water to it. The phospholipid and impurities in the miscella will react with the saline wter, at last the reactant precipitate, reaching the goal of purifying.
(5) Miscella tank 2nd: the purified miscella will be pumped into it.
(6) Miscella stripping: it will remove the remaining solvent in miscella. And the solvent will be discharged to condenser for recycling.
(7) condensers: used to cooling the solvent gas separated from the wet meal and miscella for recycling.
|Residual oil in meal
|≤ 2Kg/T (No.6 solvent oil)
|Crude oil moisture and volatile matter
|≤ 280KG/T (0.8MPa)
|Finished meal moisture
|≤ 13% (adjustable)
|Residual solvent in finished meal
|≤300PPM (qualified detonated experiment)
The brief introduction about oil solvent extraction plant:
1. The working process of solvent extractor:
Rotocel solvent extraction machine
The pressing oil cakes or pretreated oilseed flakiness firstly enter into the solvent extractor, through soaking for a while, the grease will be extracted. The concentration of miscella increases from 2% to more than 25%.
The miscella is discharged from solvent extractor and pumped into miscella filter, and the leached meal will enter into evaporation system , through 1st evaporation feed pump and finally fall-in D.T.D.C.
Loop type solvent extractor
2. Desolventizing process of solvent extraction plant:
Wet meals are discharged from the bottom of extractor, enter from the top of D.T.D.C and land on the pre-desolventizing trayer. On the pre-desolventizing trayer, wet meals are heated by the steam directly.
Next, pre-desolventized meals land on the next pre-desolventizing trayer where the pre-desolventized meals are heated by the steam again. After Desolventizing, the meals land on the following drying and cooling layer. After drying and cooling meals, dry meals are sent into meal storehouse.
Cooking oil solvent extraction flow chart
3. Evaporation process of oil solvent extraction plant：
The miscella from D.T.D.C uses the first and second steam desolventizer system. Then the miscella will enter into stripper, in which the residual solvent in miscella will be removed.
4. Condensation recovery process of oil solvent extraction plant
In the solvent recycling system, the cold paraffin will absorb the solvent gas and the final nonsolvent gas will be discharged through fire resistance valve.
Paraffin absorbed the solvent gas can be also called rich oil. After heating by oil-oil heat exchanger and steam, the rich oil will enter into desorber for desorption, and into condenser after changing solvent into gas, the final cooled paraffin can be recycled.
Solvent extraction method is usually the best choice for large scale cooking oil production plant. Henan Doing Company is professional in oil solvent extraction plant desining, manufacturing and installation. Look forward to cooperate with you.