SU1763473A1 - Method of cotton oil refining - Google Patents

Abstract

The invention relates to the oil and fat industry and concerns the purification of oils. SUBSTANCE: in the method of refining high acid cottonseed oil, including alkaline treatment with caustic soda in the presence of urea and flooding the mixture, the oil is refined in two stages, and in the second stage, a solution of 700 g / l is used as the alkaline agent at KOH consumption 2-6 kg / ton and the resulting mixture is flooded until an alkali concentration of 300 g / l is reached. 1 tab.

Description

The invention relates to the oil and fat industry and can be used in the refining of high acid cottonseed oil.

The closest to the technical essence is the method of cotton oil refining, in which the oil is neutralized with a solution of caustic soda NaOH with a concentration of 700-800 g / l in the presence of urea in the form of a 40% aqueous solution with a consumption of crystalline urea 0.2-2.0% . oil temperature during refining from 25 to 60 ° C. The duration of the alkaline treatment is 30 minutes. Watered soda is provided in an amount to dilute the initial concentration of alkali to 125 g / l.

The method has the following disadvantages:

- low efficiency in the purification of high-acid cotton oils, which is reflected in production losses:

The method does not take into account the need to reduce the consumption of caustic gas and water for the purification of oil, which must

consist in sedimentation and separation of soap stock: it also does not take into account the need to reduce oil loss, improve the quality of raffinate

The purpose of the invention is to reduce the consumption of water and alkali, reduce losses and improve the quality of the raffinate.

The goal is achieved by two-step alkaline refining using urea, and in the second stage, a caustic potassium solution with a concentration of 700 g / l is used as the alkaline agent and KOH 2-6 kg / g is consumed, and the resulting mixture is flooded. - no alkali concentration of 300 g / l.

As is well known, potassium soaps, which are formed when an oil is treated with a KOH solution, have a liquid consistency, are ineffective in alkaline refining due to the emulsification in oil and have a weak brightening ability and are characterized by difficulty in precipitating the resulting emulsified soap stock. It has been established that potassium soaps form with

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317634734

with urea (carbamide) clathrate compounds (Schf) of caustic soda NaOH as far as they are, which, firstly, have an effect that exceeds the theoretically necessary effective adsorption properties, the quantity (Schm). It has been established that for high-grade oil that contributes to better clarification of maize-acid oil, and, secondly, these compounds lack the actual consumption of caustic soda, and they are easily separated from its theoretical maximum of 1.4. times i composition in the form of solid soap stock. Schf 1.4 Scht. For black oil, having in addition, the resulting potassium carbon stock of KC 9.27 mg KOH, 6 kg / ton, therefore, to a lesser extent absorbs neutral but Schf 6.6 x 1.4 9.2 kg / ton. Therefore, on the 1st fat, than sodium soap stock, which results in 10 steps of refining, the consumption of caustic juice to an increase in the yield of refined NaOH is 9.2 kg / ton of oil. The vast majority of Meslo are Example. The cotton factories were refined because of the difficulty of cooling the oil obtained from the low-grade seeds and the black oil is not fed to the refining and which had the following characteristics: acid-15 cooled to 23-25 ° С, and at the temperature value (K) - 9, 27 mg KOH, chromaticity at 45-60 ° C. This leads to an increase in the process of Lovibonduv cm in a cuvette at 35-105 yellow saponification of neutral fat and was predisposed, humidity - 0.36%, determines the increase in losses.

According to the prototype, this raffia-B oil in the proposed method has an excess of alkali with an aqueous solution of caustic soda at the 1st stage of refining the minimum water (NaOH), which had a concentration of 700 g / l, and is 40% of the theoretically required urea, which was administered in dim amount the saponification of the neutral oil together with alkali in the form of 40% fat is expected to be insignificant, the solution at the consumption of crystalline mineral. Therefore, the temperature of the oil, supplied chevina 0.5%. The temperature of the oil during refining to the 1st stage of refining was 60 ° C, the finishes increased from 25 to 60 C. The duration of neutralization was 15 minutes and the br. The duration of the alkaline treatment was 5 minutes. Lasted 30 minutes Watering the mixture of oil and settling of the refined alkali was carried out with water in an amount, the oil for sediment deposition was diluting the initial 30 to 4 hours. After sediment deposition, the resulting concentration of alkali to 125 g / lgo at the 1st stage is carried out The new refining method includes 2- oil finishing for maximum alkaline stepped oil processing. On clarification with minimal loss x. For the first stage, the black oil is refined with refined, slightly alkaline, aqueous solution of NaOH. 35% oil is neutralized by simultaneous concentration of 125–200 g / l with a minimum introduction of the solution of caustic soda into it, since concentration, as in the prototype - 700 g / l) and a new goal, solved at this stage, - urea (concentration, as in the prototype - ensuring maximum yield of raffi-50%). The duration of neutralization on the oil injected, regardless of the 40th step, is 20-30 minutes (in the case of its chromaticity. After stock flow, water tests - 25 minutes), and the flow rate obtained on the 1st stage is spent 0.5% of the crystalline urea, i.e. These striking refining of the oil, for maximum values of the parameters, correspond to the prototype clarification with minimal loss of x. to type. After 25 minutes of neutralization. For this purpose, alkali-carbamide-45 oils are used according to the alkaline-carbamide method and refined, only instead of NaOH, the resulting mixture is flooded. It has been established that KOH is used in the form of an aqueous solution, which is to obtain 700 g / l of easily precipitated coal concentration. The consumption of a carbamide effluent containing minimum colimest (urea) as compared with the known method of absorbed neutral fat does not vary by itself and is 0.5%. After 50 watering should be carried out by diverging, the refining regimes at the 1st pressure of the initial alkali concentration of the stage do not differ from the known Pro- (KOH) not up to 125 g / l, but up to 300 g / l, i.e. The consumption of the method of refining and substance for watering is reduced by a factor of 2, the basic difference of the new method. If diluting the initial concentration consists in using alkali at the 2nd stage 55 to a concentration above 300 g / l, then the KOH solution instead of NaOH is the same - eoap stock is poorly formed due to under-concentration (700 g /). The water stock particles cannot be separated from the stock; it is well known that at the first stage it is refined from the oil, and if below 300 g / l — the nation can get the maximum, small fine emulsified raffinate is formed, when the actual consumption of oil is difficult to set up the stock that is not

only prolongs the process of its precipitation, but leads to an increase in the water consumption for the next subsequent washing of the refined oil. Therefore, the irrigation of the neutralized mixture obtained in stage 2 was conducted to an alkali concentration of 300 g / l. It has been found that in this case, along with a reduction in water consumption for watering, a fast-precipitating soap stock is obtained. The duration of the deposition is reduced to 2 times.

A. The known method (prototype) is a single-step alkali-carbamide refining (op.1-3).

Refined oil, corresponding to the quality of the second and first grade, was obtained with a yield of 86.0 and 85.4%, when the consumption of caustic soda NaOH was 15 and 18 kg / ton.

B. The proposed method of two-stage ratsination.

The first stage of refining. With Schf 1.4 x Schm and concentration of alkali (NaOH) 125, 150 and 200 g / l, refined oils of non-standard color were obtained with the output of SO, b, 90.4 and 90.1%. The higher the alkali concentration, the lower the yield of refined and the lower its color.

The second stage of refining. Compared with the prototype, a KOH solution of the same concentration is used instead of a 700 g / l NaOH solution.

When the color of the raffinate obtained in the 1st stage is 56 cranes, the target products of the second, first and highest grades are obtained at a KOH consumption of 2.4 and 6 kg / t with a yield of 88.7, 88.2 and 87.7% (op.7-9).

If the color of the raffinate fed to the secondary refining is 49 cranes, units, then with the consumption of KOH 2.4 and 6 kg / t, refined oil of the second, first and highest grades was obtained with a yield of 88.3, 87.8 and 87.3, respectively % (on. 10-12).

When the color of the raffinate is 42 red units, then when it is secondary refined with a KOH solution at a caustic consumption of 2.4 and 6 kg / t, second, first and highest grade raffinates are obtained with a yield of 87.9, 87.5 and 87.1%, respectively (op.13-15). Therefore, a KOH consumption of 4 kg / ton is sufficient to produce high-grade oil.

Analysis of the data in the table suggests that if KOH consumption is less than 2.0 5 kg / ton, non-standard color refined oil can be obtained (see op.7), if it is more than 6 kg / ton, then it is not economically feasible in DIRT with caustic overrun and increased oil loss due to

0 due to the intensification of neutral fat saponification (see op.15). Therefore, the KOH consumption is 2-6 kg / ton. The use of NaOH instead of KOH with a relatively equal color of rafmasl reduces its yield (op.7-15, data presented in the denominator).

Based on the analysis of the table data, the following advantages of the present invention can be distinguished.

0 1, Reduced consumption of caustic soda. In the prototype, it is 15–18 kg / t (average 16.5 kg / t), and in the new method it is 11.2– 15.2 kg / t (average 13.2 kg / t), i.e. 3.3 kg / ton less.

5 2. Improved refined oil quality. If in the prototype rafmaslo of the first and second grades was obtained, then in the proposed method, with a lower consumption of alkali, it is possible to obtain target products mainly of the highest and first grades.

3. Reduced oil production loss by increasing its output from the black oil.

Claims (2)

Invention Formula 5 A method of cotton oil refining, including neutralizing the oil with a solution of an alkaline agent with a concentration of 700 g / l in a mixture with urea, adding water to the mixture and separating the stock flow of the hotel 0, characterized in that, in order to reduce the loss of oil, improve its quality and reduce the consumption of water and alkali, before neutralizing the oil is pretreated with a solution 5 caustic soda and the obtained first soap stock are separated, and caustic potassium is used as an alkaline agent during neutralization at a flow rate of 2-6 kg / ton, and water is introduced until the concentration of alkali in the mixture is reached 0 300 g / l. 1 2 3 12 15 18 0.5. Alkaline-carbamide refining (prototype) 86.8 35.0 0.39 86.0 15.5 0.32 85, 8.4 0.20 2. Two-step refining (proposed method) 2.1. Primary black oil refining 125 g / l 2.1.1. Alkali concentration 56 90.6 Alkali concentration 150 g / l 90.4 Alkali concentration 200 g / l 90.1 Secondary refining of oils obtained at the first stage and having: .2.1. Chromaticity 56 cranes 9 B2 0,1Y about, 0, 0,1Y oh w 0.3