RU1822864C - Method removing wax substances from vegetable oil - Google Patents

Abstract

In a method for purifying vegetable oils from wax substances, comprising introducing a crystallization initiator into the oil and separating crystallized impurities, characterized in that, in order to increase the degree of purification and simplify the method, wax substances of vegetable oils in an amount of 0.03-0 are used as a crystallization initiator , 08% by weight of the oil, while the initiator is introduced into the oil at a temperature of 25-65 ° C, moreover, the used filter powder is used as a source of wax substances of vegetable oils, half aemy freeze-vegetable oils. 1 C.p.

Description

The invention relates to the oil and fat industry and relates to methods for the purification of vegetable oils from wax-like substances.

The purpose of the invention is to improve the quality of refined oil and simplify the process.

This goal is achieved by the fact that according to the method of purifying vegetable oils from wax substances, including introducing a crystallization initiator into the oil, cooling the oil and separating crystallized impurities, wax substances of vegetable oils in an amount of 0.03-0.08% by weight of the oil are used as initiator which are added to the oil at a temperature of 25-65 ° C.

A more complete purification of oils from wax-like substances when vegetable oils are added as a crystallization initiator of wax substances can be explained by a combination of 2 factors.

When wax substances are introduced, the initial concentration of wax substances in the oil being purified increases, therefore, with constant crystallization parameters, the degree of supersaturation of the low-melting fraction of the solution (oil) increases. With an increase in the degree of supersaturation of the solution, the likelihood of accumulation of homogeneous molecules of wax-like substances and nucleation increases, and thereby crystal growth is accelerated.

In addition, at high supersaturations, the so-called block crystal growth, i.e. growth due to aggregation of entire groups of molecules equally oriented in space, as well as nuclei and small crystals, as a result of which large crystals form, which are easier to separate from oil.

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higher degree of purification of oil from wax substances.

When carrying out the oil purification process according to the proposed method, the need to heat the oil before entering the crystallization initiator is eliminated, which greatly simplifies the technology and reduces energy costs.

It should also be noted that using the inventive invention, spent filter powders with a high wax content will be formed. Their subsequent processing, for example, degreasing according to the method (positive decision dated December 25, 90 according to application No. 4828505/13) will result in extraction oil with a high content of waxes. Such an oil is a promising raw material for the production of industrial wax.

The claimed range of quantities of waxy substances applied is selected from the following considerations:

- when wax substances are added to the oil in an amount of less than 0.03% by weight of the oil, there is no significant improvement in the crystallization conditions and, as a result, a noticeable increase in the degree of excretion of wax substances during oil refining is not achieved;

-when using wax substances in an amount of more than 0.08%, it is difficult to separate crystallized impurities due to sticking of the pores of the filter element during phase separation.

The selected oil temperature range at which wax substances are introduced is due to the fact that:

- at a temperature below 25 ° C, the viscosity of the oil increases significantly, which makes it difficult to disperse wax substances in the oil medium and leads to a deterioration in the quality of the purified oil;

- the introduction of wax substances in oil with a temperature above 65 ° C is not justified for technical and economic reasons, because at the same time, a deeper purification of the oil from wax substances is not achieved, at the same time, an increase in energy costs for the subsequent cooling of the oil is required.

To intensify the process of separating waxes by filtration, filter powders (perlite, kieselguhr) are currently used, which improve the drainage properties of the filter element and thereby prevent the pores of the element from sticking to wax-like substances. Powders are added to the frozen oil before filtration. As a result of filtration, a waste filter powder is formed, which consists of: 15-20% perlite or kieselguhr, 10-15% wax substances, 65-75% triglycerides.

Currently, spent filter powder generally has no rational use and is disposed of in a dump. A significant amount of valuable wax substances and edible vegetable oil is lost.

Taking into account the high content of wax substances, as well as the drainage properties of perlite, kieselguhr, it is possible to use spent powder as a crystallization initiator in the process of cleaning oils from wax substances. In addition, in this case, triglycerides are returned to the process, increasing the yield of frozen oil.

The proposed method is carried out under laboratory conditions as follows. In refined sunflower oil with a temperature of 25-65 ° C at

stirring (60 rpm) in the apparatus with a frame mixer, wax substances of vegetable oils in the amount of 0.03-0.08% by weight of the oil are introduced.

As a source of wax substances

Used filter powder may be used.

Continuing stirring, cool the oil for 1.9 hours to a temperature of 20 ° C. Then, the stirring intensity is reduced (10-15 rpm) and the oil is cooled for 1.5 hours to 10 ° C. At this temperature, the chilled oil is held for 1.0 hour and the crystallized impurities are separated by filtration.

The degree of purification of the oil is determined by the residual wax content of the purified oil.

Example 1. 500 g of refined

sunflower oil (acid value 0.15 mg KOH, wax content 0.11% was mixed (60 rpm) at 25 ° C with wax substances of vegetable oils in an amount of 0.03% by weight of oil. Then

within 1.0 hour, a homogeneous solution with stirring to 20 ° C. Further, the stirring intensity was reduced to 15 rpm and cooled for 1.5 hours to 10 ° C. At this temperature, the oil was held for 1.0 hour. Crystallized impurities were separated on a paper filter.

The wax content of the purified oil was 0.006%, i.e. the degree of excretion of wax substances is 94.5%.

When carrying out the process according to the prototype method, the content of wax substances was 0.009%, i.e. the degree of excretion is 91.8%.

Example 2. 500 g of refined sunflower oil (acid number 0.22 mg KOH, wax content 0.14%) was mixed (60 rpm) at 45 ° C with wax substances of vegetable oils in an amount of 0.05% by weight of oil . Then, within 1.90 hours, the homogeneous solution was cooled to 20 ° C with stirring. Further, the stirring intensity was reduced to 15 rpm and continued to cool for 1.5 hours to 10 ° C. At this temperature, the oil was held for 1.0 hour. The crystallized impurities were separated on a paper filter.

The wax content of the purified oil was 0.008%, i.e. the degree of excretion of wax substances is 97.8%.

When carrying out the process according to the prototype method, the wax content was 0.008%, i.e. the degree of excretion is 94.3%.

Example 3. 500 g of refined sunflower oil (acid value 0.18 mg KOH, wax content 0.17%) was mixed (60 rpm) at 65 ° C with wax substances of vegetable oils in an amount of 0.08% of mass of oil. Then within 1.0 hour, the homogeneous solution was cooled to 20 ° C with stirring. Further, reducing the stirring intensity to 15 rpm, cooling was continued for 1.5 hours to 10 ° C. At this temperature, the oil was held for 1.0 hour. Crystallized impurities were separated on a paper filter.

No wax substances were found in the purified oil, therefore, the degree of purification is 100%.

When carrying out the process according to the prototype method, the content of wax substances is 0.005%, i.e. the degree of purification is 97.1%.

Example 4. 500 g of refined sunflower oil (acid value 0.10 mg KOH, wax content 0.09%) was mixed) 60 rpm) at 45 ° C with wax substances. Used perlite containing 10.6% wax, 20.2% perlite was used as a source of wax substances. 69.2% triglycerides. 2.35 g was added to the spent perlite, which in terms of waxy substances is 0.05% by weight of the oil. Then within 1.0 hour, the homogeneous solution was cooled to 20 ° C with stirring. Further, the stirring intensity was reduced to 15 rpm and continued to cool for 1.5 hours to 10 ° C. At this temperature, the chilled oil was held for 1.0 hour. Crystallized impurities were separated on a paper filter,

The wax content of the purified oil was 0.004%, i.e. the degree of excretion of wax substances is 95.6%.

When carrying out the process according to the prototype method, the wax content was 0.008%, i.e. the degree of purification of the removal of wax substances is 91.1%.

The above experimental results indicate that the proposed method allows to reduce the content of wax substances in refined oil by 2.7-4.5% and thereby improve its quality. In addition, the use of the proposed method allows to simplify the process.

Claims (2)

1. A method of purifying vegetable oils from wax substances, comprising introducing a crystallization initiator into the oil and separating crystallized impurities, characterized in. that, in order to increase the degree of purification and simplify the method, wax substances of vegetable oils in the amount of 0.03-0.08% by weight of the oil are used as a crystallization initiator, while the initiator is introduced into the oil at a temperature of 25-65 ° C. 2. A method according to claim 1, characterized in that the used filter powder obtained by freezing vegetable oils is used as a source of wax substances of vegetable oils.