RU2336299C1 - Method of obtaining mixture of higher fatty acids - Google Patents

Abstract

FIELD: chemistry, organic.

SUBSTANCE: invention relates to butterfat industry, namely to methods of processing butterfat raw materials in order to obtain mixture of higher fatty acids, used in petrochemical, paint and varnish, food and other branches of industry. Method of obtaining mixture of higher fatty acids is realised by reagentless hydrolysis of oil in presence of free fatty acids, extracted from oil, with further distillation of obtained fatty acids mixture, free fatty acids being introduced in mixture, which is to be split, in form of distillate, obtained during sunflower oil distillation, mixing it with sunflower oil with the following ratio of constituting components in mixture which is being split, wt %: sunflower oil 55-80; distillated, obtained in sunflower oil distillation - 45-20.

EFFECT: reduction of consumption of sunflower oil in formulation without reducing productivity of reagentless hydrolysis process.

1 cl, 2 ex, 2 tbl

Description

The invention relates to the oil and fat industry, and in particular to methods of processing oil and fat raw materials in order to obtain a mixture of higher fatty acids used in the petrochemical, paint, varnish, food and other industries.

A known method of producing a mixture of fatty acids by the non-reactive hydrolysis of vegetable oils, followed by distillation of the selected fatty acids ("Guide to the technology for the production and processing of vegetable oils and fats." L .: VNIIZH, T. IV. - 1975).

The disadvantage of this method is the use of 100% vegetable oils, including food, for example, imported olive oil.

A known method of producing unsaturated fatty acids (olein "OM") by non-reactive hydrolysis of a composition of vegetable oils, consisting of high oleic sunflower oil in combination with rapeseed and / or mustard oil, followed by distillation of the obtained fatty acids (AS USSR No. 1373724, C11C 1 / 04, C07C 37/02, 1988).

The disadvantage of this method is the need to use 100% vegetable oils, the use of high oleic sunflower oil as a raw material, which is a valuable food product with a biologically optimal ratio of fatty acids, which makes it inappropriate to use it for technical purposes. The disadvantage is the relatively low productivity of the two-stage process of non-reactive hydrolysis.

The closest in technical essence and properties of the obtained product to the present invention is a method for producing a mixture of higher acids by non-reactive hydrolysis of a composition of vegetable oils under autoclaving in two periods in the presence of free fatty acids isolated from soap stocks corresponding to the formulation of split vegetable oils, in a mass ratio of oil : fatty acids (3-10): 1 and subsequent distillation of free fatty acids (A.S. RF No. 1664825, C11C 1/04, C07C 57/12, 1991).

This method is accepted by us as a prototype.

The disadvantage of this method is that fatty acids isolated from soap stocks do not participate in the hydrolysis reaction, playing the role of a catalyst.

Such ballast does not allow the introduction of more than 30 wt.% Free fatty acids into the reaction, since their introduction, increasing the speed of the hydrolysis reaction, simultaneously reduces the amount of degradable oil in the formulation, which leads to a decrease in the performance of the autoclave to the level of the industrial method with the ratio of free fatty acids and sunflower oil more than 1: 3.

In addition, up to 30 wt.% Of fatty acids isolated from the stocks of sunflower oil are used in the split formulation, the production technology of which is not faulty from an environmental point of view. (The need to use mineral, usually sulfuric acid, the presence of acidic effluents to be neutralized, which leads to the formation of a significant amount of wastewater containing sulfate salts).

The objective of the invention is to reduce the consumption of edible oils used to obtain technical fatty acids, without reducing the performance of the process of non-reactive hydrolysis.

The problem is achieved in that in the method for producing a mixture of higher fatty acids by the non-reactive hydrolysis of vegetable oils in the presence of free fatty acids isolated from vegetable oil, followed by distillation of the mixture of obtained fatty acids, free fatty acids are introduced into the cleavable mixture in the form of a distillate obtained by distillation of sunflower oil, mixing it with sunflower oil in the following ratio of constituent components in a split mixture, wt.%:

Sunflower oil 55-80 Distillate obtained by distillation sunflower oil 45-20

Phospholipids, pigments and other undesirable substances are preliminarily removed from the oils by deep hydration and bleaching, and then fatty acids and other compounds volatile with steam are distilled off. In this case, the deodorization process is combined with the distillation process.

Sunflower oil is subjected to distillation at a residual pressure of 0.13-0.8 kPa and a temperature of 230-260 ° C. During the distillation process, evaporation of free fatty acids and other vapor-volatile compounds is ensured, their separation from the oil stream and condensation from the gas-vapor mixture. During the distillation process, mechanical oil losses occur due to drip entrainment with sparging steam.

The distillate is a mixture of predominantly fatty acids and a neutral oil with a mass fraction of fatty acids of 65-80 wt.%.

The standard modes of non-reactive hydrolysis of the decomposable mixture and the distillation of the released fatty acids are common to the proposed method, prototype and production method are shown in table 1.

Table 1
Standard Modes Common to Fatty Acid Production Methods Process flow Non-reactive hydrolysis Distillation Notes t, ° С R, MPa Number of periods t, ° С R, kPA Non-reactive hydrolysis - distillation 225 2,5 2 230 1.33 Technological modes - common to the proposed method, prototype and production method

When the applicant conducted the analysis of the prior art, an analogue was not found that was characterized by all the features of the claimed invention, and the definition of the prototype as the closest in terms of the totality of the features of the analogue made it possible to identify the set of essential distinguishing features in the claimed object set forth in the claims.

We give examples of the proposed method and the method adopted as a prototype.

Example 1 (prototype), corresponds to 3 of table 2.

Fat mixture consisting of:

Sunflower oil 75% Fatty Acids Isolated from stocks of sunflower oil 25%

with a ratio of free fatty acids and sunflower oil 1: 3, are subjected to non-reactive hydrolysis at a temperature of 225 ° C and a pressure of 2.5 MPa in two periods.

The split mixture is distilled at a temperature of 230 ° C and a residual pressure of 1.3 kPa. After distillation, fatty acids with an acid number of 186 mg KOH / g were obtained.

The consumption of sunflower oil included in the split formula is 750 kg / t with an autoclave capacity of 540 kg / h.

Example 2 (the proposed method), corresponds to 6 of table 2,

Fat mixture consisting of:

Sunflower oil 70% Distillate obtained by distillation sunflower oil to remove free fatty acids thirty%

with a ratio of free fatty acids and sunflower oil 1: 3.8, are subjected to non-reactive hydrolysis at a temperature of 225 ° C and a pressure of 2.5 MPa in two periods.

The split mixture is distilled at a temperature of 230 ° C and a residual pressure of 1.3 kPa. After distillation, fatty acids with an acid number of 186 mg KOH / g were obtained.

The consumption of sunflower oil included in the split formula is 700 kg / t with an autoclave capacity of 540 kg / h.

Examples of the proposed method (5-15) in comparison with the prototype (1-4) and the industrial method (16) are shown in table 2.

Examples 1-3 determine the area of effectiveness of the method adopted for the prototype, and example 4 limits the scope of its application, since the performance of the autoclave drops lower than in the industrial method (example 16).

Examples 5-8, 10-11, 13-14 confirm the possibility of implementing the proposed method, which is reflected in the claims.

In examples 9, 12, 15 shows the transcendental values of the parameters at which the effectiveness of the proposed method is reduced, since the performance of the autoclave drops lower than that of the prototype and industrial method.

As can be seen from table 2, the main parameter determining the effectiveness of the method is the ratio of free fatty acids and sunflower oil, the limit value of which is 1: 2 for compositions with any acid number of the distillate used.

In this case, an increase in the acid number of the distillate reduces the efficiency of the method, since the autoclave decreases to the prototype level earlier, which makes it impossible to replace the maximum amount of sunflower oil in the formulation with physical distillation distillate.

As can be seen from table 2, the proposed method for producing a mixture of higher fatty acids can reduce the consumption of sunflower oil in the formulation by 50-200 kg / t

Thus, the proposed method for producing a mixture of higher fatty acids allows, in comparison with the prototype:

- reduce the consumption of sunflower oil in the formulation by 50-200 kg / t without reducing the productivity of the process of non-reactive hydrolysis.

table 2 No. p / p The formulation for hydrolysis, wt.% The ratio of free fatty acids and sunflower oil The acid number of the distillate, mg KOH / g Non-reactive hydrolysis Consumption of sunflower oil, kg / t The pour point of fatty acids (titer), ° C Sunflower oil Soapstock Fatty Acids The distillate from the distillation of sunflower oil Tempera, ° С Pressure, MPa Conditional productivity, kg / h one 2 3 four 5 6 7 8 9 10 eleven Prototype Examples (1-4) one. 86 fourteen - 1: 6 - 225 2,5 600 860 20,4 2. 80 twenty - 1: 4 - 225 2,5 570 800 20,4 3. 75 25 - 1: 3 - 225 2,5 540 750 20,4 four. 67 33 - 1: 2 - 225 2,5 490 670 20,4 The proposed method, examples (5-15) 5. 80 - twenty 1: 6 130 225 2,5 600 800 20,4 6. 70 - thirty 1: 3.8 130 225 2,5 565 700 20,4 7. 60 - 40 1: 2.5 130 225 2,5 550 600 20,4 8. 55 - 45 1: 2.2 130 225 2,5 505 550 20,4 9. fifty - fifty 1: 1.9 130 225 2,5 485 500 20,4 10. 80 - twenty 1: 5 150 225 2,5 585 800 20,4 eleven. 70 - thirty 1: 3 150 225 2,5 540 700 20,4 12. 60 - 40 1: 2 150 225 2,5 490 600 20,4 13. 80 - twenty 1: 4.3 170 225 2,5 580 800 20,4 fourteen. 70 - thirty 1: 2.5 170 225 2,5 550 700 20,4 fifteen. 65 - 35 1: 2 170 225 2,5 490 650 20,4 Industrial method, example (16) 16. one hundred - - - - 225 2,5 500 1000 20,4

Claims (1)

A method of obtaining a mixture of higher fatty acids by non-reactive hydrolysis of vegetable oils in the presence of free fatty acids isolated from vegetable oil, followed by distillation of the mixture of obtained fatty acids, characterized in that the free fatty acids are introduced into the cleavable mixture in the form of a distillate obtained by distillation of sunflower oil mixing it with sunflower oil in the following ratio of constituent components in a splittable mixture, wt.%: Sunflower oil 55-80 The distillate obtained with sunflower oil distillation 45-20