WO1994026683A1

WO1994026683A1 - Process and device for producing squalene from olive oil residues

Info

Publication number: WO1994026683A1
Application number: PCT/DE1994/000542
Authority: WO
Inventors: Paolo Bondioli; Armando LANZANI; Enzo FEDELI; Andrea Mossa; Adam Müller
Original assignee: Müller Extract Company Gmbh
Priority date: 1993-05-18
Filing date: 1994-05-11
Publication date: 1994-11-24
Also published as: DE4316620A1

Abstract

The invention relates to a process and device for producing squalene from olive oil residues, said process comprising four stages which may, if necessary, be reduced to two and are: saponification, cracking and esterification of the fatty acids and extraction by super and/or sub-critical gases. For the purposes of extraction by super and/or sub-critical gases, use is made of a product previously esterified with metal-containing catalysts which is sprayed into a high-pressure extraction column with independently temperable column regions. This process and device makes it possible to obtain marketable squalene with a purity of over 90 %.

Description

description

Method and device for producing squalene from

Olive oil residues

The invention relates to a process for the production of squalene from olive oil residues according to claim 1, a device for extraction according to claim 13, an extract with a high squalene content according to claim 19 and a use of such an extract according to claim 21.

Squalene (2, 6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetra-cosahexaene) is an acyclic triterpene.

Squalene can be prepared synthetically from hexaphenyl-l, 4-butanediyldiphosphonium dibromide and 6,10-dimethyl-5,9-undecadien-2-one.

Squalene, obtained by synthetic means, is very expensive because the required level of purity for commercial use can only be achieved, if at all, with unreasonable effort.

Squalene also occurs as a natural substance in large quantities in shark liver oil and in smaller quantities in many vegetable oils.

It is known to extract squalene from fish liver using organic solvents.

However, squalene products made from fish liver in commercially usable amounts are not completely odorless and still contain a lot of unpleasant taste or odor components.

In addition, it is known from Spanish Patent No. 555,112 that squalene can be obtained by saponification and esterification of vegetable oil residues using acid catalysis.

Furthermore, it is known to use, for example, sulfuric acid, p-toluenesulfonic acid or the like as acid catalysts.

However, a disadvantage of these acid-catalyzed reactions is that the squalene which is obtained in this way is subject to isomerization reactions, possibly due to shifts in the double bonds of squalene or sulfonation reactions in the olefinic system of squalene. However, such a squalene product has to be cleaned for further processing in a labor-intensive and costly manner, which is often unsatisfactory.

It is therefore an object of the present invention to provide a process for the rapid, simple and inexpensive production of a squalene product with a high proportion of squalene.

In terms of process technology, this object is achieved by the features of patent claim 1, and in terms of device technology by the features of patent claim 13.

A product according to the invention is claimed in claim 19, a use according to the invention in claim 21.

The subclaims represent advantageous embodiments of the invention.

An advantage of the squalene obtained according to the invention is that it is free of a strange smell or taste.

The production or isolation according to the invention of a high-quality squalene in its natural composition The following basic chemical steps are used for commercial purposes:

a) The alkaline saponification of a starting material (olive oil residues, especially liquid residues) in an aqueous and / or organic chemical medium.

b) The Conversion of Fatty Acid Soaps to Free Fatty Acids: To the alkaline hydroxide solution from stage a), sufficient mineral acids are added to separate the free fatty acids from their soaps, an organic and an aqueous phase being formed, the organic Phase is usually washed and dried.

c) The esterification: A polyol, in particular glycerol, and a metal-containing catalyst are added to the organic layer obtained as described above.

d) The esterified product is now extracted by a supercritical and / or subcritical gas, whereby a high-quality squalene according to the invention is obtained.

If necessary, additional steps - such as several washing steps or the like - can be added.

On the other hand, the process according to the invention of processing the olive oil residues can also be simplified under suitable conditions, in particular the choice of catalyst, in such a way that steps a) to c) can be carried out in one reaction.

In steps a) to c) above, a process is described which involves the conversion of a complex mixture, which is glycerides, squalene, methyl and ethyl esters contains free fatty acids and the free fatty acids themselves in a binary mixture which contains squalene and triglycerides in a manner which provides the optimum conditions for successful extraction by means of a supercritical and / or subcritical gas, in particular CO2.

In particular, the above steps have the following meaning:

Step 1: Naturally present esters in the olive oil residues to be processed are saponified, the acid part then being present as a soap and the alcoholic part being released and being eliminated during a washing procedure.

Step 2: The fatty acids, which are present as soap, and the organic material, which is dissolved or dispersed in the saponification solution, are released and isolated as a water-insoluble layer which essentially contains squalene and free fatty acids. The transfer of the fatty acid soaps formed in a first reaction mixture (saponification mixture), in their corresponding free fatty acids, takes place by adding acid, in particular mineral acid, preferably phosphoric acid. The organic layer which forms is then washed and dried in order to remove alcohols and inorganic impurities.

An esterification reaction between the free fatty acids and glycerin is then carried out. As a rule, the amount of glycerin added is added as a stoichiometric amount, calculated on the basis of the free fatty acids. The esterification reaction takes place in the presence of a metallic catalyst. The use of an metallic catalyst instead of the acid catalyst customary in the prior art means that the structure of the squalene is not changed. form rearrangements or isomerizations or the like. If, for example, powdered zinc is used as the catalyst, the steps of alkaline saponification, the conversion of the fatty acid soaps into free fatty acids and the esterification of the free fatty acids with glycerol must be carried out in succession, whereas the use of a tin-containing catalyst, in particular tin (II ) - oxide, tin oxalate or tin-2-ethylhexilate or other tin salts or tin metal organic compounds, however, makes it possible to carry out the transesterification reaction between methyl or ethyl esters and glycerol simultaneously - and thus in one step.

If the esterification is carried out with the aid of an acid-containing catalyst and then an extraction with a supercritical and / or subcritical gas, in particular a CO2 extraction, in generally known devices, undesirably isomerized squalene products are reduced Get quality.

It is surprising to find that a high-quality squalene with a content of more than 90% is obtained in its natural composition without isomers if the esterification with a non-acidic catalyst, e.g. a metal-containing catalyst, in particular a zinc or tin-containing catalyst, for example zinc powder or tin oxide or the like.

The quality of the squalene product can be increased further if a device according to claim 13 is used for the extraction with supercritical and / or subcritical gases.

The esterified material is e.g. B. introduced in the middle of a high-pressure extraction column, for example injected, which is specifically with different segments and is optionally equipped with a corresponding double jacket (see FIG. 1: segments A, B, C, D, E, F, G).

Due to the supercritical gas, e.g. CO2, squalene is dissolved, separated from the other constituents and finally collected in the separating tank S.

The undissolved constituents of the esterified product are obtained as a residue in the bottom zone G of the column.

The esterified product can be injected both at the top segment and in another segment of the column. It is important that the supercritical gas, e.g. CO2 is introduced at a point in the column, so that the CO2 can flow in countercurrent from the bottom to the top.

Furthermore, the type of packing in the column is responsible for optimal contact between the product and supercritical and / or subcritical gas. According to this procedure, squalene is dissolved in CO2 and conveyed over the top of the column to the separator S.

The esterified material separated from squalene is collected as a residue in the bottom zone G of the column.

To carry out the process according to the invention it is important that the column has at least two segments with temperature zones operating differently from one another. Three or more segments are preferred which can be temperature-controlled independently of one another and which operate at different temperatures, wherein during operation they have an inwardly decreasing temperature gradient.

With regard to the more precise design of the temperature gradient and further details of the high-pressure extraction device, reference is hereby made to the German patent application dated May 18, 1993 with the title "Process and device for the preservation of extracts from sawtooth palm fruits (Serenoa repens)" and the file number P4316621.0, to which full reference is made in this regard.

In the lowest segment, which lies directly above the sump zone, the temperature of the extraction gas can be subcritical, near the critical point, or supercritical. The extraction pressure is usually supercritical, but can also be subcritical if necessary. In the next segment (e.g. D of the drawing), in which, for example, the esterified mixture is fed, the extraction temperature can also be subcritical, close to the critical point, or supercritical. The extraction pressure is usually supercritical here too. In the segments located further up (e.g. B in the drawing), the extraction temperature and the extraction pressure have to be supercritical in order to separate any undissolved squalene residues.

The critical data for the supercritical gases used are known, e.g. the critical temperature for CO2 is + 31.1 ° C and the kitic pressure is 73.3 bar.

Of course, the present invention is not limited to extraction with CO2. Rather, one can also use a supercritical and / or subcritical gas as a - under normal conditions - gaseous solvent which is selected from the group consisting of: CO; Ethane; Propane; as well as their mixtures, in particular a mixture of CO2 and propane.

The critical data of these - under normal conditions - gaseous solvents for carrying out the high pressure extraction are given below: Gas T [° C] P [bar]

C0 ₂ 31.1 73.3

Ethan 32.1 48.3

Propane 96.8 42.0

In addition, a gaseous solvent can also be used which contains an entrainer, for example an alcohol, preferably ethanol.

Preferred extraction conditions are, for example, those according to claims 10 and / or 11.

In order to be able to carry out the method according to the invention, the device according to the drawing described below is used. It should be noted here that the number of segments can be more, but also less than three.

The column consists of the segments B D F and the intermediate segments A C E G, which are connected to one another by flanges. The column is filled with packs, e.g. Sulzer packs. If necessary, the segments can only be partially filled with packing material. In addition, it is also possible to use different packing materials per segment and / or in different segments.

The segments B D F each have a double jacket, which can be tempered independently and individually by flowing through them using a temperature-controlled medium.

The pump P- ^ draws liquid CO2 from the condenser L and brings it to the desired supercritical pressure. The CO2, which is supercritical in terms of pressure, flows from segment G to the top of column A. The CO2 which is subcritical or supercritical in terms of temperature is essentially purified. applies and controlled by the double jacket systems that are specific to the individual BDF segments.

The esterified material is introduced at the upper part of the segment D or the intermediate segment C of the drawing using the metering pump P2 and the valve Vj. The starting material flows continuously from P2 to C.

The invention is not limited to this point of introduction of the starting material. According to the invention it is possible to choose a different entry point on the column, either lower or higher than point C.

The separation of squalene from the accompanying substances is not yet complete in the segments C D E F.

According to the invention, the remaining solution of the squalene parts not yet dissolved in CO2 takes place in segment B. With the described process conditions, a top product dissolved in CO2 is obtained, which flows from the top of column A to the proportionally controlled valve V2, where the extraction pressure is reduced.

The extraction temperature is also reduced in the subsequent heat exchanger H ^. Under these conditions, the extract reaches the separator S, where the separation from the CO2 takes place.

The extract obtained contains almost all of the squalene and can be continuously removed from the separating tank through valve V3.

A particular advantage lies in the fact that the squalene obtained is virtually free of pesticide residues.

The bottom product, almost free of squalene, is collected in segment G and can be continuously discharged through valve 4. will wear. The evaporating CO2 in the separator S is free of extract, is liquefied in the heat exchanger H2 and flows into the so-called liquefier L, which essentially represents a collecting container for liquefied CO2.

The carbon dioxide can be used again by the pump Pj for a new extraction cycle.

example 1

500 g of liquid residues from olive oil production are treated under reflux with 500 ml of methanol, 500 ml of water and with an excess of NaOH or KOH, calculated on the basis of the saponification number. The duration of treatment is approximately three hours. The alkaline solution is then mixed with 85% phosphoric acid. The fatty acid splitting is carried out at a reaction temperature of 70 ° C. The completeness of the fatty acid splitting is achieved when two immiscible liquid layers can be observed.

The organic layer of the treated product - as described above - is transferred to a 1,000 ml glass cylinder, which is connected to a magnetic stirrer and vacuum pump.

After the water has been removed at 100 ° C. under vacuum (20 mm Hg), the temperature is raised to 180 ° C. and glycerol and zinc powder 1% are added as a catalyst. The glycerol content is calculated on the basis of the free fatty acid component.

The vacuum must be maintained during the esterification.

Treatment ends when the free fatty acid content is less than 1%. 300 ml of the present esterified product with a content of 28% squalene as starting material are injected into the described extraction column, which works with CO2 as the supercritical gas.

The extraction pressure is 150 bar, the extraction temperature in the middle segment (D) 40 ° C, in the upper segment (B) 50 ° C, in the lower segment (F) 30 ° C.

The results are:

Squalene before CO2 extraction 28.3%

Squalene in the extract 90.0% Squalene in the residue 2.9%

Mono- and diglycerides in the extract 7.0%

Extract yield 93.9%.

The flow rate of CO2 in the example is approximately 100 kg / h.

Example 2

Typically, 1000 g of a starting material which is produced as a waste product in olive oil production and which is known, for example, by the term "skam" is used. This starting material is analyzed before processing for its free fatty acid content and its saponification number. The mixture is then heated under a reduced pressure of 100 mm Hg until a temperature of 150 ° C. is reached.

It is necessary to determine the free fatty acids and the saponification number in order to be able to calculate the amount of glycerol which is required for the esterification of the free fatty acids and for the methyl and ethyl ester transesterification. The use of a reduced pressure at least during the esterification reaction has the meaning of removing the water formed during the reaction and the water which is present anyway, together with the low-boiling alcohols, such as, for example, methanol and / or ethanol.

The removal of water and the low-boiling alcohols from the reaction mixture therefore also has the purpose of shifting the reaction equilibrium in the direction of the end products.

Then, with constant stirring, about 2 g of a tin catalyst, in the example SnO, are added. The reaction mixture is then heated up to 220.degree.

The calculated amount of glycerin is added dropwise under reduced pressure during the esterification reaction. The progress of the reaction is periodically checked by analyzing the free fatty acid content and thin-layer chromatography (with hexane: diethyl ether in a ratio of 9: 1. After applying and carrying out the thin-layer chromatography, the thin-layer plate is sprayed with sulfuric acid and in an oven at 100 ° C. for 15 minutes As soon as the corresponding stains can no longer be determined on the thin-layer plate, which generally takes four hours, a new amount of glycerin, calculated on the residual content of free fatty acids, is added generally preferred because a significant part of the previously added glycerol can distill off together with water and alcohol under the pressure and temperature conditions described. The amount of this new addition depends primarily on the design of the device as long as HRT until the residual free fatty acid content lower than 0.3%, which are present as oleic acid, is. The mixture will then cooled to 80 ° C and filtered to remove the catalyst.

This reaction mixture obtained is then extracted with CO2 under supercritical and / or subcritical conditions in the device according to the invention, an extract being obtained which has a squalene content of from about 85% by weight to in particular about 97% by weight. , 96% by weight in the example.

An extract with a high squalene content obtained with the method according to the invention can be used immediately without further purification as an ointment base for pharmaceutical and / or cosmetic purposes, without having the odor nuisance which inevitably occurs due to extracts from fish liver.

The scope of the present invention is of course not limited to the conditions of the examples.

By changing the above-mentioned conditions, in particular the process conditions with regard to extraction pressure and / or temperature and / or flow rate of the supercritical gas, it is possible to optimize the process and the data obtained.

Claims

1. A process for the production of squalene from residues of olive oil production, comprising the following steps:

[1] Alkaline saponification of a, especially liquid, starting material with a low squalene content, which is obtained in the production of olive oil, in a mixture

Water and a water-miscible organic solvent to form a first reaction mixture;

[2] converting the fatty acid soaps formed in step 1 in the first reaction mixture into their corresponding fatty acids, which are thus freely present in the organic phase of the second reaction mixture thus formed;

[3] washing and drying the organic phase from step 2;

[4] esterification of the free fatty acids of the organic phase with glycerol in the presence of a metal-containing catalyst, so that a third reaction mixture is obtained;

[5] extracting the third reaction mixture with a gas under supercritical and / or subcritical conditions; and

[6] Evaporation of the gas to obtain a high squalene extract.

2. The method according to claim 1, characterized gekennzeich¬ net that one uses Skam as starting material.

3. The method according to claim 1 or 2, characterized in that alcohol, in particular methanol and / or ethanol, is used as the solvent.

4. The method according to any one of the preceding claims, characterized in that the transfer according to step 2 is carried out with an acid, in particular an inorganic acid, preferably phosphoric acid.

5. The method according to any one of the preceding claims, characterized in that the metal-containing catalyst is selected from the group consisting of: zinc; Tin; their salts of inorganic acids, their salts of organic acids, their oxides, their organometallic compounds; Tin (II) oxide, tin oxalate, tin 2-ethylhexilate.

6. The method according to any one of the preceding claims, characterized in that steps 1 to 4 are carried out in one reaction using a catalyst containing tin.

7. The method according to any one of the preceding Ansprü¬ che, characterized in that one uses such as - supercritical and / or subcritical gas - under normal conditions - gaseous solvent, which is selected from the group consisting of: CO2; Ethane; Propane; as well as their mixtures, in particular a mixture of CO2 and propane.

Method according to one of the preceding claims, characterized in that a gaseous solvent is used which contains an entrainer.

Process according to claim 8, characterized in that an alcohol, in particular ethanol, is used as the entrainer.

10. The method according to any one of the preceding claims, characterized in that supercritical and / or subcritical pressure conditions are set in a high-pressure extraction device, in particular a column, for the gaseous solvent, in particular from approximately 40 bar to 350 bar, preferably from approx. 90 bar to 160 bar.

11. The method according to any one of the preceding claims, characterized in that supercritical and / or uncritical temperature conditions are set in the high-pressure extraction device for the gas-form solvent, in particular from approximately 15 ° C. to 100 ° C., preferably from approx. 20 ° C to 80 ° C.

12. The method according to any one of the preceding Ansprü¬ che, characterized in that one carries out the method in a continuous, cyclical process.

13. Device for extracting a complex chemical mixture using a supercritical and / or subcritical gas, with a high-pressure column which has a bottom zone, has an extraction zone and a head zone; and which has both an inlet and an outlet for the gas; and at which a material inlet for a material to be extracted is also provided, and the individual zones of the high-pressure column have at least one packing material, characterized in that

the extraction zone of the high-pressure column comprises at least two, preferably three or more segments, the individual segments being temperature-controllable in such a way that a temperature gradient falling inwards is produced.

14. The apparatus according to claim 13, characterized gekenn¬ characterized in that the individual segments have a double jacket, which is flushed with a medium of defined temperature.

15. The apparatus according to claim 13 or 14, characterized in that the individual segments of the extraction zone of the high pressure column can be temperature-controlled independently of one another.

16. Device according to one of claims 13 to 15, characterized in that the material inlet is downstream with respect to the direction of flow of the supercritical and / or subcritical gas to the gas inlet.

17. Device according to one of claims 13 to 16, characterized in that the complex che see mixture is a squalene-containing mixture, in particular one according to step 4 of claim 1.

18. Device according to one of claims 13 to 17, characterized in that the packing material is selected from the group consisting of: Raschig rings, Sulzer packs; as well as their mixtures.

19. High squalene extract obtainable by a process according to claims 1 to 12.

20. Extract according to claim 18, characterized gekennzeich¬ net that the extract has a squalene content of more than about 85 wt .-%, in particular about 97 wt .-%.

21. Use of an extract according to one of claims 19 or 20 as an ointment base for pharmaceutical and / or cosmetic purposes.