KR20170024825A

KR20170024825A - De-emulsification process of oil-in-water type emulsion

Info

Publication number: KR20170024825A
Application number: KR1020150120345A
Authority: KR
Inventors: 오인선; 김종필
Original assignee: 롯데케미칼 주식회사
Priority date: 2015-08-26
Filing date: 2015-08-26
Publication date: 2017-03-08

Abstract

The present invention relates to a demulsification process for oil-in-water emulsion. According to the demulsification process, a gas injection step is carried out while a temperature of microalgae culture fluid-containing emulsion is heated up to a temperature close to the boiling point of an extraction solvent. Since the demulsification process does not require a drying process, crude oil of microalgae can be obtained in an economic way.

Description

[0001] DE-EMULSIFICATION PROCESS OF OIL-IN-WATER TYPE EMULSION [0002]

The present invention relates to a de-emulsification process of an oil-in-water emulsion for obtaining a crude oil from a microalgae culture.

Microalgae are an excellent resource for the production of polyunsaturated fatty acids, which are well tolerated in environments where light is blocked and organic in abundance, and by converting carbohydrates into useful oils, the omega- . However, omega-3 fatty acids derived from microalgae have been attracting attention due to the replacement of fish-derived omega-3 fats, which are likely to be exposed to heavy metals and other problems. The factors that underpin this tendency include the high price of polyunsaturated fatty acids, the availability of high-density unsaturated fatty acids, the superiority of oxidative stability to fish oil, the sustainability of production, the new production of biochemical metabolic pathways and genetic knowledge System and product development means.

As a source of oil (lipid), microorganisms are less well known than plants and animals. The production of microbial oil or single-cell oil (SCO) was first proposed in the 20th century as a relatively new concept. Although vegetable oils and animal fats are relatively inexpensive, microbial maintenance production is characterized by high value-added products that can not be mass-produced by plants in the future.

DHA (docosahexaenoic acid) is a highly unsaturated fatty acid in the omega-3 (ω-3) series, which is mainly composed of 22 carbon atoms and 6 double bonds. DHA is a type of polyunsaturated fatty acid, which is known to be biosynthesized mainly by phytoplankton and seaweeds living in freshwater, seawater in the natural world. Fish, crustaceans, and shellfish that can not make DHA themselves can accumulate DHA in the form of triglycerides in the body by ingesting plants containing DHA by the food chain. People also have to rely on the intake of DHA containing foods that are needed because the enzymes needed to biosynthesize DHA are not present in the body.

With respect to the production of omega-3 highly unsaturated fatty acids, especially those using docosahexaenoic acid (DHA) in a large amount, microorganisms belonging to the genus Thraustochytrium, a kind of marine microalgae, The preparation of omega-3 unsaturated fatty acids by microorganisms in Schizochytrium has been described by Ellenbogen et al. (Ellenbogen B. B et al., Comparative Biochemistry and Physiology, 29: 805-811 (1969)).

Looking at the industrial market, Martek has found that Shoshokitrium sp. ATCC 20888 (Schizochytrium sp. ATCC 20888) and Shizokatori sp. A method for preparing omega-3 unsaturated fatty acids using ATCC 20889 (Schizochytrium sp. ATCC 20888) has been disclosed (U.S. Pat. No. 5,130,242 and U.S. Pat. No. 5,340,742). In addition, Suntory has reported Schizochytrium limacinum SR21 (Japanese Patent Publication No. 1997-000284 and U.S. Patent No. 6,582,941) as a microorganism having excellent productivity of docosahexaenoic acid.

The main process for producing oil from microalgae differs depending on the field of use, but largely consists of the steps of cultivation, extraction and purification of microalgae. The production of polyunsaturated fatty acids, which are used as foods, consists of cultivation, recovery, drying, extraction, and purification. After the drying process, the intracellular lipid extraction process using a nonpolar solvent such as hexane requires a lot of energy and cost . The extraction method of oil containing microalgae is largely classified into chemical method and physical method according to microalgae pretreatment method. Specifically, it can be divided into solventless extraction and solvent extraction depending on whether solvent is used during extraction.

In the case of solventless extraction, a method of obtaining an oil by not using or minimizing an organic solvent such as hexane, is subjected to a pretreatment such as an enzymatic decomposition reaction or heat treatment which can decompose the protein constituting the cell wall of the microalgae, The difference in specific gravity between the oil and the other polar material is used to finally obtain the oil.

Conventionally used oil extraction methods are solvent extraction methods using a nonpolar organic solvent such as hexane. In the case of solvent extraction, it is a process that can realize economies of scale due to mass production in spite of the cost increase in process operation and the risk of residual solvent due to the use of organic solvent.

In the case of solvent extraction, it is applied in connection with the physical method of pretreatment concept of breaking down or pulverizing microalgae cells in order to obtain the oil present in the cells. As a typical method, a milling apparatus such as a colloid mill and a bead mill is used. In the case of a colloid mill, a superfine pulverizer capable of being dry and wet is a principle in which particles of the mixture are dispersed or disrupted because a high shear energy is generated and the rotor rotates at a high speed between a very small gap between a rotor and a stator . In the case of the bead mill, it is possible to disperse and crush the microalgae using the kinetic energy of the bead generated by the energy of the motor.

At present, a method of obtaining a crude oil containing a polyunsaturated fatty acid, particularly an omega-3 or omega-6 unsaturated fatty acid, from microalgae has been generalized after drying microalgae. This process can lead to denaturation of the oil during the drying process at high temperatures, which is directly related to the quality of the product. In addition, it is inevitable that the manufacturing cost will rise because it is a process that requires high energy from an economical point of view. Therefore, it is required to develop a new extraction process which is reasonable in terms of quality and cost.

In order to solve the problems of the prior art as described above, it is an object of the present invention to provide a method for obtaining a crude oil from a microalgae culture solution through a novel extraction process.

In order to achieve the above object,

Preparing an emulsion by adding an extraction solvent to the microalgae culture solution;

Injecting a gas while heating the emulsion to induce phase separation including an oil layer; And

And obtaining crude oil from said oil layer.

Thereby providing a de-emulsification process of an oil-in-water type emulsion.

In addition, the microalgae culture broth may be disrupted by physical or chemical methods.

The heating of the emulsion may be performed by heating the extracting solvent to a temperature within the range of the boiling point of 5 占 폚.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the microalgae are selected from the group consisting of Schizochytrium sp., Thraustochytrium sp., Japonochytrium sp., Ulkenia sp. Crypthecodinium genus, Haliphthoros genus strain, and combinations thereof.

The physical method may be selected from the group consisting of a bead mill, a colloid mill, a homogenizer, a microfluidizer, and combinations thereof, Lt; / RTI >

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the extraction solvent is selected from the group consisting of methanol, ethanol, butanol, isopropyl alcohol, pentane, hexane, cyclohexane, toluene, acetone, methyl acetate, methylene chloride, chloroform, , Benzene, ethylene glycol, propylene glycol, butylene glycol, and combinations thereof.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the emulsion may be heated to 50 to 100 ° C.

In the demulsifying process of the water-in-oil type emulsion of the present invention, the gas injected into the emulsion is selected from the group consisting of nitrogen, oxygen, carbon dioxide, hydrogen, argon, neon, creep tones, helium, xenon, .

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the amount of gas injected into the emulsion may be 1 to 20 vvm.

According to the present invention, a method of obtaining a crude oil from a microalgae culture liquid through a step of raising the temperature of the emulsion obtained by adding the extraction solvent to the microalgae to a temperature close to the boiling point of the extraction solvent and injecting gas at the same time, It is economical to reduce the process cost. Therefore, the crude oil obtained from the microalgae by the above method can be widely used in the food industry, the cosmetics industry, and the like.

1 is a schematic view showing a process of obtaining a crude oil from a microalgae culture liquid.
2 is a graph showing the yield of crude oil according to the gas injection amount

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, the present invention will be described in detail.

The present invention relates to a process for the de-emulsification of an oil-in-water emulsion, comprising the steps of: preparing an emulsion by adding an extraction solvent to a microalgae culture; Injecting a gas while heating the emulsion to induce phase separation including an oil layer; And obtaining a crude oil from the oil layer.

Preferably, the microalgae culture broth is broken by physical or chemical methods.

Preferably, the emulsion is heated to a temperature within the range of the boiling point ± 5 ° C of the extraction solvent.

According to one embodiment of the present invention, the method according to the present invention, as shown in Figure 1,

(a) disrupting the microalgae culture;

(b) adding an extraction solvent to the microalgae culture broke in (a) and stirring to produce an emulsion;

(c) stirring and raising the emulsion produced in (b) above;

(d) injecting gas into the emulsion heated in step (c);

(e) separating the water layer and the oil layer by leaving the emulsion of (d) at room temperature; And

(f) decompressing and concentrating the oil layer separated in (e) to obtain a crude oil.

Specifically, according to a preferred embodiment of the present invention, in order to extract crude oil contained in the microalgae cells of the microalgae culture broth, the microalgae culture broth is disrupted by enzymatic degradation, and an extraction solvent is added to the microalgae culture broth The resulting emulsion is stirred and heated. At the same time, air is injected into the emulsion to leave the emulsion at room temperature to separate the phases. The oil phase of the separated phase can be concentrated under reduced pressure to obtain a crude oil.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the microalgae are selected from the group consisting of Schizochytrium sp., Thraustochytrium sp., Japonochytrium sp., Ulkenia sp. Crypthecodinium genus and Haliphthoros genus, or a combination thereof. Preferably, the strain is a strain belonging to the genus Thraustochytrium, belonging to the genus Schizochytrium, Most preferred is a strain of the genus Schizochytrium.

In the demulsifying process of the water-in-oil type emulsion of the present invention, the step (a) of pulverizing the microalgae culture liquid may be performed by using a bead mill, a colloid mill, a homogenizer and a microfluidizer ), Or a chemical method using a protease and / or a proteolytic enzyme, which is a combination thereof, and is preferably performed by a method using a proteolytic enzyme.

In one embodiment of the present invention, the amount of proteolytic enzyme used is 1 to 20 parts by weight, preferably 1 to 10 parts by weight, more preferably 5 to 10 parts by weight, relative to 100 parts by weight of the microalgae cells, To 1500 minutes, preferably from 100 minutes to 1200 minutes, more preferably from 600 to 900 minutes.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the extraction solvent is selected from the group consisting of methanol, ethanol, butanol, isopropyl alcohol, pentane, hexane, cyclohexane, toluene, acetone, methyl acetate, methylene chloride, chloroform, , Benzene, ethylene glycol, propylene glycol and butylene glycol, or a combination thereof, preferably selected from the group consisting of methanol, ethanol, butanol, isopropyl alcohol, pentane and hexane, , And most preferably hexane.

In the dewaxing process of the water-in-oil type emulsion of the present invention, the temperature rising period of step (c) is from 50 to 100 ° C, preferably from 60 to 80 ° C.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the gas is selected from the group consisting of nitrogen, oxygen, carbon dioxide, hydrogen, argon, neon, creptone, helium and xenon or a combination thereof.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the amount of gas injected in step (d) is 1 to 20 vvm, preferably 1 to 10 vvm, and more preferably 1 to 5 vvm.

In the de-emulsification process of the water-in-oil type emulsion of the present invention, the crude oil is a highly unsaturated fatty acid (omega-3, omega-6, omega-9 unsaturated fatty acid), lauric acid, myristic acid ), Palmitic acid, saturated fatty acids such as stearic acid, phospholipids and steroids and / or free fatty acids, esters and other derivatives which may exist as free fatty acids, It is all kinds of oil contained in algae.

In the present invention, the polyunsaturated fatty acid is a polyunsaturated long chain fatty acid having a chain length of more than _C12 containing two or more double bonds. Preferably n-3 fatty acids and n-6 fatty acids, more preferably n-3 fatty acids.

In a preferred embodiment of the present invention, the polyunsaturated fatty acid contains omega-3-docosahexaenoic acid (DHA) and / or omega-3-docosapentaenoic acid (DPA).

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to be illustrative of the present invention and the scope of the invention as defined by the appended claims. And it is clear that such modifications and variations are included in the scope of the appended claims.

< Preparation Example 1> Culture of microalgae

The microscopic algae Schizochytrium limacinum SR21 (microorganism international accession number ATCC ^® MYA-1381 TM), which produces crude oil, was cultured to obtain a biomass in a wet state, that is, a culture solution.

Sh jokayi atrium Lima when num (Schizochytrium limacinum SR21. Microorganism international deposit number ATCC ^® MYA-1381TM) is GYP (glucose-peptone-yeast) medium (glucose 10g / ℓ, peptone 1g / ℓ, yeast extract 5g / ℓ, and water salt (Glucose 100 g / l, magnesium sulfate 2.6 g / l, potassium chloride 0.6 g / l, sodium chloride 20 g / l) were placed in a 2 l Ellenmeyer flask and shaken at 25 rpm at 170 rpm to give a seed culture. , 2 g / l of calcium chloride, 0.3 g / l of calcium nitrate, 1.0 g / l of sodium nitrate, 0.05 g / l of potassium dihydrogenphosphate, 1.0 g / l of trace component I, 5 ml of trace component II and 5 ml / 20 ml of the seed culture was inoculated and cultured with shaking at 28 DEG C and 200 rpm for 72 hours.

The culture medium as described above was washed three times to completely remove the medium components, dried at 105 ° C, and the amount of biomass was measured by weighing. The amount of biomass was measured by the method described in Article 10. General Testing Methods 1. Food test method 1.1.5.1 The amount of crude oil contained in the culture solution was measured according to the crude fat test method. As a result, the amount of biomass was 62.5 g / l and the content of crude oil was 61.7%.

< Preparation Example 2> Enzymatic Degradation of Microalgae (Chemical Fragmentation)

5% of Alcalase 2.4 L FG was added to 2 L of the microalgae culture solution of Preparation Example 1 having a solid content of 8.0%, and the mixture was stirred at 60 ° C, 200 rpm, pH 7 to 8 (the pH was adjusted to caustic soda Phosphoric acid was used for 15 hours to hydrolyze the microalgae culture. 200 parts by weight of hexane was added to 100 parts by weight of the enzyme-treated culture, followed by stirring at 200 rpm for 30 minutes. As a result, And it was confirmed that an emulsion was produced.

< Comparative Example 1> At temperature elevation Impact Assessment

The culture solution in the emulsion state prepared in Preparative Example 2 was heated to about 70 DEG C and the culture solution started to boil was allowed to stand at room temperature for about 60 minutes without stirring to form an aqueous layer and an intermediate layer containing cellular debris and an oil layer Separated.

In order to examine the yield of crude oil obtained from the separated oil layer, the process of decompressing and concentrating the separated oil layer to obtain crude oil was repeated three times.

The separation into two phases or three phases was not achieved completely, and the states and ratios of the separated interfaces were different in spite of the same conditions for each phase. As a result, the average yield was only about 27%.

< Example 1>

The culture solution in the emulsion state prepared in Preparative Example 2 was heated to about 70 DEG C and a gas was injected from the bottom using a round tube having an inner diameter of about 5 mm with many small holes of about 7 cm in the emulsion. From the point of time when the temperature rose and the solvent began to boil, the gas was injected under the conditions of 1 vvm, 2 vvm, 3 vvm, 4 vvm, and 5 vvm for about 10 minutes, After the gas injection was completed, the oil layer was slowly cooled at room temperature and finally the separated oil layer was recovered to obtain a crude oil. The results of the extraction efficiency test according to the gas injection amount are shown in FIG.

As shown in FIG. 2, the crude oil yield was 87% at a gas injection amount of 1 vvm, 89% at 2 vvm, 93% at 3 vvm, 92% at 4 vvm, and 92% at 5 vvm, The yield of crude oil was 27% at 0 vvm, which was not injected.

From the above results, it can be concluded that the method according to the present invention is a method for producing microalgae culture, which comprises preparing a microalgae culture liquid as an emulsion without additional drying process, and deoiling the microalgae culture under elevated temperature by air injection to form an oil layer as an upper layer and an aqueous layer and a precipitate layer It is possible to clearly separate the lower layer and increase the oil gain of the oil layer.

Claims

Preparing an emulsion by adding an extraction solvent to the microalgae culture solution;
Injecting a gas while heating the emulsion to induce phase separation including an oil layer; And
And a step of obtaining a crude oil from the oil layer.

The method according to claim 1,
Wherein the microalgae culture liquid is pulverized by a physical or chemical method; and a step of de-emulsifying the oil-in-water emulsion.

The method according to claim 1,
Wherein the emulsion is heated to a temperature within a range of 5 占 폚 of the extraction solvent.

The method according to claim 1,
The microalgae may be selected from the group consisting of Schizochytrium sp., Thraustochytrium sp., Japonochytrium sp., Ulkenia sp., Crypthecodinium sp., Halifetros sp. Haliphthoros genus, and combinations thereof. The process for the de-emulsification of an oil-in-

3. The method of claim 2,
Wherein the physical method is selected from the group consisting of a bead mill, a colloid mill, a homogenizer, and a microfluidizer, or a combination thereof. De emulsification process of emulsion.

3. The method of claim 2,
Wherein the chemical method is a method using a proteolytic enzyme.

The method according to claim 6,
Wherein the proteolytic enzyme is used in an amount of 1 to 20 parts by weight based on 100 parts by weight of microalgae cells.

The method according to claim 1,
The extraction solvent is selected from the group consisting of methanol, ethanol, butanol, isopropyl alcohol, pentane, hexane, cyclohexane, toluene, acetone, methyl acetate, methylene chloride, chloroform, ether, petroleum ether, benzene, ethylene glycol, And a combination thereof. [Claim 7] The process according to claim 1, wherein the water-in-oil type emulsion is a water-in-oil emulsion.

The method of claim 3,
Wherein the emulsion is heated to 50 to 100 占 폚.

The method according to claim 1,
Wherein the gas is selected from the group consisting of nitrogen, oxygen, carbon dioxide, hydrogen, argon, neon, creep tones, helium, xenon and combinations thereof.

The method according to claim 1,
Wherein the gas injection amount is 1 to 20 vvm.