A continuous fatty acid separation system

Abstract

The present application relates to a kind of fatty acid continuous separation system, utilize the different separation adsorption material to different saturation fatty acid adsorption ability different characteristics, realize the continuous separation of fatty acid on separation device, reach the accurate separation of different carbon chain length C12-C24 fatty acid, different double bond number fatty acid.The system can separate saturated fatty acid, unsaturated fatty acid and monounsaturated fatty acid, polyunsaturated fatty acid in fatty acid gradually, continuously;And saturated fatty acid separation rate is as high as 85% or more, unsaturated fatty acid separation rate is as high as 90% or more, wherein monounsaturated fatty acid separation rate is as high as 85% or more, polyunsaturated fatty acid separation rate is as high as 85% or more, with excellent market application prospect.

Description

Technical Field

[0001] This invention belongs to the field of fatty acid purification and separation, and specifically relates to a continuous fatty acid separation system. Background Technology

[0002] Fatty acids are long aliphatic hydrocarbon chains containing a carboxyl group at one end. There are many types of fatty acids, which can be divided into saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. Saturated fatty acids are mainly used in the manufacture of cleaning agents, pharmaceuticals, and food; monounsaturated fatty acids are mainly used in the soap, paint, plastics, and rubber industries; and polyunsaturated fatty acids are mainly used in health products, cosmetics, pharmaceuticals, and food industries. Woody industrial oilseed oils, such as rubber tree seed oil, scleroderma seed oil, agarwood seed oil, and litsea cubeba seed oil, contain not only saturated fatty acids like palmitic acid and stearic acid, but also rich in unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid. Separating the mixed fatty acids prepared from these raw materials, and even further separating and purifying monounsaturated fatty acids (e.g., oleic acid) and polyunsaturated fatty acids (e.g., linoleic acid and linolenic acid), is key to developing high-value-added chemicals and health products from woody industrial oils.

[0003] Researchers have developed numerous fatty acid separation techniques, such as urea inclusion complexation, low-temperature crystallization, solvent extraction, molecular distillation, and supercritical fluid extraction. However, these techniques currently only achieve partial separation of fatty acids and cannot separate saturated, monounsaturated, and polyunsaturated fatty acids in a fractional manner. For example, urea inclusion complexation can only separate polyunsaturated fatty acids, not saturated or monounsaturated fatty acids; low-temperature crystallization is often used to separate saturated and unsaturated fatty acids, but cannot separate monounsaturated and polyunsaturated fatty acids in a fractional manner; furthermore, molecular distillation is time-consuming and high-temperature, easily causing thermosensitive reactions in fatty acids, affecting product quality and efficiency; supercritical fluid extraction, due to its intermittent extraction equipment, has a complex production process and low efficiency. Using these separation techniques not only results in the loss of most fatty acids, leading to low separation efficiency, but also prevents continuous separation and even more so, continuous fractional separation of fatty acids, resulting in low production efficiency and hindering industrial-scale application.

[0004] For example, patent application CN102811781A discloses a simulated moving bed chromatography separation method for purifying polyunsaturated fatty acids. The method includes introducing the feed mixture into a simulated or actual moving bed chromatography apparatus having multiple connected columns containing an aqueous alcohol as eluent. The apparatus has multiple zones including at least a first zone and a second zone, each zone having an extract stream and a retrieval stream, capable of collecting liquid from the extract stream and the retrieval stream from the multiple connected columns. Specifically, (a) a retrieval stream containing the PUFA product along with a more polar component is collected from the columns in the first zone and introduced into a non-adjacent column in the second zone; and / or (b) an extract stream containing the PUFA product along with a less polar component is collected from the columns in the second zone and introduced into a non-adjacent column in the first zone, thereby separating the PUFA product from different components of the feed mixture in each zone.

[0005] This method is only suitable for separating binary mixtures, that is, separating highly polar fatty acids from weakly polar fatty acids. It cannot separate saturated fatty acids from unsaturated fatty acids, thus limiting the separation range. Moreover, the liquid collected by the extraction or residual liquid stream needs to be recycled back to the first or second zone for repeated separation, which is quite cumbersome due to the multiple cycles.

[0006] Compared with the separation technologies mentioned above, ion complexation technology based on π-bond complexation is a promising fatty acid separation technology for industrial application due to its advantages such as simple operation, mild operating conditions, and ease of continuous separation. Therefore, based on the structure and properties of saturated and unsaturated fatty acids, as well as the degree of unsaturation of unsaturated fatty acids, there is potential market demand for developing continuous separation processes. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems existing in the continuous separation of fatty acids and to provide a continuous separation system for fatty acids. This system achieves continuous coupling separation of fatty acids by segmenting the chromatographic column according to the different adsorption and separation performance of different fatty acids and adsorbents, which is conducive to the industrial promotion of fatty acid fractionation separation.

[0008] The specific plan is as follows:

[0009] A continuous fatty acid separation system includes a separation device. The separation device includes a power unit and a drive shaft connected to its center. The power unit is fixedly connected to a frame and drives the drive shaft to rotate, thereby causing the separation columns connected to the drive shaft to perform circumferential motion. The center of the turntable is sleeved on the drive shaft, and there are circular holes along the outer circumference of the turntable corresponding to the number and size of the separation columns. Multiple separation columns are sequentially inserted through the circular holes of the turntable, so that they rotate together with the turntable when the drive shaft drives the turntable.

[0010] The separation column is equipped with a feed inlet and a discharge inlet. The feed inlet is connected to a distribution plate installed on the top of the separation column. The distribution plate is electrically connected to a digital display control device and also communicates with a piping panel. The piping panel has multiple feed inlets and multiple discharge outlets for material input and output, corresponding one-to-one with the separation column. The distribution plate is connected to the feed inlet of the piping panel via a flexible hose, and the discharge inlet of the separation column is connected to the discharge outlet of the piping panel via a flexible hose. During operation, the piping panel connects to the feed inlets or discharge outlets of different separation columns according to the separation process. The piping panel is also equipped with a pump port, which is connected to a peristaltic pump to control the material flow rate.

[0011] The material to be separated is fed into the separation device, and the separation column of the separation device is divided into at least two separation systems according to the arrangement order. Each separation system includes an adsorption separation zone, an elution zone, and a washing zone. The adsorption separation zone is used to adsorb and separate the input material, and the liquid flowing out after passing through the adsorption separation zone is an unsaturated fatty acid product.

[0012] The unsaturated fatty acid product enters the elution zone, and the liquid flowing out after elution is the saturated fatty acid product. The saturated fatty acid product enters the cleaning zone and flows out of the system after cleaning, thereby achieving continuous separation in a single system; or, the unsaturated fatty acid product is used as raw material to enter the next separation system, and flows out of the system after being processed by the adsorption separation zone, the elution zone and the cleaning zone, respectively, thereby achieving continuous coupled separation.

[0013] Furthermore, the separation system consists of separation system 1 and separation system 2, and the separation column, the feed inlet, and the discharge outlet are numbered sequentially as 1, 2, ..., 2N-1, 2N, where N is a positive integer, preferably 10 < N < 20;

[0014] The separation system 1 consists of separation columns numbered odd, and the separation system 2 consists of separation columns numbered even. Before the separation device is in operation, separation column 1 corresponds to feed port 1. Each time the distribution plate rotates once, the separation column will be connected to the next feed port in the same system. When the first separation column of the separation system 1 reaches the Nth discharge port, the separation system 2 starts to work.

[0015] When the separation system 2 starts working, the N-1 separation column is connected to the No. 2 feed inlet. Before the separation system 2 starts working, the No. 2 feed inlet is connected to the No. N discharge outlet. In this way, after the material passes through the separation system 1, the unadsorbed unsaturated fatty acids flow into the separation system 2, and the separation column in the separation system 1 that adsorbs saturated fatty acids enters the elution zone in the separation system 1. Thus, saturated fatty acids and unsaturated fatty acids are separated, realizing graded continuous coupling separation.

[0016] Saturated fatty acids are washed out in the elution zone of separation system 1, while unsaturated fatty acids enter the separation zone of separation system 2. When the first separation column of separation system 2 reaches the last discharge port N+1 of the separation zone, the unadsorbed monounsaturated fatty acids flow out. The separation column in separation system 2 that adsorbs polyunsaturated fatty acids enters the elution zone of separation system 2. At this point, monounsaturated fatty acids and polyunsaturated fatty acids are separated. The monosaturated fatty acids flow out of the system after being eluted in the elution zone of separation system 2.

[0017] Furthermore, in the adsorption separation zone of the separation system 1, 3-8 fixed-end valve ports are connected in series for material input and output. The separation column is filled with a composite separation material of melamine and polydimethylsiloxane. The elution liquid in the elution zone is ethyl acetate or n-hexane, and the flow rate is 5-10 ml / min.

[0018] Furthermore, the 2-5 fixed-end valve ports connected in series in the adsorption separation zone of the separation system 2 are used for material input and output. The separation column is filled with metal complex adsorption separation material, preferably a bimetallic complex adsorption separation material of silver and aluminum. The elution liquid in the elution zone is acetone or 1-hexene, and the flow rate is 5-10 ml / min.

[0019] Furthermore, the cleaning zones of separation system 1 and / or separation system 2 are connected in series with 1-2 fixed-end valve ports for material input and output. The cleaning liquid is methanol, and the liquid flow rate is 5-10 ml / min.

[0020] Furthermore, the adsorption separation zone of the separation system 1 and / or the separation system 2 contains 3-5 separation columns, the elution zone contains 2-4 separation columns, and the washing zone contains 1-2 separation columns, with each separation column filled with 50-150g of adsorption separation material.

[0021] Furthermore, during the operation of the separation device, the distribution plate rotates clockwise and the separation column rotates counterclockwise. Each rotation moves 2-5 steps, with one step corresponding to one separation column. The device rotates once every 20-60 minutes, meaning that the time interval between adjacent separation columns completing the same process node is 20-60 minutes.

[0022] Furthermore, after the material to be separated passes through separation system 1, saturated fatty acids and unsaturated fatty acids are separated, with a separation rate of 85-95% for saturated fatty acids and 90-95% for unsaturated fatty acids.

[0023] Furthermore, after passing through separation system 2, unsaturated fatty acids are separated into monounsaturated fatty acids and polyunsaturated fatty acids, with a separation rate of 85-90% for monounsaturated fatty acids and 85-94% for polyunsaturated fatty acids.

[0024] Beneficial effects: Compared with traditional methods, the fatty acid continuous separation system of the present invention innovatively utilizes different separation materials to assemble fatty acids with different adsorption and separation properties, realizing continuous and coupled adsorption and separation of fatty acids. The separation efficiency of saturated fatty acids is over 85%, and the separation rate of unsaturated fatty acids is over 90%, of which the separation rate of monounsaturated fatty acids is over 85%, and the adsorption and separation efficiency of polyunsaturated fatty acids is over 85%.

[0025] More importantly, the system enables continuous fractional separation of saturated fatty acids from unsaturated fatty acids, monounsaturated fatty acids, and polysaturated fatty acids. By using different eluents, it can achieve precise separation of C12-C24 fatty acids with different carbon chain lengths and fatty acids with different double bond numbers, thereby enhancing the value and application scope of fatty acids.

[0026] The existing fatty acid separation method, such as the separation method in CN102811781A, is based on the theory that the polarity of fatty acid components affects the adsorption performance of solid adsorbents. That is, the stronger the polarity of fatty acids, the weaker the adsorption, and vice versa. Thus, separation is achieved when fatty acids flow through the chromatographic column. At the same time, the rate at which the liquid collected by the extract flow and the raffinate flow in each zone is recycled back to the same zone is adjusted so that the PUFA product can be separated from the different components of the feed mixture in each zone.

[0027] The theoretical basis for fatty acid separation in this invention is that the degree of unsaturation of fatty acids affects the adsorption performance of solid adsorbents. In the first circulation system of this invention, the chromatographic column in the separation zone is filled with melamine-polydimethylsiloxane adsorption and separation material. This material adsorbs saturated fatty acids, and the separation of saturated and unsaturated fatty acids is achieved through the first circulation system. In the second circulation system of this invention, the chromatographic column in the separation zone is filled with Ag. + -Al3+ The / SCA-DE bimetallic complex adsorption separation material adsorbs polyunsaturated fatty acids, and then separates monounsaturated fatty acids from polyunsaturated fatty acids through a second circulation system.

[0028] Furthermore, this invention innovates the specific separation method. The chromatographic column is divided into different circulation systems as needed. The separated liquid or eluent from each system (i.e., the liquid collected by the extraction or retentate streams mentioned in patent CN102811781A) does not need to be recycled back to the same system for repeated separation, achieving single-stage or fractional separation. In patent CN102811781A, the liquids collected by the extraction or retentate streams in the first and second zones need to be recycled back to the first or second zone for repeated separation, resulting in multiple cycles and inconvenience.

[0029] Furthermore, this invention innovates the design of the separation zone (or system). For example, in a specific embodiment of this invention, the separation device has 30 chromatographic columns (not limited to 30). Each column is randomly assigned to a separation system according to the separation process and number of steps required. The number of columns in each separation system is not fixed, and the columns are not adjacent. Each separation system includes separation, elution, and washing functions. In contrast, in invention patent CN102811781A, the moving bed chromatography device has 15 chromatographic columns (or more). The number of columns in the first and second zones is fixed and similar, and the columns are adjacent. Each zone includes separation and elution functions.

[0030] Finally, from the perspective of separation applicability, existing technologies are generally only suitable for separating binary mixtures, that is, separating highly polar fatty acids from weakly polar fatty acids, and cannot separate saturated fatty acids from unsaturated fatty acids, such as invention patent CN102811781A.

[0031] This invention is applicable to the graded separation of mixed fatty acids (containing saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids), and can achieve graded separation of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids with a higher degree of separation and wider applicability. Attached Figure Description

[0032] To more clearly illustrate the technical solution of the present invention, the accompanying drawings will be briefly described below. Obviously, the drawings described below only relate to some embodiments of the present invention and are not intended to limit the present invention.

[0033] Figure 1 This is a schematic diagram of the overall structure of the separation device provided in one embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of continuous coupling separation provided in one embodiment of the present invention;

[0035] Figure 3 This is a flowchart of the continuous coupling and separation of fatty acids provided in one embodiment of the present invention (2 steps / time);

[0036] Figure 4 This is a schematic diagram of the working flow of the separation system 1 provided in one embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the working flow of the separation system 2 provided in one embodiment of the present invention. Detailed Implementation

[0038] Preferred embodiments of the present invention will now be described in more detail. While preferred embodiments of the present invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Where specific techniques or conditions are not specified in the embodiments, they are performed in accordance with techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products. In the following embodiments, unless otherwise specified, "%" refers to mass percentage.

[0039] The main adsorbent materials used in the following examples are as follows:

[0040] The melamine-polydimethylsiloxane (Mel-PDMS) composite adsorption and separation material is prepared as follows:

[0041] Melamine and ethanol were stirred at 70°C for 1 hour to form a homogeneous solution. The pH of the solution was then adjusted to 8.0, and dimethylsiloxane and triethylamine were added. The mass ratio of melamine to dimethylsiloxane and triethylamine was 4:1:0.02. The reaction was carried out for 3 hours. After washing with deionized water until neutral, the solution was vacuum dried at 80°C for 5 hours to obtain melamine-polydimethylsiloxane adsorption and separation material, namely Mel-PDMS.

[0042] Bimetallic complex adsorption separation material Ag + -Al 3+ / SCA-DE, the specific preparation method is as follows:

[0043] 1) At 50°C, a certain mass of diatomaceous earth (DE) was added to hexane and stirred thoroughly for 4 hours. Then, an ethanol solution of N,N-diethyl-3-aminopropyltrimethoxysilane was slowly added dropwise to the mixture. The total mass ratio of diatomaceous earth to N,N-diethyl-3-aminopropyltrimethoxysilane was 1:8. The mixture was refluxed at 80°C for 12 hours, then washed with anhydrous ethanol and filtered. This process was repeated three times. The mixture was then dried at 100°C for 12 hours to obtain the SCA-DE material.

[0044] 2) Weigh an appropriate amount of modified diatomaceous earth SCA-DE and dissolve it in dioxane. The mass ratio of SCA-DE to dioxane is 1:5. Then, add a certain mass of anhydrous AlCl3 ethanol solution of carbon disulfide, stir thoroughly, filter, wash with dioxane and deionized water, and check until no Cl is detected. - Al was obtained after vacuum drying. 3+ / SCA-DE material.

[0045] 3) Take an appropriate amount of Al 3+ SCA-DE material was dissolved in acetone, a certain mass of AgF4 was added, and the mixture was stirred in the dark for 10-16 hours. After filtration, the mixture was washed with acetone and deionized water until no AgF4 was detected. - Ag was obtained by vacuum drying at 70°C for 6 hours. + -Al 3+ / SCA-DE bimetallic complex adsorption separation material.

[0046] Example 1

[0047] A continuous coupling separation device for fatty acids, such as Figure 1 As shown: It includes a power unit 1 and a drive shaft 2 connected to its center. The drive shaft 2 is fixedly connected to the frame 4. The power unit 1 drives the drive shaft 2 to rotate, thereby driving the separation column 5 to make a circular motion.

[0048] The center of the turntable 6 is fitted onto the drive shaft 2. Around the outer circumference of the turntable 6 are circular holes corresponding to the number and size of the separating columns 5. The separating columns 5 are sequentially inserted through these holes, so that when the drive shaft 2 drives the separating columns to rotate, the turntable 6 rotates along with them. The separating column support ring and the turntable 6 provide stable support for the separating columns 5. Each separating column 5 has upper and lower feed ports. The upper feed port of the separating column 5 is connected to the distribution plate 7 mounted on the top. The distribution plate 7 is connected to the feed inlet 10 of the piping panel 9 via a flexible hose. The lower feed port of the separating column 5 is connected to the discharge port 11 of the piping panel 9 via a flexible hose. During operation, the piping panel 9 flexibly connects the feed ports of different separating columns 5 according to the separation process, thereby allocating each separating column to different separation systems.

[0049] To ensure stable separation results, a temperature control belt is installed at the bottom of the separation column 5 for heating or heat preservation.

[0050] The distribution plate 7 is electrically connected to the digital display control device 8 and also connected to the piping panel 9. The piping panel 9 has multiple feed inlets 10 and multiple discharge outlets 11 for material input and output. The feed inlets 10 are connected to the top of the separation column 5 through the distribution plate 7 to complete the feeding. The bottom of the separation column 5 is connected to the discharge outlets 11 to output the separated products to the system or to achieve segmented gradation of different separation systems. The piping panel 9 is also equipped with a pump port 12, which is connected to a peristaltic pump 13 to control the flow rate of the material.

[0051] The device operates as follows: the mixed fatty acids to be separated enter the system through the feed inlet 10, and under the action of the peristaltic pump 13, they are transported through the distribution plate 7 to a certain separation column 5 for adsorption, elution and other treatments. After the treatment is completed, they are output through the discharge outlet 11.

[0052] Example 2

[0053] Based on Example 1, this embodiment further introduces a continuous coupling separation device for fatty acids, which includes 30 separation columns 5, numbered sequentially from 1 to 30.

[0054] Accordingly, the device includes 30 feed inlets, numbered 1-30 in sequence; and 30 discharge outlets, numbered 1-30 in sequence.

[0055] The method for continuous separation of fatty acids using the above-mentioned separation device specifically includes the following steps:

[0056] 1) The mixed fatty acids are fed into a counterclockwise rotating fatty acid continuous coupling separation device;

[0057] 2) The fixed end of the distribution plate of the fatty acid continuous coupling separation device is divided into a segmented gradation separation zone, an elution zone, and a washing zone in a counterclockwise direction according to the separation process requirements. The separation columns all adopt a counterclockwise column inlet method. The inlet and outlet of the distribution plate are numbered counterclockwise, and the distribution plate rotates clockwise in the opposite direction to the column inlet.

[0058] like Figure 2As shown, the separation column is divided into two separation systems according to process requirements: Separation System 1 and Separation System 2. The fixed end of the distribution plate, corresponding to the feed inlet, is divided into functional areas based on the number of separation stages and the number of rotations per cycle. Unsaturated fatty acids separated in Separation System 1 flow into Separation System 2 through the outlet, where they are separated from saturated fatty acids. The adsorbed saturated fatty acids move with the separation column in Separation System 1 and enter the elution zone, where they are eluted. The separation column in Separation System 1 continues to move and enters the cleaning zone, where impurities are washed out. Thus, Separation System 1 completes the separation process for saturated fatty acids. The unsaturated fatty acids flowing into Separation System 2 enter its separation zone. After adsorption and separation, monounsaturated fatty acids flow out, while polyunsaturated fatty acids are adsorbed and move with the separation column into the elution zone, where they are eluted. The separation column in Separation System 2 continues to move and enters the cleaning zone, where impurities are washed out. Thus, Separation System 2 completes the separation process for monounsaturated and polysaturated fatty acids.

[0059] Figure 3 The specific flow chart for the continuous coupling separation of fatty acids shows that Mel-PDM separation material is first filled into the separation column of separation system 1, and the bimetallic complex adsorption separation material Ag is used. + -Al 3+ / SCA-DE is filled into the separation column of separation system 2, and then the separation equipment starts to operate. The specific separation process is as follows:

[0060] Mixed fatty acids are fed into the fractional gradation separation zone through inlet 1. After passing through the separation column in separation system 1, unsaturated fatty acids flow out through outlet 15 and enter separation system 2 through inlet 2 for further fractionation. Saturated fatty acids adsorbed in separation system 1 enter the elution zone along with the separation column. The eluent flows into separation system 1 through inlets 17, eluting the saturated fatty acids from the separation column. The eluent flows out through outlet 25, is collected, and distilled to obtain high-purity saturated fatty acids. The separation column in separation system 1 then moves to the washing zone, and after washing, moves to the fractional gradation separation zone, still in the form of separation system 1, to begin a new round of separation.

[0061] Unsaturated fatty acids entering separation system 2 through inlet 2 pass through the separation column of separation system 2. The monounsaturated fatty acid liquid flows out from outlet 16 and is collected and distilled to obtain high-purity monounsaturated fatty acids. The adsorbed polyunsaturated fatty acids enter the elution zone of separation system 2 along with the separation column. The eluent enters through inlets 18 and so on, eluting the polyunsaturated fatty acids. It flows out from outlet 26 and is collected and distilled to obtain high-purity polyunsaturated fatty acids. The separation column in separation system 2 continues to move to the cleaning zone. After cleaning, it moves to the segmented gradation separation zone, still in the form of separation system 2, to start a new round of separation.

[0062] Figure 4 This is a schematic diagram of the working flow of separation system 1. Figure 4 The separation system 1 shown has 8 separation columns (column numbers 1, 3, 5, 7, 9, 11, 13, 15). Mel-PDM separation material is filled into the separation columns of separation system 1. The separation equipment operates in 2 steps per cycle, with each separation column moving counter-clockwise. The number of separation columns and the number of steps per cycle can be flexibly adjusted according to specific separation process requirements. The specific operating procedure is as follows:

[0063] Mixed fatty acids are fed into the separation column of the segmented gradation separation zone through inlet 1. The sequence of the separation columns is shown in the figure. The separation columns enter the segmented gradation separation zone sequentially. After 14 steps, the last separation column, column 15, enters the segmented gradation separation zone. At this point, all separation columns are in the segmented gradation separation zone. The residence time of separation column 1 in this zone is 14 / 2 min (time interval between each movement), completing the adsorption and separation of mixed fatty acids. Saturated fatty acids are adsorbed, and unsaturated fatty acids flow into separation system 2 through outlet 15. Separation column 1 continues to move. After 2 steps, separation column 1 enters the elution zone. The eluent enters separation column 1 through inlet 17 to begin eluting the adsorbed saturated fatty acids. Each time there are 2 steps, it is connected to inlets 19, 21, 23, and 25 for elution. After 8 steps, separation column 1 moves to the final stage of the elution zone. At the boundary between the elution zone and the washing zone, the liquid containing saturated fatty acids and eluent eluted from column 1 flows out through outlet 25, which is fatty acid 1. After collection and distillation, high-purity saturated fatty acids can be obtained. Column 1 continues to move, and after two steps, it enters the washing zone. The washing liquid flows into column 1 through inlets 27 and 29, and then exits through outlet 29. At this point, column 1 completes one complete separation process of separation system 1. The other separation columns sequentially undergo the same separation, elution, and washing process as column 1. When each separation column completes one complete separation process, it moves sequentially from the washing zone to the segmented gradation separation zone in two steps to begin a new round of separation process of separation system 1.

[0064] Figure 5This is a schematic diagram of the working flow of separation system 2. Figure 5 The separation system 2 shown consists of 8 separation columns (column numbers: 14, 16, 18, 20, 22, 24, 26, 28), with Ag as the bimetallic complex adsorption separation material. + -Al 3+ / SCA-DE is filled into the separation column of separation system 2. The separation equipment operates in two steps per cycle, with each separation column moving counter-clockwise. The number of separation columns and the number of steps per cycle can be flexibly adjusted according to specific separation process requirements. The specific operating procedure is as follows:

[0065] The unsaturated fatty acid liquid flowing out of outlet No. 15 of separation system 1 is conveyed into the separation column of the segmented gradation separation zone of separation system 2 through inlet No. 2. The sequence of each separation column is shown in the figure. The separation columns enter the segmented gradation separation zone in sequence. After 14 steps, the last separation column No. 28 enters the segmented gradation separation zone. At this time, all separation columns have entered the segmented gradation separation zone. At this point, the residence time of separation column 14 in this zone is 14 / 2 (min) * interval of each movement, completing the adsorption and separation of monounsaturated fatty acids. Polyunsaturated fatty acids are adsorbed, and the monounsaturated fatty acids flow out through outlet 16. Fatty acid 2 is collected and distilled to obtain high-purity monounsaturated fatty acids. Separation column 14 continues to move. After two steps, separation column 14 enters the elution zone. The eluent enters separation column 14 through inlet 18 to begin eluting the adsorbed polyunsaturated fatty acids. Each time there are two steps, it is sequentially connected to inlets 20, 22, 24, and 26 for elution. After eight steps, separation column 14... The separation column moves to the final stage of the elution zone, specifically the boundary between the elution and washing zones. At this point, the liquid containing polysaturated fatty acids and eluent eluted from column 14 flows out through outlet 26, which is fatty acid 3. After collection and distillation, high-purity polyunsaturated fatty acids can be obtained. Column 14 continues to move, and after two steps, it enters the washing zone. The washing liquid flows into column 14 through inlets 28 and 30, and then exits through outlet 30. At this point, column 14 completes one complete separation process of separation system 2. The other separation columns sequentially undergo the same separation, elution, and washing process as column 14. Upon completing one complete separation process, each separation column moves sequentially from the washing zone to the segmented gradation separation zone in two steps, beginning a new round of separation process in separation system 2.

[0066] Through the above separation process, continuous coupling separation of fatty acids can be achieved, enabling precise separation of C12-C24 fatty acids with different carbon chain lengths and fatty acids with different double bond numbers.

[0067] Example 3

[0068] Two separation systems were used to separate mixed fatty acids (17% saturated fatty acids, 29% monounsaturated fatty acids, and 54% polyunsaturated fatty acids) from rubber seed oil. The feed rate of the mixed fatty acids from rubber seed oil was 5 ml / min. Each separation system used three chromatographic columns in the separation zone, two columns in the elution zone, and two columns in the washing zone. Separation was carried out at room temperature.

[0069] Separation System 1: Each separation column is filled with 100g of Mel-PDMS. Ethyl acetate with a feed rate of 5ml / min is used to elute the saturated fatty acids of the separation product (in this process, saturated fatty acids are adsorbed, and unsaturated fatty acids flow out from the separation column and enter Separation System 2, the same below). Methanol with a feed rate of 5ml / min is used for washing.

[0070] Separation System 2: Each separation column is filled with 100g Ag + -Al 3+ / SCA-DE1, acetone with a feed rate of 5 ml / min is used to elute and separate the polyunsaturated fatty acids (in this process, monounsaturated fatty acids flow out and polyunsaturated fatty acids are adsorbed, the same below), and methanol is used for washing with a feed rate of 5 ml / min.

[0071] The specific operation is as follows: When starting the separation of mixed fatty acids from rubber seed oil, the fatty acid continuous coupling separation column is rotated counterclockwise, 5 steps at a time, rotating once every 30 minutes. The entire separation system completes one complete process in about 3 hours, and the time interval between the completion of one process between adjacent columns is 30 minutes. After collection, each separated product is purified by conventional vacuum distillation.

[0072] Under the above raw material usage and process conditions, the feed amount of mixed fatty acids from rubber seed oil is 300 ml per hour. After passing through separation system 1, 44 ml of saturated fatty acids and 225 ml of unsaturated fatty acids are separated, with a separation rate of 86.3% for saturated fatty acids and 90.3% for unsaturated fatty acids. After passing through separation system 2, 75.8 ml of monounsaturated fatty acids and 145 ml of polyunsaturated fatty acids are separated, with a separation rate of 87.1% for monounsaturated fatty acids and 89.5% for polyunsaturated fatty acids.

[0073] Example 4

[0074] Using the separation apparatus described in Example 2, the mixed fatty acids (14% saturated fatty acids, 22% monounsaturated fatty acids, and 64% polyunsaturated fatty acids) of *Gnaphalium affine* seed oil were separated using its two separation systems. The feed rate of the mixed fatty acids from *Gnaphalium affine* seed oil was 10 ml / min. Each separation system used 8 chromatographic columns in the separation zone, 5 columns in the elution zone, and 2 columns in the washing zone. Separation was performed at room temperature.

[0075] Separation System 1: Each separation column is filled with 100g of Mel-PDMS separation adsorption material. The saturated fatty acid products are eluted with n-hexane at a feed rate of 10ml / min and washed with methanol at a feed rate of 10ml / min.

[0076] Separation System 2: Each separation column is filled with 100g Ag + -Al 3+ The SCA-DE separation and adsorption material was used to elute the polyunsaturated fatty acids by feeding 10 ml / min of 1-hexene, and the product was cleaned with methanol at a feed rate of 10 ml / min.

[0077] The specific operation is as follows: When starting the separation of mixed fatty acids from the seed oil of the *Pterocarya stenoptera* tree, the fatty acid continuous coupling separation column is rotated counterclockwise, two steps at a time, rotating once every 30 minutes. The entire separation system completes one complete process in approximately 7.5 hours, with a 30-minute interval between the completion of one process between adjacent columns. After collection, each separated product is purified by conventional vacuum distillation.

[0078] Under the above raw material usage and process conditions, the feed rate of mixed fatty acids from *Gnaphalium affine* seed oil is 10 ml / min, with a feed rate of 600 ml per hour. After passing through separation system 1, 74.3 ml of saturated fatty acids and 482 ml of unsaturated fatty acids are separated, with a separation rate of 88.5% for saturated fatty acids and 93.4% for unsaturated fatty acids. After passing through separation system 2, 114.8 ml of monounsaturated fatty acids and 357.5 ml of polyunsaturated fatty acids are separated, with a separation rate of 86.9% for monounsaturated fatty acids and 93.1% for polyunsaturated fatty acids.

[0079] Example 5

[0080] Using the separation apparatus described in Example 2, the mixed fatty acids (18% saturated fatty acids, 76% monounsaturated fatty acids, and 6% polyunsaturated fatty acids) of agarwood seed oil were separated using its two separation systems. The feed rate of the mixed fatty acids of agarwood seed oil was 8 ml / min. Each separation system used 5 chromatographic columns in the separation zone, 3 chromatographic columns in the elution zone, and 2 chromatographic columns in the washing zone. Separation was carried out at room temperature.

[0081] Separation System 1: Each separation column is filled with 100g of Mel-PDMS separation adsorption material. Ethyl acetate at a feed rate of 8ml / min is used to elute the saturated fatty acid products, and methanol at a feed rate of 8ml / min is used for washing.

[0082] Separation System 2: Each separation column is filled with 100g Ag + -Al3+ The SCA-DE separation and adsorption material was used to elute the polyunsaturated fatty acids by feeding 1-hexene at a rate of 8 ml / min, and then washing with methanol at a rate of 8 ml / min.

[0083] The specific operation is as follows: When starting the separation of mixed fatty acids from agarwood seed oil, the fatty acid continuous coupling separation chromatographic column is rotated counterclockwise, three steps at a time, rotating once every 30 minutes. The entire separation system completes one complete process in approximately 5 hours, with a 30-minute interval between the completion of one process between adjacent columns. After collection, each separated product is purified by conventional vacuum distillation.

[0084] Under the above raw material usage and process conditions, the feed rate of agarwood seed oil mixed fatty acids is 8 ml / min, which is 480 ml per hour. After passing through separation system 1, 74 ml of saturated fatty acids and 356.3 ml of unsaturated fatty acids can be separated, with a separation rate of 85.6% for saturated fatty acids and 90.5% for unsaturated fatty acids. After passing through separation system 2, 322.6 ml of monounsaturated fatty acids and 24.7 ml of polyunsaturated fatty acids can be separated, with a separation rate of 88.4% for monounsaturated fatty acids and 85.7% for polyunsaturated fatty acids.

[0085] Example 6

[0086] Using the separation apparatus described in Example 2, the mixed fatty acids (18% saturated fatty acids, 76% monounsaturated fatty acids, and 6% polyunsaturated fatty acids) of agarwood seed oil were separated using its two separation systems. The feed rate of the mixed fatty acids from litsea cubeba seed oil was 8 ml / min. Each separation system used 5 chromatographic columns in the separation zone, 3 columns in the elution zone, and 2 columns in the washing zone. Separation was carried out at 45°C.

[0087] Separation System 1: Each separation column is filled with 100g of Mel-PDMS separation adsorption material. The saturated fatty acid product is eluted with n-hexane at a feed rate of 8ml / min and washed with methanol at a feed rate of 8ml / min.

[0088] Separation System 2: Each separation column is filled with 100g Ag + -Al 3+ The SCA-DE separation and adsorption material was used to elute the polyunsaturated fatty acids by feeding 1-hexene at a rate of 8 ml / min, and then washing with methanol at a rate of 8 ml / min.

[0089] The specific operation is as follows: When starting the separation of mixed fatty acids from agarwood seed oil, the fatty acid continuous coupling separation chromatographic column is rotated counterclockwise, three steps at a time, rotating once every 30 minutes. The entire separation system completes one complete process in approximately 5 hours, with a 30-minute interval between the completion of one process between adjacent columns. After collection, each separated product is purified by conventional vacuum distillation.

[0090] Under the above raw material usage and process conditions, the feed amount of mixed fatty acids of agarwood seed oil is 480ml per hour. After passing through separation system 1, 82ml of saturated fatty acids and 362.5ml of unsaturated fatty acids can be separated, with a separation rate of 94.9% for saturated fatty acids and 92.1% for unsaturated fatty acids. After passing through separation system 2, 329.5ml of monounsaturated fatty acids and 25.7ml of polyunsaturated fatty acids can be separated, with a separation rate of 90.0% for monounsaturated fatty acids and 89.4% for polyunsaturated fatty acids.

[0091] Example 7

[0092] Using the separation apparatus described in Example 2, the mixed fatty acids (69% saturated fatty acids, 23% monounsaturated fatty acids, and 8% polyunsaturated fatty acids) of Litsea cubeba seed oil were separated using its two separation systems. The feed rate of the mixed fatty acids was 5 ml / min. Each separation system used 5 chromatographic columns in the separation zone, elution zone capable of simultaneously eluting 3 columns, and washing zone capable of simultaneously washing 2 columns. Separation was performed at 45°C.

[0093] Separation System 1: Each separation column is filled with 100g of Mel-PDMS separation adsorption material. The saturated fatty acids of the separation product are eluted with n-hexane at a feed rate of 5ml / min, and washed with methanol at a feed rate of 5ml / min.

[0094] Separation System 2: Each separation column is filled with 100g Ag + -Al 3+ The SCA-DE separation and adsorption material was used to elute the polyunsaturated fatty acids by feeding 1-hexene at a rate of 5 ml / min, and then washing with methanol at a rate of 5 ml / min.

[0095] The specific operation is as follows: When starting the separation of mixed fatty acids from Litsea cubeba oil, the fatty acid continuous coupling separation column is rotated counterclockwise, three steps at a time, rotating once every 30 minutes. The entire separation system completes one complete process in approximately 5 hours, with a 30-minute interval between the completion of one process between adjacent columns. After collection, each separated product is purified by conventional vacuum distillation.

[0096] Under the above raw material usage and process conditions, the feed amount of mixed fatty acids from Litsea cubeba oil is 300 ml per hour. After passing through separation system 1, 181.5 ml of saturated fatty acids and 87.5 ml of unsaturated fatty acids can be separated, with a separation rate of 87.6% for saturated fatty acids and 94.1% for unsaturated fatty acids. After passing through separation system 2, 59 ml of monounsaturated fatty acids and 20.5 ml of polyunsaturated fatty acids can be separated, with a separation rate of 85.5% for monounsaturated fatty acids and 85.4% for polyunsaturated fatty acids.

[0097] Comparative Example

[0098] Based on Example 4, the following operations are explored:

[0099] 1) With other conditions remaining unchanged, when the feed rate of mixed fatty acids from the seed oil of the *Pterocarya stenoptera* is 15 ml / min:

[0100] The separation rates of saturated fatty acids were 87.5% and unsaturated fatty acids were 82.2%; the separation rates of monounsaturated fatty acids were 76.7% and polyunsaturated fatty acids were 72.6%.

[0101] 2) With other conditions remaining unchanged, when both separation systems use 4 columns in their separation zones, the elution zone can simultaneously elute 3 columns, and the washing zone can simultaneously wash 2 columns:

[0102] The separation rates of saturated fatty acids were 92.6% and unsaturated fatty acids were 74.5%; the separation rates of monounsaturated fatty acids were 65.3% and polyunsaturated fatty acids were 63.2%.

[0103] 3) With other conditions unchanged, when the fatty acid continuous coupling separation column is rotated counterclockwise, 3 steps each time, and once every 70 minutes:

[0104] The separation rates of saturated fatty acids were 80.5% and unsaturated fatty acids were 89.7%; the separation rates of monounsaturated fatty acids were 63.6% and polyunsaturated fatty acids were 71.9%.

[0105] 4) With other conditions unchanged, when the fatty acid continuous coupling separation column is rotated counterclockwise once every 15 minutes:

[0106] The separation rates of saturated fatty acids were 66.7% and unsaturated fatty acids were 60.2%; the separation rates of monounsaturated fatty acids were 72.5% and polyunsaturated fatty acids were 56.1%.

[0107] The above exploration process shows that the number of chromatographic columns, the rotation speed of the chromatographic columns, and the feed flow rate in the separation system all affect the separation efficiency. Therefore, appropriate conditions must be adopted for different separation targets to achieve better fractionation separation results.

[0108] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0109] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0110] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A continuous fatty acid separation system, characterized in that: Includes a separation device, The separation device includes a power unit and a drive shaft connected to its center. The power unit is fixedly connected to the frame and drives the drive shaft to rotate, thereby causing the separation columns connected to the drive shaft to perform circumferential motion. The center of the turntable is sleeved on the drive shaft, and there are circular holes along the outer circumference of the turntable corresponding to the number and size of the separation columns. Multiple separation columns are sequentially inserted through the circular holes of the turntable, so that they rotate together with the turntable when the drive shaft drives the turntable. The separation column is equipped with a feed inlet and a discharge inlet. The feed inlet is connected to a distribution plate installed on the top of the separation column. The distribution plate is electrically connected to a digital display control device and also communicates with a piping panel. The piping panel has multiple feed inlets and multiple discharge outlets for material input and output, corresponding one-to-one with the separation column. The distribution plate is connected to the feed inlet of the piping panel via a flexible hose, and the discharge inlet of the separation column is connected to the discharge outlet of the piping panel via a flexible hose. During operation, the piping panel connects to the feed inlets or discharge outlets of different separation columns according to the separation process. The piping panel is also equipped with a pump port, which is connected to a peristaltic pump to control the material flow rate. The material to be separated is fed into the separation device, and the separation column of the separation device is divided into at least two separation systems according to the arrangement order. Each separation system includes an adsorption separation zone, an elution zone, and a washing zone. The adsorption separation zone is used to adsorb and separate the input material, and the liquid flowing out after passing through the adsorption separation zone is an unsaturated fatty acid product. The unsaturated fatty acid product enters the elution zone, and the liquid flowing out after elution is the saturated fatty acid product. The saturated fatty acid product enters the cleaning zone for cleaning before flowing out of the system, thus achieving continuous separation in a single system; or, the unsaturated fatty acid product is used as raw material to enter the next separation system, and flows out of the system after being processed by the adsorption separation zone, the elution zone, and the cleaning zone, thus achieving continuous coupled separation; the separation system consists of separation system 1 and separation system 2, and the separation column, the inlet, and the outlet are numbered sequentially as 1, 2, ..., 2N-1, 2N, where N is a positive integer; The separation system 1 consists of separation columns numbered odd, and the separation system 2 consists of separation columns numbered even. Before the separation device is in operation, separation column 1 corresponds to feed port 1. Each time the distribution plate rotates once, the separation column will be connected to the next feed port in the same system. When the first separation column of the separation system 1 reaches the Nth discharge port, the separation system 2 starts to work. When the separation system 2 starts working, the N-1 separation column is connected to the No. 2 feed inlet. Before the separation system 2 starts working, the No. 2 feed inlet is connected to the No. N discharge outlet. In this way, after the material passes through the separation system 1, the unadsorbed unsaturated fatty acids flow into the separation system 2, and the separation column in the separation system 1 that adsorbs saturated fatty acids enters the elution zone in the separation system 1. Thus, saturated fatty acids and unsaturated fatty acids are separated, realizing graded continuous coupling separation. Saturated fatty acids are washed out in the elution zone of separation system 1, while unsaturated fatty acids enter the separation zone of separation system 2. When the first separation column of separation system 2 reaches the last discharge port N+1 of the separation zone, the unadsorbed monounsaturated fatty acids flow out. The separation column in separation system 2 that adsorbs polyunsaturated fatty acids enters the elution zone of separation system 2. At this point, monounsaturated fatty acids and polyunsaturated fatty acids are separated. The monosaturated fatty acids flow out of the system after being eluted in the elution zone of separation system 2. In separation system 1, the separation column is filled with a composite separation material of melamine and polydimethylsiloxane, and the eluent in the elution zone is ethyl acetate or n-hexane; in separation system 2, the separation column is filled with a metal complex adsorption separation material, and the eluent in the elution zone is acetone or 1-hexene.

2. The fatty acid continuous separation system according to claim 1, characterized in that: 10＜N＜20。 3. The fatty acid continuous separation system according to claim 2, characterized in that: In the adsorption separation zone of the separation system 1, 3-8 fixed-end valve ports are connected in series for material input and output, and the elution liquid flow rate in the elution zone is 5-10 ml / min.

4. The fatty acid continuous separation system according to claim 2, characterized in that: The separation system 2 has 2-5 fixed-end valves connected in series in the adsorption separation zone for material input and output. The separation column is filled with a bimetallic complex adsorption separation material composed of silver and aluminum. The elution liquid flow rate in the elution zone is 5-10 ml / min.

5. The fatty acid continuous separation system according to claim 3 or 4, characterized in that: The cleaning zones of separation system 1 and / or separation system 2 are connected in series with 1-2 fixed-end valve ports for material input and output. The cleaning liquid is methanol, and the liquid flow rate is 5-10 ml / min.

6. The fatty acid continuous separation system according to claim 3 or 4, characterized in that: The adsorption separation zone of the separation system 1 and / or the separation system 2 contains 3-5 separation columns, the elution zone contains 2-4 separation columns, and the washing zone contains 1-2 separation columns. Each separation column is filled with 50-150g of adsorption separation material.

7. The fatty acid continuous separation system according to claim 6, characterized in that: When the separation device is in operation, the distribution plate rotates clockwise and the separation column rotates counterclockwise. Each rotation moves 2-5 steps, with one step corresponding to one separation column. The device rotates once every 20-60 minutes, meaning that the time interval between adjacent separation columns completing the same process node is 20-60 minutes.

8. The fatty acid continuous separation system according to claim 7, characterized in that: After passing through separation system 1, the material to be separated is separated into saturated fatty acids and unsaturated fatty acids. The separation rate of saturated fatty acids is 85-95%, and the separation rate of unsaturated fatty acids is 90-95%.

9. The fatty acid continuous separation system according to claim 8, characterized in that: After passing through separation system 2, unsaturated fatty acids are separated into monounsaturated fatty acids and polyunsaturated fatty acids. The separation rate of monounsaturated fatty acids is 85-90%, and the separation rate of polyunsaturated fatty acids is 85-94%.

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