Extraction system

Abstract

To provide a system capable of reliably extracting polysaccharides from biomass, where a configuration for extracting polysaccharides from biomass is embodied as an extraction system.SOLUTION: An extraction system 10 is for extracting polysaccharides from biomass BM. The extraction system 10 according to an embodiment of the present invention includes: an extractor 11 into which the biomass BM and an extraction fluid EF for extracting the polysaccharides from the biomass BM are introduced; and a separator 12 for separating, from the extraction fluid EF, the polysaccharides extracted by the extraction fluid EF in the extractor 11. The extraction fluid EF includes carbon dioxide in a supercritical state, and a co-solvent, where the co-solvent contains ethanol in an amount greater than 5% with respect to the extraction fluid EF.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an extraction system for extracting polysaccharides from biomass. [Background technology]

[0002] Conventionally, methods for extracting polysaccharides from biomass have been known. For example, the aloe extract described in Patent Document 1 below contains polysaccharides. This aloe extract is extracted with any suitable solvent, including supercritical carbon dioxide, water, methanol, ethanol, acetone, alcohol, a water-mixed solvent, or a combination thereof.

[0003] Patent Document 2 below discloses a method for extracting active ingredients from oleander leaves. The active ingredients are extracted using a mixture of carbon dioxide and 5% ethanol as an extraction fluid under conditions of a pressure of 28 MPa and a temperature of 50°C. Under these conditions, it is presumed that the carbon dioxide in the extraction fluid is in a supercritical state. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. WO2022 / 015559 [Patent Document 2] International Publication No. WO2021 / 201903 Summary of the Invention [Problem to be solved by the invention]

[0005] In this way, by using supercritical carbon dioxide as the extraction fluid, the extraction fluid can easily penetrate into the biomass, making it easier for specific components to dissolve in the extraction fluid. Therefore, even when extracting components that are sensitive to heat, deterioration can be suppressed. Furthermore, by reducing the pressure after extraction, the extraction fluid can be easily desorbed. As a result, components can be easily extracted from biomass.

[0006] However, the above-mentioned patent documents do not provide specific details regarding the extraction. In particular, there is thought to be room for improvement in order to reliably extract polysaccharides from biomass.

[0007] In view of the above, an object of the present invention is to provide an extraction system for extracting polysaccharides from biomass, which can reliably extract polysaccharides. [Means for solving the problem]

[0008] The technical solution of the present invention to solve this technical problem is characterized as follows. The extraction system of the present invention is for extracting polysaccharides from biomass. The extraction system of the present invention includes an extractor into which the biomass and an extraction fluid for extracting the polysaccharides from the biomass are input, and a separator for separating the polysaccharides extracted by the extraction fluid in the extractor from the extraction fluid. The extraction fluid includes carbon dioxide in a supercritical state and a co-solvent, and the co-solvent includes ethanol in an amount greater than 5% of the extraction fluid.

[0009] In the extraction system of the present invention, the co-solvent comprises ethanol in an amount greater than 5% and less than or equal to 10% of the extraction fluid.

[0010] In the extraction system of the present invention, the biomass input into the extractor contains aloe gel derived from an aloe plant, and the polysaccharides separated in the separator contain acemannan as a majority compound.

[0011] In the extraction system of the present invention, the separator is composed of a plurality of separators, a first separator is connected to the extractor, and the extraction fluid containing the extracted polysaccharides is introduced from the extractor, and a second separator is connected to the first separator, and the extraction fluid containing the extracted polysaccharides is introduced from the first separator, and the polysaccharides are separated in each of the separators.

[0012] In the extraction system of the present invention, the extraction in the extractor and the separation in the separator are operated in any one of a batch mode, a semi-batch mode, and a continuous flow mode. [Effects of the Invention]

[0013] According to the present invention, a configuration for extracting polysaccharides from biomass is embodied as an extraction system, which can reliably extract polysaccharides from biomass. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic diagram of an extraction system according to an embodiment of the present invention; [Figure 2] FIG. 2 is a phase diagram of the carbon dioxide and ethanol mixture that constitutes the extraction fluid used in the extraction system shown in FIG. 1. [Figure 3] FIG. 2 illustrates a process and corresponding valve actuation for performing a batch type operation in the extraction system shown in FIG. 1. [Figure 4] FIG. 2 illustrates a process and corresponding valve actuation for performing semi-batch type operation in the extraction system shown in FIG. 1. [Figure 5] FIG. 2 illustrates a process and corresponding valve actuation for performing continuous flow type operation in the extraction system shown in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] As shown in FIG. 1, an extraction system 10 according to an embodiment of the present invention is for extracting polysaccharides from biomass. Here, biomass refers to organic resources derived from living organisms. The resources may be derived from, for example, various types of plants, grains, vegetables, fruits, algae, etc. The plant may be any plant, such as an aloe plant.

[0017] The aloe plant used for the extraction may be any species of aloe plant, for example, Aloe Vera, Aloe arborescens, Aloe Barbadense, Aloe Ferox, etc., and one or more species may be selected and used for the extraction.

[0018] The extraction system 10 includes an extractor 11 and a separator 12. The extractor 11 is configured to receive biomass BM and an extraction fluid EF. When the biomass used is derived from an aloe plant, the biomass BM fed into the extractor 11 may be in any state, such as liquid, solid, semi-solid, gel, or a combination thereof.

[0019] It is preferable that the biomass BM has fluidity from the viewpoints of ease of handling when being introduced into the extractor 11 and improving diffusibility in the extractor 11. For this reason, when an aloe plant is used, it is preferable to use, for example, aloe gel derived from an aloe plant.

[0020] The extractor 11 is a pressure-resistant vessel having a substantially cylindrical shape and may be made of stainless steel or the like. Pipes La1 and La2 are connected to the extractor 11 on the upstream side. The pipes La1 and La2 can communicate with the inside of the extractor 11, respectively. Valves Va1 and Va2 are provided in the pipes La1 and La2.

[0021] When valve Va1 is open, biomass BM (in this example, fluid aloe gel) is introduced into the extractor 11 via pipe La1. When valve Va2 is open, extraction fluid EF is introduced into the extractor 11 via pipe La2. Pipe La2 is equipped with a pump PM and a heat exchanger HE. The extractor 11 is equipped with a pressure gauge PG and a thermometer TC. The temperature and pressure of the extraction fluid EF are adjusted based on the readings of the pressure gauge PG and the thermometer TC, respectively.

[0022] When biomass BM and extraction fluid EF are introduced into the extractor 11, the extraction fluid EF extracts polysaccharides from the biomass BM. The extraction fluid EF contains carbon dioxide in a supercritical state and a co-solvent. The co-solvent contains ethanol in an amount greater than 5% relative to the extraction fluid EF. More specifically, the co-solvent contains ethanol in an amount greater than 5% and less than or equal to 10% relative to the extraction fluid EF. For example, the ethanol content in the extraction fluid EF may be in the range of 10% to 9%, 9% to 8%, 8% to 7%, or 7% to 6%.

[0023] FIG. 2 is a phase diagram for a mixture composed of carbon dioxide and ethanol. The horizontal axis of the phase diagram represents the ethanol content. The left end of the horizontal axis corresponds to an ethanol content of 100% (carbon dioxide content of 0%), and the right end corresponds to an ethanol content of 0% (carbon dioxide content of 100%). The vertical axis of the phase diagram represents the pressure of the mixture composed of carbon dioxide and ethanol. The pressure increases toward the top of the vertical axis.

[0024] Graph G in the phase diagram corresponds to the equilibrium line for a mixture of carbon dioxide and ethanol. Graph G divides the phase into three states: the liquid state, the liquid-gas mixed phase state, and the gas state. In this example, graph G is shown for a temperature of 60°C.

[0025] In this case, the ethanol content at the critical point is approximately 9%. Even if the temperature changes from 60°C, it is preferable that the ethanol content remains in the range of 10% to 5% so that the mixture of carbon dioxide and ethanol is maintained in the critical state.

[0026] As shown in Fig. 1, in the extraction system 10, the separator 12 separates polysaccharides extracted by the extraction fluid EF in the extractor 11 from the extraction fluid EF. The separator 12 is composed of multiple separators. The separator 12 includes a first separator 121 and a second separator 122. In this embodiment, the separator 12 includes two separators, but it is sufficient that the separator 12 includes multiple separators, and it may also include three or more separators.

[0027] The first separator 121 and the second separator 122 are pressure-resistant containers having a substantially cylindrical shape and may be made of stainless steel or the like. The first separator 121 is connected to the extractor 11 via a pipe Lb. The second separator 122 is connected to the first separator 121 via a pipe Lc.

[0028] A pipe Lb is connected to the extractor 11 on the downstream side, and a pipe Lb is connected to the first separator 121 on the upstream side. The pipe Lb can communicate with the interiors of the extractor 11 and the first separator 121, respectively. A pipe Lc is connected to the first separator 121 on the downstream side, and a pipe Lc is connected to the second separator 122 on the upstream side. The pipe Lc can communicate with the interiors of the first separator 121 and the second separator 122, respectively. Valves Vb and Vc are provided in the pipes Lb and Lc.

[0029] When valve Vb is open, the extraction fluid EF containing the extracted polysaccharides is introduced from the extractor 11 through pipe Lb into the first separator 121. When valve Vc is open, the extraction fluid EF containing the extracted polysaccharides is introduced from the first separator 121 into the second separator 122 through pipe Lc.

[0030] The first separator 121 and the second separator 122 are provided with a valve Vd and a valve Ve, respectively. When the valves Vd and Ve are opened, the pressure in the first separator 121 and the second separator 122 is reduced, the extraction fluid EF is vaporized, and polysaccharides are separated from the extraction fluid EF.

[0031] When valve Vd is open, the polysaccharides separated in first separator 121 are taken out from first separator 121 via valve Vd. When valve Ve is open, the polysaccharides separated in second separator 122 are taken out from second separator 122 via valve Ve.

[0032] When the biomass BM is derived from an aloe plant, the polysaccharides separated in the separator 12 may have any chemical structure or molecular weight as long as they have a sugar chain based on a sugar skeleton such as glucose, mannose, or galactose. One sugar chain of the polysaccharide contains at least -OH (hydroxyl group) and -COCH3 (acetyl group).

[0033] More specifically, -OH may be contained in each of the glucose backbone and the mannose backbone constituting the sugar chain. -COCH3 may be contained in the mannose backbone constituting the sugar chain. In one sugar chain of a polysaccharide, the number of -COCH3 may be less than the number of -OH. For example, in one sugar chain, one, two, or three of the -OH of the mannose backbone may be replaced with -COCH3, while the -OH of the glucose backbone is maintained, so that the number of -COCH3 is less than the number of -OH.

[0034] Furthermore, the degree of acetylation in one sugar chain of a polysaccharide is, for example, in the range of 30% to 70%. More specifically, the degree of acetylation may be, for example, in the range of 30% to 45%, 45% to 55%, or 55% to 70%. Here, the degree of acetylation corresponds to the proportion of -OH groups in the mannose backbone that have been replaced with -COCH3. For example, when no -OH groups in the mannose backbone are replaced with -COCH3, the degree of acetylation is zero. When all -OH groups in the mannose backbone are replaced with -COCH3, the degree of acetylation is 100%.

[0035] The polysaccharides separated in separator 12 contain acemannan as a compound in majority. More specifically, the content of acemannan in the polysaccharides may be within the range of 50% to 60%, 60% to 70%, 70% to 80%, 80% to 90%, or 90% to 100%. Note that the polysaccharides may contain polysaccharides other than acemannan.

[0036] Here, in the acemannan, one sugar chain of the polysaccharide may have at least a β(1,4)-mannose backbone and a β(1,4)-glucose backbone. One sugar chain of the polysaccharide includes a sugar chain in which a compound of the following formula (1) or the following formula (2) is repeatedly bonded as a unit. In the following formulas (1) and (2), the β(1,4)-mannose backbone contains -COCH3 (acetyl group). Ac in the above formulas (1) and (2) represents -COCH3. n in the above formulas (1) and (2) represents the degree of polymerization. The degree of polymerization n may be adjusted so that the mass of the sugar chain falls within the above range.

[0037] [ka]

[0038] [ka]

[0039] The compound shown in formula (1) above has four saccharide skeletons, which, from left to right, are a β(1,4)-mannose skeleton, a β(1,4)-mannose skeleton, a β(1,4)-glucose skeleton, and a β(1,4)-mannose skeleton.

[0040] Each mannose skeleton has a ring structure. The ring structure is composed of five carbon atoms (C) and one oxygen atom (O). Starting from the oxygen atom, the five carbon atoms are numbered 1, 2, 3, 4, and 5 clockwise on the paper. The carbon atom bonded to the fifth carbon atom and outside the ring structure is numbered 6.

[0041] In the leftmost β(1,4)-Mannose skeleton, only the -OH corresponding to the C3 is replaced with -COCH3. In the second β(1,4)-Mannose skeleton from the left, only the -OH corresponding to the C2 is replaced with -COCH3. In the rightmost β(1,4)-Mannose skeleton, only the -OH corresponding to the C3 is replaced with -COCH3.

[0042] The compound shown in the formula (2) above is the compound shown in the formula (1) above with an α(1,6)-galactose skeleton added. More specifically, one α(1,6)-galactose skeleton is connected to the C at the 6th position of the β(1,4)-mannose skeleton second from the left. This is the only point in which the compound shown in the formula (2) above differs from the compound shown in the formula (1) above.

[0043] The molecular mass of the polysaccharides separated in the separator 12 is in the range of 50 kDa (kilodaltons) to 800 kDa (kilodaltons). From the viewpoint of water solubility and ease of diffusion into a medium, the smaller the mass, the better, and may be, for example, in the range of 50 kDa to 100 kDa, 100 kDa to 200 kDa, 200 kDa to 300 kDa, 300 kDa to 400 kDa, 400 kDa to 500 kDa, 500 kDa to 600 kDa, 600 kDa to 700 kDa, or 700 kDa to 800 kDa.

[0044] 1, in the extraction system 10, the extraction in the extractor 11 and the separation in the separator 12 may be operated in any of batch, semi-batch, and continuous flow modes. These modes of operation can be changed by opening and closing valves Va1, Va2, Vb, Vc, Vd, and Ve, respectively.

[0045] As shown in Figure 3, when performing a batch-type operation, the following five processes are executed in the order 1 to 5.

[0046] Process 1. Feeding biomass BM into extractor 11 (Feed of biomass for extractor) Process 2. Feeding of extraction fluid EF into extractor 11 Process 3. Extraction of polysaccharides in extractor 11 Process 4. Feeding of extraction fluid containing polysaccharides EF into first separator 121 and second separator 122 Process 5. Separation of polysaccharides from extraction fluid in first separator 121 and second separator 122

[0047] First, in process 1, only valve Va1 is in an open state, and valves Va2, Vb, Vc, Vd, and Ve are in a closed state. In this state, biomass BM is introduced into the extractor 11 via pipe La1.

[0048] Next, in process 2, valve Va1 is closed and valve Va2 is opened. Valves Vb, Vc, Vd, and Ve are maintained in the closed state. In this state, the extraction fluid EF is introduced into the extractor 11 via the pipe La2. The extraction fluid EF is maintained in a supercritical state by the pump PM and the heat exchanger HE.

[0049] Next, in process 3, valve Va2 is closed, and valves Va1, Vb, Vc, Vd, and Ve are maintained in the closed state. In this state, biomass BM and extraction fluid EF are sealed inside the extractor 11.

[0050] Polysaccharides are extracted from the biomass BM while the biomass BM and extraction fluid EF are sealed inside the extractor 11. Because the extraction fluid EF is in a supercritical state inside the extractor 11, the degree of diffusion and penetration is high, and stirring is not necessary. However, stirring may be performed depending on the situation, such as when increasing the extraction rate. Furthermore, to maintain the supercritical state, the inside of the extractor 11 may be heated by a heat source.

[0051] Next, in process 4, valves Vb and Vc are opened, and valves Va1, Va2, Vd, and Ve are kept closed. In this state, an extraction fluid EF containing polysaccharides is introduced into the first separator 121 via pipe Lb and into the second separator 122 via pipe Lc.

[0052] Next, in process 5, valves Vb and Vc are closed, and valves Vd and Ve are opened. Valves Va1 and Va2 are maintained in the closed state. In this state, polysaccharides are separated from the extraction fluid EF inside the first separator 121 and the second separator 122, and the separated polysaccharides PS are taken out via valves Vd and Ve.

[0053] As shown in FIG. 4, when semi-batch type operation is performed, the following two processes are executed in the order 1. to 2.

[0054] Process 1. Feeding biomass BM into extractor 11 (Feed of biomass for extractor) Process 2. Feeding of extraction fluid EF into extractor 11, extraction of polysaccharides in extractor 11, feeding of extraction fluid EF containing polysaccharides into first separator 121 and second separator 122, and separation of polysaccharides from extraction fluid in first separator 121 and second separator 122.

[0055] First, in process 1, only valve Va1 is in an open state, and valves Va2, Vb, Vc, Vd, and Ve are in a closed state. In this state, biomass BM is introduced into the extractor 11 via pipe La1.

[0056] Next, in process 2, valve Va1 is closed, and valves Va2, Vb, Vc, Vd, and Ve are opened. The closed states are maintained. In this state, extraction fluid EF is introduced into the extractor 11 via pipe La2. The extraction fluid EF is maintained in a supercritical state by pump PM and heat exchanger HE. Polysaccharides are extracted from the biomass BM in the extractor 11 by the introduced extraction fluid EF.

[0057] The extraction fluid EF containing polysaccharides is introduced into the first separator 121 via the pipe Lb and into the second separator 122 via the pipe Lc. The polysaccharides are separated from the extraction fluid EF inside the first separator 121 and the second separator 122, and the separated polysaccharides PS are taken out via the valves Vd and Ve. In this way, the extraction fluid EF flows continuously through the extractor 11 and the separator 12.

[0058] As shown in FIG. 5, when a continuous flow type operation is performed, the following single process is carried out.

[0059] Process 1. Feeding biomass BM into extractor 11 (Feed of biomass for extractor), feeding extraction fluid EF into extractor 11 (Feed of extraction fluid for extractor), extraction of polysaccharides in extractor 11 (Extraction of polysaccharides in extractor), feeding extraction fluid EF containing polysaccharides into first separator 121 and second separator 122 (Feed of extraction fluid containing polysaccharides for first separator and second separator), and separation of polysaccharides from extraction fluid in first separator 121 and second separator 122 (Separation of polysaccharides from extraction fluid in first separator and second separator).

[0060] In process 1, valves Va1, Va2, Vb, Vc, Vd, and Ve are set to an open state. In this state, biomass BM is introduced into the extractor 11 via pipe La1, while extraction fluid EF is introduced into the extractor 11 via pipe La2. The extraction fluid EF is maintained in a supercritical state by pump PM and heat exchanger HE. Polysaccharides are extracted from the biomass BM inside the extractor 11 by the introduced extraction fluid EF.

[0061] The extraction fluid EF containing polysaccharides is introduced into the first separator 121 via the pipe Lb and into the second separator 122 via the pipe Lc. The polysaccharides are separated from the extraction fluid EF inside the first separator 121 and the second separator 122, and the separated polysaccharides PS are taken out via the valves Vd and Ve. In this way, the biomass BM and the extraction fluid EF flow continuously through the extractor 11 and the separator 12.

[0062] [Effects of the embodiment] As described above, the extraction system 10 according to an embodiment of the present invention is for extracting polysaccharides from biomass BM. The extraction system 10 according to an embodiment of the present invention includes an extractor 11 to which the biomass BM and an extraction fluid EF for extracting the polysaccharides from the biomass BM are input, and a separator 12 for separating the polysaccharides extracted by the extraction fluid EF in the extractor 11 from the extraction fluid EF. The extraction fluid EF contains carbon dioxide in a supercritical state and a co-solvent, and the co-solvent contains ethanol in an amount greater than 5% of the extraction fluid EF.

[0063] According to this, a configuration for extracting polysaccharides from biomass BM is embodied as an extraction system 10, which can reliably extract polysaccharides from biomass BM. In particular, in the extraction fluid EF, the co-solvent contains more than 5% ethanol. This makes it easier to maintain a supercritical state in the mixture of carbon dioxide and ethanol. Therefore, when extracting polysaccharides with a supercritical fluid, an appropriate amount of ethanol produces a synergistic effect, allowing polysaccharides to be extracted from biomass BM more efficiently and reliably.

[0064] In particular, in the extraction system 10, the co-solvent contains ethanol in an amount greater than 5% and less than 10% of the extraction fluid EF. This makes it easier to maintain a supercritical state even when the temperature of the extraction fluid EF fluctuates. This allows for more reliable extraction of polysaccharides from biomass BM. Furthermore, the amount of ethanol used during polysaccharide extraction can be reduced.

[0065] In particular, in the extraction system 10, the biomass BM fed into the extractor 11 contains aloe gel derived from aloe plants, and the polysaccharide PS separated in the separator 12 contains acemannan as a majority compound.

[0066] This allows for reliable extraction of highly effective and valuable acemannan. Furthermore, the use of aloe gel improves handling when feeding the aloe gel into the extractor 11. The use of fluid aloe gel allows for continuous flow of the raw material into the extractor 11. Furthermore, the aloe gel can be easily mixed with the extraction fluid EF inside the extractor 11.

[0067] In particular, in the extraction system 10, the molecular mass of the polysaccharide PS separated in the separator 12 is in the range of 50 kDa (kilodaltons) to 800 kDa (kilodaltons).

[0068] This allows the molecular weight of the polysaccharide to be relatively small, and improves the ease of diffusion in a medium (particularly water solubility), which, for example, makes it easier to purify the polysaccharide and allows a relatively large amount of the polysaccharide to be uniformly contained in supplements, foods, beverages, medicines, etc.

[0069] In particular, in the extraction system 10, the separator 12 is composed of multiple separators, and a first separator 121 is connected to the extractor 11, and the extraction fluid EF containing the extracted polysaccharides is introduced from the extractor 11, and a second separator 122 is connected to the first separator 121, and the extraction fluid EF containing the extracted polysaccharides is introduced from the first separator 121, and the polysaccharides PS are separated in each of the separators 12.

[0070] According to this, since a plurality of separators 12 are used, the yield of polysaccharide PS can be improved.

[0071] In particular, in the extraction system 10, the extraction in the extractor 11 and the separation in the separator 12 are operated in any one of batch, semi-batch, and continuous flow modes.

[0072] This allows, for example, the selection of an appropriate type of operation depending on the conditions and goals (polysaccharide yield, amount, efficiency, cost, etc.) by operating the valves of the extraction system 10, etc.

[0073] The above-described embodiments disclosed herein are to be considered as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0074] 10...Extraction system 11...Extractor 12...Separator 121...1st separator 122…Second separator BM...Biomass EF...Extraction fluid PS…polysaccharide

Claims

1. 1. An extraction system for extracting polysaccharides from biomass, comprising: an extractor into which the biomass and an extraction fluid for extracting the polysaccharides from the biomass are input; a separator for separating the polysaccharides extracted by the extraction fluid in the extractor from the extraction fluid; Equipped with The extraction fluid is carbon dioxide in a supercritical state and a co-solvent, The co-solvent is The extraction fluid contains more than 5% ethanol. Extraction system.

2. 10. The extraction system of claim 1, The co-solvent is The extraction fluid contains ethanol in an amount greater than 5% and less than 10%. Extraction system.

3. In the extraction system according to claim 1 or 2, The biomass input into the extractor is Contains aloe gel derived from the aloe plant, The polysaccharides separated in the separator include: Contains the majority of acemannan as a compound Extraction system.

4. 4. The extraction system of claim 3, The separator is composed of a plurality of separators, The first separator comprises: connected to the extractor, wherein the extraction fluid containing the extracted polysaccharides is input from the extractor; The second separator comprises: a first separator connected thereto, wherein the extraction fluid containing the extracted polysaccharides is input from the first separator; The polysaccharide is Separated in each of the separators Extraction system.

5. 5. The extraction system of claim 4, The extraction in the extractor and the separation in the separator are It can be operated in batch, semi-batch, or continuous flow mode. Extraction system.

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