JP3802325B2 - Pressurized hydrothermal decomposition method and system for plant biomass - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressurized hydrothermal decomposition method and system for plant biomass that generates sugar, fuel gas, and the like by a pressurized hot water treatment method. More specifically, the present invention relates to a method and a system for producing small sugars such as monosaccharides and oligosaccharides, fuel gas, and the like from plant-based biomass only by controlling the temperature and pressure of water.
[0002]
[Prior art]
Plant biomass is a natural polymer composed of cellulose, hemicellulose, lignin and the like. Cellulose is a major component of the cell wall and fiber of plant biomass and is said to be the most carbohydrate on the earth. It is a chain polymer compound formed by binding glucose. Hemicellulose is a polysaccharide that constitutes cell walls and intercellular layers of plants together with cellulose.
[0003]
This plant biomass is subjected to chemical pretreatment with acid or alkali, physical pretreatment by steaming or blasting, and concentrated xylan, or raw materials such as corn core, which originally contains xylan, such as xylanase Xylooligosaccharides are produced by the action of enzymes. However, these methods require a large amount of energy that cannot be recovered due to pretreatment, time is required for enzymatic degradation, and only a low concentration xylo-oligosaccharide solution can be obtained due to feedback inhibition by the product. It is not an industrially efficient production method because cost and energy are required for concentration.
[0004]
There has also been proposed a method for producing a water-soluble oligosaccharide by contacting cellulose powder with pressurized hot water heated to 200 to 300 ° C. to hydrolyze it (Japanese Patent Laid-Open No. 10-327900). By developing this, attention is paid to the fact that the ion product of pressurized hot water around 250 ° C. (pressurized hot water pressurized above the saturated vapor pressure and kept in a liquid state) rises to 1000 times or more of room temperature water. In addition, a method has been proposed in which plant biomass is hydrolyzed using this pressurized hot water and the components constituting it are sequentially recovered (Kyushu Institute News, 1999.10, Vol.7 No.3).
[0005]
When the pressurized hot water temperature is gradually increased, the first group of tannin and lignin system flows out first, then the second group of hemicellulose system flows out at 140-150 ° C. or more, and further about 230 ° C. It has been reported that a third group of cellulosics flows out. That is, it is a method of decomposing plant biomass such as Itagii and extracting components of each group by the temperature of pressurized hot water.
[0006]
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following object.
An object of the present invention is to provide a pressurized hydrothermal decomposition method for plant biomass and a system thereof capable of decomposing various products from plant biomass at high speed and efficiently only by controlling the temperature and pressure of pressurized hot water. There is.
[0007]
Another object of the present invention is to provide a pressurized hydrothermal decomposition method of plant biomass and its system for producing saccharides such as monosaccharides and oligosaccharides from plant biomass.
Still another object of the present invention is to provide a pressurized hydrothermal decomposition method and system for plant biomass that can produce fuel gas from plant biomass.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention employs the following means.
In the method for pressurized hydrothermal decomposition of plant biomass according to the present invention, the plant biomass is hydrolyzed with pressurized hot water pressurized to a saturated vapor pressure or higher at 140 to 230 ° C. for a predetermined time. Decomposing and extracting hemicellulose from biomass, extracting the hemicellulose, heating the plant biomass above the decomposition temperature of the hemicellulose and hydrolyzing with pressurized hot water, decomposing and extracting cellulose from the plant biomass, The cellulose is decomposed with a catalyst and gasified.
[0009]
In principle, the plant-based biomass may be any organic material such as broad-leaved trees such as shii, conifers such as bamboo and cedar, kenaf, furniture waste, rice straw, straw, and rice husks. The temperature of the pressurized hot water for extracting the hemicellulose is more preferably 160 to 220 ° C. The extraction time of the hemicellulose is about several minutes to about 1 hour, although it varies depending on the type of plant biomass raw material. The gas produced by decomposing the cellulose contains methane, hydrogen, carbon dioxide, and carbon monoxide.
[0010]
The catalyst is preferably nickel-based, and may be decomposed with a nickel-based catalyst in an atmosphere heated to 380 to 420 ° C. An oligosaccharide is preferably extracted from the hemicellulose, which is a polysaccharide. However, the temperature during decomposition is preferably 380 to 420 ° C. when methane gas is the main component and heated to 320 to 360 ° C. when hydrogen gas is the main component.
[0011]
The pressurized plant hydrothermal decomposition system of the first plant biomass of the present invention includes a reactor for charging plant biomass and a pressurized unit for supplying pressurized hot water heated and pressurized to the reactor. A hot water supply circuit, a pressurized hot water circulation circuit for circulating the pressurized hot water supplied to the reactor at a set temperature, and a first cooling for cooling and taking out the hemicellulose fraction decomposed in the reactor A gasifier for gasifying the cellulose content decomposed in the reactor, and a gas-liquid separator for separating the gasified gas-liquid-integrated pressurized hot water into gas and liquid .
[0012]
The pressurized hydrothermal decomposition system for plant biomass of the second aspect of the present invention includes a reactor for charging plant biomass and pressurization for supplying pressurized hot water heated and pressurized to the reactor. A hot water supply circuit; a first cooler that cools and extracts the hemicellulose fraction decomposed in the reactor; a gasification device for gasifying the cellulose content decomposed in the reactor; and the gasification It consists of a gas-liquid separator that separates the gas-liquid integrated pressurized hot water into gas and liquid.
[0013]
The pressurized hydrothermal decomposition system for the first or second plant biomass comprises a tank for storing a combustible gas separated from the gas-liquid separator, and a pressurized hot water separated from the gas-liquid separator. It is good to comprise the 2nd cooler to cool. Moreover, what consists of a concentration apparatus which concentrates the said hemicellulose fraction which came out of the said cooler may be sufficient. Further, a lid made of a sintered alloy having voids that are through holes may be provided on both sides of the reactor.
[0014]
Furthermore, the thing which consists of a cooling circuit for collect | recovering the heat | fever of the said 1st cooler and the said 2nd cooler, and returning them to the said reactor may be sufficient. Furthermore, efficient operation is possible if two or more reactors are arranged in parallel. Even if two or more of the reactors are arranged so as to be indexable, efficient operation is possible.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. FIG. 1 shows an outline of a pressurized hydrothermal decomposition system for plant biomass according to the present invention. The reactors 1 and 2 are reactors that heat and pressurize the plant-based biomass that has been crushed or cut into small pieces and decomposed. In principle, the plant-based biomass may be any organic material such as hardwood (for example, shii), bamboo, conifer (for example, cedar), kenaf, furniture waste, rice straw, straw, and rice husk.
[0016]
The strip method may be any method, but preferably the one that does not consume energy as much as possible. This size is a few cm or less, preferably about 100 μm or less. The reactor 1 is a pressure vessel that can withstand a pressure higher than the saturated vapor pressure and heating. On both sides of the reactor 1, lids made of a sintered alloy having voids that are through holes are provided. A sintered alloy lid provided with a through-hole is provided. In this example, it is a lid (broken line in the figure) provided with a through hole of about 5 μm. Therefore, solids having a diameter of about 5 μm or more do not pass through this lid. Similarly to the reactor 1, the reactor 2 is also arranged in parallel, and the reactor 2 has the same structure as the reactor 1.
[0017]
Since the plant biomass is alternately fed into the reactor 1 and the reactor 2 in a batch manner, continuous treatment is possible. Pressurized hot water is supplied to the reactor 1 and the reactor 2 through piping. This pressurized hot water (pressurized hot water pressurized above the saturated vapor pressure and kept in a liquid state) is pressurized from the water tank 7 by the high-pressure pump 6, and the interlock switching valve 5, heat exchanger (main heater) After being heated by 4, it is supplied to the reactor 1 or the reactor 2 through the raw material switching interlock valve 3.
[0018]
That is, the water tank 7, the high-pressure pump 6, and the heat exchanger 4 constitute a pressurized hot water supply circuit 9 for supplying pressurized hot water. The heat exchanger 4 heats water with a heating wire (not shown) to a desired temperature, and the temperature of the pressurized hot water is controlled and heated. The pipes exiting the reactor 1 and the reactor 2 are connected to the raw material switching interlock valve 10. The raw material switching interlock valve 3 and the raw material switching interlock valve 10 are control valves that are driven in conjunction to operate the reactor 1 and the reactor 2 alternately. The material switching interlocking valve 10 is connected to an interlocking switching valve 11, and the interlocking switching valve 11 is an electromagnetic control valve that can be switched in three directions.
[0019]
The interlocking switching valve 5 and the interlocking switching valve 11 are electromagnetic control valves that can be simultaneously switched in conjunction with each other. The pressurized hot water discharged from the reactor 1 or the reactor 2 is driven by the high-pressure pump 12 through the interlocking switching valve 11 and returned to the interlocking switching valve 5 to be reused. That is, the pressurized hot water circulation circuit 14 is constituted by circulating the reactor 1, the raw material switching interlocking valve 10, the interlocking switching valve 11, the high pressure pump 12, the interlocking switching valve 5, the heat exchanger 4 and the raw material switching interlocking valve 3.
[0020]
If the water in the water tank 7 is heated by the solar water heater 15, the thermal efficiency is further improved. The electric power supplied to the heat exchanger 4 is preferably used from the viewpoint of using natural energy when the electric power generated by the wind power generator 16 and the solar battery 17 is used. The interlock switching valve 11 is connected to the gasifier 20 by a pipe 19. The gasifier 20 decomposes the components that have come out of the reactor 1 or 2 with a nickel catalyst into a gas-liquid integrated gas containing methane, hydrogen, carbon monoxide, carbon dioxide, and the like.
[0021]
The gas is connected to the gas-liquid separator 23 via the pipe 21 and the pressure holding valve 22. The pressure holding valve 22 is a pressure control valve that does not open below a certain pressure when the gas-liquid gas is sent to the gas-liquid separator 23. The gas-liquid separator 23 is for separating the gas-liquid gas that has passed through the pressure holding valve 22 into fuel gas and liquid. The separated gas is stored in the gas storage tank 24 as fuel gas.
[0022]
The fuel gas in the gas storage tank 24 is used as various fuels and raw materials. The liquid in the gas-liquid gas is sent to the cooler 29. The cooler 29 is a heat exchanger for cooling the heated liquid with a heat medium. A part of the fuel gas in the gas storage tank 24 is burned by the gas boiler 25 to heat a heating medium such as water. The heating medium heated by the gas boiler 25 receives heat via the heat exchanger 26. The heating medium is forcibly circulated with the concentrator 27 by a pump 28.
[0023]
The concentrating device 27 may be of any principle as long as it can concentrate the target one, but as a device for concentrating oligosaccharide sugars, a thin film descending multi-effect can system used in the concentration of food is preferable. Since the high-temperature liquid separated by the gas-liquid separator 23 is kept at a temperature of 350 ° C. to 400 ° C., it is wasteful in terms of energy to throw it away as a waste liquid. Therefore, it is desirable to recover the thermal energy.
[0024]
For this purpose, the high-temperature liquid is passed through a cooler 29 which is a heat exchanger. The cooler 29 collects heat from the high temperature liquid and then discharges it as a waste liquid. This waste liquid is a product obtained by decomposing organic substances and does not contain anything other than water, so even if it is released into the environment as it is, it does not pollute the environment.
[0025]
On the other hand, the hemicellulose fraction fractionated at a pressurized hot water temperature of 140 to 230 ° C. flows from the interlock switching valve 11 to the cooler 30. The hemicellulose fraction cooled by the cooler 30 flows to a pressure holding valve 31 that operates only at a set pressure or higher. The hemicellulose fraction that has passed through the pressure holding valve 31 contains monosaccharides and oligosaccharides, flows to the concentration device 27, and is concentrated to a predetermined concentration.
[0026]
The cooler 30 and the cooler 29 are cooled by being supplied with a heat medium by a cooling circuit 35. The heat medium of the cooling circuit 35 is connected between the cooling water / air cooling device 36, the reactor 1, the reactor 2, the cooler 30, and the cooler 29 by piping. The flow of the heat medium in the cooling circuit 35 is controlled by a pump 37 to flow. The cooling water / air cooling device 36 cools at a temperature difference between the heat medium and the outside air temperature. In addition, the control valve (not shown) is arrange | positioned so that a heat medium may flow into only one of the flow of the heat medium to the reactor 1 and the reactor 2 selectively.
[0027]
The interlocking valve 38 and the interlocking valve 39 are arranged so that the heat medium flows selectively to only one of the cooler 30 and the cooler 29. In the interlock valve 38 and the interlock valve 39, the heat medium of the cooling circuit 35 is caused to flow through the cooler 30 when the oligosaccharide is produced, thereby cooling the hemicellulose fraction into a liquid. Then, the pressurized hot water is cooled from the gas-liquid separator 23. The pressurized hydrothermal decomposition system for plant biomass as described above operates as follows.
[0028]
[When producing oligosaccharides]
A raw material is obtained by crushing plant biomass such as wheat bran, shii, bamboo, kenaf, etc. into small pieces with a crusher. The ground plant biomass is charged into the reactor 1 and closed. The interlock switching valve 5 and the raw material switching interlock valve 3 are opened, and water is pressurized from the water tank 7 by the high pressure pump 6 and sent to the reactor 1. The pressurized water is heated by the heat exchanger 4 which is a heater. The heated pressurized hot water leaves the reactor 1 and flows to the raw material switching interlock valve 10 and the interlock switching valve 11, and flows from the interlock switching valve 11 to the high-pressure pump 12. That is, the pressurized hot water circulates through the pressurized hot water circulation circuit 14.
[0029]
The pressurized hot water temperature at this time is set to 140 to 230 ° C. However, when the temperature is 230 ° C. or higher, decomposition of the cellulose component starts and the purity of the xylo-oligosaccharide decreases, and therefore 160 to 220 ° C. is preferable. The pressure of the high-pressure pump 6 needs to be equal to or higher than the saturated vapor pressure of pressurized hot water. Since the extraction time varies depending on the type of biomass, the optimum time is set for each raw material, but it may be about several minutes to several tens of minutes. By this operation, a water-soluble liquid mainly composed of monosaccharides such as xylose and oligosaccharides to which about 2 to 20 xyloses are bonded is obtained.
[0030]
Circulation of pressurized hot water is performed at this temperature until the hemicellulose degradation product (oligosaccharide derived from hemicellulose) is almost extracted. After completing the extraction of the hemicellulose-derived oligosaccharide, the interlock switching valve 11 is opened and allowed to flow through the cooler 30. A heat medium is caused to flow from the cooling circuit 35 to the cooler 30 to cool the hemicellulose fraction, which is a main component, into a liquid, and the pressurized hot water containing oligosaccharides derived from hemicellulose is cooled. However, the preheating of the cooling circuit 35 at this time is used for preheating the reactor 2.
[0031]
[At the time of gas production]
When the oligosaccharide extraction is completed, the interlocking switching valve 11 is switched to guide the pressurized hot water to the gasifier 20. The temperature at this time is heated to 200 ° C. or higher, preferably 230 ° C. or higher. Decomposition of the cellulose component begins at about 230 ° C or higher. When this decomposition starts, the interlock switching valve 11 is switched, and the cellulose in the reactor 1 flows to the gasifier 20.
[0032]
The gasifier 20 has a heating mechanism, and when the temperature in the reactor (not shown) is obtained from 380 to 420 ° C. when methane gas is obtained as the main component, and when hydrogen gas is obtained as the main component. Heat to 320-360 ° C. With the nickel catalyst heated to this temperature, the components coming out of the reactor 1 or 2 are decomposed into gas-liquid integrated gas containing methane, hydrogen, carbon dioxide, carbon monoxide and the like. When the gas-liquid integrated gas becomes equal to or higher than the set pressure, the pressure holding valve 22 opens from the pipe 21 and flows to the gas-liquid separator 23. The gas-liquid separator 23 separates the gas-liquid gas into fuel gas and liquid. The separated gas is stored in the gas storage tank 24 as fuel gas.
[0033]
The fuel gas in the gas storage tank 24 is used as various fuels and raw materials. The liquid in the gas-liquid gas is sent to the cooler 29. The cooler 29 is a heat exchanger for cooling the heated liquid with a heat medium. A part of the fuel gas in the gas storage tank 24 is burned by the gas boiler 25 to heat a heating medium such as water. The heating medium heated by the gas boiler 25 receives heat via the heat exchanger 26. The fuel gas may be directly used for power generation of the gas turbine, fuel for the fuel cell, and fuel for the gas boiler 25. Furthermore, the steam turbine is driven by the steam of the gas boiler 25, the generator is rotated, the power is generated, and the power supply of this system is very good.
[0034]
(Experimental example)
In order to confirm the principle and system described above, an experiment was conducted using a pressurized hot water flow type reaction experimental apparatus as shown in the conceptual diagram of FIG. The high pressure pump 6 pressurizes water from a water tank (not shown) and sends it to the reactor 1 through the heat exchanger 4 as a heater. The reactor 1 is a plant in which plant-based biomass is put and decomposed with pressurized hot water. The reactor 1 is provided with a lid made of a sintered alloy having a void that is a through hole. In this experimental example, it is a lid (broken line in the figure) provided with a through hole of about 5 μm. Therefore, solids having a diameter of about 5 μm or more do not pass through this lid.
[0035]
The pressurized hot water exiting from the reactor 1 enters the cooler 45 and is cooled. A pressure retainer 46 is connected to the outlet of the cooler 45 and does not operate unless the pressure is higher than the set pressure. A product decomposed by pressurized hot water is discharged from the pressure retainer 46. Data obtained by analyzing this product is shown below.
[0036]
FIG. 3 shows the relationship between product yield and pressurized hot water temperature when kenaf is decomposed. The horizontal axis represents the sample number of the product taken out every 5 minutes at each pressurized hot water temperature, and the vertical axis represents the yield (wt%) and the pressurized hot water temperature (° C.). The yield is a value indicating the weight by which the kenaf charged into the reactor 1 is decomposed as a percentage. After raising the temperature of the pressurized hot water to 130 ° C. (about 5 ° C./min), further raising the temperature to 200 ° C. (about 5 ° C./min), and further up to 300 ° C. Heating was performed at a three-step temperature increase in which the temperature was raised (about 5 ° C./min) to raise the pressurized hot water temperature.
[0037]
Extraction (outflow) of the first group estimated to be ash, protein, and readily soluble lignin was completed at 190 ° C. When the pressurized hot water temperature reaches 190 ° C.-200 ° C., the second group (No. 4) starts to flow out. When the temperature was further increased, the third group started to flow out from 200 ° C or higher. When the effluents of the first group, the second group, and the third group were analyzed by ion chromatogram, the first group was estimated to be tannin, lignin, protein, and the like. The second group detected hemicellulose-derived monosaccharides and oligosaccharides.
[0038]
Furthermore, the third group was estimated to be cellulosic. FIG. 4 shows an analysis of the second group by ion chromatogram, and shows that the second group is mainly monosaccharides and oligosaccharides. Kenaf is promising as a raw material because it has few effluents from the first group and has a sharp hemicellulose fraction. It can be seen from FIG. 4 that kenaf degradation products are promising for the production of oligosaccharides. The integrated yield of the kenaf decomposition product was 90%. The kenaf degradation product contains a large amount of xylose (X1), xylobiose (X2), and xylooligosaccharide (X3).
[0039]
A similar experiment was conducted for rice straw. FIG. 5 shows the relationship between product yield of rice straw, pressurized hot water temperature, and water flow time. The eluate of rice straw is highly viscous and difficult to handle. The result was not so different from that of shii, but there was a lot of silica, and further investigation was necessary as a raw material for oligosaccharide extraction. FIG. 6 shows the relationship between the product yield of wheat bran, the pressurized hot water temperature, and the water passage time.
[0040]
However, the temperature rise of wheat bran was up to 200 ° C., but the integrated yield of decomposed products was 50%. However, the residue can be gasified. Wheat bran is rich in hemicellulose, and a high yield can be expected. However, since the starch contained in the bran is about 10% in the lid of the reactor 1, it needs to be removed beforehand. Further, if pretreatment with amylase or the like is performed, glucose can also be obtained, and it is determined that it is suitable as a raw material.
[0041]
FIG. 7 shows the relationship between the product yield of straw, the pressurized hot water temperature, and the water flow time. The temperature rise of the straw was up to 200 ° C., but the integrated yield of the decomposed product was 50%. However, the residue will be gasified. Since the fraction of hemicellulose is sharp, it is suitable as a raw material. FIG. 8 shows the relationship between cedar (coniferous) product yield, heated hot water temperature, and water passage time. The yield of cedar is slightly inferior to that of broad-leaved trees, but the hemicellulose and cellulose fractions are sharp and easy to fractionate. The residue is presumed to be poorly soluble lignin.
[0042]
(Other experiments)
In the above embodiment, hemicellulose is recovered as an oligosaccharide, but the nickel catalyst described above may be used as a fuel gas.
[0043]
[Other pressurized hot water decomposition system 40]
FIG. 9 shows an outline of another pressurized hot water decomposition system of the plant biomass of the present invention. In the pressurized hydrothermal decomposition system of the above-described embodiment, the reactor 1, the raw material switching interlocking valve 10, the interlocking switching valve 11, the high pressure pump 12, the interlocking switching valve 5, the heat exchanger 4, and the raw material switching are performed at the time of oligosaccharide production. The interlocking valve 3 was circulated to constitute a pressurized hot water circulation circuit 14.
[0044]
However, the pressurized hot water circulation circuit 14 is not always necessary. The pressurized hot water splitting system 40 shown in FIG. 9 does not include the pressurized hot water circulation circuit 14, and the other configuration is not different from the system described above, but the operation method is different. At the time of oligosaccharide production by the pressurized hydrothermal decomposition system 40, water is passed at about 150 ° C. for about 5 minutes at a low flow rate until the decomposition of hemicellulose sufficiently proceeds, depending on the raw material.
[0045]
Next, solubilized hemicellulose is extracted while increasing the flow rate to prevent secondary decomposition. During this extraction, heat is recovered by the cooler 30 to prevent energy loss, and the reactor 2 is preheated with this heat. At the time of gas production in the pressurized hot water decomposition system 40, the hot water temperature is raised to 200 ° C. or higher, and the interlock switching valve 11 is switched to induce the cellulose in the reactor 1 to the gasifier 20.
[0046]
The gasifier 20 decomposes the components that have come out of the reactor 1 or the reactor 2 into a gas-liquid integrated gas containing methane, hydrogen, carbon dioxide, carbon monoxide, etc., using a nickel catalyst in the same manner as described above. It is stored in the gas storage tank 24 as fuel gas. At the time of gas production, the flow is the same as that of the system described above.
[0047]
Further, the reactors 1 and 2 described above were arranged in parallel. However, it is also possible to use a rotary type that can be indexed and used by sequentially turning and using it, and on the other hand, the empty material is filled with a new material.
[0048]
【The invention's effect】
As described above in detail, the pressurized hydrothermal decomposition method and system for plant biomass according to the present invention aims at various products from plant biomass at high speed and efficiency only by controlling the temperature and pressure of pressurized hot water. It can be disassembled separately. In particular, it is possible to produce saccharides such as oligosaccharides derived from hemicellulose and to produce fuel gas from cellulose using a catalyst.
[Brief description of the drawings]
FIG. 1 shows an outline of a pressurized hydrothermal decomposition system for plant biomass according to the present invention.
FIG. 2 is a conceptual diagram of a pressurized hot water flow type reaction experimental apparatus.
FIG. 3 shows the relationship between the product yield of kenaf stalk and the pressurized hot water temperature.
FIG. 4 is a diagram showing an ion chromatogram of each degradation product of kenaf.
FIG. 5 shows the relationship between rice straw product yield and pressurized hot water temperature.
FIG. 6 shows the relationship between the product yield of wheat bran and the pressurized hot water temperature.
FIG. 7 shows the relationship between the product yield of straw and the pressurized hot water temperature.
FIG. 8 shows the relationship between the product yield of cedar (conifers), the heated hot water temperature, and the water passage time.
FIG. 9 shows an outline of another pressurized hydrothermal decomposition system for plant biomass according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Reactor 2 ... Reactor 3 ... Raw material switching interlock valve 4 ... Heat exchanger (main heater)
5 ... Interlocking switching valve 7 ... Water tank 11 ... Interlocking switching valve 12 ... High pressure pump 14 ... Pressurized hot water circulation circuit 22 ... Holding pressure valve 23 ... Gas-liquid separator 24 ... Gas storage tank

Claims (11)

Hydrolyzing the stripped plant biomass with pressurized hot water pressurized to a saturated vapor pressure or higher at 140 to 230 ° C. for a predetermined time, decomposing and extracting hemicellulose from the plant biomass,
After extracting the hemicellulose, the plant biomass is heated above the decomposition temperature of the hemicellulose and hydrolyzed with pressurized hot water, and cellulose is decomposed and extracted from the plant biomass.
A pressurized hydrothermal decomposition method for plant biomass, characterized in that the cellulose is decomposed and gasified with a catalyst. In claim 1,
The pressurized hot water decomposition method of plant biomass, wherein the temperature of the pressurized hot water for extracting the hemicellulose is 160 to 220 ° C. In claim 1 or 2,
The method for pressurized hydrothermal decomposition of plant biomass, wherein the gas contains methane, hydrogen, carbon dioxide, and carbon monoxide. In claim 1 or 2,
A method for decomposing and extracting oligosaccharides from the hemicellulose, wherein the plant biomass is subjected to pressurized hydrothermal decomposition. A reactor for charging plant biomass;
A pressurized hot water supply circuit for supplying pressurized hot water heated and pressurized to the reactor;
A pressurized hot water circulation circuit for circulating the pressurized hot water supplied to the reactor at a set temperature;
A first cooler that cools and removes the hemicellulose fraction decomposed in the reactor;
A gasifier for gasifying the cellulose content decomposed in the reactor;
A pressurized hydrothermal decomposition system for plant biomass comprising a gas-liquid separator that separates the gasified gas-liquid integrated hot water into gas and liquid. A reactor for charging plant biomass;
A pressurized hot water supply circuit for supplying pressurized hot water heated and pressurized to the reactor;
A first cooler that cools and removes the hemicellulose fraction decomposed in the reactor;
A gasifier for gasifying the cellulose content decomposed in the reactor;
A pressurized hydrothermal decomposition system for plant biomass comprising a gas-liquid separator that separates the gasified gas-liquid integrated hot water into gas and liquid. In claim 5 or 6,
A tank for storing a combustible gas separated from the gas-liquid separator;
A pressurized hydrothermal decomposition system for plant biomass, comprising a second cooler for cooling the pressurized hot water separated from the gas-liquid separator. In claim 5 or 6,
A pressurized hydrothermal decomposition system for plant biomass, characterized by comprising a concentrating device for concentrating the hemicellulose fraction discharged from the cooler. In claim 5 or 6,
A pressurized hydrothermal decomposition system for plant biomass, comprising a cooling circuit for recovering heat of the first cooler and the second cooler and returning it to the reactor. In claim 5 or 6,
Two or more said reactors are arrange | positioned in parallel, The pressurized hydrothermal decomposition system of the plant biomass characterized by the above-mentioned. In claim 5 or 6,
Two or more reactors are arranged in a rotary manner that can be indexed, and the pressurized hydrothermal decomposition system for plant biomass is characterized in that:

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