JP5835183B2 - Method for producing furfurals, monosaccharides and oligosaccharides from biomass - Google Patents

Description

  The present invention consists of a concentrated liquid containing a high concentration of furfurals, monosaccharides and oligosaccharides using a continuous hydrolysis apparatus that continuously hydrolyzes a biomass raw material suspension under pressure and heating. The present invention relates to a method for efficiently producing saccharides.

  Biomass resources are organic resources produced by photosynthesis from water, carbon dioxide and solar energy, and can be used as energy sources or chemical raw materials. Biomass resources are renewable resources that can be used without increasing carbon dioxide emissions, provided that the production of products produced from biomass resources can be harmonized with the usage of the products.

  Biomass refers to “waste biomass”, which is organic waste that is discharged as an unnecessary waste in the process of living and industrial activities, and non-edible parts of crops that are scraped into farmland or left in mountain forests ( For example, “unused biomass” such as corn stalks and leaves) and thinned wood, current fallow land and unused land for the purpose of obtaining materials and energy resources without the purpose of producing food and wood. This refers to “resource crops” that are plants cultivated in Japan, and “new crops” that are resource crops whose functions such as productivity have been improved by variety improvement and genetic recombination techniques using conventional techniques.

Biomass is composed of components such as cellulose, hemicellulose, lignin, and intracellular components, and the component ratio varies depending on the type of biomass. For example, woody biomass is composed of about 50% cellulose, 20-25% hemicellulose, 20-25% lignin, and about 5% intracellular components. These components can be used industrially.
For example, cellulose can be used as paper pulp or dissolving pulp. In addition, since cellulose is a glucose polymer, glucose and cellooligosaccharide can be obtained from cellulose. Glucose can be used as a fermentation raw material for ethanol and lactic acid, and cellooligosaccharide can be used as a functional food. Sugar alcohol (sorbitol) obtained by reducing glucose is widely used as a sweetener having a cool feeling, and has recently attracted attention as a biomass-derived plastic raw material (Non-patent Document 1).

  By treating the biomass with pressurized hot water, the components constituting the biomass can be decomposed and extracted. Pressurized hot water is high-temperature and high-pressure liquid water having a temperature of 100 to 374 ° C. and pressurized to a saturated vapor pressure or higher. By utilizing the difference in the reactivity of biomass constituents with pressurized hot water, it is possible to separate the constituents of biomass. For example, it has been reported that when the temperature of pressurized hot water is 100 to 140 ° C., useful intracellular components (tannin, terpene, organic acid) and water-soluble lignin can be recovered. Moreover, it is reported that oligosaccharides derived from hemicellulose and monosaccharides such as xylose, arabinose, mannose, and galactose can be recovered at a pressurized hot water temperature of 140-230 ° C. (Patent Document 1, Patent Document) 2, non-patent documents 1 to 3).

  Among the above-mentioned pressurized hot water treatments, the pressurized hot water treatment used as a pre-process for kraft cooking at the time of dissolving pulp production is called a pre-hydrolysis step. In order to produce dissolving pulp from biomass, it is necessary to selectively remove hemicellulose and lignin in the biomass to increase the purity of the cellulose. Prehydrolysis at the time of pulp production is carried out under conditions that suppress decomposition of cellulose and decompose only hemicellulose. In the prehydrolysis step, simply adding water to the biomass and heating it results in elimination of the acetyl group in hemicellulose to produce acetic acid, which becomes acidic and acid hydrolysis proceeds. Hemicellulose contains hexose, mannose, glucose, galactose, pentose, xylose, and arabinose as constituent sugars.

  In the prehydrolysis step, when hemicellulose is hydrolyzed, oligosaccharides composed of the above sugars are produced. Further, when the oligosaccharide is further hydrolyzed, a monosaccharide is produced. Among these sugars, xylose and arabinose, which are pentose sugars, are converted to furfural by the dehydration reaction of three molecules of water (Non-patent Document 4). The hydrolyzate (solid content) after pre-hydrolyzing the biomass is highly purified by removing the lignin and hemicellulose remaining in the hydrolyzate in the subsequent kraft cooking step, and further performing bleaching in the next step. Of cellulose (dissolving pulp) is obtained.

  As described above, in the prehydrolysis step, the primary purpose is to efficiently produce dissolved pulp (cellulose), and therefore the prehydrolysis conditions are performed under conditions suitable for the production of dissolved pulp. Generally, water is added at a liquid ratio of about 2 to 5 with respect to the raw material chips (dry weight), and the processing is performed at 150 to 180 ° C. for 1 to several hours. Moreover, suitable prehydrolysis conditions are set according to the kind of raw material and the quality of the target dissolving pulp. Therefore, there is a problem that furfurals, monosaccharides and oligosaccharides cannot be efficiently produced only by prehydrolysis. If the hydrolyzate obtained by pre-hydrolysis can be subjected to secondary treatment to produce furfurals, monosaccharides, and oligosaccharides efficiently, it is economical when producing on an industrial scale. This is also advantageous.

  As a system for producing furfural from lignocellulosic raw materials, a method has been reported in which wood chips are digested with a continuous digester using lower aliphatic alcohol as a solvent, and byproducts such as furfural are recovered from black liquor as a by-product during pulp production. (Patent Document 3). In this system, the black liquor after cooking is transferred to a flash tank and separated into a gas phase (a fraction containing ethanol) and a liquid phase (a fraction containing furfural), and the ethanol used as the chemical for cooking is removed. Recovered from the phase. On the other hand, the furfural concentration contained in the liquid phase is 0.2 to 0.8%, and the furfural is concentrated in the subsequent step. In order to efficiently produce furfural, it is desirable to increase the furfural concentration (yield) in the previous step as much as possible. At present, regarding the production of furfural using biomass as a raw material, an efficient method for separating and recovering furfural that can be put into practical use has not been reported. Therefore, establishment of a method for efficiently recovering furfural by secondarily treating a hydrolyzed solution obtained by continuous hydrolysis is desired.

  As a method for producing xylose and xylooligosaccharides from biomass raw materials, a water-insoluble residue obtained by removing a component extracted from hot water of 110 ° C. or higher and 140 ° C. or lower from a xylan-containing natural product is treated with hot water of the processing temperature or higher and 200 ° C. or lower. (Patent Document 4), and a method of hydrolyzing biomass at 140 to 230 ° C. and decomposing and extracting hemicellulose, and then decomposing and extracting cellulose by treating with pressurized hot water at the above temperature (Patent Document 5) ) Has been reported. However, there is no report regarding a technique for efficiently separating and recovering monosaccharides, oligosaccharides, and furfurals obtained simultaneously by prehydrolyzing biomass.

Japanese Patent Laid-Open No. 10-327900 JP 2002-59118 A Japanese National Patent Publication No. 8-500854 JP 2000-236899 A JP 2002-59118 A

Masao Shibata, “Toward the development of biomass utilization technology -Treatment technology with pressurized hot water”, 2001 AIST Kyushu Center research lecture summary Takeshi Sakaki, “Separation of Biomass Components by Pressurized Hot Water” Vol. 7, pp. 245-248, Abstracts of the Japan Institute of Energy, 1998 Hiroshi Ando and five others, "Decomposition behavior of woody biomass using pressurized hot water", Kagoshima Prefectural Industrial Technology Center research report No. 14, page, 2000 Furrural: Hemicellose / xylosed biochemical, Ajing Singh Maman, Biofuels Bioproducts and Biorefining, Volume 2, Issue 5, p. p. 438-454 (2008)

  An object of the present invention is to provide a method for efficiently producing furfurals, monosaccharides and oligosaccharides contained in a hydrolyzed solution obtained by continuously hydrolyzing biomass.

  The inventors continuously supply an aqueous suspension containing raw material biomass from the raw material supply port of the continuous hydrolysis apparatus, and produce monosaccharides, oligosaccharides, and furfurals while moving through the apparatus. In a method in which biomass is hydrolyzed under pressurized and heated conditions, and a hydrolyzed suspension composed of hydrolyzed biomass and hydrolyzed product-containing aqueous solution is taken out from the outlet of the hydrolyzing device, continuous hydrolysis A secondary hydrolysis treatment is performed in which the hydrolyzed liquid is separated and removed from the hydrolyzed suspension at an intermediate position of the apparatus, and the secondary hydrolyzer forms a vapor phase containing furfurals and a liquid phase containing monosaccharides and oligosaccharides. It has been found that by combining the steps to be performed, a high-concentration liquid of furfurals can be efficiently produced, and the following invention has been completed.

(1) Biomass under pressure and heating conditions to produce monosaccharides, oligosaccharides, and furfurals while continuously supplying an aqueous suspension of biomass from the supply port of the continuous primary hydrolysis apparatus and moving through the apparatus The solid-liquid separation device at the intermediate position between the supply port and the discharge port of the primary hydrolysis device is continuously discharged from the discharge port of the primary hydrolysis device. The primary hydrolysis treatment liquid separated from the hydrolysis treatment suspension in the apparatus is taken out from an intermediate outlet provided with the apparatus, and the primary hydrolysis treatment liquid is sent to a secondary hydrolysis apparatus for secondary hydrolysis treatment. To produce a secondary decomposition product, separate and remove the furfural-containing vapor phase from the secondary hydrolysis product in the secondary hydrolysis apparatus, and perform distillation treatment to recover the furfural-containing concentrated liquid, full And wherein the retrieving the saccharide-containing liquid containing the monosaccharides and oligosaccharides as a liquid phase after separation of Lahr analog-containing vapor phase, furfurals method of monosaccharides and oligosaccharides from biomass.

(2) At least a part of the saccharide-containing liquid containing the monosaccharide and oligosaccharide extracted from the secondary hydrolysis treatment product is circulated and supplied to a secondary hydrolysis apparatus to be hydrolyzed together with the primary hydrolysis treatment liquid. The method for producing furfurals, monosaccharides and oligosaccharides from biomass as described in the item (1), wherein the treatment is performed.

(3) The removal of the furfural-containing vapor phase from the secondary hydrolysis product is obtained by removing the furfural-containing vapor phase generated during the secondary hydrolysis process in the secondary hydrolysis apparatus from the secondary hydrolysis apparatus. It is carried out by any method selected from a method of continuously taking out and a method of taking out the furfural-containing vapor phase generated from the secondary hydrolysis product after the completion of the secondary hydrolysis treatment from the secondary hydrolysis apparatus. A method for producing furfurals, monosaccharides and oligosaccharides from biomass according to (1) or (2).

(4) In the liquid phase after separating the furfural-containing vapor phase from the secondary hydrolysis treatment product, before taking out the liquid phase from the secondary hydrolysis apparatus, the inside of the secondary hydrolysis apparatus is depressurized. At least one selected from a treatment for generating furfural-containing vapor from the liquid phase and a treatment for generating an inert gas or water vapor into the liquid phase in the secondary hydrolysis apparatus to generate the furfural-containing vapor from the liquid phase The process (1) to (3) is characterized in that by the treatment of (2), a furfural remaining in the liquid phase is additionally recovered and a saccharide concentration in the liquid phase is improved. A method for producing furfurals, monosaccharides and oligosaccharides from the biomass described in 1.

)
(5) With respect to a saccharide-containing liquid containing monosaccharides and oligosaccharides composed of a liquid phase taken out from the secondary hydrolyzer, the saccharide-containing liquid is newly added after being taken out from the secondary hydrolyzer. (1) to (4), wherein the furfurals produced in the process are separated and recovered, and the saccharide concentration in the saccharide-containing liquid is increased. A method for producing furfurals, monosaccharides and oligosaccharides.

(6) An aqueous cleaning liquid is supplied into the primary hydrolyzer from the vicinity of the outlet of the continuous primary hydrolyzer, and water is added between the intermediate outlet provided with the solid-liquid separator and the outlet. The method for producing furfurals, monosaccharides and oligosaccharides from biomass according to any one of items (1) to (5), wherein the solution is brought into countercurrent contact with the decomposition-treated suspension.

(7) The method for producing furfurals, monosaccharides and oligosaccharides from biomass according to any one of (1) to (6), wherein the biomass is woody biomass.

  According to the present invention, monosaccharides, oligosaccharides, and furfurals are obtained by solid-liquid separation from a hydrolyzed suspension that moves in a primary hydrolysis apparatus that continuously hydrolyzes biomass in the form of an aqueous suspension. The primary hydrolysis treatment liquid containing sucrose is taken out and subjected to a hydrolysis treatment under the conditions of further hydrolyzing monosaccharides and oligosaccharides in the secondary hydrolysis device, and the secondary hydrolysis treatment from within the secondary hydrolysis device The product is separated into a liquid phase composed of a furfural-containing vapor phase and an aqueous solution containing monosaccharides and oligosaccharides, and the vapor phase is sent to a distillation apparatus to concentrate, whereby a high-concentration furfural-containing liquid is obtained. A method is provided that can be produced in a yield and at a low cost.

It is a figure which shows an example of the apparatus for enforcing the manufacturing method of furfurals, monosaccharides, and oligosaccharides from the biomass of this invention. It is a figure which shows the apparatus which implements the method of the comparative example different from the apparatus for implementing the method of this invention. It is a figure which shows an example for implementing the manufacturing method of the furfurals, monosaccharide, and oligosaccharide from the biomass of this invention. It is a figure which shows an example for implementing the manufacturing method of the furfurals, monosaccharide, and oligosaccharide from the biomass of this invention.

  Hereinafter, the method for producing the furfurals, monosaccharides and oligosaccharides of the present invention will be described in more detail.

(Type of biomass)
As the biomass used in the present invention, any material containing pentose sugar as a constituent sugar can be used without particular limitation. For example, wood-based materials include chips, bark of wood, forest residue, thinned wood, waste wood, sawdust generated from sawmills, pruned branches of street trees, construction waste, etc. Can be used. Agricultural waste such as kenaf, rice straw, straw, corn cob, bagasse, etc., residue and waste of industrial crops such as oil crops and rubber (for example, EFB: Empty Fruit Bunch), herbaceous energy crop areas And lignocellulosic biomass such as Nanthus, Miscanthus and Napiergrass. Further, as biomass, food waste such as paper derived from wood, waste paper, pulp, pulp sludge, sludge, sewage sludge, and the like can be used as raw materials. These biomasses can be used alone or in combination. The biomass can be used as a dry solid, a solid containing water, or a slurry. If the biomass is a dry solid or a solid containing water, it is preferably mixed with water to form a slurry and then supplied to the hydrolysis reaction apparatus.

(Primary hydrolysis equipment)
The primary hydrolysis apparatus used in the method of the present invention is capable of continuously hydrolyzing biomass under pressure and heating conditions, as well as hydrolyzed biomass, monosaccharides, oligosaccharides, and furfurals. And other hydrolyzed suspensions comprising hydrolyzed products such as organic acids, and the hydrolyzed aqueous solution containing hydrolyzed products and maintaining the hydrolyzing temperature and pressure. It is a continuous pressurization and heating hydrolysis treatment device having an intermediate outlet provided with a solid-liquid separation device capable of separating and taking out the treatment liquid.

  As shown in FIG. 1, as a primary hydrolysis apparatus, a hydrolyzed suspension containing a hydrolyzed biomass and a supply port A to which a raw material suspension supply pipe 1 made of biomass and water is connected. Monosaccharides, oligosaccharides, and furfurals at the intermediate portion between the outlet B to which the liquid outlet pipe 2 is connected, and the feed port A for the raw material suspension and the outlet B for the hydrolyzed suspension From the hydrolyzed suspension in which the biomass in the suspension is hydrolyzed under pressure and temperature conditions to produce a primary hydrolyzed liquid consisting of an aqueous solution containing a water-soluble hydrolyzed product. And a column-type primary hydrolysis apparatus R1 having an intermediate outlet G equipped with a solid-liquid separation apparatus S that can be separated and taken out.

  In the apparatus of FIG. 1, the raw material biomass is continuously supplied into the primary hydrolysis apparatus R1 in the state of an aqueous suspension from a supply port A to which the raw material suspension supply pipe line 1 is connected. Hydrolysis containing biomass hydrolyzed from the outlet B to which the transfer line 2 for discharging the other hydrolyzed suspension is connected while being hydrolyzed under heating conditions. The hydrolyzed suspension is continuously discharged as a hydrolyzed suspension to the transfer line 2. Then, from the hydrolysis treatment suspension moving in the apparatus, the water-soluble hydrolysis is performed by the solid-liquid separation apparatus S installed in the intermediate part from the supply port A to the discharge port B of the primary hydrolysis apparatus 1. The hydrolyzed liquid containing the product is separated and continuously taken out from the intermediate outlet G of the intermediate part of the apparatus to the transfer line 3 of the primary hydrolyzed liquid while maintaining the pressure and temperature of the hydrolyzing process. Then, it is sent to the secondary hydrolysis apparatus R2 (secondary reaction kettle BR2) and subjected to secondary hydrolysis treatment.

  In the primary hydrolysis apparatus R1 in the apparatus of FIG. 1, the aqueous liquid used for the raw material suspension is added to the hydrolysis treatment suspension in the apparatus after the hydrolysis treatment liquid is taken out from the intermediate outlet G. For the purpose of replenishing the same kind of aqueous liquid, an aqueous liquid supply port may be provided at a position below the intermediate outlet G.

  In the primary hydrolysis apparatus R1 in the apparatus of FIG. 1, only one intermediate outlet G is provided on the side surface of the cylindrical portion of the primary hydrolysis apparatus R1, but the intermediate outlet G is not limited to one. It can also be provided at two or more positions. For example, the hydrolyzing apparatus may be provided with a second intermediate outlet that can separate only the hydrolysis treatment liquid portion and take it out of the apparatus at a position below the intermediate outlet G. Further, for example, when a third intermediate outlet is further provided, an aqueous liquid supply port is also provided between the second intermediate outlet and the third intermediate outlet, and the aqueous liquid is supplied as the primary liquid as necessary. It can be made possible to supply into the hydrolysis apparatus R1.

  As the solid-liquid separator S, a strainer or a filter having a mesh (mesh) in the range of 10 μm to 5 cm is employed. As the strainer, a strainer in the range of 40 to 500 μm is preferably employed in order to avoid clogging troubles and avoid the entrainment of suspended substances in the separated aqueous solution as much as possible.

  As shown in FIG. 1, the cleaning liquid is supplied from the cleaning liquid supply device W to the bottom of the primary hydrolyzing device R1 through the supply pipe 6, and is passed from the intermediate outlet G of the primary hydrolyzing device R1 to the bottom outlet B. It can be in countercurrent contact with the moving hydrolyzed suspension. The cleaning liquid from the cleaning liquid supply line 6 may be supplied continuously or intermittently. As the cleaning liquid from the supply pipe 6, it is desirable to use an aqueous solution containing water or acid, but there is no particular limitation as long as it does not adversely affect the hydrolysis treatment liquid taken out from the intermediate outlet G to the transfer pipe 3. Can be used. The cleaning liquid supplied to the bottom moves upward from the bottom in the direction opposite to the direction of movement of the hydrolysis treatment suspension, and the hydrolysis treatment liquid and the intermediate treatment outlet G provided with the solid-liquid separation device S in the middle of the apparatus. It is taken out to the transfer line 3 in a mixed state.

  By adopting the counter-current washing operation as described above, an aqueous suspension containing hydrolyzed biomass that moves from the upper part to the lower part, which is hydrolyzed by the solid-liquid separator S Since the hydrolysis products (monosaccharides, oligosaccharides, furfurals, etc.) in the suspension from which a part has been removed can be transferred to the washing liquid and recovered as a hydrolysis treatment liquid taken out to the transfer pipe 3 The loss of the hydrolysis product accompanying the suspension containing the hydrolyzed biomass and being discharged into the pipeline 2 together with the hydrolyzed suspension from the outlet B at the bottom of the hydrolyzer R1 is suppressed. There is a merit.

(Primary hydrolysis conditions)
In the method of the present invention, the hydrolysis treatment in the primary hydrolysis apparatus R1 can be performed using a method such as hydrothermal treatment, acid treatment, alkali treatment under pressure, but the monosaccharides and oligosaccharides produced In order to efficiently recover furfurals, a treatment using pressurized or heated water or an aqueous acid solution is desirable. In the case of treatment with pressurized and heated water, the biomass is mixed with water and hydrolyzed by applying pressure and heating. As a method for the acid aqueous solution treatment, biomass is mixed with water containing an acid, and hydrolyzed by pressurization and heating. The acid used in the acid aqueous solution treatment is not particularly limited, and sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, oxalic acid, and the like can be used.

The pH of the aqueous suspension containing biomass to be subjected to hydrolysis treatment is preferably in the range of 0.5 to 5.0.
Although it can carry out at 120-250 degreeC as a temperature of a hydrolysis process, 140-230 degreeC is preferable and 150-180 degreeC is more preferable.
The hydrolysis treatment pressure is preferably 0.35 MPa to 2.8 MPa.
The mass ratio (aqueous liquid / biomass) of the aqueous liquid and biomass mixed with the biomass is preferably in the range of 2-8. A biomass and an aqueous liquid are mixed to prepare an aqueous suspension raw material, which is supplied to a primary hydrolysis apparatus and hydrolyzed at a predetermined temperature and pressure in the hydrolysis apparatus.

The hydrolysis treatment time of biomass can be appropriately selected according to the type of biomass, the temperature in the primary hydrolysis apparatus R1, and the like. For example, when the hydrolysis treatment is performed at 140 to 230 ° C., the hydrolysis treatment time is appropriately selected within the range of 0.5 to 180 minutes.
By hydrolyzing under the above conditions, hydrolyzed biomass mainly composed of cellulose, furfurals that are hydrolyzed products of hemicellulose in the biomass, and various oligos that are hydrolyzed products of hemicellulose and cellulose. A hydrolyzed suspension comprising a hydrolyzed liquid containing saccharides, monosaccharides and the like is obtained.

  Examples of the generated furfural include furfural and 5-hydroxymethylfurfural. Examples of oligosaccharides to be generated include xylooligosaccharides, cellooligosaccharides, galactooligosaccharides, and the like. Sugar is also included. Examples of monosaccharides to be generated include xylose, arabinose, glucose, galactose, mannose and the like.

  The hydrolyzed suspension containing the biomass hydrolyzed in the primary hydrolyzer R1 is water-soluble and hydrolyzed by the solid-liquid separator S installed at the intermediate position of the primary hydrolyzer R1. After the primary hydrolysis treatment liquid composed of the aqueous solution containing the product is separated and taken out from the intermediate outlet G to the transfer pipe 3, the primary hydrolysis is carried out as a suspension containing hydrolysis treatment biomass mainly composed of cellulose. It is discharged out of the apparatus from the transfer pipe 2 for the hydrolyzed suspension connected to the outlet B of the apparatus R1. A hydrolyzed suspension that moves in the direction of the discharge port B from the solid-liquid separator S at the intermediate position of the primary hydrolyzer R1 is supplied from the cleaning liquid supply device W into the primary hydrolyzer R1 through the supply line 6. It can also be cleaned and discharged from the outlet by making countercurrent contact with the cleaning liquid.

Solid content composed of biomass mainly composed of cellulose in the hydrolysis-treated suspension discharged from the primary hydrolysis apparatus R1 to the transfer pipeline 2 of the hydrolysis-treated suspension is a raw material for producing useful components derived from biomass. Can be used.
Moreover, since it can be sent to a cooking process by the solid content transfer pipe line 7 and can be used as a raw material for pulp production, the hydrolysis method of the present invention is a pre-hydrolysis which is a pre-process of kraft cooking in a dissolving pulp manufacturing process. It can also be a process.

When primary hydrolysis treatment (prehydrolysis) is performed in the primary hydrolysis apparatus R1 for the purpose of producing dissolved pulp, the primary hydrolysis treatment is performed under conditions suitable for producing dissolved pulp (conditions for preventing excessive decomposition of cellulose). Therefore, the furfurals, monosaccharides and oligosaccharides obtained as by-products cannot be efficiently produced only by the primary hydrolysis treatment. However, even when such a primary hydrolysis treatment is performed, furfurals are efficiently produced by subjecting the hydrolysis treatment liquid obtained by the primary hydrolysis apparatus R1 to a secondary hydrolysis treatment. It is possible.
In the method of the present invention, the primary hydrolysis treatment liquid taken out from the primary hydrolysis apparatus R1 to the transfer pipe 3 is supplied to the secondary hydrolysis apparatus R2.

(Secondary hydrolysis equipment)
The secondary hydrolysis apparatus R2 used in the method of the present invention is a continuous or batch hydrolysis apparatus that can hydrolyze the primary hydrolysis treatment liquid under pressure and heating conditions. Although the form of secondary hydrolysis apparatus R2 is not specifically limited, For example, secondary reaction kettle BR2 as shown in FIG. 1 is mentioned.
The secondary hydrolysis apparatus R2 can also install a plurality of apparatuses in parallel, and can simultaneously treat the primary hydrolysis treatment liquid with the plurality of secondary hydrolysis apparatuses.

  In the apparatus of FIGS. 1 to 4, the primary hydrolysis treatment liquid is taken out in the form of an aqueous solution from the intermediate outlet G of the primary hydrolysis apparatus R1 to which the transfer pipe 3 is connected, and is pressurized and heated for hydrolysis. Is supplied to the secondary reaction vessel BR2. The supply of the primary hydrolysis treatment liquid to the secondary reaction kettle BR2 may be continuous or intermittent.

(Secondary hydrolysis conditions)
In the method of the present invention, the hydrolysis treatment in the secondary hydrolysis apparatus R2 can be carried out using a method such as hot water treatment, acid treatment, alkali treatment under pressure, but the generated furfurals are efficiently treated. In order to recover the water, a treatment using pressurized or heated water or an aqueous acid solution is desirable. As a method of the acid aqueous solution treatment, water containing an acid is mixed with the primary hydrolysis treatment liquid, and hydrolysis is performed by applying pressure and heating. The acid used in the acid aqueous solution treatment is not particularly limited, and sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, acetic acid, oxalic acid, and the like can be used.

The pH of the primary hydrolysis treatment solution supplied to the secondary hydrolysis apparatus is preferably in the range of 0.5 to 5.0.
Although it can carry out at 120-250 degreeC as a temperature of a hydrolysis process, 140-230 degreeC is preferable and 170-200 degreeC is more preferable. If it exceeds 230 ° C., furfural tends to polymerize and the loss of furfural tends to proceed, which is not preferable. The pressure is preferably 0.35 to 2.8 MPa.

  When the method of the present invention is carried out batchwise using the apparatus of FIG. 1, the valve V (transfer line 21) at the top of the secondary hydrolysis apparatus (secondary reaction kettle BR2) is opened after the secondary hydrolysis treatment, The phase is removed and transferred to the distillation apparatus EV, and the furfural concentrate is separated by the distillation apparatus EV. On the other hand, in the case of continuous operation, a pressure reducing valve is used as an alternative to the valve V (transfer line 21) at the upper part of the secondary hydrolysis apparatus (secondary reaction kettle BR2), and the pressure reducing valve is used while performing the secondary hydrolysis treatment And the vapor phase is taken out, transferred to the distillation apparatus EV, and the furfural-containing concentrate is separated by the distillation apparatus EV. The vapor phase taken out from the secondary hydrolysis apparatus (batch type or continuous type) may be condensed in the condenser C (condenser) before being transferred to the distillation apparatus EV. The distillation apparatus EV for distilling and concentrating a vapor phase containing furfurals may be an apparatus in which a plurality of devices are installed in series or in parallel. The method of distilling the vapor phase taken out from the secondary hydrolyzer with the distillation device can reduce the amount of liquid to be distilled compared to the method of distilling the secondary hydrolyzed liquid (liquid phase) directly with the distiller. The time required for this can be shortened, and the energy required for distillation can also be reduced, so that the productivity of furfurals, monosaccharides and oligosaccharides is increased.

The liquid phase obtained by separating the vapor phase in the secondary hydrolysis apparatus mainly contains monosaccharides and oligosaccharides. The liquid phase from which the vapor phase has been removed can be taken out to the liquid phase extraction pipe 11 and transferred to a process for separating and purifying oligosaccharides and monosaccharides, or stored in a tank or the like. When storing in a tank etc., you may install the cooling device which cools aqueous solution containing saccharides etc. taken out as a liquid phase after a secondary hydrolysis apparatus.
In addition, when furfurals are produced from oligosaccharides or monosaccharides in the pipeline after being taken out into the liquid phase transfer pipeline 11, the furfurals are separated and recovered by transfer to a concentration / separation apparatus or distillation apparatus. You can also As the concentration separator, a flash tank, a flash cyclone, or the like is used.

Since the liquid phase after removing the vapor phase contains an organic acid such as acetic acid that promotes hydrolysis of biomass in addition to saccharides composed of oligosaccharides and monosaccharides as main components, as shown in FIG. In addition, the mixture can be circulated and mixed into the raw material suspension in the supply line 1 at the top of the primary hydrolysis apparatus R1 via the circulation line 22 of the aqueous solution containing sugars or the like.
When a saccharide-containing liquid composed of a liquid phase after removing the vapor phase is circulated and supplied to the primary hydrolysis apparatus, the contained oligosaccharides and monosaccharides are decomposed into furfurals. In addition, the hydrolysis of monosaccharides and oligosaccharides is promoted by the primary hydrolysis treatment with the organic acid, and the yield of furfural is improved.

  As shown in FIG. 3, the saccharide-containing liquid taken out as the liquid phase after removing the vapor phase is supplied to the secondary hydrolysis apparatus via the circulation line 24 for the saccharide-containing liquid. It can also be circulated and supplied to the transfer line 3. By supplying the liquid phase (liquid containing saccharides or the like) after removing the vapor phase to the primary hydrolysis treatment liquid supplied to the secondary hydrolysis apparatus, oligosaccharides and monosaccharides are decomposed into furfurals. In addition, the hydrolysis of monosaccharides and oligosaccharides is promoted by the secondary hydrolysis treatment with the organic acid, and the yield of furfural is improved.

As shown in FIG. 1, the liquid phase (liquid containing saccharides, etc.) after removing the vapor phase is energized by a transfer line 27 for liquids containing saccharides etc. branched from the circulation line 22 for liquids containing saccharides etc. It can also be transferred to a boiler (recovery boiler BO) for recovering and recovered as energy. As a boiler, in a pulp manufacturing process, a black liquor recovery boiler is mentioned, for example. The saccharide-containing liquid from the secondary hydrolysis apparatus may be concentrated by a vacuum concentration apparatus or the like before being transferred to the boiler.
The energy recovered by the recovery boiler can be used in the production process of furfurals, monosaccharides and oligosaccharides.

  The liquid phase (liquid containing saccharides, etc.) after removing the vapor phase by the secondary hydrolysis apparatus may be newly generated in the middle of the furfurals remaining in the liquid phase and the transfer process. In order to recover the furfurals, the saccharide-containing liquid can be transferred to a step of recovering an additional amount of furfurals for processing.

As shown in FIG. 4, the furfurals remaining in the liquid phase after the vapor phase is removed by the secondary hydrolysis apparatus are reduced by reducing the pressure in the secondary hydrolysis apparatus R2 using the pressure reduction apparatus VAC. Further furfurals can be recovered from the phase. Further, furfurals can be recovered from the liquid phase by blowing air or steam into the liquid phase after the vapor phase is removed by the secondary hydrolysis apparatus. By the above operation, there is an advantage that a fraction containing furfurals and a fraction containing saccharides can be easily separated.
In addition, furfurals can be efficiently recovered with reduced energy costs.

(Oligosaccharide, monosaccharide separation process)
Monosaccharides and oligosaccharides contained in the liquid phase (sugar-containing liquid) after removing the vapor phase can be separated and purified by a method generally used in a sugar purification process. An evaporator or the like can be used as an apparatus for concentrating a saccharide sugar-containing liquid containing monosaccharides and oligosaccharides. In addition, oligosaccharides can be concentrated using UF membrane (ultrafiltration membrane), RO membrane (reverse osmosis membrane), NF membrane (nanofiltration), molecular sieve chromatography, simulated moving bed chromatography, etc. Saccharides and monosaccharides can be separated. Impurities such as coloring components contained in the saccharide sugar-containing liquid can be removed using activated carbon, a cation exchange resin, an anion exchange resin, an adsorption resin, or the like. The aqueous solution containing the purified monosaccharide can be purified by crystallization. Moreover, it is also possible to pulverize the refined sugar solution using a spray dryer or a freeze-drying apparatus.

  Hereinafter, the method of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Examples 1-5
A raw material suspension containing raw material biomass is prepared by mixing eucalyptus and perita chips (thickness 2 mm) and ion-exchanged water at a ratio of 5 parts by weight of ion-exchanged water to 1 part by weight of chip (dry). did.
The raw material suspension is continuously supplied at 400 parts by mass / hour from the raw material suspension supply pipe 1 connected to the top supply port A of the primary hydrolysis apparatus R1 (manufactured by Kimura Chemical Co., Ltd.) shown in FIG. Then, hydrolysis is performed at 170 ° C. and 0.79 MPa in the primary hydrolysis device R1, and the hydrolyzed raw material-containing suspension is hydrolyzed by opening the decompression valve VP from the bottom outlet B of the hydrolysis device. The suspension was continuously discharged to the transfer line 2. The residence time in the hydrolysis apparatus was set to 3 hours.
Further, the cleaning water is supplied from the counter-current cleaning liquid supply device W at the bottom of the apparatus through the supply pipe 6 at 400 parts by mass / hour, and a stainless steel wire mesh having an opening of 80 μm at the center of the hydrolysis apparatus (solid-liquid separation apparatus S). ) Is placed in countercurrent contact with the hydrolyzed suspension that moves downward from the intermediate outlet G at the center of the primary hydrolyzer R1.
From 3 hours after the start of the supply of the raw material suspension, the hydrolysis treatment suspension is maintained in the state where the temperature and pressure in the hydrolysis apparatus are maintained from the intermediate outlet G (position of the hydrolysis treatment time of 1.5 hours). The primary hydrolysis treatment liquid (260 parts by mass / hour) was taken out by opening the valve V of the transfer line 3 and transferred to the secondary reaction vessel BR2.
When the amount of the primary hydrolysis treatment liquid transferred to the secondary reaction kettle BR2 reached 100 L, the valve V (pipe 3) was closed to stop the transfer of the primary hydrolysis treatment liquid from the primary hydrolysis apparatus. . However, in the example in which the pressure in the primary hydrolysis apparatus is higher than the pressure in the secondary hydrolysis apparatus, the primary hydrolysis treatment liquid was taken out using the pressure reducing valve VP instead of the valve V (not shown). . Sulfuric acid was added to the primary hydrolysis treatment liquid transferred to the secondary reaction kettle BR2 so that the sulfuric acid concentration was 0.3% (W / V).

Next, the secondary hydrolysis treatment with the sulfuric acid added thereto as described above was subjected to secondary hydrolysis treatment at 200 ° C. in the secondary reaction kettle BR2. The reaction time of the secondary hydrolysis treatment was 10 minutes (Example 1), 30 minutes (Example 2), 60 minutes (Example 3), 120 minutes (Example 4), and 180 minutes (Example 5). did. After the secondary hydrolysis treatment, the vapor phase is taken out by opening the valve V of the vapor phase transfer line 21 connected to the secondary reaction kettle BR2, and the vapor phase is cooled to 100 ° C. with the condenser C. It extracted to the transfer pipe line 4 as a condensate (furfural containing aqueous solution). The taken out condensate was sent to a distillation apparatus EV and concentrated, and a concentrate (20 ° C.) containing furfurals was recovered from the furfurals concentrated liquid recovery line 25. The content of furfural contained in the recovered furfural concentrate was measured by the following method, and the yield of furfural with respect to the raw material (dry mass) was calculated.
Further, the energy required for distillation required for recovery per kg of furfural (MJ / furfural-kg) and the time required for distillation of furfurals (minute / furfural-kg) were measured.
Further, the liquid phase after the vapor phase is removed is taken out by the transfer line 11 at the bottom of the secondary reaction kettle BR2, and monosaccharides and oligosaccharides contained in the liquid phase are measured by the following method to obtain a raw material (dried The yields of monosaccharides and oligosaccharides relative to (mass) were calculated. The results are shown in Table 1.

[Sugar analysis]
For sugar analysis, a sugar analysis system (ICS5000) manufactured by DIONEX was used. Carbo Pac PA-1 (2 × 250 mm) was used as a column, and a monosaccharide was eluted at a flow rate of 0.25 ml / min using a 20 mM NaOH solution as an eluent. For detection, a pulse amperometry detector was used. Glucose, galactose, mannose, arabinose, and xylose were used as preparations of monosaccharides. A calibration curve for each of these components was prepared, and the content of each monosaccharide in the sample was determined.

[Calculation of oligosaccharide content]
The value obtained by subtracting the content of each monosaccharide in the sample before hydrolysis with 4% by mass sulfuric acid from the total amount of sugar in the sample was taken as the oligosaccharide content.

[Quantitative determination of furfurals]
For the determination of furfurals, an HPLC system manufactured by Agilent Technologies was used. The column was Aminex HPX87P (7.8 × 300 mm) manufactured by Bio-Rad, and 5 mM sulfuric acid was used as an eluent to elute furfurals at a flow rate of 1 ml / min. A UV-Vis detector was used for detection. Using a furfural as a standard for furfurals, a calibration curve was created to determine the content in the sample.

Comparative Examples 1-5
A primary hydrolysis treatment and a secondary hydrolysis treatment were performed in the same manner as in Example 1 using the apparatus shown in FIG. The reaction time for the secondary hydrolysis treatment was 10 minutes (Comparative Example 1), 30 minutes (Comparative Example 2), 60 minutes (Comparative Example 3), 120 minutes (Comparative Example 4), and 180 minutes (Comparative Example 5). did.
After the secondary hydrolysis treatment, the total amount of the secondary hydrolysis treatment product in the secondary reaction vessel BR2 is transferred to the transfer line 11a after the pressure in the secondary hydrolysis apparatus (secondary reaction vessel BR2) reaches normal pressure. The valve V was opened and taken out, transferred to the distillation apparatus EV, and separated by distillation with the distillation apparatus EV, and the furfural-containing concentrate was recovered from the recovery line 25. On the other hand, an aqueous solution containing monosaccharides and oligosaccharides was recovered from the recovery line 26.
The content of furfurals contained in the furfurals-containing concentrated solution was measured by the same method as in Example 1, and the yield of furfurals with respect to the raw material (dry mass) was calculated. Further, the energy required for distillation required for recovery per kg of furfural (MJ / furfural-kg) and the time required for distillation of furfurals (minute / furfural-kg) were measured. In addition, the monosaccharides and oligosaccharides contained in the aqueous solution recovered from the recovery line 26 of the aqueous solution containing sugars and the like of the distillation apparatus EV are measured by the same method as in Example 1, and the monosaccharides and oligos relative to the raw material (dry mass) are measured. The yield of saccharide was calculated. The results are shown in Table 1.

  Vapor taken out from secondary reaction kettle BR2 after secondary hydrolyzing treatment (200 ° C.) in batch type secondary hydrolyzing apparatus (secondary kettle BR2) of Examples 1 to 5 In the method of recovering furfurals from the phase with a distillation apparatus and recovering monosaccharides and oligosaccharides from the liquid phase taken out from the secondary reaction kettle, the secondary reaction kettle after the secondary hydrolysis treatment of Comparative Examples 1 to 5 Compared with the method of separating and recovering the furfurals, monosaccharides and oligosaccharides by directly sending the total amount of the secondary hydrolysis treatment liquid to a distillation apparatus, the energy required for distillation could be reduced. Moreover, since the amount of the vapor phase containing furfurals can be reduced, the time required for concentrating the furfurals with a distillation apparatus can be shortened. From the above results, it has been found that efficient production of furfurals, monosaccharides and oligosaccharides is possible by the methods of Examples 1 to 5.

Examples 6-10
In Example 1, in secondary reaction kettle BR2, at 170 ° C., 10 minutes (Example 6), 30 minutes (Example 7), 60 minutes (Example 8), 120 minutes (Example 9), 180 minutes The secondary hydrolysis treatment was performed in the reaction time of (Example 10). The other operations were performed in the same manner as in Example 1. The results are shown in Table 2.

Comparative Examples 6-10
In Comparative Example 1, in the secondary reaction kettle BR2, at 170 ° C. for 10 minutes (Comparative Example 6), 30 minutes (Comparative Example 7), 60 minutes (Comparative Example 8), 120 minutes (Comparative Example 9), 180 minutes ( The secondary hydrolysis treatment was performed for the reaction time of Comparative Example 10). Other operations were carried out in the same manner as in Comparative Example 1. The results are shown in Table 2.

  A secondary hydrolysis treatment (170 ° C.) was performed in the batch type secondary hydrolysis apparatus (secondary reaction kettle BR2) of Examples 6 to 10, and the furfurals were removed from the vapor phase taken out from the secondary reaction kettle BR2 by a distillation apparatus. In the method of recovering monosaccharides and oligosaccharides from the liquid phase taken out from the secondary reaction kettle BR2, the total amount of hydrolysis treatment products in the secondary reaction kettle BR2 of Comparative Examples 6 to 10 is directly distilled. Compared with the method of separating and recovering furfurals from monosaccharides and oligosaccharides, the energy required for distillation could be reduced. Moreover, since the amount of the aqueous solution containing furfurals can be reduced, the time required for concentrating the furfurals with a distillation apparatus can be shortened.

Examples 11-15
In Example 1, it is 10 minutes (Example 11), 30 minutes (Example 12), 60 minutes (Example 13), 120 minutes (Example 14), 180 minutes at 140 ° C. in the secondary reaction kettle BR2. The secondary hydrolysis treatment was performed in the reaction time of (Example 15). The other operations were performed in the same manner as in Example 1. The results are shown in Table 3.

Comparative Examples 11-15
In Comparative Example 1, in the secondary reaction kettle BR2 at 140 ° C., 10 minutes (Comparative Example 11), 30 minutes (Comparative Example 12), 60 minutes (Comparative Example 13), 120 minutes (Comparative Example 14), 180 minutes ( The secondary hydrolysis treatment was performed for the reaction time of Comparative Example 15). Other operations were carried out in the same manner as in Comparative Example 1. The results are shown in Table 3.

  In the batch-type secondary hydrolysis apparatus (secondary reaction vessel BR2) of Examples 11 to 15, secondary hydrolysis treatment (140 ° C.) is performed, and the furfurals are obtained from the vapor phase taken out from the secondary reaction vessel BR2 using a distillation apparatus. In the method of recovering the monosaccharide and oligosaccharide from the liquid phase taken out from the secondary reaction kettle BR2, the hydrolysis treatment in the secondary kettle BR2 after the secondary hydrolysis treatment of Comparative Examples 11-15 Compared with the method in which the entire amount of the product was sent directly to a distillation apparatus to separate and recover the furfurals, monosaccharides and oligosaccharides, the energy required for distillation could be reduced. Moreover, since the amount of the aqueous solution containing furfurals can be reduced, the time required for concentrating the furfurals with a distillation apparatus can be shortened.

Examples 16-20
The primary hydrolysis treatment was performed in the same manner as in Example 1 using the apparatus shown in FIG. The primary hydrolysis treatment liquid (260 parts by mass / hour) was continuously removed by opening the valve V of the transfer line 3 and transferred to the secondary reaction kettle BR2. Secondary hydrolysis was continuously performed at 170 ° C. in the secondary reaction vessel BR2. The residence time of the secondary hydrolysis treatment (secondary reaction kettle BR2) is 10 minutes (Example 16), 30 minutes (Example 17), 60 minutes (Example 18), 120 minutes (Example 19), 180 minutes. (Example 20). After the start of the secondary hydrolysis treatment, the vapor phase transfer line 21 connected to the secondary reaction vessel BR2 is opened (pressure reduction valve) to continuously take out the vapor phase. After cooling to 0 ° C., a condensate (furfural-containing aqueous solution) was taken out to the transfer line 4. The condensate was transferred to the distillation apparatus EV and concentrated, and a concentrate containing furfurals was recovered from the recovery line 25.
The content of the furfural contained in the furfural concentrate was measured by the following method, and the yield of the furfural with respect to the raw material (dry mass) was calculated. Further, the energy required for distillation required for recovery per kg of furfural (MJ / furfural-kg) and the time required for distillation of furfurals (minute / furfural-kg) were measured.
Further, the liquid phase of the secondary reaction kettle is continuously taken out to the transfer line 11 at the bottom of the secondary reaction kettle BR2, and the monosaccharides and oligosaccharides contained in the liquid phase of the secondary reaction kettle are the same as in Example 1. It measured by the method and the yield of the monosaccharide and oligosaccharide with respect to the raw material (dry mass) was computed. The results are shown in Table 4.

Comparative Examples 16-20
The primary hydrolysis treatment and the secondary hydrolysis treatment were performed in the same manner as in Example 16 using the apparatus shown in FIG. The reaction time for the secondary hydrolysis treatment was 10 minutes (Comparative Example 16), 30 minutes (Comparative Example 17), 60 minutes (Comparative Example 18), 120 minutes (Comparative Example 19), and 180 minutes (Comparative Example 20). did.
After starting the secondary hydrolysis treatment, the valve (pressure reduction valve) of the pipe line 11a connected to the secondary reaction kettle BR2 is opened, and the secondary hydrolysis treatment liquid is continuously transferred to the distillation device EV. The furfural concentrate was recovered by a recovery line 25.
The content of furfural contained in the furfural concentrate was measured, and the yield of furfural with respect to the raw material (dry mass) was calculated. Further, the energy required for distillation required for recovery per kg of furfural (MJ / furfural-kg) was measured. In addition, the monosaccharides and oligosaccharides contained in the aqueous solution recovered from the pipeline 26 of the distillation apparatus EV are measured by the same method as in Example 1, and the yields of the monosaccharides and oligosaccharides relative to the raw material (dry mass) are calculated. did.
The results are shown in Table 4.

A secondary hydrolyzing treatment (170 ° C.) was performed in the continuous secondary hydrolyzing apparatus (secondary reaction kettle BR2) of Examples 16 to 20, and a distillation apparatus was obtained from the vapor phase continuously taken out from the secondary reaction kettle BR2. In the method of recovering furfurals in the above and recovering monosaccharides and oligosaccharides from the liquid phase taken out from the secondary reaction kettle BR2, the continuous secondary hydrolysis apparatus (secondary kettle BR2) of Comparative Examples 16-20 is used. A secondary hydrolysis process (170 ° C) is performed in the process, and furfurals (gas phase), monosaccharides and oligosaccharides (liquid phase) are separated and recovered continuously from the secondary hydrolysis process liquid using a distillation apparatus. Compared with, the energy required for distillation could be reduced. Moreover, since the volume of the aqueous solution containing furfurals could be reduced, the time required for concentration of furfurals with a distillation apparatus could be shortened.
Furthermore, in Examples 16 to 20, saccharides (monosaccharides and oligosaccharides) contained in the hydrolyzate are obtained by continuously removing furfurals (vapor phase) from the secondary reaction vessel BR2 in the secondary hydrolysis treatment. It is presumed that the yield of furfurals was improved as a result of the suppression of the side reaction between the saccharides and furfurals and the promotion of the production of mono- and oligosaccharides into furfurals.

Example 21
It implemented by the method similar to Example 17 with the apparatus shown in FIG. However, after starting the secondary hydrolysis treatment, the valve (pressure reducing valve) of the transfer line 11 of the secondary reaction vessel BR2 is opened to continuously take out the liquid phase from the secondary reaction vessel BR2, and a part of the liquid phase ( 100 parts by mass / hour) was continuously circulated and supplied to the primary hydrolysis treatment liquid (line 3) supplied to the secondary reaction vessel BR2 via the circulation line 24. All other operations were tested in the same manner as in Example 17. The results are shown in Table 5.

Comparative Example 21
In Example 21, a test in which the liquid phase taken out from the secondary reaction kettle was not circulated was performed as Comparative Example 21 (same as Example 17). The results are shown in Table 5.

  In the test (Example 21) in which the liquid phase taken out from the secondary reaction kettle BR2 to the transfer line 11 was continuously circulated (Furfural compared with the test in which the secondary hydrolysis treatment liquid was not circulated (Comparative Example 21)). The yield of the product was improved.

Example 22
The test was carried out in the same manner as in Example 7. After the secondary hydrolysis treatment, the vapor phase was taken out by opening the valve V of the transfer line 21 connected to the secondary reaction vessel BR2, and the same as in Example 7. In this way, a concentrated liquid (20 ° C.) containing furfurals was recovered from the vapor phase (furfurals concentrated liquid A).
Next, as shown in FIG. 4, the secondary reaction kettle BR2 (liquid phase) is maintained at 90 ° C., and the pressure in the secondary reaction kettle BR2 is reduced using the pressure reducing device VAC, and steam containing furfurals from the liquid phase. The phase was removed to transfer line 21 and sent to condenser C for condensation. The condensate was sent to a distillation apparatus EV and concentrated to recover a concentrate (20 ° C.) containing furfurals (furfurals concentrate B).
The content of furfurals contained in each of the above-mentioned furfural concentrates (furfural concentrate A and furfural concentrate B) is measured, and the yield of furfurals relative to the raw material (dry mass) (furfural concentrates A and A). The total value of the furfural concentrate B) was calculated. A test (Example 7) in which the liquid phase after removing the vapor phase after the secondary hydrolysis treatment was not recovered with the decompression device VAC was used as a comparative example. The results are shown in Table 6.

  As a result of further recovering furfural remaining in the liquid phase by distillation under reduced pressure at 90 ° C., the liquid phase after the vapor phase after the secondary hydrolysis treatment was removed, Improved.

  The method of the present invention is based on waste biomass discharged as unnecessary substances in the process of living and industrial activities, raw biomass such as non-edible parts of crops and thinned wood, raw materials such as pharmaceutical intermediates and furan resins. To provide a stable supply of useful substances such as furfurals used as raw materials for furfuryl alcohol, a raw material for plastics, and monosaccharides and oligosaccharides used in foods, food additives, fermentation raw materials, etc. It opens the way and contributes greatly to the fields of forest management and waste disposal.

1: Raw material suspension supply lines 2, 3, 4, 7, 11, 11a, 21, 27: Transfer line 6: Cleaning liquid supply line 7: Solid content transfer line 22, 24: Circulation line 25, 26: Recovery line 27: Transfer line 28: Pressure reduction line A: Raw material suspension supply port B: Hydrolysis treatment suspension discharge port BO: Energy recovery boiler BR2: Secondary reaction kettle C: Condenser EV: Distillation Device VAC: Pressure reducing device G: Intermediate outlet R1: Primary hydrolysis device R2: Secondary hydrolysis device S: Solid-liquid separation device V, VP: Valve W: Cleaning liquid supply device

Claims (8)

Primary biomass is added under pressure and heating conditions that produce monosaccharides, oligosaccharides, and furfurals while continuously supplying an aqueous suspension of biomass from the supply port of a continuous primary hydrolysis device and moving through the device. A hydrolyzed suspension was continuously discharged from the outlet of the primary hydrolyzer, and a solid-liquid separation device was provided at an intermediate position between the supply port and the outlet of the primary hydrolyzer. From the intermediate outlet, the primary hydrolysis treatment liquid separated from the hydrolysis treatment suspension in the apparatus is taken out, and the primary hydrolysis treatment liquid is sent to the secondary hydrolysis apparatus to carry out the secondary hydrolysis treatment. to produce a hydrolysis product, it is taken out by separating the furfural analog-containing vapor phase from the secondary hydrolysis product in the secondary hydrolysis system, distillation and recovered as furfural analog-containing concentrate, the Acquisition of full Removed saccharide-containing liquid which contains monosaccharides and oligosaccharides as a liquid phase after separating Lumpur analog-containing vapor phase, circulated and supplied to together with the primary hydrolysis treatment liquid on at least a portion of the secondary hydrolysis system A method for producing furfurals, monosaccharides and oligosaccharides from biomass, which comprises hydrolyzing . Primary biomass is added under pressure and heating conditions that produce monosaccharides, oligosaccharides, and furfurals while continuously supplying an aqueous suspension of biomass from the supply port of a continuous primary hydrolysis device and moving through the device. A hydrolyzed suspension was continuously discharged from the outlet of the primary hydrolyzer, and a solid-liquid separation device was provided at an intermediate position between the supply port and the outlet of the primary hydrolyzer. From the intermediate outlet, the primary hydrolysis treatment liquid separated from the hydrolysis treatment suspension in the apparatus is taken out, and the primary hydrolysis treatment liquid is sent to the secondary hydrolysis apparatus to carry out the secondary hydrolysis treatment. A hydrolyzed product is produced, and the furfural-containing vapor phase is separated from the secondary hydrolyzed product in the secondary hydrolyzing apparatus, taken out, and subjected to distillation treatment to be recovered as a furfural-containing concentrated liquid. Before taking out a saccharide-containing liquid containing monosaccharides and oligosaccharides as a liquid phase after separating the vapor-containing vapor phase, the pressure in the secondary hydrolysis apparatus is reduced to remove furfural-containing vapor from the liquid phase. The liquid is produced by at least one treatment selected from a treatment for generating and a treatment for generating a furfural-containing vapor from the liquid phase by blowing an inert gas or water vapor into the liquid phase in the secondary hydrolysis apparatus. A method for producing furfurals, monosaccharides and oligosaccharides from biomass , which comprises additionally collecting furfurals remaining in the phase and improving the concentration of sugars in the liquid phase . Before the liquid phase is taken out from the secondary hydrolysis apparatus, the pressure in the secondary hydrolysis apparatus is reduced from the liquid phase to the liquid phase after separating the furfural-containing vapor phase from the secondary hydrolysis treatment product. At least one process selected from a process for generating a furfural-containing vapor and a process for generating a furfural-containing vapor from the liquid phase by blowing an inert gas or water vapor into the liquid phase in the secondary hydrolysis apparatus. The furfurals, monosaccharides and oligos from biomass according to claim 1, wherein the furfurals remaining in the liquid phase are additionally recovered and subjected to a treatment for improving the saccharide concentration in the liquid phase. A method for producing sugars. Primary biomass is added under pressure and heating conditions that produce monosaccharides, oligosaccharides, and furfurals while continuously supplying an aqueous suspension of biomass from the supply port of a continuous primary hydrolysis device and moving through the device. A hydrolyzed suspension was continuously discharged from the outlet of the primary hydrolyzer, and a solid-liquid separation device was provided at an intermediate position between the supply port and the outlet of the primary hydrolyzer. From the intermediate outlet, the primary hydrolysis treatment liquid separated from the hydrolysis treatment suspension in the apparatus is taken out, and the primary hydrolysis treatment liquid is sent to the secondary hydrolysis apparatus to carry out the secondary hydrolysis treatment. A hydrolyzed product is produced, and the furfural-containing vapor phase is separated from the secondary hydrolyzed product in the secondary hydrolyzing apparatus, taken out, and subjected to distillation treatment to be recovered as a furfural-containing concentrated liquid. The saccharide-containing liquid containing monosaccharides and oligosaccharides is taken out from the secondary hydrolyzer as a liquid phase after separating the vapor-containing vapor phase, and the extracted saccharide-containing liquid containing monosaccharides and oligosaccharides is removed. And furfurals, monosaccharides and oligosaccharides from biomass, characterized in that the furfurals newly produced in the saccharide-containing liquid are separated and recovered and subjected to a distillation treatment for improving the saccharide concentration in the saccharide-containing liquid. Manufacturing method. The saccharide-containing liquid that separates and recovers furfurals newly produced in the saccharide-containing liquid with respect to the saccharide-containing liquid containing monosaccharides and oligosaccharides composed of a liquid phase taken out from the secondary hydrolysis apparatus. The method for producing furfurals, monosaccharides and oligosaccharides from biomass according to any one of claims 1 to 3, wherein a distillation treatment for improving the concentration of saccharides therein is performed . Extraction of the furfural-containing vapor phase from the secondary hydrolysis product is performed by continuously removing the furfural-containing vapor phase generated during the secondary hydrolysis process in the secondary hydrolysis apparatus from the secondary hydrolysis apparatus. It is performed by any method selected from a method of taking out and a method of taking out a furfural-containing vapor phase generated from the secondary hydrolysis product after the completion of the secondary hydrolysis treatment from the secondary hydrolysis apparatus , The manufacturing method of the furfurals, monosaccharide, and oligosaccharide from the biomass of any one of Claims 1-5. Aqueous cleaning liquid is supplied into the primary hydrolyzer from the vicinity of the outlet of the continuous primary hydrolyzer, and the hydrolysis treatment is suspended between the intermediate outlet provided with the solid-liquid separator and the outlet. The method for producing furfurals, monosaccharides and oligosaccharides from biomass according to any one of claims 1 to 6, characterized in that they are brought into countercurrent contact with a turbid liquid . The method for producing furfurals, monosaccharides and oligosaccharides from biomass according to any one of claims 1 to 7, wherein the biomass is woody biomass.

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