Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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DESCRIPTION
BIOMASS HYDROTHERMAL DECOMPOSITION APPARATUS AND METHOD
[0001] The present invention relates to a biomass
hydrothermal decomposition apparatus and a method thereof
that enable efficient hydrothermal decomposition of biomass
material, and to an organic material production system
using biomass material, which system enables efficient
production of organic materials such as alcohols,
substitutes for petroleum, or amino acids by using such
apparatus and method.
BACKGROUND ART
[0002] Technologies for producing ethanol or the like
have been commercialized that involve converting woody
biomass or other biomass into sugars with dilute sulfuric
acid or concentrated sulfuric acid, and then subjecting
them to solid-liquid separation, neutralizing the liquid
phase thereof, and utilizing the resultant components as
biomass materials for ethanol fermentation or the like
(Patent Documents 1 and 2). Further, by using sugar as
starting material, production of chemical industrial raw
material (e.g., lactic fermentation) has been considered.
Biomass as used herein refers to a living organism
integrated in material circulation in the global biosphere
or accumulation of organic materials derived from living
organisms (see JIS K 3600 1258).
[0003] Sugarcane, corn, and other materials, currently
used as alcohol raw materials, have been originally used
for food. Using such food resources as long-term stable
industrial resources is not preferable in view of life
cycle of valuable food.
[0004] For this reason, it is a challenge to efficiently
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use cellulose resources such as herbaceous biomass and
woody biomass, which are considered as potentially useful
resources.
[0005] Cellulose resources include cellulose ranging
from 38% to 50%, hemicelluloses components ranging from 23%
to 32%, and lignin components, which are not used as
fermentation materials, ranging from 15% to 22%. Due to
many challenges, the industrial studies have been conducted
targeting certain fixed materials, and no technologies have
been disclosed yet on production systems taking into
account diversity of the materials.
[0006] Production systems targeting fixed materials see
almost no point regarding countermeasures for waste
problems and global warming, because those systems have
attempted such countermeasures with a method that brings
more disadvantages to fermentation materials than starch
materials. Thus, there has been a need for a method
applicable to a variety of wastes in broader sense.
Enzymatic saccharification methods are also considered as a
future challenge due to its low efficiency. Acid treatment
only achieves a low saccharification rate of about 75% (a
basis for components that can be saccharified), due to
excessive decomposition of sugar. Thus, the ethanol yield
achieves only 25% by weight of cellulose resources (Non-
Patent Document 1 and Patent Document 3).
[0007] [Patent Document 1] Japanese Patent Application
Laid-open No. 9-507386
[Patent Document 2] Japanese Patent Application Laid-open
No. 11-506934
[Patent Document 3] Japanese Patent Application Laid-open
No. 2005-168335
[Non-Patent Document 1] Nikkei Biotechnology & Business, p.
52, September 2002
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[Non-Patent Document 2] Biomass-Extensive Use of
Bioresources, edited by Japanese Society for Bioscience,
Biotechnology, and Agrochemistry, Asakura Publishing Co.,
Ltd., September 1985
DISCLOSURE OF INVENTION
PROBLEM TO BE SOLVED BY THE INVENTION
[0008] In the proposals disclosed in Patent Documents 1
and 2 above, sulfuric acid necessary for reaction needs to
be constantly supplied from outside the reaction system.
With increasing the production scale, this poses problems,
such as increasing the cost for purchasing equipment
resistant to the acid and large amounts of sulfuric acid,
while increasing the cost for disposing used sulfuric acid
(e.g., cost for processing with a gypsum desulfulation),
and the cost for recovering such sulfuric acid.
[0009] The proposal disclosed in Patent Document 3 above
involves subjecting various types of cellulose resources to
hydrothermal treatment, and converting them into sugars
with enzymatic saccharification. During the hydrothermal
treatment, cellulase inhibitors such as lignin components
(Non-Patent Document 2) that inhibit enzymatic
saccharification of cellulose are not removed and mixed
with cellulose. This poses a problem of reducing the
efficiency in cellulose enzymatic saccharification.
[0010] Other than cellulose, hemicellulose components
are also contained in cellulose resources. This poses a
problem that enzymes respectively suitable for cellulose
and hemicellulose components are necessary for enzymatic
saccharification.
[0011] The resulting sugar solution includes a hexose
solution from cellulose, and a pentose solution from
hemicellulose components. For example, for alcohol
fermentation, yeasts suitable for the respective solutions
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are necessary. Thus, alcohol fermentation needs to be
improved low efficiency for fermenting a mixture of a
hexose solution and a pentose solution.
[0012] As such, conventional technologies have caused a
phenomenon that side reaction products inhibit enzymatic
saccharification, reducing the sugar yield. Thus, what has
been needed is a hydrothermal decomposition apparatus that
removes inhibitors for enzymatic saccharification and
thereby improves enzymatic saccharification of cellulose-
based components.
[0013] In view of the foregoing problems, the present
invention has an object to provide: a biomass hydrothermal
decomposition apparatus and a method thereof that enable
separation of cellulose-based components from biomass
material; and an organic material production system using
biomass material, which can efficiently produce a sugar
solution using such apparatus and method, and can
efficiently produce various types of organic materials
(e.g., alcohols, substitutes for petroleum, or amino acids)
using the sugar solution as a base material.
MEANS FOR SOLVING PROBLEM
[0014] According to an aspect of the present invention, a
biomass hydrothermal decomposition apparatus includes: a biomass
feeder that feeds biomass material under noLmal pressure to under
increased pressure; a hydrothermal decomposition device
that allows the fed biomass material to be conveyed inside
a device main body from either end thereof with a screw
unit, and also allows hot compressed water to be fed from
an other end of a feed section for the biomass material
into the main body, so as to cause the biomass material and
the hot compressed water to countercurrently contact with
each other and undergo hydrothermal decomposition, and that
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transfers a lignin component and a hemicellulose component into
the hot compressed water, so as to separate the lignin
component and the hemicellulose component from the biomass
material; and a biomass discharger that discharges, from an
upper end of the device main body, a biomass solid residue
under increased pressure to under normal pressure.
[0015] Advantageously, in the biomass hydrothermal
decomposition apparatus, the conveying screw unit includes a
scraper that prevents occlusion of an outlet for discharged hot
water.
[0016] Advantageously, in the biomass hydrothermal
decomposition apparatus, the hydrothermal decomposition device
has a reaction temperature ranging from 180 C to 240 C and has
a condition of hot compressed water.
[0017] Advantageously, in the biomass hydrothermal
decomposition apparatus, a weight ratio of the fed biomass
material to the fed hot compressed water is within 1:1 to 1:10.
[0017a] Another aspect of the invention relates to a biomass
hydrothermal decomposition apparatus comprising: a biomass
feeder configured to receive biomass material under normal
pressure and feed the biomass material under normal pressure to
under increased pressure; a hydrothermal decomposition device
that allows the biomass material under increased pressure to be
conveyed inside a device main body from a lower end side
thereof with a screw unit, and also allows hot compressed water
to be fed from an upper end side thereof into the main body,
the hydrothermal decomposition device configured to transfer a
lignin component and a hemicellulose component into the hot
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compressed water, and to separate the lignin component and the
hemicellulose component from the biomass material by
countercurrent contact of the biomass material and the hot
compressed water, and hydrothermal decomposition; and a biomass
discharger positioned near an upper end of the hydrothermal
decomposition device configured to receive a biomass solid
residue under increased pressure and discharge it under normal
pressure.
[0018] According to another aspect of the present invention,
a method for biomass hydrothermal decomposition includes:
feeding biomass material under normal pressure to under
increased pressure; allowing the fed biomass material to be
conveyed inside a device main body from either end thereof with
a screw unit, and also allowing hot compressed water to be fed
from another end of a feed section for the biomass material
into the main body, so as to cause the biomass material and the
hot compressed water to countercurrently contact with each
other and undergo hydrothermal decomposition; transfering a
lignin component and a hemicellulose component into the hot
compressed water, so as to separate the lignin component and
the hemicellulose component from the biomass material; and
discharging, from an upper end of the device main body, a
biomass solid residue under increased pressure to under normal
pressure.
[0018a] Another aspect of the invention relates to a method
for biomass hydrothermal decomposition comprising: feeding
biomass material under normal pressure to under increased
pressure; allowing the biomass material under increased
pressure to be conveyed inside a device main body from a lower
end side thereof with a screw unit, and also allowing hot
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compressed water to be fed from an upper end side thereof into
the device main body, so as to cause the biomass material and
the hot compressed water to countercurrently contact with each
other and undergo hydrothermal decomposition; transferring a
lignin component and a hemicellulose component into the hot
compressed water, so as to separate the lignin component and
the hemicellulose component from the biomass material; and
discharging, from an upper end of the device main body, a
biomass solid residue under increased pressure to under normal
pressure.
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[0019] Advantageously, an organic material production
system using biomass material includes: a pretreatment
device that pretreats the biomass material; the
hydrothermal decomposition apparatus of the present
inventions; a first enzymatic hydrolysis
device that treats, with an enzyme, cellulose in the
biomass solid residue discharged from the hydrothermal
decomposition device, so as to enzymatically hydrolyze the
cellulose to a sugar solution containing hexose; and a
fermenter that produces, using the sugar solution obtained
by the first enzymatic hydrolysis device, any one of
alcohols, substitutes for petroleum, or amino acids by
fermentation.
[0020] Advantageously, the organic material production
system using biomass material includes: a second enzymatic
hydrolysis device that treats, with an enzyme, a
hemicellulose component in discharged hot water, so as to
enzymatically hydrolyze the hemicellulose component to a
sugar solution containing pentose; and a fermenter that
produces, using the sugar solution obtained by the second
enzymatic hydrolysis device, any one of alcohols,
substitutes for petroleum, or amino acids by fermentation.
EFFECT.OF THE INVENTION
[0021] According to the present invention, with use of a
hydrothermal decomposition apparatus that causes biomass
material conveyed by a screw and hot compressed water to
countercurrently contact with each other, side reaction
products (lignin components and hemicellulose components)
resulting from the reaction for producing a target
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component, i.e., cellulose, (that is enzymatically
saccharified to a hexose solution) are transferred into the
hot compressed water. In this way, the cellulose-based
biomass solid residue can be obtained. Accordingly, by
efficiently saccharifying it to the hexose solution and
using the sugar solution as a substrate material, various
types of organic materials (e.g., alcohols, substitutes for
petroleum, or amino acids) can be produced efficiently.
[0022] By causing biomass material and hot compressed
water to countercurrently contact with each other, their
components are sequentially discharged to the outside the
reaction system in order of solubility in the hot water.
Further, due to the temperature gradient from a portion
where the biomass is fed to a portion where the hot water
is fed, excessive decomposition of hemicellulose components
is prevented. As a result, pentose components can be
recovered efficiently.
BRIEF DESCRIPTION OF DRAWINGS
[0023] [Fig. 1] Fig. 1 is a schematic of a hydrothermal
decomposition apparatus according to a first embodiment.
[Fig. 2] Fig. 2 is a schematic of another hydrothermal
decomposition apparatus according to a first embodiment.
[Fig. 3] Fig. 3 is a schematic of another hydrothermal
decomposition apparatus according to a first embodiment.
[Fig. 4] Fig. 4 is a schematic of another hydrothermal
decomposition apparatus according to a first embodiment.
[Fig. 5] Fig. 5 is a schematic of an alcohol production
system according to a second embodiment.
[Fig. 6] Fig. 6 is a schematic of an alcohol production
system according to a third embodiment.
EXPLANATIONS OF LETTERS OR NUMERALS
[0024] 11 biomass material
12 pretreatment device
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13 pulverized biomass
15 hot compressed water
16 discharged hot water
17 biomass solid residue
18 enzyme
19 enzymatic hydrolysis device
19-1 first enzymatic hydrolysis device
19-2 second enzymatic hydrolysis device
20-1 first sugar solution (hexose)
20-2 second sugar solution (pentose)
23 ethanol
41A to 41D hydrothermal decomposition apparatus
BEST MODE(S) FOR CARRYING OUT THE INVENTION
[0025] Exemplary embodiments of the present invention
are described with reference to the accompanying drawings.
The present invention is not limited to the embodiments.
Constituting elements in the embodiments include elements
easily achieved by a person skilled in the art, or elements
being substantially equivalent to those elements.
First Embodiment
[0026] A biomass hydrothermal decomposition apparatus
according to an embodiment of the present invention is
described with reference to the drawings. Fig. 1 is a
schematic of a biomass hydrothermal decomposition apparatus
according to the embodiment. As shown in Fig. 1, a biomass
hydrothermal decomposition apparatus 41A according to the
present embodiment includes: a biomass feeder 31 that feeds
a biomass material 11 under normal pressure to under
increased pressure; the hydrothermal decomposition
apparatus 41A that allows the fed biomass material (e.g.,
straw in the present embodiment) 11 to be gradually
conveyed inside a gradient device main body (hereinafter,
"device main body") 42 from a lower end thereof with a
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conveyor screw 43, and also allows hot compressed water 15
to be fed into the device main body 42 from an upper end
thereof, which is different from a feed section for the
biomass material 11, so as to cause the biomass material 11
and the hot compressed water 15 to countercurrently contact
with each other and undergo hydrothermal decomposition, and
that transfers lignin components and hemicellulose
components into the hot compressed water 15, so as to
separate the lignin components and the hemicellulose
components from the biomass material 11; and a biomass
discharger 51 that discharges a biomass solid residue 17
under increased pressure to under normal pressure, at the
upper end of the device main body 42.
[0027] In the present embodiment, the biomass material
11 is fed from the lower end. The present invention is not
limited to this, and the biomass material 11 may be fed
from the upper end reversely. In this case, the hot
compressed water 15 is fed from the lower end. Examples of
the biomass feeder 31 that feeds biomass under normal
pressure to under increased pressure may include a pump
unit such as a piston pump or a slurry pump.
[0028] In the present embodiment, the hydrothermal
decomposition apparatus 41A is a gradient type apparatus as
shown in Fig. 1. The present invention is not limited to
this, and a vertical hydrothermal decomposition apparatus
41B may be adopted, as shown in Fig. 2. Alternatively, a
horizontal hydrothermal decomposition reactor may be
adopted.
[0029] The apparatus may be arranged as a gradient type
or a vertical type, because it is preferable regarding that
the gas resulting from the hydrothermal decomposition
reaction, the gas brought into the feedstock, and the like
can be released quickly from the upper side. This
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arrangement is also preferable in view of the discharging
efficiency, because decomposed products are discharged with
the hot compressed water 15 and therefore the concentration
of the discharged materials is increased from the upper
side to the lower side.
[0030] By providing the conveyor screw 43, 1) the
delivery of the solid is possible by the counter-current
flow of solid and liquid, 2) the solid-liquid separation is
possible inside the device main body 42, and 3) the hot
compressed water on the surface of the solid and inside the
solid is progressively mixed inside the device main body 42,
so that the reaction is facilitated.
[0031] As shown in a hydrothermal decomposition
apparatus 41C in Fig. 3, the conveyor screw 43 may include
a scraper 43a that prevents occlusion of an outlet 16a for
discharged hot water 16.
[0032] Biomass to be fed to the hydrothermal
decomposition apparatus 41 is not limited to any specific
type, and is a living organism integrated in material
circulation in global biosphere or accumulation of organic
materials derived from living organisms (see JIS K 3600
1258). In the present invention, particularly,
lignocellulose resources of wood materials such as
broadleaf trees and plant materials; agricultural wastes;
and food wastes are preferably used.
[0033] The biomass material 11 is preferably broken into
particles having a diameter of 5 millimeters or less,
though not limited to this particle diameter. In the
present embodiment, biomass may be subjected to
pretreatment with pretreatment equipment such as
pulverizing equipment, before being fed. In addition,
biomass may be cleaned with cleaning equipment. When the
biomass material 11 is rice husk for example, the biomass
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material 11 can be fed to the hydrothermal decomposition
apparatus 41A, without being subjected to pulverization.
[0034] In the hydrothermal decomposition apparatus 41A,
the reaction temperature ranges from 180 C to 240 C
preferably, and from 200 C to 230 C more preferably. This
is because, at temperatures below 180 C, the hydrothermal
decomposition takes place at a low rate and requires a
longer time, increasing the apparatus size, which are not
preferable. On the contrary, at temperatures above 240 C,
the decomposition rate is too high and more cellulose
components are transferred from the solid phase to the
liquid phase, facilitating excessive decomposition of
hemicellulose sugars, which are not preferable.
Dissolution of hemicellulose components starts at about
140 C, dissolution of cellulose starts at about 230 C, and
dissolution of lignin components starts at about 140 C.
The temperature is preferably set within a range from 180 C
to 240 C that allows cellulose to be remained in the
biomass solid residue, and that enables hemicellulose
components and lignin components to be decomposed at
adequate rates.
[0035] The reaction pressure is preferably set to a
pressure higher by 0.1 MPa to 0.5 MPa than the saturated
vapor pressure of water at each temperature, which allows
the hot compressed water to stay inside the device main
body. The reaction time is preferably three minutes to ten
minutes, not more than 20 minutes. This is because a
longer reaction time increases the ratio of excessively
decomposed products and is not preferable.
[0036] According to the present invention, for the
flowage of the hot compressed water 15 and the flowage of
the biomass material 11 inside the device main body 42A of
the hydrothermal decomposition apparatus 41-1A, the hot
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compressed water 15 and the biomass material 11 are
countercurrently contacted, preferably stirred and flowed
by so called counter-current flow.
[0037] In the hydrothermal decomposition apparatus, the
solid of the biomass material 11 is fed from the left side
in the figure, while the hot compressed water 15 is fed
from the right side in the figure. Because the biomass
material 11 and the hot compressed water 15 move in an
opposite direction to one another, the hot compressed water
15 (hot water, the liquid dissolving decomposed products)
is moved while being soaked in solid particles by the
counter-current flow against the solid, the biomass
material 11.
[0038] When countercurrently contacting each other, the
solid biomass material 11 is decomposed with the hot
compressed water 15, and the resulting decomposed products
are dissolved and transferred to the hot compressed water
15.
[0039] As a ratio of the solid to the liquid, the liquid
ratio is preferably less, because it enables reduction in
amount of water to be recovered and in amount of steam used
for heating water. The weight ratio of the biomass
material to the hot compressed water both to be fed is, for
example, 1:1 to 1:10 preferably, and 1:1 to 1:5 more
preferably, though it varies accordingly depending on the
apparatus configuration.
[0040] According to the present embodiment, in a slurry
transport reactor that mixes the biomass material 11 and
water in advance and feeds the mixture into the device main
body, water needs to be added in large amounts (10 times to
20 times in weight ratio) relative to the solid so as to
provide flowability to the slurry. However, because the
feedstock, i.e., the biomass material 11, and the hot
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compressed water 15 for removing lignin components and
hemicelullose components in the biomass are fed into the
hydrothermal decomposition apparatus 41A with separate
systems, the weight ratio of the liquid can be made small
relative to that of the solid, thus improving economic
efficiency.
[0041] According to the present invention, because a gas
portion is present inside the device main body 42,
pressurized nitrogen (N2) is fed inside.
[0042] Inside the hydrothermal decomposition apparatus
41A, the temperature of the biomass material 11 is
increased by causing it to contact the hot compressed water
in the device main body 42 and directly exchanging the
heat. The temperature may be increased by using steam or
15 the like from the outside as necessary.
[0043] The biomass feeder 31 employs a screw feeding
mechanism 32 that has a material seal mechanism realized by
the biomass itself, and feeds the solid biomass material 11
under normal pressure to under increased pressure.
Specifically, with the feeding mechanism 32 including a
screw feeder 32a and a hydraulic cylinder 32b, the biomass
material 11 fed inside is compressed, so that a biomass
plug 33 is formed. The biomass plug 33 serves as a
material seal for keeping the pressure inside the
hydrothermal decomposition apparatus. Gradually pressed by
the screw feeder 32a, the biomass can be gradually
discharged from an edge of the hydraulic cylinder 32b, so
that the biomass material 11 is reliably fed into the
device main body 42.
[0044] The biomass discharger 51 has a similar
configuration to that of the biomass feeder 31. With a
feeding mechanism including a screw feeder 52a and a
hydraulic cylinder 52b, the biomass solid residue 17
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reacted in the hydrothermal decomposition apparatus is
compressed, so that a biomass plug 53 is formed. The
biomass plug 53 serves as a material seal for keeping the
pressure inside the hydrothermal decomposition apparatus.
The biomass solid residue 17 under increased pressure, from
which lignin components and hemicellulose components have
been transferred to the discharged hot water 16, can be
discharged to under normal pressure. When the biomass
solid residue 17 compressed, the residual water is removed
from the biomass plug 53. This dewatered solution 54
includes components soluble in hot compressed water (lignin
components and hemicellulose components). Thus, the
dewatered solution 54 is sent to the discharged hot water
16 and treated together with the discharged hot water 16.
[0045] Because the pressure is changed from increased
pressure to normal pressure inside the biomass discharger
51, the biomass solid residue 17 to be discharged is steam-
exploded, causing breakage of its fiber structure. This
improves the efficiency of enzymatic saccharification in
the subsequent process.
[0046] The biomass discharger 51 can remove both of
enzymatic saccharification inhibitors and ethanol
fermentation inhibitors, or either of them, which are low-
molecular-weight volatile inhibitors.
[0047] In the present invention, by causing biomass
material and hot compressed water to countercurrently
contact with each other, their components are sequentially
discharged in order of solubility in the hot water.
Further, due to the concentration gradient and the
temperature gradient from where the biomass is fed to where
the hot water is fed, excessive decomposition of
hemicellulose components is prevented. As a result,
pentose components can be recovered efficiently. Further,
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by causing the biomass material and the hot compressed
water to countercurrently contact with each other, the heat
is recovered, which is preferable in view of system
efficiency.
[0048] In a hydrothermal decomposition apparatus 41D
shown in Fig. 4, the dewatered solution 54, separated in
the biomass discharger 51, may be fed again into the device
main body 42. This arrangement reduces the amount of the
hot compressed water to be fed into the apparatus. Further,
a desirable counter-current flow is realized.
[0049] As shown in Fig. 4, a hydrothermal decomposition
apparatus 41D includes an excess water removal line 32, so
that excess water 34 contained in the biomass is removed
from the section for feeding the biomass material 11 into
the device main body 42A. The excess water 34 may be used
to make the biomass material 11 wet.
Second Embodiment
[0050] With reference to the drawings, the following
describes a system of producing an organic material, i.e.,
alcohol, with use of biomass material according to a second
embodiment of the present invention. Fig. 5 is a schematic
of an organic material production system using biomass
material according to the embodiment. As shown in Fig. 5,
an alcohol production system 10-1 using biomass material
according to the present embodiment includes: a
pretreatment device 12 that pulverizes the biomass material
11; the hydrothermal decomposition apparatus 41A (shown in
Fig. 1) that hydrothermally decomposes pulverized biomass
13 by causing it to countercurrently contact the hot
compressed water 15, transfers lignin components and
hemicellulose components into the hot compressed water 15,
and separates the lignin components and the hemicellulose
components from the biomass; a first enzymatic hydrolysis
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device 19-1 that treats cellulose in the biomass solid
residue 17, discharged from the hydrothermal decomposition
apparatus 41A, with an enzyme (cellulase) 18-1 to
enzymatically hydrolyze it to a sugar solution containing
hexose; a first alcohol fermenter 21-1 that produces an
alcohol (ethanol in the present embodiment) by fermentation
using a first sugar solution (hexose) 20-1 obtained by the
first enzymatic hydrolysis device 19-1; and a first refiner
25-1 that refines a first alcohol fermentation liquid 22-1,
so as to separate it into a target product, i.e., ethanol
23, and a residue 24-1.
[0051] According to the present invention, in the
hydrothermal decomposition apparatus 41A shown in Fig. 1,
use of the counter-current flow transfers lignin components
and hemicellulose components to the liquid phase, i.e., the
hot compressed water 15, while allowing cellulose to remain
in the solid phase, i.e., the biomass solid residue 17. In
this way, the first sugar solution (hexose) 20-1 is
obtained at the first enzymatic hydrolysis device 19-1 for
performing enzymatic saccharification. Accordingly, it is
possible to establish a fermentation process suitable for a
hexose (fermentation suitable for an end product: in the
present embodiment, fermentation for obtaining the ethanol
23 using the first alcohol fermenter 21-1).
[0052] Although the present embodiment describes an
example that an alcohol, ethanol, is obtained by
fermentation, the present invention is not limited to this
example. Other than alcohols, substitutes for petroleum
used as chemical product material, or amino acids used as
food and feed materials can be obtained with a fermenter.
[0053] Examples of industrial products produced from a
sugar solution as a substrate material may include
liquefied petroleum gas (LPG), auto fuel, aircraft jet fuel,
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heating oil, diesel oil, various types of heavy oils, fuel
gas, naphtha, and naphtha decomposed products such as
ethylene glycol, ethanolamine, alcohol ethoxylate, vinyl
chloride polymer, alkylaluminum, polyvinyl acetate (PVA),
vinyl acetate emulsion, polystyrene, polyethylene,
polypropylene, polycarbonate, methyl methacrylate (MMA)
resin, nylon, and polyester. Thus, substitutes for
industrial products derived from crude oil, which is fossil
fuel, and sugar solution derived from biomass, which is a
feedstock for producing such substitutes, can be used
efficiently.
Third Embodiment
[0054] With reference to the drawings, the following
describes a system of producing an organic material, i.e.,
alcohol, with use of biomass material according to a third
embodiment of the present invention. Fig. 6 is a schematic
of a system of producing an organic material, i.e., alcohol,
with use of biomass material according to the present
embodiment. As shown in Fig. 6, an alcohol production
system 10-2 using biomass material according to the present
embodiment is constituted by the alcohol production system
10-1 shown in Fig. 5 that includes a second enzymatic
hydrolysis device 19-2. The second enzymatic hydrolysis
device 19-2 treats hemicellulose components, transferred
into the hot water 16 discharged from the hydrothermal
decomposition apparatus 41A, with an enzyme to
enzymatically hydrolyze it to a second sugar solution 20-2
containing pentose. Two enzymatic hydrolysis devices, two
alcohol fermenters, and two refiners are provided (the
first enzymatic hydrolysis device 19-1, the second
enzymatic hydrolysis device 19-2, the first alcohol
fermenter 21-1, a second alcohol fermenter 21-2, the first
refiner 25-1, and a second refiner 25-2). The ethanol 23
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is obtained by performing an enzymatic hydrolysis process,
an alcohol fermentation process, and an alcohol refining
process that are suitable for each of the first sugar
solution (hexose) 20-1 and a second sugar solution
(pentose) 20-2.
[0055] In the present embodiment, the ethanol 23 can be
produced by fermentation, using the second sugar solution
(pentose) 20-2 obtained by the second enzymatic hydrolysis
device 19-2.
[0056] The discharged hot water is not necessarily
treated in a separate system. For example, processes
subsequent to the enzymatic hydrolysis devices, processes
subsequent to the alcohol fermenters, or processes
subsequent to the refiners may be arranged as common
processes, or other modification may be made appropriately.
[0057] According to the present invention, in the
hydrothermal decomposition apparatus 41A, use of the
counter-current flow allows cellulose to remain in the
solid phase which is the biomass solid residue 17.
Accordingly, the first sugar solution (hexose) 20-1 is
obtained by the first enzymatic hydrolysis device 19-1 for
performing enzymatic saccharification. Further,
hemicellulose components dissolved in the liquid phase
which is the hot compressed water 15, are separated as the
discharged hot water 16, and the second sugar solution
(pentose) 20-2 is obtained by the second enzymatic
hydrolysis device 19-2. This enables the solid and the
liquid to be separated efficiently and saccharified in
different processes. Accordingly, fermentation processes
suitable for hexose and pentose (fermentation suitable for
an end product: e.g., ethanol fermentation) can be
established.
[0058] As such, in the hydrothermal decomposition
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apparatus 41A, use of the counter-current flow transfers a
side reaction product and a lignin component soluble in hot
compressed water, both acting as inhibitors during
enzymatic saccharification reaction for obtaining hexose,
to the hot compressed water 15. Accordingly, the
cellulose-based biomass solid residue 17 is obtained,
improving the yield of hexose in the subsequent enzymatic
saccharification reaction.
[0059] On the other hand, hemicellulose components
contained in the separated discharged hot water 16 is
saccharified later at the second enzymatic hydrolysis
device 19-2, so that a sugar solution containing pentose
can be obtained. Then, by using yeasts etc. suitable for
hexose and pentose, ethanol can be obtained by fermentation
individually and efficiently.
[0060] As described above, the present invention
provides: a biomass hydrothermal decomposition apparatus
and a method that can produce, by transferring cellulose-
based components and hemicellulose components from the
biomass material to the hot compressed water and separating
them from each other, sugar solutions suitable for the
cellulose-based components and the hemicellulose components
(hexose sugar solution and pentose sugar solution), and
that can efficiently produce, using the sugar solutions as
substrate materials, various types of organic materials
(e.g., alcohols, substitutes for petroleum, or amino
acids); and an organic material production system using
biomass material. However, a conventional technology
causes a phenomenon that a side reaction product inhibits
enzymatic saccharification and a sugar yield is reduced.
INDUSTRIAL APPLICABILITY
[0061] As described, according to the present invention,
a hydrothermal decomposition apparatus separates cellulose-
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based components from biomass material, so as to
efficiently produce a sugar solution. Further, using the
sugar solution as a substrate material, various types of
organic materials (e.g., alcohols, substitutes for
petroleum, or amino acids) can be efficiently produced.
