JP2008271910A - Method for producing ethanol and device for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing ethanol by culturing sea algae in open sea for immobilizing carbon dioxide in the algae body of the sea algae by photosynthesis, aimed at reduction of the concentration of carbon dioxide in the atmosphere and protection of petroleum resources. <P>SOLUTION: This method for producing ethanol includes an ethanol production stage having: a process of harvesting and crushing the sea algae 1 forming air vesicles in its growth period and becoming self floating; a process of suspending the crushed plants with water; heating under a high temperature and high pressure, while avoiding ebullism and obtaining an insoluble part consisting mainly of cellulose by releasing the high temperature high pressure suspension to a normal atmosphere; a process of collecting a cellulose fraction by ozone-treating the insoluble parts obtained in the above process; a process of hydrolyzing the cellulose fraction; a process of ethanol fermentation of glucose solution; a process of collecting 60 to 90% ethanol containing water from ethanol fermentation liquid; a process of obtaining 98 to 99.8% ethanol from the 60 to 90% ethanol, containing water; and a waste liquid-treating process. The device of the method is also provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a method for producing ethanol used as a fuel for a gasoline engine from a plant for the purpose of reducing the concentration of carbon dioxide in the atmosphere and protecting petroleum resources.
More specifically, floating algae beds are installed in the open ocean, seaweed is cultivated, cellulose is synthesized from carbon dioxide and water by a photosynthesis reaction using solar energy, seaweed is collected, and ethanol from cellulose contained in seaweed is ethanol. The present invention relates to a method and an apparatus therefor.

The massive use of coal and oil has led to depletion of fossil fuel resources such as oil and coal, and an increase in the concentration of carbon dioxide in the atmosphere. In particular, an increase in the concentration of carbon dioxide in the atmosphere causes global warming due to the greenhouse effect, which causes environmental destruction.
As one of the methods for solving this problem, development of a technology that uses biomass (resource crop) that is photosynthesised from carbon dioxide and water by plants as an energy source to replace petroleum and coal is being promoted.

  The relationship between the use of biomass and the concentration of carbon dioxide in the atmosphere is as follows: `` Even if the biomass is burned and carbon dioxide is released, the biomass was originally synthesized by the plant by absorbing solar energy and photosynthesis from carbon dioxide and water in the atmosphere. The amount of carbon dioxide in the atmosphere has not increased.

  As one of the biomass utilization methods, a method has been developed in which biomass is ethanol-fermented to produce ethanol, and the obtained ethanol is used as a fuel for a gasoline engine of an automobile, thereby reducing oil consumption.

Agricultural products were first used as raw materials for producing ethanol. In the United States, ethanol is produced from corn. In Brazil, ethanol is produced from sugarcane.
Since the starch which is the main component of the hydrocarbons of these agricultural products can be subjected to ethanol fermentation using yeast as it is, ethanol can be produced relatively easily.

Development of technology using wood as a second raw material for producing ethanol is underway.
Since cellulose, which is the main component of wood hydrocarbons, cannot be used as it is in ethanol fermentation, a method has been developed in which cellulose is hydrolyzed to produce glucose and the resulting glucose is ethanol-fermented.

  For hydrolysis of cellulose, a method using an enzyme and a method using an acid catalyst such as dilute sulfuric acid are used. However, the method using an enzyme is expensive and not economical, and the method using an acid catalyst has a low yield, resulting in a large amount of acidic wastewater, and waste generated to neutralize the acid. Have.

  Also, lignin contained in wood inhibits ethanol fermentation using yeast, so it must be removed before ethanol fermentation, but the lignin removal step reduces the overall yield of the process for producing ethanol from wood. ing.

Further, wood has a large amount of C5 monosaccharides, and C5 monosaccharides are not fermented with ethanol, so that the yield of ethanol is low.
In Patent Documents 1 and 2, ethanol is obtained in a high yield from a wood material containing C5 monosaccharide using a genetically modified bacterium in which the ethanol fermentation gene possessed by the bacterium used in the production of tequila is incorporated into Escherichia coli. A production method is disclosed.

  As a new method for hydrolyzing cellulose in wood, Patent Document 3 describes a method for producing oligosaccharides by steaming and detonating wood with high-temperature and high-pressure subcritical water. However, this method also has not been completed as a technique that can be practically used for industrial production because the total yield is reduced in the process of removing lignin.

As a third raw material for producing ethanol, marine biomass (marine resource crops) that has not been used so far can be mentioned.
Patent Document 4 describes a marine plantation that grows seaweed in the ocean, an offshore plant ship that harvests seaweed and partially burns it to produce methanol, formic acid, and hydrogen, and a marine satellite system that supports this. Yes.

  Patent Document 5 discloses a method for producing ethanol by using starch as a raw material by heating and removing starch contained in seaweed. However, the amount of starch contained in normal seaweed is small. The carbohydrates contained in seaweed are different from those of land plants, and no method for producing ethanol from carbohydrates unique to seaweed has been reported.

  Regarding a method for artificially cultivating seaweed, Patent Document 6 describes a method for cultivating seedlings for aquaculture from young embryos of Honda walla. Patent Document 7 describes a method for cultivating seedlings for aquaculture by callus culture of buds of Honda walla.

US Patent No. 5,000,000 specification US Pat. No. 5,821,093 JP 2004-229607 A JP 2006-204264 A JP 2003-310288 A JP 2004-187574 A JP 2006-129833 A

The plan to replace part of the fuel for automobiles with ethanol requires a large amount of ethanol, so if existing biomass raw materials are used, the shortage of raw materials and the increase in raw material prices cannot be avoided.
For example, the production of ethanol from agricultural products such as corn and sugar cane is actually experiencing rising raw material prices and food problems.

  Also, trees take time to grow, and forests are not highly self-regenerating. In order to supply a large amount of woody biomass from forests to replace gasoline, it is necessary to create a new and vast forest, and enormous effort and time are required.

For this reason, development of new biomass that has not been used until now is required.
As a new biomass candidate, seaweed, which is marine biomass (marine resource crop), attracts attention. Seaweed grows quickly and has a high ability to immobilize carbon dioxide by photosynthesis, so it is expected to be advantageous as a new energy resource that effectively immobilizes carbon dioxide.

For example, Eisenia and beforehand of brown algae, per submarine 1m ^2, it is said that the leaves of 2~3kg is produced by dry weight per year, which is greater than the production amount of land of the forest. Also, the same brown algae Honda Walla is said to produce 8 kg of leaf by dry weight annually, which is more than that of the rainforest.
However, at present, carbon dioxide fixed by seaweed is decomposed into carbon dioxide and water by microorganisms when seaweed dies, and is released again into the atmosphere through seawater.

  In addition, seaweeds can naturally live only in shallow water with a depth of 2 to 30 meters where sunlight can penetrate, and most of the solar energy poured into the deeper ocean is absorbed by seawater and reaches the seabed. Absent. In addition, seaweed such as seaweed and kelp, fishery ginger, pearls and other aquaculture mainly consisted of coastal facilities. On the coast, the terrain that can be installed was limited, and it was difficult to enlarge the equipment.

  An object of the present invention to solve such problems is a seaweed cultivation method for cultivating seaweed by installing a floating-type seaweed basin in the open ocean, and a seaweed harvesting method for efficiently harvesting the seaweed. To develop a method for producing ethanol from seaweed by establishing a method for producing a large amount of seaweed as a raw material in a stable manner and establishing a method for producing cellulose by extracting cellulose from the seaweed. It is.

The method for producing ethanol from the plant of the present invention to solve the above problems is as follows.
A pretreatment stage in which plants containing cellulose are harvested and pulverized, and the pulverized plants are suspended in water, heated under high temperature and high pressure while avoiding boiling, and then the high temperature and high pressure suspension is released to atmospheric pressure. In order to obtain an insoluble part mainly composed of cellulose, a steaming / explosion stage, a purification stage in which the insoluble part is purified and a cellulose fraction is collected, and the cellulose fraction is suspended in water under high temperature and high pressure while avoiding boiling. And then hydrolyzing the high-temperature and high-pressure suspension to atmospheric pressure to produce a glucose solution, an ethanol fermentation step for fermenting the glucose solution in ethanol, and an ethanol concentration step for collecting hydrous ethanol from the ethanol fermentation solution And an ethanol drying step for producing dry ethanol by removing water from the hydrous ethanol.

  According to the present invention, the present invention is the seaweed 1 in which the plant attaches air vesicles during the growing period and becomes self-floating, and the harvesting of the plant causes the attachment device 2 of the seaweed 1 to be held by the seaweed holding device 15; It is preferable to be made by a cultivation stage for ripening in this holding state and a harvesting stage for harvesting the main branch 4 of seaweed by harvesting the attachment device 2 and stem 3 from the seaweed holding device 15 after the seaweed 1 has matured. .

  According to the third aspect of the present invention, it is preferable that the seaweed 1 is a seaweed of the genus Hidamataceae.

  According to the present invention, in the present invention, the purification step preferably includes a step of treating the insoluble part with ozone to purify the cellulose fraction.

  According to claim 5, after separating the soluble part from the insoluble part, the present invention recovers the useful substance from the soluble part, the inhibitory substance removing process of removing the fermentation inhibitor from the soluble part, It is preferable to perform at least one of an unnecessary substance removing step for removing unnecessary substances from the soluble portion and a carbohydrate collecting step for collecting carbohydrates from the soluble portion.

  According to the sixth aspect of the present invention, the useful substance to be recovered is one or more selected from heavy metals, natural uranium, alginic acid, fucodyne, plant protein, and fat.

  According to claim 7, an apparatus for producing ethanol from a plant according to the present invention comprises a pretreatment means for pulverizing a plant containing harvested cellulose, and the pulverized plant is suspended in water, while avoiding boiling and high temperature and pressure. Steaming / explosion means for obtaining an insoluble part mainly composed of cellulose by heating under and then releasing a high-temperature and high-pressure suspension to atmospheric pressure, and a purification means for collecting the cellulose fraction by purifying the insoluble part, Hydrolysis means for hydrolyzing the cellulose fraction to produce a glucose solution, ethanol fermentation means for fermenting the glucose solution in ethanol, ethanol concentration means for concentrating the ethanol fermentation liquid and collecting hydrous ethanol, and water from the hydrous ethanol It is preferable to provide an ethanol drying means for removing dry water to produce dry ethanol.

According to the eighth aspect of the present invention, the purification means is preferably means for treating the insoluble part with ozone to purify the cellulose fraction.

According to claim 9, in the apparatus for producing ethanol from the plant of the present invention, the plant containing cellulose is seaweed 1 harvested by a seaweed culture device,
The seaweed aquaculture device includes an anchor in which a net 14 having a rope-like seaweed holding device 15 for holding the attachment device 2 of the seaweed 1 and a buoyancy adjusting device 16 for floating and sinking the seaweed holding device 15 is installed on the seabed. A seaweed bed unit 9 that is anchored substantially horizontally below the sea surface to a mooring line 13 that connects the buoyant body 12 and the buoyant body 12; It is preferable that the seaweed bed set 8 includes a plurality of seaweed beds 7 installed at predetermined intervals.

  By producing ethanol from seaweed and using the obtained ethanol as gasoline fuel for automobiles, it is possible to prevent an increase in carbon dioxide in the atmosphere and contribute to global warming countermeasures. In addition, the amount of petroleum gasoline used can be reduced and oil resources can be protected.

Since seaweed absorbs nutrients such as nitrogen and phosphorus from seawater, the seaweed bed of the present invention can purify the water quality of the sea area where it is installed. In addition, floating garbage is collected.
The floating seaweed pond provides a place for spawning fish and a place for growing fry, which can contribute to the activation of the fishery.

  Since seaweed takes in heavy metals from seawater, it is possible to use the sea as a valuable heavy metal resource by collecting heavy metals from seaweed. In particular, recovery of natural uranium, which is a raw material for nuclear power generation, is expected.

Seaweeds produce different compounds than terrestrial plants, so they can be collected and used. As already used, large-scale and inexpensive production of alginic acid, fucodyne, plant protein, etc. is possible.
The seaweed fat content is recovered, reformed into biodiesel oil, and used as fuel for ships used in the present invention.

  As a ripple effect of developing technology for producing ethanol from seaweed according to the present invention, basic research on marine organisms, establishment of large-scale aquaculture technology in the open ocean, and establishment of a method for utilizing marine resources are expected.

In order to carry out the present invention, for example, it is planned to install a seaweed bed of about 10,000 km ^{2 in the} Sea of Japan. This is 3% of the total land area of Japan, which is equivalent to the size of 15 Lake Biwa.

  If this plan is implemented, regional science and technology promotion accompanying the creation of new industries can be expected as a ripple effect by the formation of large-scale seaweed beds. Including the promotion of fisheries, the environment including neighboring countries, such as algae ground unit manufacturing factory, seedling culture plant, protein processing factory, biofuel processing factory, marine work robot maintenance factory, offshore waste sorting, processing factory, etc. The formation of the Sea of Japan economic zone can be expected.

The present invention is characterized by installing a floating-type seaweed bed in the open ocean, cultivating and harvesting the seaweed 1, and producing ethanol from the harvested seaweed.
Embodiments of the present invention will be described below with reference to the drawings. The following description is for clearly explaining the present invention, and does not limit the scope of rights of the present invention.

(A) Seaweed cultivation (selection of seaweed to grow)
The present invention is characterized by cultivating a seaweed 1 that is self-floating by attaching air bubbles 6.
By making the seaweed 1 self-floating, the weight of the seaweed 1 applied to the cultivation device can be reduced, and the device can be simplified. Further, at the time of harvesting, the harvested work can be made more efficient by cutting the mature seaweed 1 from the seaweed holding device 15 and harvesting the seaweed 1 that has been cut and floated on the sea surface by the medium-sized work boat 31.

  Further, it is more preferably a perennial seaweed having a height of 2 m or more. If it is a large seaweed with a height of 2 m or more, it is expected that the yield per unit area of the seaweed basin 7 will increase, and if the seaweed 1 is perennial, from the second year from seedling breeding to transplanting This step is preferable because it can be omitted.

As the seaweed 1 that satisfies the above-described conditions, specifically, seaweeds of the order Hibamatidae are preferred. The seaweeds of the family Honda are characterized by having air vesicles.
There are many varieties of seaweeds belonging to the genus Hondaraceae, but preferred examples include the genus Hondawala, Akamoku, Isomoku, Salebamok, Tsukushimoku, Majirimoku, Fushijimoku, Atsubamoku, Tosakamoku and Futaemok. , Hijiki, Yokomoku, Miyabemoku, Oobamoku, Yoremoku, Sugimoku Sugimoku, Uganomok Uganomok, Yabamoku Yabanmoku, Joromoku Joromok.

  Among these, the most preferred example is Hibamataceae Honda Wallaceae Honda Walla (hereinafter abbreviated as Honda Walla). Honda Walla is a perennial seaweed that grows to 2-4 meters in height.

(Ecology of Honda Walla)
Honda Walla is a brown algae distributed in the Sea of Japan from the northern tip of Honshu to Kyushu and on the Pacific Ocean from off Sanriku to the Seto Inland Sea. Although the water depth to grow varies depending on the sea area, it usually grows in a rocky area with a depth of 3 to 10 m, and a depth of 20 m is said to be the lower limit of growth.

  In Honda Walla, fertilized eggs germinate in the spring to become young embryos. The size of the young embryo is about 0.25 to 0.3 mm. In about 4 months, it becomes a young body with a body length of 0.5 to 15 mm. After that, the growth period begins, but growth is slow for a year and a half until the fall of the second year when the body length is about 50 mm. It grows rapidly after the fall of the second year, and then matures from the winter of the second year to the summer of the third year.

  FIG. 1 shows a Honda walla. The mature Honda walla is provided with an attachment device 2 and a disk-shaped stem 3 for attaching algae to the rocks on the seabed. Several main branches 4 extend from the top of the stem 3 and grow to a height of 2 to 4 m. The main branch 4 is provided with a large number of spatula-shaped or elliptical leaves 5 and a large number of egg-shaped airves 6 having protrusions and floats in water (self-floating).

After a while after maturity, the upper part is cut off to become a flowing algae, and only the attachment device 2 and the stem 3 remain on the seabed, and a new main branch 4 extends from the stem 3 again in the spring of the following year. In this way, the main branch 4 is renewed every year and has a life of about 3 years. Therefore, in order to harvest Honda straw, it is important to leave the applicator 2 and the stem 3 and cut only the main branch 4.
Honda Walla, which has become a floating algae, is important as a place for spawning eggs and fry. Algae is edible.

(Equipment for cultivating seaweed)
FIG. 2 is a diagram showing the configuration of the seaweed bed 7 according to the present invention.
Seaweed bed 7 for cultivating seaweed 1 of the present invention, the effective cultivation area thereof is preferably 1,000～50,000Km ^2, the effective cultivation area is more preferably from 5,000~40,000km ^2.

If the effective cultivation area is smaller than 1,000 km ² , the effect of increasing the size of the seaweed bed cannot be exhibited, and the operation efficiency is deteriorated. Although there is no restriction | limiting in the upper limit of an effective cultivation area, when it exceeds 40,000 km ² , since one side of the algae ground 7 will exceed 200 km, management will become inadequate.

The seaweed basin 7 is supported by a ground concentration support system (not shown).
A management center 26 is installed in the seaweed bed 7. The management center 26 manages the entire algae ground 7 in cooperation with the ground concentration support system that supports the algae ground 7.

Since the seaweed bed 7 is a vast one with a side of 100 km, it is preferably managed using the marine satellite system 27 composed of a plurality of artificial satellites described in Patent Document 4.
The marine satellite system 27 preferably includes a GPS satellite, a communication satellite, an ocean observation satellite, and a weather satellite. Ocean observation satellites and meteorological satellites collect information on seaweed growth, iso-burning and damage to aquaculture equipment, weather, ocean currents, and suspended waste.

  In addition, the marine satellite system 27 performs commands and transmissions related to unmanned operation such as automatic operation of the small high-speed seaweed cutter boat 32 and automatic buoyancy adjustment of the buoyancy adjustment device 16 by remote operation commands from the GPS communication satellite. Further, the marine satellite system 27 transmits information to the management base 28 of the seaweed bed set 8 and exchanges information with the ground concentration support system that supports the seaweed bed 7 via a communication satellite.

  Since it is practically impossible to install such a large-scale seaweed bed 7 in the coastal area, the present invention installs a floating-type seaweed bed in the open ocean.

As shown in FIG. 2 (A), the seaweed basin 7 is configured by opening a water surface that will be a route 24 and a fishing ground 25 for a general ship, and a plurality of seaweed basin sets 8 are installed. The number of seaweed bed sets 8 installed in the seaweed bed 7 is 2 to 100, more preferably 5 to 50, and most preferably 5 to 20.
The seaweed basin set 8 is a combined set of aquaculture-manufacturing equipment having a seaweed aquaculture equipment and an ethanol production equipment 29. The seaweed bed set 8 includes a management base 28, a seaweed transport tanker 30 with a displacement of 300,000 tons, a medium-sized work boat 31 with a loading weight of 600 tons, and a small high-speed seaweed cutter boat 32.

The medium-sized work ship 31 is a catamaran, and performs harvesting of Honda straw, washing of the harvested Honda straw, construction of a seaweed pit, and repair of damaged parts. For this purpose, the medium-sized work boat 31 is equipped with a marine cogeneration generator and has multiple functions.
The small high-speed seaweed cutter boat 32 includes a water jet propulsion device and is remotely operated in accordance with a command from the marine satellite system.
The fuel of the medium-sized work boat 31 and the small high-speed seaweed cutter boat 32 is preferably a biodiesel fuel obtained by collecting and reforming fat content in Honda straw.

As shown in FIG. 1 (B), the seaweed bed set 8 includes a small water passage 21 through which a small high-speed seaweed cutter boat 32 can pass, a middle water passage 22 through which a medium-sized work boat 31 can pass, and a sea route of the seaweed transport tanker 30. A large water channel 23 is installed, and a plurality of seaweed units 9 are arranged and juxtaposed on the sea surface divided by various water channels.
The number of seaweed bed units 9 installed in the seaweed bed set 8 is 1,000 to 50,000, preferably 4,000 to 40,000, and most preferably 5,000 to 20,000.

  As shown in FIGS. 1 (C) and (D), the minimum constituent unit of the seaweed bed 7 of the present invention is a seaweed bed unit 9. The seaweed bed unit 9 has a square or rectangular net 14 with a side of 10 to 1000 m, which is anchored approximately horizontally below the surface of the mooring line 13 connecting the anchor 11 and the buoyant body 12 installed on the seabed 17, and seaweed. 1 is a floating seaweed bed including a seaweed holding device 15 for holding one attachment device 2 and one or more buoyancy adjusting devices 16 for floating and sinking the seaweed holding device 15.

  As the seaweed bed unit 9 is larger, the efficiency at the time of cultivation and harvesting is higher, but the tension for stretching the seaweed holding device 15 is increased. Considering these points, the seaweed bed unit 9 is preferably a square or rectangle having a side of 1 to 10,000 m, more preferably a square or rectangle having a side of 10 to 1,000 m, and a square having a side of 50 to 500 m being the most. preferable.

  The seaweed does not have an organ corresponding to the “root” of the land plant, and is attached to the seabed with the attachment device 2 (provisional root). Therefore, in order to cultivate the seaweed 1, the seaweed holding device 15 for holding the attachment device 2 of the seaweed 1 is necessary.

  Any type of seaweed holding device 15 may be used as long as it can firmly hold the attachment device 2 of seaweed 1, but in consideration of convenience of harvesting, a rope-like device is preferable. Since it is used in large quantities and discarded after being used for several years, biodegradable natural materials are more preferable in view of environmental impact. As a most preferable example, a rope in which a rope of rice straw is reinforced with natural fibers can be exemplified. The rice straw rope can be used as a raw material for ethanol by mixing with seaweed at the time of disposal.

  Since the anchor 11, the buoyant body 12, and the mooring line 13 must be enlarged in order to install the seaweed bed 7 at a deep water depth, it is not economical. The depth of the place where the seaweed basin 7 is constructed is preferably within 700 m, more preferably within 500 m.

  The seaweed bed unit 9 of the present invention includes one or more buoyancy control devices 16 for floating and sinking the seaweed holding device 15. The buoyancy control device 16 is one or more buoys, and levitation / sedimentation is performed by enclosing a liquefied gas that vaporizes / condenses in accordance with the increase / decrease of the volume of gas sealed in the buoyancy control device 16 and / or the water temperature. be able to.

In the case where the volume of the gas to be sealed is increased and decreased to rise and sink, it is preferable to automatically adjust the volume of the gas by remote control, and the command is transmitted through a communication network via the GPS satellite of the marine satellite system 27. It is preferable to do so. Information that contributes to the weather judgment as to whether or not the seaweed retainer 15 is to be levitated / sinked is collected by a meteorological satellite.
The depth of sinking the seaweed holding device 15 is preferably 7 to 13 m when settling for a long time in winter, and even if it is settling for a short period of time due to storminess, it is limited to the natural habitat limit of 20 m. To do.

(Growing seedlings)
Since Honda Walla is a male and female different strain, male and female genital beds are taken out and fertilized artificially. It is preferable to grow at a seedling breeding facility installed on land for one and a half years after fertilization.
In April, fertilized eggs germinate and 0.25-0.3 mm embryos are grown in a water tank. In 4 to 6 months after fertilization, the young embryo becomes a young body having a body length of 0.5 to 15 mm, and after that, it becomes a stem elongation stage. The seedlings are grown while being transferred to a large water tank as they grow, irradiating light from under the water tank, sending air, and stirring the air. In the fall of the second year, one and a half years after fertilization, Honda Walla grown to a length of about 200 mm is transplanted as a seedling into a seaweed bed and attached to the seaweed holding device 15 to start cultivation in the open sea.

  It is also possible to collect seedlings from stems and cultivate and grow the above-mentioned seedlings of 2 to 3 mm square by a clone technique.

(Culture of seaweed)
In the fall of the second year, Honda Walla transplanted to the seaweed as a seedling grows rapidly, becomes airborne and becomes self-floating, and grows to 2-4 m. Cultivation is preferably carried out from early spring to summer of the following year so that the upper leaves of hondawala, which has become airborne by air bubbles, float on the sea surface and receive sufficient sunlight.

The seaweed bed 7 of the present invention is installed in the open ocean, but the open ocean has larger waves than the coastal sea area. It may become rough due to low pressure passing or typhoon. When the seaweed basin 7 is installed on the Japanese side, the days when the sea is rough due to the seasonal wind increase in winter. The winter season is a season in which the seaweed 1 held in the seaweed holding device 15 is grown.
If the seaweed bed unit 9 is floated near the sea surface when the sea is rough, there is a possibility that the seaweed 1 will be cut off by the waves and the cultivation apparatus may be damaged. In the case of stormy weather, it is desirable to sink the seaweed bed unit 9 below the sea surface so as to avoid the influence of rough waves.

(Seaweed harvest)
The harvest of seaweed 1 begins in the spring of the third year and ends at least by the typhoon season.
Harvesting winds up the small high-speed seaweed cutter boat 32 that cuts off the main branch 4 from the seaweed holding device 15 and the honda walla 1 that is cut off and floats on the sea, leaving the attachment device 2 and stem 3 of the seaweed 1. This is carried out in collaboration with a medium-sized work boat 31 that sucks and harvests the Honda Walla 1 with water.

The unit area yield of seaweed 1 is desirably 5.5 to 8.0 kg / m ² or more per year in dry weight.
Since the unit area yield of corn, the current raw material for ethanol production, is about 0.4 kg / m ² per year, Honda Walla is promising as a new biomass.

(B) Production of ethanol Conventionally, a method for producing ethanol by applying a steaming / explosion process from a plant containing cellulose has decomposed the raw material cellulose to glucose in one step.
However, when seaweed is used as a raw material, in this method, seaweed also contains carbohydrates other than cellulose, and the resulting glucose solution contains a large amount of sugars other than glucose. In addition, when a raw material containing lignin is used, operation is performed under conditions involving excessive decomposition of glucose and hemicellulose to remove lignin. As a result, the sugar hydrolysis yield is low, and the overall yield of ethanol is reduced. It was difficult to increase it to 30% or more.

The present invention is characterized in that the raw material is heated at 130 to 230 ° C., and then the high-temperature and high-pressure suspension is discharged to atmospheric pressure to perform a steaming / explosion process to obtain an insoluble part mainly composed of cellulose.
Under this mild cooking / explosion process, cellulose and glucose are not decomposed, and hemicellulose is decomposed and becomes soluble.

When seaweed is selected as the raw material plant, sugars other than cellulose are decomposed and become soluble by performing the steaming / explosion process under these conditions, so that high-purity cellulose is obtained as an insoluble matter by a simple purification process. I can do it. Moreover, when a plant containing lignin is applied as a raw material plant, lignin can be efficiently decomposed and removed by performing a purification step including ozone treatment following the cooking / explosion step under these conditions.
Subsequent to the purification step, glucose can be produced with good yield by subjecting the obtained cellulose to a steaming / explosion step at 230 to 260 ° C.
Below, each process of an ethanol manufacturing stage is demonstrated according to the flowchart of FIG.

(First step) Pretreatment The harvested seaweed is washed with water to remove the adhering salt, and is chopped, pulverized, or ground while being heated to 50 to 90 ° C. to produce a raw material. The reason for heating is to prevent the components in seaweed from gelling.
Furthermore, it is preferable to add an alkali metal salt to the raw material. Examples of the alkali metal salt include sodium hydroxide, potassium hydroxide, and sodium carbonate. The purpose of the addition of the alkaline substance is to improve the yield of the insoluble part mainly composed of cellulose in the steaming / explosion process and to prevent the components in the seaweed from gelling.
In addition, woody floats such as driftwood, used seaweed retainer 15 and the like can be crushed and used in addition to the raw materials.

(2nd process) Steaming / explosion process The steaming / explosion apparatus 40 is shown in FIG.
The steaming / explosion device 40 is a vertically long pressure cooker 43 having 1) a raw material supply unit 41 installed above, and 2) a wide pretreatment unit 48 for pretreatment of the raw material with high-temperature and high-pressure steam 46 at the top. The raw material pressure inlet 44 connected to the raw material supply unit 41, preheating means 45 for supplying steam to the raw material supply unit 41, piping 47 for supplying high-temperature and high-pressure steam 46, and a lower portion of the pressure cooker 43 are stored. A sub-critical water 49 and an adiabatic expansion nozzle 50 installed at the bottom, and 3) a steaming part 42 connected to the adiabatic expansion nozzle 50, an atmospheric pressure steam outlet 51, and a soluble part outlet. 52 and an adiabatic expansion section 54 including a solid-liquid separation device 53.

  The seaweed 1 is preheated by the preheating means 45 in the raw material supply section 41, then supplied from the pressure inlet 44 to the pressure cooker 43, and pretreated by the high temperature and high pressure steam 46 in the upper pretreatment section 48. Later it falls into the lower subcritical water 49 and is cooked at 130-230 ° C. under pressure while avoiding boiling. In this temperature range, hemicellulose is hydrolyzed, but cellulose is not hydrolyzed. Below 130 ° C, hemicellulose is not hydrolyzed, and above 230 ° C, cellulose is also rapidly hydrolyzed. Although reaction time is influenced by reaction temperature, the range for 1 to 60 minutes is preferable, and the range for 5 to 20 minutes is more preferable. It is preferable that the optimum conditions for the reaction temperature and reaction time be determined in advance in accordance with the apparatus and purpose.

  The steamed raw material is expelled from the adiabatic expansion nozzle 50 to the adiabatic expansion part 54 by suddenly reducing the pressure to atmospheric pressure. The produced slurry is separated into a soluble part and an insoluble part by the solid-liquid separator 53. The target cellulose is contained in the insoluble part. Preferable examples of the solid-liquid separation device 53 include a screw press, a filtration device, and a centrifuge.

  Low-boiling components such as iodine and furfural and useful components flowing out by steam distillation are recovered from atmospheric steam. The liquid obtained by condensing the atmospheric pressure vapor is sent to the eighth step when recovering useful substances and carbohydrates, and is sent to the eleventh step when not recovering, or discharged as waste water as it is. The soluble part 52 is sent to the eighth step.

(3rd process) Purification process When seaweed is used as a raw material, carbohydrates other than cellulose are removed by washing with water, and cellulose is separated. Oil-soluble parts such as fat are extracted with an organic solvent. The organic solvent is preferably ethanol, which is a product of this project. Fat is recovered and reformed into biodiesel oil and used as fuel for medium-sized workboats, and ethanol as an extraction solvent is recovered and reused.
When a raw material containing lignin, such as used seaweed holding device 15 or driftwood, is used, the insoluble part contains lignin that becomes a fermentation inhibitor, so that the lignin is decomposed by chemical treatment.

  Preferable chemicals include ozone, chlorine, hypochlorite, hydrogen peroxide, etc. Among them, ozone can be given as the most preferable example. Ozone can be produced using electric power, and has a strong decomposing power for compounds with unsaturated bonds such as lignin, does not react with cellulose, has its own water purification effect, and decomposes by releasing oxygen if left untreated. So there is no negative impact on the environment.

In addition, when high purity cellulose is obtained in the steaming / explosion process of the second step, the insoluble matter obtained in the second step is sent as it is to the hydrolysis step of the fourth step without performing the purification step. Can do.
The effluent of the purification process using chemicals in the third step is preferably collected separately from other effluents to recover useful materials and treat the waste liquid, or send it to the waste water treatment process.

(4th process) Hydrolysis process The method of hydrolyzing a cellulose is not specifically limited, Any method can be used. Below, the typical thing is illustrated.
The hydrolysis method of cellulose currently used for industrial production of woody bioethanol is an acid catalyst method. The acid catalyst method is a method in which cellulose is hydrolyzed at 140 to 260 ° C. using a dilute sulfuric acid method, and is a simple method, but has a large yield of sugar and a low yield. Although there is an acid catalyst method combined with concentrated sulfuric acid and steam cooking, the amount of sulfuric acid used is large. In addition, the acid catalyst method has a common problem that the concentration of the resulting glucose solution is low and a large amount of acidic effluent is generated.

  Since the enzyme method is a method in which a glucose solution and an enzyme are brought into contact with each other at a predetermined temperature, it uses less energy and is a clean method, but the enzyme to be used is expensive. In addition, enzymes have high substrate specificity and may be affected by saccharifying enzyme inhibitors. As an enzyme, there is a method using a genetically modified bacterium as a new method, in addition to a conventional method using a living bacterium and a method using an immobilized enzyme. In order to use enzymes in industrial production, basic research is required to develop enzymes with higher activity, lower substrate specificity, and lower costs.

The steaming / explosion method is a method of performing hydrolysis at 230 to 280 ° C. with the steaming / explosion device used in the second step.
Of these methods, steaming and blasting are preferred. As a particularly preferred method, when seaweed is used as a raw material, glucose is obtained by the second step of steaming / explosion method, the step of separating cellulose in the third step, and the step of hydrolysis / explosion method of cellulose in the fourth step. A combination of steps for producing a solution can be exemplified. When a raw material containing lignin is used, the second step of steaming / explosion method, the step of decomposing lignin by the ozone treatment of the third step, and the step of steaming / The combination of the process of manufacturing a glucose solution by the hydrolysis method of the cellulose by the explosion method can be illustrated.

When isolating glucose, after completion of the reaction, the glucose solution is concentrated to make glucose a concentrated solution and crystallized by adding a seed crystal. As a method for concentrating the reaction solution, there are a reverse osmotic pressure membrane method, a distillation method, a method using a functional membrane, and a method using an adsorbent such as a hydroxyapatite gel or a hydrophilic polymer substance. In the case of crystallization, a hydrophilic organic solvent such as ethanol or methanol can be added to promote the crystallization and make the separation operation more efficient.
Moreover, it can refine | purify using the said adsorption agent.

Depending on the case, the glucose solution can be sent to the fifth step as a concentrated solution of the reaction solution without purifying glucose.
The effluent from this step is preferably neutralized and discarded when the acid catalyst method is used. When other methods are used, it is preferably sent to the eighth step when recovering useful substances and carbohydrates, and to the eleventh step when not recovering.

(5th process) Ethanol fermentation process Ethanol fermentation is performed by making ethanol fermentation yeast contact the solution which melt | dissolved glucose in water.
As ethanol-fermenting yeast, there are a method using a genetically modified bacterium and a method using a survival-independent bacterium (RITE bacterium) in addition to a conventional method using a living bacterium and a method using an immobilized enzyme. When using a woody raw material, it is preferable to use a genetically modified bacterium capable of degrading C5 carbon sugar described in Patent Documents 1 and 2.
Since there are differences in resistance to yeast inhibitors and substrate selectivity between these methods, it is desirable to select the optimal yeast according to the raw material.
In the present invention, the ethanol-fermenting yeast is not particularly limited, and any method can be used.

In the fourth step, when the reaction liquid obtained by hydrolyzing the cellulose fraction is subjected to ethanol fermentation as it is without purification by crystallization of cellulose, the problems are the presence or absence of fermentation inhibitors in the reaction liquid and the sugar of the raw material. And the amount of monosaccharides available for ethanol fermentation contained in the liquid.
If the reaction yield of ethanol fermentation is poor, purify and purify by crystallization of glucose in the fourth step, or carry out the recovery of useful substances, fermentation inhibitory substances, and waste materials described in the eighth step. Then, it is necessary to recover the sugar and perform the ethanol fermentation process.

  The recovered carbohydrate solution obtained by treating the soluble part when seaweed is used as the raw material in the eighth and ninth steps may contain a large amount of monosaccharides that cannot be used for ethanol fermentation. Development of yeast that ferments ethanol using saccharides other than glucose and development of enzymes that isomerize sugars to glucose are desired.

(6th process) Ethanol concentration process The ethanol concentration method should just be an efficient thing, and a method is not specifically limited.
Conventionally, ethanol fermentation liquid was distilled to produce azeotropic ethanol. When azeotropic ethanol is produced by this method, a large amount of fuel is consumed, and carbon dioxide gas is released to obtain this energy. Therefore, there is a problem in that the effect of reducing carbon dioxide gas does not increase.

Various membrane separation methods have been studied for ethanol-water separation. Recently, an ethanol concentration method using the principle of the gate film was developed. This membrane is coated with a special polymer that shrinks and opens the pores when the ethanol concentration increases, inside the fine pores formed in the ethanol-permeable polyethylene membrane. A regulated molecular recognizing functional membrane, and 60 to 90% ethanol can be obtained by using this membrane.
The effluent from this step is sent to the eighth step when recovering useful substances and carbohydrates, and to the eleventh step when not recovering.

(Seventh step) Ethanol drying step Ethanol is passed through a zeolite column to absorb moisture. The zeolite that has absorbed moisture is dried by sending heated air and reused. 99.5% ethanol is obtained.

(Eighth step) Useful substance recovery, fermentation inhibitor removal, unnecessary substance removal, carbohydrate recovery process Since this process is a process of adjusting the balance of the entire process, the unit reaction is performed according to various factors at the time of operation. It is preferable that the selection is executed. The unit process included in this process is described.
Low-boiling organic substances such as furfural are recovered by fractional distillation of the condensate from the effluent obtained by condensing the atmospheric steam in the second steaming / explosion process. Iodine is recovered by oxidizing the condensate with, for example, hypochlorite, converting iodine ions into iodine, and depositing iodine completely, followed by steam distillation.

As needed, the soluble part 42 of the steaming / explosion process of the second step, the effluent (other than the acid decomposition method) of the hydrolysis step of the fourth step, and the effluent of the ethanol concentration step of the sixth step The useful substances are collected separately and / or together.
The heavy metal is recovered using an ion exchange resin.
Natural uranium is adsorbed by passing natural uranium concentrated in alginic acid through a column of tannin adsorbent, and eluted with 0.01 molar hydrochloric acid and recovered.

The fat in the effluent is left to stand for oil-liquid separation or extracted with an organic solvent insoluble in water and recovered. The recovered fat is reformed into biodiesel oil by a methanolysis reaction and used as fuel for medium-sized work boats.
Undecomposed alginic acid is recovered by acidifying the effluent or by adding a calcium salt to precipitate.
Plant proteins are separated using a semipermeable membrane or adsorbed on an adsorbent. Alginate can also be used as the adsorbent.

After recovering the useful substance from the effluent, if the saccharide has a usable amount and purity, the inhibitory substance and unnecessary substance are removed to recover the saccharide. When the available amount and purity of saccharide is not contained, it is sent to the waste liquid treatment process of the eleventh step as an insoluble substance / inhibitor substance liquid.
The expected method for removing the fermentation inhibitor is as follows.
When the fermentation inhibitor is a heavy metal, it is removed using an ion exchange resin.
When the fermentation inhibitor is lignin, ozone is added to decompose and remove lignin.
Since water is the most abundant substance in the effluent, concentration is performed. Concentration methods include reverse osmosis, distillation, functional membrane, hydroxyapatite gel, and hydrophilic polymer. There is a method using an adsorbent such as.

The method of collecting carbohydrates in the effluent is
1) Collect using an adsorbent such as hydroxyapatite gel or hydrophilic polymer.
2) The aqueous solution is concentrated and crystallized and collected. As a concentration method, there are a reverse osmotic pressure method, a distillation method, and a method using a functional membrane, and a method using the adsorbent can also be applied. During crystallization, a hydrophilic organic solvent such as ethanol or methanol can be added to promote crystallization.
3) In some cases, the separation of carbohydrates is not performed, and useful substances and fermentation-inhibiting substances in the effluent are removed, and a liquid concentrated until the sugar concentration becomes 5 to 50% is used as the recovered sugar liquid. Send to process hydrolysis step.

(9th process) Hydrolysis process The recovered carbohydrate which processed the soluble part of the cooking / explosion process of the 2nd process, and the waste liquid of the ethanol concentration of the 6th process at the 8th process is once a hydrolysis process. However, it may contain unreacted oligosaccharides. Unless the content of oligosaccharide is negligible by inspection, it is preferable to hydrolyze the recovered carbohydrate solution. The method is the same as in the fourth step.

(10th process) Waste water treatment process The waste liquids of the 2nd to 4th, 6th, 8th and 9th processes are combined and concentrated by membrane filtration to recover biomass. The ethanol production stage of the present invention uses only a small amount of inorganic substances and can be operated without using pollutants, so the concentrated liquid of the effluent is mainly composed of hydrocarbons. If this is burned with a waste liquid recovery boiler to generate electricity, it is possible to supply more power than the required power of the ethanol production facility. Moreover, distilled water condensed with steam and hot water can be supplied. An actual calculation example is shown in the examples.
If an extraction back pressure turbine generator is used for power generation, high temperature and high pressure steam necessary for the second and fourth steps can be extracted from the turbine and supplied.

Below, as an example for carrying out the present invention, an example of cultivating and harvesting hondawala in a 10,000 km ² algae bed and producing ethanol together with a calculation example showing a substance balance will be shown.

(A) Honda Walla cultivation (algae)
FIG. 2 is a schematic view showing the configuration of the seaweed bed 7. The seaweed place 7 was installed in the sea area with an average water depth of about 400 m of Daiwa Bank in the Sea of Japan.
As shown in FIG. 2 (A), the seaweed basin 7 was configured by installing ten seaweed basins 8 with an open water surface serving as a channel 24 or a fishing ground 25 having a width of 1 km or more. The effective cultivation area is 10,000 km ² .
A management center was set up in Mogaba 7. The management center managed the entire algae basin in cooperation with a ground concentration support system (not shown in the figure) that supports the algae basin 7.

  The seaweed bed 7 was managed using a marine satellite system. The marine satellite system includes a GPS satellite, a communication satellite, a marine observation satellite, and a weather satellite. The marine satellite system collected information on the development status of Honda straw, damage status such as isoburning, weather, ocean currents, and floating waste. In addition, command transmission related to the unmanned operation of the small high-speed seaweed cutter boat 32 and the buoyancy control device 16 and information transmission for transmitting management information to the management base of the seaweed bed set via the satellite monitoring system, We also exchanged information with the ground-based support system.

As shown in FIG. 2 (B), the seaweed bed set 8 has 10,000 seaweed bed units 9 aligned and juxtaposed on the sea surface divided by the small waterway 21, the middle waterway 22, and the large waterway 23. Formed.
The seaweed bed set 8 includes 10 management bases, 300,000 gross ton class seaweed transport tankers as seaweed transportation means, 10 medium-sized workboats 31 with a loading capacity of 600 tons and 10 small high-speed seaweed cutter ships 32 as harvesting means. A ship and an ethanol production facility 29 were installed.

  The minimum structural unit of the seaweed bed 7 is the seaweed bed unit 9 shown in FIGS. 2 (C) and (D). The seaweed bed unit 9 has a square net 14 with a side of 100 m that is anchored substantially horizontally below the sea surface to a mooring line 13 that connects the anchor 11 and the buoyant body 12 installed on the seabed 17, A seaweed holding device 15 made of a rope reinforced by a rice bran rope holding the applicator 2 and a net 14 and a seaweed holding device 15 for rising and sinking by increasing or decreasing the volume of gas to be sealed. And one buoyancy adjusting device 16.

The volume of the enclosed gas was automatically increased or decreased by remote control, and the command was transmitted through a communication network via a marine surveillance satellite.
The depth of settling is 10 m when settling for a long time in winter, and the limit is 20 m even when settling for a short period due to a storm.
Information that contributes to the weather judgment on whether to ascend and sink is collected from the data of the marine surveillance satellites.

(Cultivation of Honda Walla)
In April, Honda's male and female genital beds were taken out and fertilized. 0.25-0.3 mm embryos were grown in a water tank. The breeding was carried out with light agitation from the bottom of a transparent aquarium, sending air, and agitating the air while moving to a large aquarium with the growth of Honda Walla. From 4 to 6 months after fertilization, the young embryo became a juvenile with a length of 0.5 to 15 mm. In October of the second year, one and a half years after fertilization, it became a Honda Walla at a stem elongation period of about 200 mm in length. The interval between the seaweed holding devices 15 was 1 m, and 10 honda straw per 1 m was attached at an interval of 10 cm to start cultivation in the open ocean.

  In winter, the seaweed holding device 15 was submerged to a depth of 10 m and grown. From early spring to summer, when the sea is calm, the seaweed retainer 15 is kept at a depth of 4 m, and the leaves 5 of the upper part of Honda Walla, which is self-floating with air bubbles 6 drifts on the surface of the sea, and the sunlight is sufficient I tried to receive it. Honda Walla grew rapidly and grew to 2-4 m.

(Honda Walla harvest)
In May of the third year, a small cutter boat 32 was used to cut the main branch 4 of the seaweed from the seaweed holding device 15, leaving the applicator 2, stem and 3.
The medium-sized workboat 31 harvested the Honda Walla that had been cut and floated on the sea with seawater and filtered.
As a result, 6.5 kg per year was harvested per 1 m ² , and 65 million tons (converted to dry weight) of Honda Walla were harvested with 10 sets of seaweed beds (whole seaweed beds).

(B) Ethanol Production Hereinafter, the steps for producing ethanol from seaweed harvested according to the flowchart of FIG. 3 will be described.
(First step) Pretreatment The harvested seaweed was washed with water to remove the adhering components, and pulverized with a fine crusher while heating to 50 to 90 ° C, and a small amount of sodium hydroxide was added to produce a raw material. . Woody floats such as driftwood, used seaweed holding device 15 and the like were also pulverized into powder and used in addition to the raw materials.

(2nd process) Steaming / explosion process The steaming / explosion apparatus 40 is shown in FIG.
The raw material is preheated by supplying steam from the preheating means 45 in the raw material supply unit 41, and then supplied from the pressure inlet 44 to the pressure cooker 43, and 130-230 in the upper pretreatment unit 48 during the fall. After being treated with steam 46 at 0 ° C., it was added to the lower subcritical water 49 and steamed at 130-230 ° C. for 5 minutes under such a pressure that the subcritical water 49 would not boil at this reaction temperature.
The steamed raw material was explosively depressurized to atmospheric pressure by ejecting it from the adiabatic expansion nozzle 50 to the adiabatic expansion part 54. The produced slurry was separated into a soluble part and an insoluble part by a screw press. In this example, the liquid obtained by condensing the normal-pressure vapor and the soluble part were sent to the 10th step for waste liquid treatment without collecting useful substances and carbohydrates.

(Third step) Purification step The insoluble part obtained in the second step was washed several times with ethanol, and the washings were combined and concentrated to recover fat and ethanol. The insoluble part was treated with ozone-containing water to decompose the colored substance containing lignin to obtain a cellulose fraction. The effluent from this step was sent to the eleventh step.

(Fourth Step) Hydrolysis Step The cellulose fraction obtained in the third step was again used in the steaming / explosion apparatus used in the second step, except that hydrolysis was performed at 230 to 280 ° C. for 5 minutes to obtain a glucose solution. .
(5th process) Ethanol fermentation process The ethanol fermentation was performed through the column which added the ethanol fermentation microbe (RITE microbe) which made the glucose solution the living independence.

(6th process) Ethanol concentration process 60-90% ethanol was able to be obtained by the ethanol concentration method which applied the principle of the gate membrane.
(Seventh Step) Ethanol Drying Step Ethanol was passed through a zeolite column to adsorb moisture to obtain 99.5% ethanol.
About 65 million tons of Honda Walla (dry weight) produced about 20 million m ² (20,000,000 kiloliters) of ethanol.

(Eighth Step) Useful Substance Recovery, Fermentation Inhibitory Substance Removal, Unnecessary Substance Removal, Carbohydrate Recovery Step and (Ninth Step) Sugar Hydrolysis )

(Tenth step) The wastewater treatment steps 2, 4, and 6 were combined and concentrated by membrane filtration to recover biomass. The recovery rate was 65%. This was burned with a waste liquid recovery boiler, and power was generated using a bleed back pressure turbine generator.
The calculation example of the substance and energy balance based on the said Example is shown.

(Example of balance calculation)
1) Yield of Honda Wallet Planting area: 10,000 km ²
Yield per unit area: 6.5 kg / m ²
Total yield: 65 million tons

2) Ethanol production Carbohydrate content: 88%
Estimated ethanol yield: 289 kg / ton ^{* 1)} ÷ 0.79 (specific gravity)
= 0.365 kiloliters / ton Honda Walla ethanol annual production: 6,500 x 0.88 x 0.365
= 20.78 million kiloliters * 1) Source: National Institute of Advanced Industrial Science and Technology China Center Biomass Research Center data

3) Waste liquid recovery (approximate)
Setting conditions: Biomass recovery rate 65%
Boiler efficiency 0.7
Generator efficiency 0.35
Hydrocarbon combustion heat 4020Kcal
Molecular weight: Carbohydrate / ethanol = 180 / (46 × 2)
= 2
Biomass recovery amount
(6,500 x 0.88-2, 000 x 0.79 x 2) x 0.65
= 16.6 million tons Waste heat recovery boiler calorific value
1,660 × 4020 × 0.7 × (1,000 / 860)
= 54.3 million MWh
Generator output
(5430 × 0.34) / (365 days × 24 hours)
= 2,100 MW

The amount of power generated by waste liquid recovery is much higher than the power consumed by the seaweed beds and ethanol production factories, and can be sold to the outside.
In view of the estimated cost balance, it was estimated that the method for producing ethanol from the seaweed of the present invention was economically established only by the method for producing ethanol described in the Examples. Furthermore, it is estimated that sufficient profits can be obtained if the yield is improved by using the recovered carbohydrate, the recovery of useful substances, the sale of power from the waste liquid recovery power generation, and the like.

It is a schematic diagram of Honda Walla. It is a schematic diagram explaining the form of the seaweed bed of the system which manufactures ethanol from seaweed. (2A) shows the algae field, (2B) shows the algae field set, (2C) shows the algae field unit, and (2D) shows the aa sectional view of (2C). It is a flowchart which shows the outline of the process of manufacturing ethanol. It is a conceptual diagram which shows the cross section of a steaming and detonation apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seaweed 2 Adhering device 3 Stem 4 Main branch 5 Leaf 6 Air vesicle 7 Algae field 8 Algae field set 9 Algae field unit 11 Anchor 12 Buoyant body 13 Mooring line 14 Net 15 Seaweed holding device 16 Buoyancy control device 17 Sea bottom 18 Sea surface 21 Small waterway 22 Middle Waterway 23 Large Waterway 24 Route 25 Fishing Ground 26 Management Center 27 Marine Satellite System 28 Management Base 29 Ethanol Production Equipment 30 Seaweed Transport Tanker 31 Medium Work Ship 32 Small High-Speed Seaweed Cutter Boat 40 Steaming / Detonation Equipment 41 Raw Material Supply Section 42 Steaming Part 43 pressure kettle 44 pressure inlet 45 preheating means 46 high-temperature high-pressure steam 47 piping 48 pretreatment part 49 subcritical water 50 adiabatic expansion nozzle 51 atmospheric pressure steam outlet 52 soluble part 53 solid-liquid separator 54 adiabatic expansion part

Claims (9)

A pretreatment stage for harvesting and pulverizing plants containing cellulose, suspending the pulverized plants in water, heating under high temperature and high pressure while avoiding boiling, and then releasing the high temperature and high pressure suspension to atmospheric pressure Then, a steaming / explosion stage for obtaining an insoluble part mainly composed of cellulose, a purification stage for purifying the insoluble part and collecting a cellulose fraction, and suspending the cellulose fraction in water while avoiding boiling A hydrolysis step for producing a glucose solution by heating under high temperature and high pressure and then releasing the high temperature and high pressure suspension to atmospheric pressure, an ethanol fermentation step for ethanol fermentation of the glucose solution, and hydrous ethanol from the ethanol fermentation solution An ethanol concentration step of collecting the ethanol, and an ethanol drying step of producing dry ethanol by removing water from the water-containing ethanol,
An ethanol production method comprising:   The plant is a seaweed that becomes self-floating by attaching air vesicles during the growth period, and the harvesting of the plant is performed by causing the seaweed attachment device to be held in the seaweed holding device and maturing in this holding state, 2. The method for producing ethanol according to claim 1, wherein after the seaweed has matured, the harvesting step is carried out by harvesting the main branch of the seaweed by cutting off the attachment device and the stem from the seaweed holding device.   The method for producing ethanol according to claim 2, wherein the seaweed is a seaweed belonging to the order of the scorpionidae.   The method for producing ethanol according to claim 1, wherein the purification step includes a step of purifying the cellulose fraction by treating the insoluble part with ozone.   After separating the soluble part from the insoluble part, the useful substance recovery step of recovering the useful substance from the soluble part, the inhibitory substance removing step of removing the fermentation inhibitor from the soluble part, the unnecessary substance from the soluble part The method for producing ethanol according to claim 1, wherein at least one of an unnecessary substance removing step of removing saccharide and a saccharide collecting step of collecting saccharide from the soluble part is performed.   6. The method for producing ethanol according to claim 5, wherein the useful substance is one or more selected from heavy metals, natural uranium, alginic acid, fucodyne, plant protein, and fat.   Pretreatment means for pulverizing the plant containing the harvested cellulose, suspending the pulverized plant in water, heating under high temperature and high pressure while avoiding boiling, and then releasing the high temperature and high pressure suspension to atmospheric pressure Cooking / explosion means for obtaining an insoluble part mainly composed of cellulose, purification means for purifying the insoluble part and collecting a cellulose fraction, and hydrolysis for producing a glucose solution by hydrolyzing the cellulose fraction Means, ethanol fermentation means for subjecting the glucose solution to ethanol fermentation, ethanol concentration means for concentrating the ethanol fermentation liquid to collect hydrous ethanol, and ethanol drying means for removing water from the hydrous ethanol to produce dry ethanol An ethanol production apparatus comprising:   The ethanol production apparatus according to claim 7, wherein the purification means is a purification stage in which the cellulose fraction is purified by ozone treatment of the insoluble part. The plant containing cellulose is a seaweed harvested by a seaweed culture device,
The seaweed aquaculture device has a net including a rope-like seaweed holding device for holding the seaweed attachment device and a buoyancy adjusting device for floating and sinking the seaweed holding device, and connects an anchor and a buoyant body installed on the seabed. A seaweed bed unit anchored substantially horizontally below the surface of the mooring line, a seaweed bed set in which a plurality of the seaweed bed units are aligned and gathered at predetermined intervals, and a plurality of the seaweed bed sets at predetermined intervals. The ethanol production apparatus according to claim 7, further comprising a seaweed bed installed individually.

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