Nothing Special   »   [go: up one dir, main page]

WO2010070716A1 - Method of producing ethanol and apparatus therefor - Google Patents

Method of producing ethanol and apparatus therefor Download PDF

Info

Publication number
WO2010070716A1
WO2010070716A1 PCT/JP2008/072733 JP2008072733W WO2010070716A1 WO 2010070716 A1 WO2010070716 A1 WO 2010070716A1 JP 2008072733 W JP2008072733 W JP 2008072733W WO 2010070716 A1 WO2010070716 A1 WO 2010070716A1
Authority
WO
WIPO (PCT)
Prior art keywords
ethanol
fermentation
liquid
gas
concentration
Prior art date
Application number
PCT/JP2008/072733
Other languages
French (fr)
Japanese (ja)
Inventor
茂 坂下
勉 川▲崎▼
Original Assignee
株式会社前川製作所
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社前川製作所 filed Critical 株式会社前川製作所
Priority to PCT/JP2008/072733 priority Critical patent/WO2010070716A1/en
Publication of WO2010070716A1 publication Critical patent/WO2010070716A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
    • C07B63/00—Purification; Separation; Stabilisation; Use of additives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D1/00—Evaporating
    • B01D1/28—Evaporating with vapour compression
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
    • B01D3/001—Processes specially adapted for distillation or rectification of fermented solutions
    • B01D3/002—Processes specially adapted for distillation or rectification of fermented solutions by continuous methods
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
    • B01D5/0027—Condensation of vapours; Recovering volatile solvents by condensation by direct contact between vapours or gases and the cooling medium
    • B01D5/003—Condensation of vapours; Recovering volatile solvents by condensation by direct contact between vapours or gases and the cooling medium within column(s)
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M21/00—Bioreactors or fermenters specially adapted for specific uses
    • C12M21/12—Bioreactors or fermenters specially adapted for specific uses for producing fuels or solvents
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12M—APPARATUS FOR ENZYMOLOGY OR MICROBIOLOGY; APPARATUS FOR CULTURING MICROORGANISMS FOR PRODUCING BIOMASS, FOR GROWING CELLS OR FOR OBTAINING FERMENTATION OR METABOLIC PRODUCTS, i.e. BIOREACTORS OR FERMENTERS
    • C12M43/00—Combinations of bioreactors or fermenters with other apparatus
    • C12M43/02—Bioreactors or fermenters combined with devices for liquid fuel extraction; Biorefineries
    • C—CHEMISTRY; METALLURGY
    • C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
    • C12P7/00—Preparation of oxygen-containing organic compounds
    • C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
    • C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
    • C12P7/06—Ethanol, i.e. non-beverage
    • C12P7/08—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate
    • C12P7/10—Ethanol, i.e. non-beverage produced as by-product or from waste or cellulosic material substrate substrate containing cellulosic material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E50/00—Technologies for the production of fuel of non-fossil origin
    • Y02E50/10—Biofuels, e.g. bio-diesel

Definitions

  • the present invention relates to a method and an apparatus for producing ethanol in a technology for producing ethanol by saccharifying and fermenting biomass to prevent fermentation inhibition of ethanol-fermenting yeast and improve ethanol yield.
  • Bioethanol is produced by fermenting biomass as a measure for reducing carbon dioxide concentration in the atmosphere and depleting fossil fuels.
  • Bioethanol is vegetable ethyl alcohol produced by saccharification, fermentation and distillation of biomass resources such as sugarcane, cassava, corn, and waste wood, and has attracted attention as a new fuel energy.
  • FIG. 4 shows a conventional general bioethanol production apparatus.
  • Biomass is pulverized in advance, saccharified biologically or chemically to recover a liquid containing sugar, and this sugar-containing liquid is put into the fermentation tank 51.
  • an ethanol fermentation yeast is put into the fermentation tank 51 and fermented for a predetermined time to generate an ethanol solution.
  • ethanol fermentation is an exothermic reaction, a temperature rise in the fermentation tank 51 is observed.
  • the function of the yeast is reduced, so that the fermentation liquid in the fermentation tank 51 can be cooled. Necessary.
  • FIG. 4 shows a conventional general bioethanol production apparatus.
  • Biomass is pulverized in advance, saccharified biologically or chemically to recover a liquid containing sugar, and this sugar-containing liquid is put into the fermentation tank 51.
  • an ethanol fermentation yeast is put into the fermentation tank 51 and fermented for a predetermined time to generate an ethanol solution.
  • a temperature rise in the fermentation tank 51 is observed.
  • the function of the yeast is
  • a cooling line 52 is provided that pulls out the fermentation broth from the bottom of the fermentation tank 51 by the pump 53, cools the fermentation broth via a cooler 54 that indirectly cools the fermentation broth, and then returns it to the fermentation tank 51.
  • the fermentation broth is cooled and maintained at a temperature suitable for fermentation, so that the fermentation is stably performed.
  • Patent Document 1 Japanese Patent Laid-Open No. 2008-182925.
  • Patent Document 1 discloses a reactor that pressurizes and heats an aqueous slurry of biomass, hydrolyzes cellulose and cellulose contained in the biomass to produce sugar, and ethanol that ferments the produced sugar to produce ethanol.
  • a bioethanol production apparatus including a fermentation apparatus is disclosed.
  • An object of the present invention is to provide an ethanol production method and apparatus that can prevent ethanol fermentation inhibition, maintain a high ethanol yield, and efficiently produce ethanol in view of the above-described problems of the conventional techniques.
  • the present invention in an ethanol production method for producing ethanol by distilling a fermentation liquid after fermenting a sugar-containing liquid obtained by hydrolyzing biomass in a fermentation tank,
  • the temperature or ethanol concentration of the fermentation liquid in the fermentation tank is measured, and when the measured temperature or ethanol concentration exceeds a predetermined value, at least a part of the fermentation liquid is extracted from the fermentation tank, and the extracted fermentation liquid is Evaporating gas containing ethanol is separated by vacuum evaporation in a vacuum evaporator, and the residual liquid cooled by the vacuum evaporation and reduced in ethanol concentration is returned to the fermentation tank.
  • the temperature or ethanol concentration of the fermentation liquor in the fermentation tank is monitored, the fermentation liquor is withdrawn before reaching the temperature or ethanol concentration causing fermentation inhibition, the fermentation liquor is cooled by vacuum evaporation,
  • the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
  • the condensate containing condensed ethanol and the non-condensable gas are separated into gas and liquid, and the condensate is distilled to recover ethanol.
  • the evaporated gas generated by the vacuum evaporator ethanol having a higher concentration than the residual liquid exists. Therefore, the ethanol yield can be increased by cooling and condensing the evaporated gas to recover ethanol.
  • the non-condensable gas is brought into contact with water, ethanol in the non-condensable gas is transferred to the water side, and the ethanol-containing water obtained is distilled to recover ethanol.
  • This makes it possible to recover the ethanol remaining in the non-condensed gas after cooling the vaporized gas and separating it from gas and liquid, thereby further improving the ethanol yield.
  • an ethanol production apparatus comprising a fermentation tank for fermenting a sugar-containing liquid obtained by hydrolyzing biomass, and a distiller for distilling the fermentation liquid discharged from the fermentation tank, A circulation cooling line for extracting a part of the fermentation liquor in the fermentation tank and circulating it externally; A valve provided on the outlet side of the fermentation tank; A vacuum evaporator that is provided on the circulating cooling line and that separates the fermentation liquor by evaporating the fermentation liquid into an evaporating gas containing ethanol and a residual liquid cooled by the vacuum evaporating and having a reduced ethanol concentration; A temperature measuring means for measuring the temperature of the fermentation broth in the fermentation tank or a concentration measuring means for measuring the ethanol concentration; A controller that controls to circulate the fermentation broth on the circulating cooling line by opening the valve when the temperature or ethanol concentration measured by the temperature measuring means or the concentration measuring means exceeds a predetermined value. It is characterized by that.
  • a cooler for cooling the evaporative gas A gas-liquid separator that is vapor-liquid separated into a condensate containing ethanol condensed by cooling and a non-condensed gas introduced through the cooler, and The condensate is fed to the distiller. Furthermore, the non-condensable gas separated by the gas-liquid separator is introduced, and the non-condensable gas is brought into contact with water, and an absorption tower for transferring ethanol in the gas to the water side is provided. Ethanol-containing water obtained in the absorption tower is supplied to the distiller.
  • the controller is configured such that the temperature measured by the temperature measuring means is 32 ° C. or higher, or the ethanol concentration measured by the concentration measuring means is set to 6% or higher as a condition for opening the valve. It is characterized by.
  • the temperature of the fermentation broth is 32 ° C. or higher or the ethanol concentration is 6% or higher, fermentation inhibition tends to occur. Therefore, when the temperature or the ethanol concentration is exceeded, the fermentation broth is discharged onto the circulation cooling line, and the ethanol concentration is lowered and cooled by the vacuum evaporator, whereby the fermentation can be continued stably.
  • a heater is provided in front of the vacuum evaporator, and the fermentation broth is heated to a temperature set based on a gas-liquid equilibrium curve of ethanol.
  • the temperature set based on the vapor-liquid equilibrium curve of ethanol is the temperature at which ethanol most moves to the gas phase side when vacuum-evaporated with a vacuum evaporator.
  • the temperature or ethanol concentration of the fermentation liquid in the fermentation tank is monitored, the fermentation liquid is drawn out before reaching the temperature or ethanol concentration causing fermentation inhibition, and the fermentation liquid is cooled by vacuum evaporation.
  • the fermentation liquid is drawn out before reaching the temperature or ethanol concentration causing fermentation inhibition, and the fermentation liquid is cooled by vacuum evaporation.
  • the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
  • the ethanol yield can be increased by cooling and condensing the evaporated gas generated in the vacuum evaporator to recover ethanol. Furthermore, the ethanol yield can be further improved by absorbing and recovering ethanol remaining in the non-condensable gas after cooling and evaporating the vaporized gas.
  • 1 is an overall configuration diagram of an ethanol production apparatus according to an embodiment of the present invention. It is a graph which shows the relationship between the ethanol concentration in fermentation liquid, and fermentation time. 1 is an overall configuration diagram of an ethanol production apparatus to which an embodiment of the present invention is applied. It is a block diagram of the conventional ethanol manufacturing apparatus.
  • the ethanol production apparatus is equipped with a pretreatment device (not shown) in the preceding stage.
  • the pretreatment device pulverizes biomass as appropriate, hydrolyzes it at a predetermined temperature and a predetermined pressure with water, and contains sugar.
  • a liquid is produced.
  • This sugar-containing liquid is a raw material for the ethanol production apparatus.
  • the biomass is an organic substance resulting from photosynthesis, which is biomass such as woody material, vegetation, agricultural products, and moss, and in the present embodiment, is a plant resource that contains a large amount of sugar or starch. Is preferred.
  • the ethanol production apparatus includes a fermentation tank 1 in which a sugar-containing liquid 21 is charged and fermentation yeast is added thereto to perform ethanol fermentation.
  • the fermentation tank 1 is connected to a circulating cooling line 2 that draws out at least a part of the fermentation liquid in the tank, cools it, and returns it to the fermentation tank 1.
  • a valve 3 On the circulating cooling line 2, a valve 3 is provided on the outlet side of the fermentation tank 1, and a vacuum evaporator 4 is provided on the downstream side thereof.
  • the vacuum evaporator 4 is sucked by a vacuum pump (not shown) and the inside is maintained at a vacuum low pressure.
  • the vacuum evaporator 4 is preferably maintained at about 0.005 to 0.02 atm, more preferably about 0.01 atm.
  • the fermentation tank 1 is provided with a temperature sensor 15 for measuring the temperature of the fermentation broth in the tank and a concentration sensor 16 for measuring the ethanol concentration. Further, based on the measured values measured by the temperature sensor 15 and the concentration sensor 16, a controller 17 that performs opening / closing control of the valve 3 of the circulation cooling line 2 and a valve 19 provided on a discharge line 18 described later is provided. I have.
  • a discharge line 18 is connected to the lower part of the fermentation tank 1 for discharging the fermented liquor that has been fermented.
  • a valve 19 is provided at the tank outlet, and a distiller 20 is provided downstream thereof.
  • the distiller 20 is a device that distills the fermentation broth to remove impurities, and an ethanol concentrator (not shown) may be provided in the previous stage or subsequent stage of the distiller 20.
  • the evaporated gas generated in the vacuum evaporator 4 is discharged to a gas line 5 different from the circulation cooling line 2.
  • a cooler 6, a gas-liquid separator 7, a pump 8, and an ethanol absorption tower 9 are provided in this order from the upstream side.
  • the cooler 6 is a device that cools the evaporative gas by indirect cooling.
  • an ammonia cooler using ammonia as a refrigerant is used.
  • the gas-liquid separator 7 is a device that separates the condensate 22 that has been cooled by the cooler 6 and partially condensed and the non-condensable gas 23.
  • the ethanol absorption tower 9 is a device for introducing the non-condensable gas 23 and bringing the non-condensable gas 23 into contact with water to transfer ethanol in the gas to the water side and recover it.
  • water is sprayed from a plurality of nozzles installed at the upper side, brought into countercurrent contact with the non-condensable gas 23 introduced from the lower side to transfer ethanol to the water side, and CO 2 , O 2, etc. It is set as the apparatus which isolate
  • the ethanol-containing water 24 may be circulated on the circulation line 10 by the pump 11 and discharged when the ethanol concentration exceeds a predetermined concentration.
  • the condensate 22 condensed in the gas-liquid separator 7 contains a large amount of ethanol, it is led to the distiller 20 together with the fermentation liquid discharged from the fermentation tank 1 and recovered as ethanol. Similarly, the ethanol-containing water 24 discharged from the ethanol absorption tower 9 is also led to the distiller 20 to recover ethanol.
  • the sugar-containing liquid 21 obtained by hydrolyzing biomass is put into the fermentation tank 1 and fermented yeast is added and fermented for a predetermined time.
  • the valve 3 on the circulation cooling line 2 and the valve 19 on the discharge line 18 are set to be closed.
  • the temperature of the fermentation broth in the fermentation tank 1 is measured by the temperature sensor 15 and the temperature of the fermentation broth is monitored.
  • the controller 17 opens the valve 3 and discharges the fermented liquid to the circulation cooling line 2.
  • the temperature in the fermentation tank 1 when the valve 3 is opened is preferably 32 ° C. or higher.
  • bulb 3 was made into the temperature above, it is good also considering the ethanol concentration of the fermentation liquid in the fermentation tank 1 as an opening condition.
  • the ethanol concentration of the fermentation broth is measured and monitored by the concentration sensor 16, and the valve 3 is opened by the controller 17 when the concentration exceeds a predetermined ethanol concentration.
  • the ethanol concentration in the fermentation tank 1 when the valve 3 is opened is preferably 6% or more.
  • the fermentation liquor discharged to the circulation cooling line 2 is introduced into the vacuum evaporator 4.
  • the fermentation liquor brought to a low pressure state in the vacuum evaporator 4 is boiled and evaporated to obtain an evaporating gas and a residual liquid.
  • the evaporative gas contains ethanol having a concentration along the vapor-liquid equilibrium curve of ethanol, but the evaporated gas contains ethanol having a higher concentration than the residual liquid.
  • the evaporated gas contains CO 2 , O 2 and the like.
  • the residual liquid is cooled by vacuum evaporation and returned to the fermentation tank 1 through the circulation cooling line 2 in a state where the ethanol concentration is lowered.
  • the evaporated gas is discharged to the gas line 5 and introduced into the cooler 6 provided on the gas line 5.
  • the evaporative gas is cooled in the cooler 6 and is introduced into the gas-liquid separator 7 in a partially condensed state.
  • the gas-liquid separator 7 is separated into a condensate 22 containing condensed ethanol and a non-condensable gas 23 mainly composed of CO 2 and O 2 .
  • the non-condensable gas 23 is guided to the absorption tower 9 by the pump 8.
  • ethanol remaining in the gas moves to the water side and is recovered as ethanol-containing water 24.
  • the condensate 22 separated by the gas-liquid separator 7 and the ethanol-containing water 24 recovered by the absorption tower 9 are guided to the distiller 20 and recovered as high-concentration ethanol.
  • the circulation cooling line 2 closes the valve 3 by the controller 17 to stop the circulation of the fermentation broth.
  • the circulation stop condition may be ethanol concentration in addition to temperature.
  • fermentation is performed continuously.
  • the temperature in the fermentation tank 1 is monitored by the temperature sensor 15 in the same manner as described above, and when the temperature becomes equal to or higher than the predetermined temperature, the valve 3 on the circulation cooling line 2 is opened again to cool the fermentation broth.
  • the change in ethanol concentration in the fermentation tank 1 is monitored by the concentration sensor 16, and when no change is observed in the ethanol concentration, it is determined that fermentation has ended, and the controller 17 determines the discharge line 18.
  • the upper valve 19 is opened, the fermented liquid in the fermentation tank 1 is fed to the still 20 and high-concentration ethanol is recovered.
  • the temperature or ethanol concentration of the fermentation liquor in the fermentation tank 1 is monitored, the fermentation liquor is withdrawn before reaching the temperature or ethanol concentration causing fermentation inhibition, and the liquid is cooled and cooled by vacuum evaporation.
  • the ethanol concentration therein it is possible to prevent fermentation inhibition from occurring in the fermentation tank 1, to perform ethanol fermentation stably, and to improve the ethanol yield.
  • the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
  • FIG. 2 shows a graph comparing ethanol concentrations in the ethanol production apparatus of the present embodiment shown in FIG. 1 and the conventional ethanol production apparatus shown in FIG.
  • the horizontal axis in FIG. 2 is the fermentation time, and the vertical axis is the ethanol concentration.
  • the ethanol concentration in the fermentation liquid increases with time and increases to a concentration that causes fermentation inhibition.
  • the ethanol concentration does not exceed 6%. It has become. Therefore, the concentration does not become so high as to cause fermentation inhibition, and the fermentation can be performed stably, and the ethanol yield can be improved.
  • FIG. 3 shows an embodiment in which the ethanol production apparatus shown in FIG. 1 is applied.
  • This ethanol production apparatus has a configuration in which a heater 14 is provided in front of the vacuum evaporator 4 on the circulation cooling line 2.
  • the heater 14 is a device that heats the fermented liquid discharged from the fermentation tank 1 to the circulation cooling line 2 to a temperature set based on a gas-liquid equilibrium curve of ethanol.
  • the temperature set based on the vapor-liquid equilibrium curve of ethanol is the temperature at which ethanol moves most to the gas phase side when the vacuum evaporator 4 is used for vacuum evaporation.
  • the fermented liquid heated by the heater 14 is introduced into the vacuum evaporator 4, and evaporating gas containing ethanol is generated by vacuum evaporation.
  • the evaporative gas contains a higher concentration of ethanol than when the heater 14 is not installed.
  • the evaporative gas is cooled by the cooler 6 and then gas-liquid separated by the gas-liquid separator 7 to recover the ethanol. Is done.
  • the residual liquid from which the evaporated gas has been separated by the vacuum evaporator 4 is returned to the fermentation tank 1 via the circulation cooling line 2. According to this embodiment, more ethanol can be transferred to the evaporation gas side, and the ethanol concentration in the residual liquid returned to the fermentation tank 1 can be reliably reduced.
  • the present invention prevents ethanol fermentation inhibition, maintains a high ethanol yield, and can produce ethanol efficiently, it is suitably used for the production of bioethanol used for fuels and chemical raw materials.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Zoology (AREA)
  • Bioinformatics & Cheminformatics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Genetics & Genomics (AREA)
  • General Health & Medical Sciences (AREA)
  • Microbiology (AREA)
  • Biochemistry (AREA)
  • General Engineering & Computer Science (AREA)
  • Biotechnology (AREA)
  • Sustainable Development (AREA)
  • Biomedical Technology (AREA)
  • General Chemical & Material Sciences (AREA)
  • Molecular Biology (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Apparatus Associated With Microorganisms And Enzymes (AREA)

Abstract

The purpose of this object is to provide a method of producing ethanol, whereby ethanol can be efficiently produced while preventing ethanol fermentation from inhibition and maintaining a high ethanol yield, and an apparatus for producing the same. A method of producing ethanol wherein a sugar-containing liquid obtained by biologically or chemically saccharifying a biomass is fermented in a fermentation tank (1) and then the fermented liquid is distilled to give ethanol, which has the constitution comprising: measuring the temperature or ethanol concentration of the fermented liquid in the above-described fermentation tank (1) with a temperature sensor (15) or a concentration sensor (16); when the temperature or ethanol concentration thus measured attains a predetermined value or more, withdrawing at least a portion of the fermented liquid from the fermentation tank (1); introducing the thus withdrawn fermented liquid to a vacuum evaporator (4) via a circulation cooling line (2); evaporating the fermented liquid in vacuo to thereby separate the evaporated gas containing ethanol; and then returning the residual liquid which has been cooled and shows a lowered ethanol concentration into the fermentation tank (1).

Description

エタノール製造方法及び装置Ethanol production method and apparatus
　本発明は、バイオマスを糖化、発酵してエタノールを製造する技術において、エタノール発酵酵母の発酵阻害を防止し、エタノール収率を向上させるようにしたエタノール製造方法及び装置に関する。 [Technical Field] The present invention relates to a method and an apparatus for producing ethanol in a technology for producing ethanol by saccharifying and fermenting biomass to prevent fermentation inhibition of ethanol-fermenting yeast and improve ethanol yield.
　近年、大気中の炭酸ガス濃度削減、及び化石燃料の枯渇化への対策として、バイオマスを発酵させてバイオエタノールを製造することが行われている。バイオエタノールは、サトウキビ、キャッサバ、とうもろこし、廃木材などのバイオマス資源を糖化、発酵、蒸留して作られる植物性のエチルアルコールであり、新たな燃料用エネルギーとして注目されている。 In recent years, bioethanol is produced by fermenting biomass as a measure for reducing carbon dioxide concentration in the atmosphere and depleting fossil fuels. Bioethanol is vegetable ethyl alcohol produced by saccharification, fermentation and distillation of biomass resources such as sugarcane, cassava, corn, and waste wood, and has attracted attention as a new fuel energy.
　図４に、従来の一般的なバイオエタノールの製造装置を示す。予めバイオマスを粉砕し、生物的又は化学的に糖化して糖を含む液を回収し、この糖含有液を発酵タンク５１に投入する。さらに発酵タンク５１内にエタノール発酵酵母を投入し、所定時間発酵させることによりエタノール溶液を生成する。このとき、エタノール発酵は発熱反応であるため発酵タンク５１内の温度上昇がみられるが、ある温度以上となると酵母の働きが低下してしまうため、発酵タンク５１内の発酵液を冷却することが必要となる。図４では、発酵タンク５１の底部からポンプ５３により発酵液を引き抜き、発酵液を間接冷却する冷却器５４を介して発酵液を冷却した後、発酵タンク５１に戻す冷却ライン５２を設けている。ここで発酵液を冷却し、発酵に適した温度に維持することにより安定的に発酵を行うようになっている。 FIG. 4 shows a conventional general bioethanol production apparatus. Biomass is pulverized in advance, saccharified biologically or chemically to recover a liquid containing sugar, and this sugar-containing liquid is put into the fermentation tank 51. Furthermore, an ethanol fermentation yeast is put into the fermentation tank 51 and fermented for a predetermined time to generate an ethanol solution. At this time, since ethanol fermentation is an exothermic reaction, a temperature rise in the fermentation tank 51 is observed. However, when the temperature exceeds a certain temperature, the function of the yeast is reduced, so that the fermentation liquid in the fermentation tank 51 can be cooled. Necessary. In FIG. 4, a cooling line 52 is provided that pulls out the fermentation broth from the bottom of the fermentation tank 51 by the pump 53, cools the fermentation broth via a cooler 54 that indirectly cools the fermentation broth, and then returns it to the fermentation tank 51. Here, the fermentation broth is cooled and maintained at a temperature suitable for fermentation, so that the fermentation is stably performed.
　発酵タンク５１から回収されたエタノール溶液は、バルブ５５を開放して蒸留器５６に送られ、該蒸留器５６にて蒸留されて高濃度エタノール溶液として回収される。
　このようなエタノール製造装置は、例えば特許文献１（特開２００８－１８２９２５号公報）等に開示されている。特許文献１には、バイオマスの水スラリーを加圧して加熱し、バイオマスに含まれるセルロース及びセルロースを加水分解して糖を生成する反応器と、生成された糖を発酵させてエタノールを生成するエタノール発酵装置とを備えたバイオエタノール製造装置が開示されている。 The ethanol solution recovered from the fermentation tank 51 is sent to the distiller 56 with the valve 55 opened, and is distilled by the distiller 56 and recovered as a high-concentration ethanol solution.
Such an ethanol production apparatus is disclosed in, for example, Patent Document 1 (Japanese Patent Laid-Open No. 2008-182925). Patent Document 1 discloses a reactor that pressurizes and heats an aqueous slurry of biomass, hydrolyzes cellulose and cellulose contained in the biomass to produce sugar, and ethanol that ferments the produced sugar to produce ethanol. A bioethanol production apparatus including a fermentation apparatus is disclosed.
特開２００８－１８２９２５号公報JP 2008-182925 A
　このようなエタノール製造装置では、エタノール発酵において発酵タンク内のエタノール濃度がある一定濃度以上になるとエタノール発酵阻害が発生し、発酵効率の低下あるいは発酵が停止してしまうという問題がある。エタノールは高濃度で回収することが求められる一方、発酵タンク内のエタノール濃度が高くなりすぎると安定して発酵が行われなくなってしまう。
　本発明は上記従来の技術の問題点に鑑み、エタノール発酵阻害を防ぎ、エタノール収率を高く維持し、効率よくエタノールを製造することができるエタノール製造方法及び装置を提供することを目的とする。 In such an ethanol production apparatus, when ethanol concentration in a fermentation tank exceeds a certain level in ethanol fermentation, ethanol fermentation inhibition occurs, and there is a problem that fermentation efficiency is reduced or fermentation is stopped. While ethanol is required to be collected at a high concentration, if the ethanol concentration in the fermentation tank becomes too high, fermentation will not be performed stably.
An object of the present invention is to provide an ethanol production method and apparatus that can prevent ethanol fermentation inhibition, maintain a high ethanol yield, and efficiently produce ethanol in view of the above-described problems of the conventional techniques.
　そこで、本発明はかかる課題を解決するために、バイオマスを加水分解して得られる糖含有液を発酵タンクで発酵させた後、発酵液を蒸留してエタノールを製造するエタノール製造方法において、
　前記発酵タンク内の発酵液の温度又はエタノール濃度を測定し、該測定された温度又はエタノール濃度が所定値以上となったら前記発酵タンクから発酵液の少なくとも一部を引き抜き、該引き抜いた発酵液を真空蒸発器にて真空蒸発させエタノールを含む蒸発ガスを分離し、該真空蒸発により冷却されるとともにエタノール濃度が低下した残留液を前記発酵タンクに返送することを特徴とする。 Therefore, in order to solve such problems, the present invention, in an ethanol production method for producing ethanol by distilling a fermentation liquid after fermenting a sugar-containing liquid obtained by hydrolyzing biomass in a fermentation tank,
The temperature or ethanol concentration of the fermentation liquid in the fermentation tank is measured, and when the measured temperature or ethanol concentration exceeds a predetermined value, at least a part of the fermentation liquid is extracted from the fermentation tank, and the extracted fermentation liquid is Evaporating gas containing ethanol is separated by vacuum evaporation in a vacuum evaporator, and the residual liquid cooled by the vacuum evaporation and reduced in ethanol concentration is returned to the fermentation tank.
　本発明によれば、発酵タンク内の発酵液の温度又はエタノール濃度を監視し、発酵阻害を引き起こす温度又はエタノール濃度となる前に発酵液を引き抜き、真空蒸発により発酵液を冷却するとともに液中のエタノール濃度を低下させることにより、発酵タンク内で発酵阻害が生じることを防止し、安定してエタノール発酵を継続することが可能となり、エタノール収率を向上させることができる。また、発酵液を真空蒸発させることにより冷却しているため、発酵液の冷却エネルギーを削減でき、コスト低減が図れる。 According to the present invention, the temperature or ethanol concentration of the fermentation liquor in the fermentation tank is monitored, the fermentation liquor is withdrawn before reaching the temperature or ethanol concentration causing fermentation inhibition, the fermentation liquor is cooled by vacuum evaporation, By reducing the ethanol concentration, fermentation inhibition can be prevented from occurring in the fermentation tank, and ethanol fermentation can be continued stably, and the ethanol yield can be improved. Moreover, since it cools by vacuum-evaporating a fermented liquid, the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
　また、前記蒸発ガスを冷却した後、凝縮したエタノールを含む凝縮液と不凝縮ガスとを気液分離し、前記凝縮液を蒸留してエタノールを回収することを特徴とする。
　真空蒸発器にて発生した蒸発ガス中には、残留液よりも高濃度のエタノールが存在する。従って、この蒸発ガスを冷却し凝縮させてエタノールを回収することにより、エタノール収率を増大させることが可能となる。 In addition, after the evaporative gas is cooled, the condensate containing condensed ethanol and the non-condensable gas are separated into gas and liquid, and the condensate is distilled to recover ethanol.
In the evaporated gas generated by the vacuum evaporator, ethanol having a higher concentration than the residual liquid exists. Therefore, the ethanol yield can be increased by cooling and condensing the evaporated gas to recover ethanol.
　さらに、前記不凝縮ガスを水と接触させて該不凝縮ガス中のエタノールを水側に移行させ、得られたエタノール含有水を蒸留してエタノールを回収することを特徴とする。
　これにより、蒸発ガスを冷却して気液分離した後に不凝縮ガス中に残存するエタノールを回収することが可能となり、エタノール収率をより一層向上させることが可能となる。 Furthermore, the non-condensable gas is brought into contact with water, ethanol in the non-condensable gas is transferred to the water side, and the ethanol-containing water obtained is distilled to recover ethanol.
This makes it possible to recover the ethanol remaining in the non-condensed gas after cooling the vaporized gas and separating it from gas and liquid, thereby further improving the ethanol yield.
　また、バイオマスを加水分解して得られる糖含有液を発酵させる発酵タンクと、該発酵タンクから排出された発酵液を蒸留する蒸留器とを備えたエタノール製造装置において、
　前記発酵タンク内の発酵液を一部引き抜いて外部循環させる循環冷却ラインと、
　前記発酵タンクの出口側に設けられたバルブと、
　前記循環冷却ライン上に設けられ、前記発酵液を真空蒸発させてエタノールを含む蒸発ガスと、該真空蒸発により冷却されるとともにエタノール濃度が低下した残留液とに分離する真空蒸発器と、
　前記発酵タンク内の発酵液の温度を測定する温度測定手段又はエタノール濃度を測定する濃度測定手段と、
　前記温度測定手段又は前記濃度測定手段にて測定された温度又はエタノール濃度が所定値以上となったら前記バルブを開放して前記循環冷却ライン上に発酵液を循環させる制御を行うコントローラと、を備えることを特徴とする。 Further, in an ethanol production apparatus comprising a fermentation tank for fermenting a sugar-containing liquid obtained by hydrolyzing biomass, and a distiller for distilling the fermentation liquid discharged from the fermentation tank,
A circulation cooling line for extracting a part of the fermentation liquor in the fermentation tank and circulating it externally;
A valve provided on the outlet side of the fermentation tank;
A vacuum evaporator that is provided on the circulating cooling line and that separates the fermentation liquor by evaporating the fermentation liquid into an evaporating gas containing ethanol and a residual liquid cooled by the vacuum evaporating and having a reduced ethanol concentration;
A temperature measuring means for measuring the temperature of the fermentation broth in the fermentation tank or a concentration measuring means for measuring the ethanol concentration;
A controller that controls to circulate the fermentation broth on the circulating cooling line by opening the valve when the temperature or ethanol concentration measured by the temperature measuring means or the concentration measuring means exceeds a predetermined value. It is characterized by that.
　また、前記蒸発ガスを冷却する冷却器と、
　前記冷却器を通った蒸発ガスが導入され、冷却により凝縮したエタノールを含む凝縮液と不凝縮ガスとに気液分離する気液分離器と、を備え、
　前記凝縮液は前記蒸留器に送給されることを特徴とする。
　さらに、前記気液分離器にて分離された不凝縮ガスが導入され、該不凝縮ガスを水と接触させてガス中のエタノールを水側に移行させる吸収塔を備え、
　前記吸収塔にて得られたエタノール含有水は前記蒸留器に送給されることを特徴とする。 A cooler for cooling the evaporative gas;
A gas-liquid separator that is vapor-liquid separated into a condensate containing ethanol condensed by cooling and a non-condensed gas introduced through the cooler, and
The condensate is fed to the distiller.
Furthermore, the non-condensable gas separated by the gas-liquid separator is introduced, and the non-condensable gas is brought into contact with water, and an absorption tower for transferring ethanol in the gas to the water side is provided.
Ethanol-containing water obtained in the absorption tower is supplied to the distiller.
　また、前記コントローラは、前記バルブを開放する条件として前記温度測定手段にて測定された温度が３２℃以上、又は前記濃度測定手段にて測定されたエタノール濃度が６％以上に設定されていることを特徴とする。
　発酵液の温度が３２℃以上又はエタノール濃度が６％以上となると、発酵阻害が発生しやすくなる。従って、この温度又はエタノール濃度以上になったら発酵液を循環冷却ライン上に排出し、真空蒸発器によりエタノール濃度の低下及び冷却を行うことによって、安定して発酵を継続することが可能となる。 In addition, the controller is configured such that the temperature measured by the temperature measuring means is 32 ° C. or higher, or the ethanol concentration measured by the concentration measuring means is set to 6% or higher as a condition for opening the valve. It is characterized by.
When the temperature of the fermentation broth is 32 ° C. or higher or the ethanol concentration is 6% or higher, fermentation inhibition tends to occur. Therefore, when the temperature or the ethanol concentration is exceeded, the fermentation broth is discharged onto the circulation cooling line, and the ethanol concentration is lowered and cooled by the vacuum evaporator, whereby the fermentation can be continued stably.
　さらにまた、前記真空蒸発器の前段に加熱器を設け、エタノールの気液平衡曲線に基づき設定された温度まで前記発酵液を加熱することを特徴とする。
　このように発酵液を加熱することにより、真空蒸発器にて蒸発ガス側に移行するエタノール濃度が高くなり、発酵液中のエタノール濃度を大幅に低下させることが可能となる。尚、エタノールの気液平衡曲線に基づき設定された温度とは、真空蒸発器にて真空蒸発させた際に最もエタノールが気相側に移行する温度とする。 Furthermore, a heater is provided in front of the vacuum evaporator, and the fermentation broth is heated to a temperature set based on a gas-liquid equilibrium curve of ethanol.
By heating the fermentation broth in this way, the ethanol concentration transferred to the evaporative gas side in the vacuum evaporator is increased, and the ethanol concentration in the fermentation broth can be greatly reduced. Note that the temperature set based on the vapor-liquid equilibrium curve of ethanol is the temperature at which ethanol most moves to the gas phase side when vacuum-evaporated with a vacuum evaporator.
　以前記載のごとく本発明によれば、発酵タンク内の発酵液の温度又はエタノール濃度を監視し、発酵阻害を引き起こす温度又はエタノール濃度となる前に発酵液を引き抜き、真空蒸発により発酵液を冷却するとともに液中のエタノール濃度を低下させることにより、発酵タンク内で発酵阻害が生じることを防止し、安定してエタノール発酵を継続することが可能となり、エタノール収率を向上させることができる。
　また、発酵液を真空蒸発させることにより冷却しているため、発酵液の冷却エネルギーを削減でき、コスト低減が図れる。 As described above, according to the present invention, the temperature or ethanol concentration of the fermentation liquid in the fermentation tank is monitored, the fermentation liquid is drawn out before reaching the temperature or ethanol concentration causing fermentation inhibition, and the fermentation liquid is cooled by vacuum evaporation. At the same time, by reducing the ethanol concentration in the liquid, fermentation inhibition can be prevented from occurring in the fermentation tank, and ethanol fermentation can be continued stably, and the ethanol yield can be improved.
Moreover, since it cools by vacuum-evaporating a fermented liquid, the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
　また、真空蒸発器にて発生した蒸発ガスを冷却し凝縮させてエタノールを回収することにより、エタノール収率を増大させることが可能となる。
　さらにまた、蒸発ガスを冷却して気液分離した後に不凝縮ガス中に残存するエタノールを水に吸収させて回収することにより、エタノール収率をより一層向上させることが可能となる。 In addition, the ethanol yield can be increased by cooling and condensing the evaporated gas generated in the vacuum evaporator to recover ethanol.
Furthermore, the ethanol yield can be further improved by absorbing and recovering ethanol remaining in the non-condensable gas after cooling and evaporating the vaporized gas.
本発明の実施形態に係るエタノール製造装置の全体構成図である。1 is an overall configuration diagram of an ethanol production apparatus according to an embodiment of the present invention. 発酵液中のエタノール濃度と発酵時間の関係を示すグラフである。It is a graph which shows the relationship between the ethanol concentration in fermentation liquid, and fermentation time. 本発明の実施形態を応用させたエタノール製造装置の全体構成図である。1 is an overall configuration diagram of an ethanol production apparatus to which an embodiment of the present invention is applied. 従来のエタノール製造装置の構成図である。It is a block diagram of the conventional ethanol manufacturing apparatus.
　以下、図面を参照して本発明の好適な実施例を例示的に詳しく説明する。但しこの実施例に記載されている構成部品の寸法、材質、形状、その相対的配置等は特に特定的な記載がない限りは、この発明の範囲をそれに限定する趣旨ではなく、単なる説明例に過ぎない。 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
　図１を参照して、本実施形態に係るエタノール製造装置の全体構成を説明する。
　エタノール製造装置は、その前段に前処理装置（不図示）を備えており、この前処理装置にてバイオマスを適宜粉砕し、水を加えて所定温度、所定圧力にて加水分解し、糖を含む液を生成する。この糖含有液がエタノール製造装置の原料となる。前記バイオマスとは、光合成に起因する有機物であって、木質類、草木類、農作物類、厨芥類等のバイオマスであり、本実施形態においては、糖質あるいはデンプン質を多く含む植物資源であることが好ましい。
　エタノール製造装置は、糖含有液２１が投入され、これに発酵酵母が加えられてエタノール発酵を行う発酵タンク１を備える。該発酵タンク１には、タンク内の発酵液の少なくとも一部を引き抜き、冷却した後に発酵タンク１内に戻す循環冷却ライン２が接続されている。 With reference to FIG. 1, the whole structure of the ethanol manufacturing apparatus which concerns on this embodiment is demonstrated.
The ethanol production apparatus is equipped with a pretreatment device (not shown) in the preceding stage. The pretreatment device pulverizes biomass as appropriate, hydrolyzes it at a predetermined temperature and a predetermined pressure with water, and contains sugar. A liquid is produced. This sugar-containing liquid is a raw material for the ethanol production apparatus. The biomass is an organic substance resulting from photosynthesis, which is biomass such as woody material, vegetation, agricultural products, and moss, and in the present embodiment, is a plant resource that contains a large amount of sugar or starch. Is preferred.
The ethanol production apparatus includes a fermentation tank 1 in which a sugar-containing liquid 21 is charged and fermentation yeast is added thereto to perform ethanol fermentation. The fermentation tank 1 is connected to a circulating cooling line 2 that draws out at least a part of the fermentation liquid in the tank, cools it, and returns it to the fermentation tank 1.
　循環冷却ライン２上には、発酵タンク１出口側にバルブ３が設けられており、その下流側に真空蒸発器４が設けられている。真空蒸発器４は、不図示の真空ポンプにより吸引されて内部が真空低圧に維持される。このとき、好適には真空蒸発器４は０．００５～０．０２ａｔｍ、さらに好適には０．０１ａｔｍ程度に維持される。
　また、発酵タンク１には、タンク内の発酵液の温度を測定する温度センサ１５と、エタノール濃度を測定する濃度センサ１６が設けられている。さらに、この温度センサ１５及び濃度センサ１６にて測定された測定値に基づいて、循環冷却ライン２のバルブ３と、後述する排出ライン１８上に設けられたバルブ１９の開閉制御を行うコントローラ１７を備えている。 On the circulating cooling line 2, a valve 3 is provided on the outlet side of the fermentation tank 1, and a vacuum evaporator 4 is provided on the downstream side thereof. The vacuum evaporator 4 is sucked by a vacuum pump (not shown) and the inside is maintained at a vacuum low pressure. At this time, the vacuum evaporator 4 is preferably maintained at about 0.005 to 0.02 atm, more preferably about 0.01 atm.
The fermentation tank 1 is provided with a temperature sensor 15 for measuring the temperature of the fermentation broth in the tank and a concentration sensor 16 for measuring the ethanol concentration. Further, based on the measured values measured by the temperature sensor 15 and the concentration sensor 16, a controller 17 that performs opening / closing control of the valve 3 of the circulation cooling line 2 and a valve 19 provided on a discharge line 18 described later is provided. I have.
　発酵タンク１の下部には、発酵が終結した発酵液を排出する排出ライン１８が接続されている。排出ライン１８上には、タンク出口にバルブ１９が設けられ、その下流側に蒸留器２０が設けられている。
　蒸留器２０は、発酵液を蒸留して不純物を除去する装置であり、さらに蒸留器２０の前段又は後段にエタノール濃縮装置（不図示）を設けるようにしてもよい。 A discharge line 18 is connected to the lower part of the fermentation tank 1 for discharging the fermented liquor that has been fermented. On the discharge line 18, a valve 19 is provided at the tank outlet, and a distiller 20 is provided downstream thereof.
The distiller 20 is a device that distills the fermentation broth to remove impurities, and an ethanol concentrator (not shown) may be provided in the previous stage or subsequent stage of the distiller 20.
　真空蒸発器４で発生した蒸発ガスは、循環冷却ライン２とは別のガスライン５に排出される。このガスライン５上には、上流側から順に、冷却器６、気液分離器７、ポンプ８、エタノール吸収塔９が設けられている。
　冷却器６は、間接冷却により蒸発ガスを冷却する装置である。好適にはアンモニアを冷媒としたアンモニア冷却器が用いられる。
　気液分離器７は、冷却器６にて冷却され一部が凝縮した凝縮液２２と、不凝縮ガス２３とを分離する装置である。 The evaporated gas generated in the vacuum evaporator 4 is discharged to a gas line 5 different from the circulation cooling line 2. On the gas line 5, a cooler 6, a gas-liquid separator 7, a pump 8, and an ethanol absorption tower 9 are provided in this order from the upstream side.
The cooler 6 is a device that cools the evaporative gas by indirect cooling. Preferably, an ammonia cooler using ammonia as a refrigerant is used.
The gas-liquid separator 7 is a device that separates the condensate 22 that has been cooled by the cooler 6 and partially condensed and the non-condensable gas 23.
　エタノール吸収塔９は、不凝縮ガス２３が導入され、この不凝縮ガス２３を水と接触させることによりガス中のエタノールを水側に移行させて回収する装置である。エタノール吸収塔９の一例として、上方に複数設置されたノズルより水を噴霧し、下方より導入した不凝縮ガス２３と向流接触させてエタノールを水側に移行させ、ＣＯ２、Ｏ２等を含む不凝縮ガス２５と、エタノール含有水２４とを分離する装置とする。エタノール含有水２４は循環ライン１０上をポンプ１１により循環させ、エタノール濃度が所定濃度以上となったら排出するとよい。 The ethanol absorption tower 9 is a device for introducing the non-condensable gas 23 and bringing the non-condensable gas 23 into contact with water to transfer ethanol in the gas to the water side and recover it. As an example of the ethanol absorption tower 9, water is sprayed from a plurality of nozzles installed at the upper side, brought into countercurrent contact with the non-condensable gas 23 introduced from the lower side to transfer ethanol to the water side, and CO 2 , O 2, etc. It is set as the apparatus which isolate | separates the non-condensable gas 25 and ethanol-containing water 24 to contain. The ethanol-containing water 24 may be circulated on the circulation line 10 by the pump 11 and discharged when the ethanol concentration exceeds a predetermined concentration.
　気液分離器７で凝縮された凝縮液２２はエタノールを多く含むため、発酵タンク１から排出された発酵液とともに蒸留器２０に導き、エタノールとして回収する。同様に、エタノール吸収塔９から排出されるエタノール含有水２４も蒸留器２０に導き、エタノールを回収する。 Since the condensate 22 condensed in the gas-liquid separator 7 contains a large amount of ethanol, it is led to the distiller 20 together with the fermentation liquid discharged from the fermentation tank 1 and recovered as ethanol. Similarly, the ethanol-containing water 24 discharged from the ethanol absorption tower 9 is also led to the distiller 20 to recover ethanol.
　このような構成を備えたエタノール製造装置の作用を以下に説明する。
　まず、バイオマスを加水分解して得られる糖含有液２１を発酵タンク１に投入し、発酵酵母を加えて所定時間発酵させる。このとき、循環冷却ライン２上のバルブ３及び排出ライン１８上のバルブ１９は閉に設定しておく。
　発酵時に、発酵タンク１内の発酵液の温度を温度センサ１５で測定し、発酵液の温度を監視する。発酵液が予め設定された所定の温度以上となったらコントローラ１７によりバルブ３を開放し、循環冷却ライン２に発酵液を排出する。バルブ３を開放する時の発酵タンク１内の温度は、好適には３２℃以上とする。尚、上記にはバルブ３の開放条件を温度とした場合につき記載したが、発酵タンク１内の発酵液のエタノール濃度を開放条件としてもよい。この場合、発酵液のエタノール濃度を濃度センサ１６で測定して監視し、所定のエタノール濃度以上となったらコントローラ１７によりバルブ３を開放する。バルブ３を開放する時の発酵タンク１内のエタノール濃度は、好適には６％以上とする。 The operation of the ethanol production apparatus having such a configuration will be described below.
First, the sugar-containing liquid 21 obtained by hydrolyzing biomass is put into the fermentation tank 1 and fermented yeast is added and fermented for a predetermined time. At this time, the valve 3 on the circulation cooling line 2 and the valve 19 on the discharge line 18 are set to be closed.
During fermentation, the temperature of the fermentation broth in the fermentation tank 1 is measured by the temperature sensor 15 and the temperature of the fermentation broth is monitored. When the fermented liquid reaches a predetermined temperature or higher, the controller 17 opens the valve 3 and discharges the fermented liquid to the circulation cooling line 2. The temperature in the fermentation tank 1 when the valve 3 is opened is preferably 32 ° C. or higher. In addition, although it described about the case where the opening condition of the valve | bulb 3 was made into the temperature above, it is good also considering the ethanol concentration of the fermentation liquid in the fermentation tank 1 as an opening condition. In this case, the ethanol concentration of the fermentation broth is measured and monitored by the concentration sensor 16, and the valve 3 is opened by the controller 17 when the concentration exceeds a predetermined ethanol concentration. The ethanol concentration in the fermentation tank 1 when the valve 3 is opened is preferably 6% or more.
　循環冷却ライン２に排出された発酵液は、真空蒸発器４に導入される。真空蒸発器４にて、低圧状態にされた発酵液は沸騰蒸発し、蒸発ガスと残留液とが得られる。蒸発ガス中にはエタノールの気液平衡曲線に沿った濃度のエタノールが含有されるが、残留液よりも高濃度のエタノールが蒸発ガスに含まれることとなる。その他にも、蒸発ガス中には、ＣＯ２、Ｏ２等が含まれる。
　残留液は、真空蒸発により冷却されるとともにエタノール濃度が低下した状態で、循環冷却ライン２を通って発酵タンク１に戻される。一方、蒸発ガスは、ガスライン５に排出され、ガスライン５上に設けられた冷却器６に導入される。冷却器６にて蒸発ガスは冷却され、その一部が凝縮した状態で気液分離器７に導入される。 The fermentation liquor discharged to the circulation cooling line 2 is introduced into the vacuum evaporator 4. The fermentation liquor brought to a low pressure state in the vacuum evaporator 4 is boiled and evaporated to obtain an evaporating gas and a residual liquid. The evaporative gas contains ethanol having a concentration along the vapor-liquid equilibrium curve of ethanol, but the evaporated gas contains ethanol having a higher concentration than the residual liquid. In addition, the evaporated gas contains CO 2 , O 2 and the like.
The residual liquid is cooled by vacuum evaporation and returned to the fermentation tank 1 through the circulation cooling line 2 in a state where the ethanol concentration is lowered. On the other hand, the evaporated gas is discharged to the gas line 5 and introduced into the cooler 6 provided on the gas line 5. The evaporative gas is cooled in the cooler 6 and is introduced into the gas-liquid separator 7 in a partially condensed state.
　気液分離器７では、凝縮したエタノールを含む凝縮液２２と、ＣＯ２、Ｏ２を主とした不凝縮ガス２３とに分離される。不凝縮ガス２３は、ポンプ８により吸収塔９に導かれる。吸収塔９では、不凝縮ガス２３が水と接触することによりガス中に残留したエタノールが水側に移行し、エタノール含有水２４として回収される。
　気液分離器７で分離された凝縮液２２と、吸収塔９で回収されたエタノール含有水２４は蒸留器２０に導かれ、高濃度のエタノールとして回収される。 The gas-liquid separator 7 is separated into a condensate 22 containing condensed ethanol and a non-condensable gas 23 mainly composed of CO 2 and O 2 . The non-condensable gas 23 is guided to the absorption tower 9 by the pump 8. In the absorption tower 9, when the non-condensable gas 23 comes into contact with water, ethanol remaining in the gas moves to the water side and is recovered as ethanol-containing water 24.
The condensate 22 separated by the gas-liquid separator 7 and the ethanol-containing water 24 recovered by the absorption tower 9 are guided to the distiller 20 and recovered as high-concentration ethanol.
　循環冷却ライン２は、発酵タンク１内の温度が所定温度以下となったらコントローラ１７にてバルブ３を閉止して発酵液の循環を停止する。尚、循環停止の条件は、温度以外にもエタノール濃度を用いてもよい。そして、発酵を継続して行う。このとき、上記と同様に発酵タンク１内の温度を温度センサ１５で監視しておき、所定温度以上になったら再度循環冷却ライン２上のバルブ３を開放して発酵液の冷却を行う。
　また、発酵時に、発酵タンク１内のエタノール濃度の変化を濃度センサ１６にて監視しておき、エタノール濃度に変化がみられなくなったら発酵が終結したものと判断し、コントローラ１７にて排出ライン１８上のバルブ１９を開放し、発酵タンク１内の発酵液を蒸留器２０に送給し、高濃度エタノールを回収する。 When the temperature in the fermentation tank 1 becomes equal to or lower than the predetermined temperature, the circulation cooling line 2 closes the valve 3 by the controller 17 to stop the circulation of the fermentation broth. The circulation stop condition may be ethanol concentration in addition to temperature. And fermentation is performed continuously. At this time, the temperature in the fermentation tank 1 is monitored by the temperature sensor 15 in the same manner as described above, and when the temperature becomes equal to or higher than the predetermined temperature, the valve 3 on the circulation cooling line 2 is opened again to cool the fermentation broth.
Further, during fermentation, the change in ethanol concentration in the fermentation tank 1 is monitored by the concentration sensor 16, and when no change is observed in the ethanol concentration, it is determined that fermentation has ended, and the controller 17 determines the discharge line 18. The upper valve 19 is opened, the fermented liquid in the fermentation tank 1 is fed to the still 20 and high-concentration ethanol is recovered.
　本実施形態によれば、発酵タンク１内の発酵液の温度又はエタノール濃度を監視し、発酵阻害を引き起こす温度又はエタノール濃度となる前に発酵液を引き抜き、真空蒸発により発酵液を冷却するとともに液中のエタノール濃度を低下させることにより、発酵タンク１内で発酵阻害が生じることを防止し、安定してエタノール発酵を行うことが可能となり、エタノール収率を向上させることができる。また、発酵液を真空蒸発させることにより冷却しているため、発酵液の冷却エネルギーを削減でき、コスト低減が図れる。 According to this embodiment, the temperature or ethanol concentration of the fermentation liquor in the fermentation tank 1 is monitored, the fermentation liquor is withdrawn before reaching the temperature or ethanol concentration causing fermentation inhibition, and the liquid is cooled and cooled by vacuum evaporation. By reducing the ethanol concentration therein, it is possible to prevent fermentation inhibition from occurring in the fermentation tank 1, to perform ethanol fermentation stably, and to improve the ethanol yield. Moreover, since it cools by vacuum-evaporating a fermented liquid, the cooling energy of a fermented liquid can be reduced and cost reduction can be aimed at.
　ここで、図１に示した本実施形態のエタノール製造装置と、図４に示した従来のエタノール製造装置におけるエタノール濃度を比較したグラフを図２に示す。図２の横軸は発酵時間、縦軸はエタノール濃度である。従来のエタノール製造装置では、時間とともに発酵液中のエタノール濃度が上昇し、発酵阻害を引き起こす濃度まで上昇してしまうが、本実施形態のエタノール製造装置では、エタノール濃度が６％以上とならないようになっている。従って、発酵阻害を引き起こす程度まで高濃度となることはなく、安定して発酵を行うことが可能であり、延いてはエタノール収率を向上させることが可能となる。 Here, FIG. 2 shows a graph comparing ethanol concentrations in the ethanol production apparatus of the present embodiment shown in FIG. 1 and the conventional ethanol production apparatus shown in FIG. The horizontal axis in FIG. 2 is the fermentation time, and the vertical axis is the ethanol concentration. In the conventional ethanol production apparatus, the ethanol concentration in the fermentation liquid increases with time and increases to a concentration that causes fermentation inhibition. However, in the ethanol production apparatus of the present embodiment, the ethanol concentration does not exceed 6%. It has become. Therefore, the concentration does not become so high as to cause fermentation inhibition, and the fermentation can be performed stably, and the ethanol yield can be improved.
　図３は図１に示したエタノール製造装置を応用させた実施形態である。
　このエタノール製造装置は、循環冷却ライン２上の真空蒸発器４の前段に、加熱器１４を設けた構成となっている。加熱器１４は、発酵タンク１から循環冷却ライン２に排出された発酵液をエタノールの気液平衡曲線に基づき設定された温度まで加熱する装置である。ここで、エタノールの気液平衡曲線に基づき設定された温度とは、真空蒸発器４にて真空蒸発させた際に最もエタノールが気相側に移行する温度とする。 FIG. 3 shows an embodiment in which the ethanol production apparatus shown in FIG. 1 is applied.
This ethanol production apparatus has a configuration in which a heater 14 is provided in front of the vacuum evaporator 4 on the circulation cooling line 2. The heater 14 is a device that heats the fermented liquid discharged from the fermentation tank 1 to the circulation cooling line 2 to a temperature set based on a gas-liquid equilibrium curve of ethanol. Here, the temperature set based on the vapor-liquid equilibrium curve of ethanol is the temperature at which ethanol moves most to the gas phase side when the vacuum evaporator 4 is used for vacuum evaporation.
　加熱器１４で加熱された発酵液は真空蒸発器４に導入され、真空蒸発によりエタノールを含む蒸発ガスが生成する。蒸発ガス中には加熱器１４を設置しない場合よりも高濃度のエタノールが含まれ、この蒸発ガスは冷却器６にて冷却された後、気液分離器７で気液分離され、エタノールが回収される。一方、真空蒸発器４にて蒸発ガスが分離された残留液は、循環冷却ライン２を介して発酵タンク１に返送される。
　本実施形態によれば、より多くのエタノールを蒸発ガス側に移行させることができ、発酵タンク１内に返送される残留液中のエタノール濃度を確実に低下させることが可能となる。 The fermented liquid heated by the heater 14 is introduced into the vacuum evaporator 4, and evaporating gas containing ethanol is generated by vacuum evaporation. The evaporative gas contains a higher concentration of ethanol than when the heater 14 is not installed. The evaporative gas is cooled by the cooler 6 and then gas-liquid separated by the gas-liquid separator 7 to recover the ethanol. Is done. On the other hand, the residual liquid from which the evaporated gas has been separated by the vacuum evaporator 4 is returned to the fermentation tank 1 via the circulation cooling line 2.
According to this embodiment, more ethanol can be transferred to the evaporation gas side, and the ethanol concentration in the residual liquid returned to the fermentation tank 1 can be reliably reduced.
　本発明は、エタノール発酵阻害を防ぎ、エタノール収率を高く維持し、効率よくエタノールを製造することができるため、燃料や化学原料等に用いられるバイオエタノールの製造に好適に用いられる。 Since the present invention prevents ethanol fermentation inhibition, maintains a high ethanol yield, and can produce ethanol efficiently, it is suitably used for the production of bioethanol used for fuels and chemical raw materials.

Claims (8)

  1. 　バイオマスを生物的又は化学的に糖化して得られる糖含有液を発酵タンクで発酵させた後、発酵液を蒸留してエタノールを製造するエタノール製造方法において、
    　前記発酵タンク内の発酵液の温度又はエタノール濃度を測定し、該測定された温度又はエタノール濃度が所定値以上となったら前記発酵タンクから発酵液の少なくとも一部を引き抜き、該引き抜いた発酵液を真空蒸発器にて真空蒸発させエタノールを含む蒸発ガスを分離し、該真空蒸発により冷却されるとともにエタノール濃度が低下した残留液を前記発酵タンクに返送することを特徴とするエタノール製造方法。     In an ethanol production method for producing ethanol by distilling a fermentation liquid after fermenting a sugar-containing liquid obtained by saccharification of biomass biologically or chemically in a fermentation tank,
    The temperature or ethanol concentration of the fermentation liquid in the fermentation tank is measured, and when the measured temperature or ethanol concentration exceeds a predetermined value, at least a part of the fermentation liquid is extracted from the fermentation tank, and the extracted fermentation liquid is A method for producing ethanol, comprising: evaporating an evaporation gas containing ethanol by vacuum evaporation in a vacuum evaporator; and returning the residual liquid cooled by the vacuum evaporation and having a reduced ethanol concentration to the fermentation tank.
  2. 　前記蒸発ガスを冷却した後、凝縮したエタノールを含む凝縮液と不凝縮ガスとを気液分離し、前記凝縮液を蒸留してエタノールを回収することを特徴とする請求項１記載のエタノール製造方法。 The ethanol production method according to claim 1, wherein after the evaporative gas is cooled, a condensate containing condensed ethanol and a non-condensable gas are separated into gas and liquid, and the condensate is distilled to recover ethanol. .
  3. 　前記不凝縮ガスを水と接触させて該不凝縮ガス中のエタノールを水側に移行させ、得られたエタノール含有水を蒸留してエタノールを回収することを特徴とする請求項２記載のエタノール製造方法。 The ethanol production according to claim 2, wherein the non-condensable gas is brought into contact with water to transfer ethanol in the non-condensable gas to the water side, and the ethanol-containing water obtained is distilled to recover ethanol. Method.
  4. 　バイオマスを生物的又は化学的に糖化して得られる糖含有液を発酵させる発酵タンクと、該発酵タンクから排出された発酵液を蒸留する蒸留器とを備えたエタノール製造装置において、
    　前記発酵タンク内の発酵液を一部引き抜いて外部循環させる循環冷却ラインと、
    　前記発酵タンクの出口側に設けられたバルブと、
    　前記循環冷却ライン上に設けられ、前記発酵液を真空蒸発させてエタノールを含む蒸発ガスと、該真空蒸発により冷却されるとともにエタノール濃度が低下した残留液とに分離する真空蒸発器と、
    　前記発酵タンク内の発酵液の温度を測定する温度測定手段又はエタノール濃度を測定する濃度測定手段と、
    　前記温度測定手段又は前記濃度測定手段にて測定された温度又はエタノール濃度が所定値以上となったら前記バルブを開放して前記循環冷却ライン上に発酵液を循環させる制御を行うコントローラと、を備えることを特徴とするエタノール製造装置。     In an ethanol production apparatus comprising a fermentation tank for fermenting a sugar-containing liquid obtained by saccharification of biomass biologically or chemically, and a distiller for distilling the fermentation liquid discharged from the fermentation tank,
    A circulation cooling line for extracting a part of the fermentation liquor in the fermentation tank and circulating it externally;
    A valve provided on the outlet side of the fermentation tank;
    A vacuum evaporator that is provided on the circulating cooling line and that separates the fermentation liquor by evaporating the fermentation liquid into an evaporating gas containing ethanol and a residual liquid cooled by the vacuum evaporating and having a reduced ethanol concentration;
    A temperature measuring means for measuring the temperature of the fermentation broth in the fermentation tank or a concentration measuring means for measuring the ethanol concentration;
    A controller that controls to circulate the fermentation broth on the circulating cooling line by opening the valve when the temperature or ethanol concentration measured by the temperature measuring means or the concentration measuring means exceeds a predetermined value. An ethanol production apparatus characterized by that.
  5. 　前記蒸発ガスを冷却する冷却器と、
    　前記冷却器を通った蒸発ガスが導入され、冷却により凝縮したエタノールを含む凝縮液と不凝縮ガスとに気液分離する気液分離器と、を備え、
    　前記凝縮液は前記蒸留器に送給されることを特徴とする請求項４記載のエタノール製造装置。     A cooler for cooling the evaporative gas;
    A gas-liquid separator that is vapor-liquid separated into a condensate containing ethanol condensed by cooling and a non-condensed gas introduced through the cooler, and
    The ethanol production apparatus according to claim 4, wherein the condensate is fed to the distiller.
  6. 　前記気液分離器にて分離された不凝縮ガスが導入され、該不凝縮ガスを水と接触させてガス中のエタノールを水側に移行させる吸収塔を備え、
    　前記吸収塔にて得られたエタノール含有水は前記蒸留器に送給されることを特徴とする請求項５記載のエタノール製造装置。     The non-condensable gas separated by the gas-liquid separator is introduced, and the non-condensable gas is brought into contact with water to provide an absorption tower for transferring ethanol in the gas to the water side.
    6. The ethanol production apparatus according to claim 5, wherein the ethanol-containing water obtained in the absorption tower is fed to the distiller.
  7. 　前記コントローラは、前記バルブを開放する条件として前記温度測定手段にて測定された温度が３２℃以上、又は前記濃度測定手段にて測定されたエタノール濃度が６％以上に設定されていることを特徴とする請求項４記載のエタノール製造装置。 In the controller, as a condition for opening the valve, the temperature measured by the temperature measuring means is set to 32 ° C. or more, or the ethanol concentration measured by the concentration measuring means is set to 6% or more. The ethanol production apparatus according to claim 4.
  8. 　前記真空蒸発器の前段に加熱器を設け、エタノールの気液平衡曲線に基づき設定された温度まで前記発酵液を加熱することを特徴とする請求項４記載のエタノール製造装置。 The ethanol production apparatus according to claim 4, wherein a heater is provided in front of the vacuum evaporator to heat the fermentation broth to a temperature set based on a vapor-liquid equilibrium curve of ethanol.
PCT/JP2008/072733 2008-12-15 2008-12-15 Method of producing ethanol and apparatus therefor WO2010070716A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2008/072733 WO2010070716A1 (en) 2008-12-15 2008-12-15 Method of producing ethanol and apparatus therefor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2008/072733 WO2010070716A1 (en) 2008-12-15 2008-12-15 Method of producing ethanol and apparatus therefor

Publications (1)

Publication Number Publication Date
WO2010070716A1 true WO2010070716A1 (en) 2010-06-24

Family

ID=42268407

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2008/072733 WO2010070716A1 (en) 2008-12-15 2008-12-15 Method of producing ethanol and apparatus therefor

Country Status (1)

Country Link
WO (1) WO2010070716A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013183704A (en) * 2012-03-09 2013-09-19 Oji Holdings Corp Method for producing ethanol from lignocellulosic raw material
CN109852535A (en) * 2019-04-01 2019-06-07 安徽逸能生物科技有限公司 A kind of bio-fermented liquid extraction system
CN110455681A (en) * 2019-09-06 2019-11-15 云南大唐汉方制药股份有限公司 A kind of recycling of Resina Draconis concentration process ethyl alcohol and concentration on-line detection method
CN115074208A (en) * 2022-05-26 2022-09-20 厦门大学 Stirring type gas-lift fermentation tank and system
IT202200010538A1 (en) * 2022-05-20 2023-11-20 Francesco Vitale VACUUM EVAPORATION GROUP

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6211088A (en) * 1985-07-08 1987-01-20 Hitachi Zosen Corp Method of concentrating alcohol

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6211088A (en) * 1985-07-08 1987-01-20 Hitachi Zosen Corp Method of concentrating alcohol

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
SABURO SHICHIJI: "Biseibutsu Kogaku no Oyo", 1 December 1972, KYORITSU SHUPPAN CO., LTD., pages: 110 - 112 *
SHADAN HOJIN KAGAKU KOGAKU KYOKAI: "Kagaku Sochi Binran", 30 March 1989, MARUZEN CO., LTD., pages: 431 - 432 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013183704A (en) * 2012-03-09 2013-09-19 Oji Holdings Corp Method for producing ethanol from lignocellulosic raw material
CN109852535A (en) * 2019-04-01 2019-06-07 安徽逸能生物科技有限公司 A kind of bio-fermented liquid extraction system
CN110455681A (en) * 2019-09-06 2019-11-15 云南大唐汉方制药股份有限公司 A kind of recycling of Resina Draconis concentration process ethyl alcohol and concentration on-line detection method
IT202200010538A1 (en) * 2022-05-20 2023-11-20 Francesco Vitale VACUUM EVAPORATION GROUP
CN115074208A (en) * 2022-05-26 2022-09-20 厦门大学 Stirring type gas-lift fermentation tank and system

Similar Documents

Publication Publication Date Title
US4349628A (en) Fermentation process for the manufacture of an organic compound
US9732362B2 (en) Processes and systems for alcohol production and recovery
US4425433A (en) Alcohol manufacturing process
US4564595A (en) Alcohol manufacturing process
CN103221547B (en) For producing the continuation method of ethanol from lignocellulosic biomass
US9102951B2 (en) Process for recovering salt during a lignocellulosic conversion process
US8906204B2 (en) Methods for alcohol recovery and concentration of stillage by-products
US8574406B2 (en) Process to remove product alcohol from a fermentation by vaporization under vacuum
US4424275A (en) Continuous process for producing N-butanol employing anaerobic fermentation
US8981146B2 (en) Recovery of volatile carboxylic acids by a stripper-extractor system
US20120301928A1 (en) Preprocessing method of hydrolyzing lignocellulosic biomass and methods of manufacturing sugar compound and bioethanol from biomass processed using the preprocessing method
CN102037128A (en) Purification treatment method for fermented alcohol
CN102171355A (en) Method of production of alcohol
CN103687954A (en) Method for reducing water usage in a cellulosic conversion process
US20150087040A1 (en) Production of ethanol and recycle water in a cellulosic fermentation process
WO2010070716A1 (en) Method of producing ethanol and apparatus therefor
CN114980997A (en) Integrated CO with vapor compression 2 System and method for reuse
WO2012103609A1 (en) Process for producing ethanol from the fermentation of sugar sources in a fermentation medium with high ethanol content
US20140127768A1 (en) Solar-assisted volatile fermentation products production processes
WO1981001154A1 (en) Alcohol manufacturing process
AU540923B2 (en) Alcohol manufacturing process
JPS6394966A (en) Concentration and recovery of fermentation alcohol
NZ201370A (en) A process for disrupting the internal structure of cellulose;production of alcohol from disrupted cellulose

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08878884

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08878884

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: JP