JP2008297229A - Production apparatus and production method for bioethanol - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production apparatus and a production method for a bioethanol that can continuously and efficiently treat a large amount of lignocellulose and are satisfactorily economical from the view point of production cost. <P>SOLUTION: The bioethanol production apparatus for producing ethanol from lignocellulose is provided with a mill 3 for grinding a biomass 1, a preheater 4 for mixing a biomass powder fed from the mill 3 with a catalyst and preheating steam, and a hydrolysis column 6 for heating biomass powder slurry fed from the preheater 4 with heating steam 11. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bioethanol production apparatus and production method, and more particularly to a production apparatus and production method for efficiently producing bioethanol from woody biomass resources.

  In recent years, ethanol, which has attracted attention as an alternative fuel for gasoline, has been conventionally made using edible materials such as corn and sugar. However, since corn is mainly feed for livestock and sugar is human food, there is a limit to stably supplying such edible raw materials for ethanol production.

  Therefore, it has been studied to use woody biomass that has not been effectively used so far, such as wood and corn stalks, and has abundant resources, and lignocellulose, the main component of woody biomass. The production of ethanol using as a raw material has become an important research theme recently.

  Lignocellulose is a natural polymer composed of cellulose, hemicellulose, lignin and the like. Among these, cellulose is the main component of the plant cell wall and is present in the largest amount among organic substances produced in nature, and is a chain polymer compound in which many glucoses are bonded by β1 → 4 bonds. In order to produce ethanol from cellulose, cellulose is hydrolyzed into glucose, which is subjected to alcohol fermentation with yeast and distilled.

  As a hydrolysis method of cellulose, there is a method in which cellulose is decomposed into cellodextrin, cellohexaose, cellotetraose, cellotriose, cellobiose, etc. by cellulase which is a saccharifying enzyme, and further decomposed into D-glucose by β-D-glucosidase. Generally known. In addition, a method is known in which cellulose is boiled with dilute acid or ammonia and hydrolyzed to form D-glucose.

  Furthermore, by hydrothermal method using pressurized hot water, lignocellulose powder is brought into contact with pressurized hot water heated to 200 to 300 ° C., preferably 240 to 280 ° C. to hydrolyze cellulose (patent Reference 1), the ion product (product of hydrogen ion concentration and hydroxide ion concentration) of pressurized hot water near 250 ° C. (hot water pressurized above the saturated vapor pressure and kept in a liquid state) is 1000 Paying attention to the fact that it rises more than twice, a method (Non-Patent Document 1) or the like for sequentially recovering components constituting it while hydrolyzing woody biomass using this pressurized hot water has been proposed. In addition, it has also been proposed that after cellulose is pretreated, cellulose is separated with concentrated acid and the cellulose is decomposed into sugar by cellulase (Non-patent Document 2).

  As another method, there is a method in which lignocellulose is converted into a sugar that can be fermented at one time using supercritical water (374 ° C. or higher, 22.1 MPa or higher) or subcritical water without using any chemicals. (Patent Document 2).

Furthermore, as a hydrolysis method using a catalyst, a method is proposed in which lignocellulose is mixed with dispersed water, and a solid catalyst or metal oxide is allowed to act at a temperature of 100 ° C. to 350 ° C. to hydrolyze the cellulose to produce glucose. (Patent Document 3).
Japanese Patent Laid-Open No. 10-327900 JP 2005-206468 A JP 2006-129735 A “Kyushu Institute News 991001” 2001 "NEDO Overseas Report; No. 977", April 26, 2006, P58-60

  As mentioned above, there are many types of processes for producing ethanol from lignocellulose, which is the main component of woody biomass, but each method takes a long time for the reaction or has a problem in yield. Because of its high cost, it has not been put into practical use. In particular, in a method using concentrated acid, a large cost is required for the equipment and means for collecting and neutralizing concentrated acid.

  In addition, in the method using subcritical water or supercritical water, the energy efficiency is very important. However, as seen in Patent Document 2, the energy efficiency is not considered at all, such as using an electric heater as a heating source. In addition, since a pressurizing device is required, the device is unsuitable for practical use, such as an increase in size of the device.

  Furthermore, the cellulose hydrolysis method using the catalyst shown in Patent Document 3 is a method in which lignocellulose, water and a catalyst are mixed and heated in a pressure-resistant airtight container and heated to carry out hydrolysis. Therefore, it has been difficult to process a large amount of lignocellulose continuously and efficiently.

  The present invention uses a highly environmentally friendly catalyst as a hydrolysis treatment process, can produce a large amount of lignocellulose continuously and efficiently, and is sufficiently economical to produce bioethanol. An object is to provide an apparatus and a method for manufacturing the same.

  In order to achieve the above object, a bioethanol production apparatus according to the present invention is a bioethanol production apparatus for producing ethanol from lignocellulose, a mill for pulverizing biomass, a biomass powder supplied from the mill, a catalyst, and preheating. A preheater that mixes steam and a hydrolysis tower that heats the biomass powder slurry supplied from the preheater with steam for heating are provided.

  Further, the bioethanol production apparatus according to the present invention is a bioethanol production apparatus for producing ethanol from lignocellulose, a preheat for mixing a mill for pulverizing biomass, a biomass powder supplied from the mill, a catalyst, and preheated steam. , A first hydrolysis tower for heating the biomass powder slurry supplied from the preheater with steam for heating, and a biomass powder provided on the downstream side of the first hydrolysis tower and supplied from the first hydrolysis tower And a second hydrolysis tower that heats the slurry with steam for heating.

  The bioethanol production method according to the present invention is a bioethanol production method for producing ethanol from lignocellulose, wherein the biomass is pulverized by a mill, and the pulverized biomass powder, catalyst and preheated steam are mixed with a preheater. The biomass powder slurry is generated by the above, and the biomass powder slurry supplied from the preheater is heated with steam for heating in a hydrolysis tower.

  The bioethanol production method according to the present invention is a bioethanol production method for producing ethanol from lignocellulose, wherein the biomass is pulverized by a mill, and the pulverized biomass powder, catalyst and preheated steam are mixed with a preheater. The biomass powder slurry is generated by the above, and the biomass powder slurry is supplied to the first hydrolysis tower and then to the second hydrolysis tower, and the inside of the first and second hydrolysis towers is heated by heating steam. It is characterized by.

  By adopting a hydrolysis process consisting of a preheater and hydrolysis tower, etc., using a catalyst with high environmental compatibility, it is possible to perform hydrolysis treatment at low pressure and low temperature with high environmental compatibility. The apparatus can be reduced in size and cost, and ethanol can be continuously and efficiently produced from a large amount of lignocellulose.

Hereinafter, the lignocellulose hydrolysis process in the bioethanol production apparatus according to the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is an overall configuration diagram of a bioethanol production apparatus according to the first embodiment of the present invention. The lignocellulose hydrolysis process according to the first embodiment of the present invention will be described with reference to FIG.

  In the first embodiment, for example, a woody biomass 1 made of wood chips is used for hydrolysis by a hydrothermal / catalytic method. The mill 3 is pulverized and finely pulverized upon supply, the preheater 4 that mixes the catalyst, steam, and biomass powder to produce a biomass powder slurry, The high-pressure feeder 5 fed into the decomposition tower 6 and the hydrolysis tower 6 are configured.

  Since the biomass 1 and the hopper 2 used in the first embodiment are not different from those in a normal papermaking plant, description thereof is omitted. The mill 3 is for pulverizing woody biomass by placing an appropriate amount of balls (steel balls) in a cylindrical container called a drum mill and rotating the cylindrical container to move the balls. Conventionally used in coal pulverization means and the like.

  In the mill 3, the biomass powder pulverized to about 100 μm is supplied to the preheated air 4 together with the catalyst 9 made of zeolite having an acidic functional group and the preheated steam 8. The inside of the preheater 4 is maintained at about 120 ° C., and is homogenized by a stirring device (not shown) inside the preheater 4 for a time corresponding to the amount of biomass powder, for example, about 10 minutes. As a result, a part of the biomass powder starts to be hydrolyzed to become a paste-like biomass powder slurry. This is fed into the hydrolysis tower 6 by the high-pressure feeder 5. The catalyst is not limited to zeolite, and coal fly ash may be used.

  In the first embodiment, the high-pressure feeder 5 feeds the biomass powder slurry directly to the hydrolysis tower 6 by a pump. However, other transfer means such as a rotary steam press-in means may be used as a matter of course. .

  In the hydrolysis tower 6, the heating steam 11 passes through the center, and the temperature is controlled to 200 ° C. to 250 ° C. according to the properties of the biomass. The normal holding time is about 1 hour although it depends on the amount of biomass powder slurry. Further, the biomass powder slurry in the hydrolysis tower is constantly circulated and made uniform by the solution circulation device 7. As a result, not only hemicellulose but also cellulose is degraded and saccharified by about 70%. This is supplied as an aqueous sugar solution 10 to the next ethanol fermentation process.

  According to the first embodiment, a high environmental compatibility catalyst is used, and a hydrolysis treatment process including a preheater and a hydrolysis tower is adopted, so that environmental compatibility is high, and low pressure and low temperature. As a result, the apparatus can be reduced in size and cost, and ethanol can be continuously and efficiently produced from a large amount of lignocellulose.

(Second Embodiment)
A lignocellulose hydrolysis process according to the second embodiment of the present invention is shown in FIG.
This 2nd Embodiment consists of the 2nd hydrolysis tower 13 which decomposes | disassembles the lignin which is difficult to decompose | disassemble with the 1st hydrolysis tower 12 which decomposes | disassembles the hemicellulose which is easy to hydrolyze. The first hydrolysis tower is maintained at about 170 ° C., and the residence time of the biomass powder slurry is about 30 minutes. Thereby, hemicellulose is almost completely saccharified. This hemicellulose is separated by a centrifugal separator and supplied as an aqueous sugar solution to the ethanol fermentation process.

  Next, the biomass powder slurry from which hemicellulose has been separated is supplied to the second hydrolysis tower and held at about 250 ° C. for about 1 hour. By setting it as such a structure, a high saccharification rate can be achieved, avoiding decomposition | disassembly of produced | generated glucose.

  According to the second embodiment, by adopting the hydrolysis process comprising the first and second hydrolysis towers, it is possible to hydrolyze lignocellulose more efficiently and from a large amount of lignocellulose. Ethanol can be produced continuously and efficiently.

In addition, by installing a bioethanol production system with the above configuration in, for example, a thermal power plant, a large amount of necessary steam can be procured at low cost, and lignin and unreacted cellulose that could not be saccharified can be used as fuel. And the amount of CO ₂ generated from the thermal power plant can be greatly reduced.

1 is an overall configuration diagram of a bioethanol production apparatus according to a first embodiment of the present invention. The block diagram of the bioethanol manufacturing apparatus which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Biomass, 2 ... Hopper, 3 ... Mill, 4 ... Preheater, 5 ... High pressure feeder, 6 ... Hydrolysis tower, 7 ... Solution circulation apparatus, 8 ... Preheating steam, 9 ... Catalyst, 11 ... Steam for heating, 12 ... 1st hydrolysis tower, 13 ... 2nd hydrolysis tower, 14 ... Centrifugal separator.

Claims (11)

  In a bioethanol production apparatus for producing ethanol from lignocellulose, a mill for crushing biomass, a preheater for mixing biomass powder, catalyst and preheated steam supplied from the mill, and biomass powder supplied from the preheater A bioethanol production apparatus comprising: a hydrolysis tower that heats slurry with steam for heating.   The bioethanol production apparatus according to claim 1, wherein the preheater is maintained at about 120 ° C. by the preheated steam.   The bioethanol production apparatus according to claim 1 or 2, wherein the preheater includes a stirring device.   The bioethanol production apparatus according to any one of claims 1 to 3, wherein the hydrolysis tower is maintained at 200 ° C to 250 ° C by the heating steam.   In a bioethanol production apparatus for producing ethanol from lignocellulose, a mill for crushing biomass, a preheater for mixing biomass powder, catalyst and preheated steam supplied from the mill, and biomass powder supplied from the preheater A first hydrolysis tower that heats the slurry with heating steam, and a second hydrolysis that heats the biomass powder slurry that is provided downstream from the first hydrolysis tower and is supplied from the first hydrolysis tower with heating steam. A bioethanol production apparatus comprising: a tower.   6. The bioethanol production apparatus according to claim 5, wherein a centrifuge is provided between the first hydrolysis tower and the second hydrolysis tower.   The bioethanol production apparatus according to claim 5 or 6, wherein the first hydrolysis tower is maintained at about 170 ° C, and the second hydrolysis tower is maintained at about 250 ° C.   The bioethanol production apparatus according to any one of claims 1 to 7, wherein a solution circulation device is provided in the hydrolysis tower.   The bioethanol production apparatus according to any one of claims 1 to 8, wherein the catalyst is zeolite having an acidic functional group or coal fly ash.   In a bioethanol production method for producing ethanol from lignocellulose, biomass is pulverized by a mill, and a biomass powder slurry is produced by mixing the pulverized biomass powder, catalyst and preheated steam with a preheater, from the preheater A bioethanol production method comprising heating the supplied biomass powder slurry with steam for heating in a hydrolysis tower.   In the bioethanol production method for producing ethanol from lignocellulose, biomass is pulverized by a mill, and the biomass powder slurry is produced by mixing the pulverized biomass powder, catalyst and preheated steam with a preheater, Is supplied to the first hydrolysis tower and then to the second hydrolysis tower, and the interiors of the first and second hydrolysis towers are heated with heating steam.

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