JP2012205988A - Method and apparatus for producing modified plant biomass, and method for producing ethanol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe and efficient method and apparatus for producing modified plant biomass, and to provide an efficient method for producing ethanol.SOLUTION: The method for producing a modified plant biomass includes: a first step for supplying a particulate plant biomass raw material to a first container; a second step for discharging air from the first container; a third step for supplying ammonia to the first container; a fourth step for transferring the plant biomass raw material into a second container; a fifth step for discharging the ammonia which remains in the first container; a sixth step for modifying the plant biomass raw material in the second container; a seventh step for transferring the modified plant biomass into a third container; an eighth step for discharging the ammonia from the third container; a ninth step for collecting the modified plant biomass; a tenth step for discharging air from the third container; and an eleventh step for collecting the discharged ammonia and re-using the ammonia.

Description

  The present invention relates to a method for producing plant biomass with enhanced reactivity, an apparatus for producing the same, and a method for producing ethanol using the plant biomass with enhanced reactivity produced by the method.

  From the viewpoint of protecting the global environment, ethanol that is obtained by fermentation using plant-derived biomass as a raw material has been actively used as fuel for automobiles and the like. Conventionally, as a method for producing such ethanol, mainly starch derived from grains such as corn and wheat and sugar derived from sugar cane are used as raw materials. However, with these raw materials, only a part of the plant body is used, and there are problems such as low ethanol production per plant cultivation area and competition with uses as food and feed. ing.

  Therefore, in recent years, it has become wastes such as wheat straw, rice straw, rice husks, bagasse), thinned wood, waste wood, waste paper, etc., or plants that do not become food or feed, especially food. Attempts have been made to produce ethanol from plants that can be cultivated efficiently even in climates and soils that are not suitable for plant production.

  The raw materials derived from these herbs and woody plants contain cellulose, and many of them are mainly composed of lignocellulose, which is a complex composed of cellulose, hemicellulose and lignin. And in order to produce ethanol from the said raw material, the method of hydrolyzing a cellulose and hemicellulose to monosaccharide (saccharification), and using the obtained sugar liquid for fermentation by yeast etc. is employ | adopted.

  In the above saccharification, when a method of chemically hydrolyzing using sulfuric acid or the like is used, it is easy to cause excessive decomposition, and the yield of effective sugar tends to decrease. Therefore, it is preferable to employ a method utilizing an enzyme. However, cellulose itself does not have a high saccharification rate by an enzyme, and cellulose and hemicellulose in lignocellulose are strongly bound to lignin, so that saccharification by an enzyme tends not to proceed further.

  Therefore, by pre-treating plant-derived raw materials containing cellulose (hereinafter sometimes referred to as “plant biomass”) prior to saccharification, chemical or biogenic properties of cellulose and hemicellulose, particularly cellulose and hemicellulose in lignocellulose are obtained. Increasing chemical reactivity, in particular, reactivity to enzymatic saccharification. As the pretreatment, in addition to treatment with hot water or steam (hydrothermal treatment), sulfuric acid treatment, steam explosion treatment for releasing pressure after contact with pressurized steam, treatment with basic aqueous solution, treatment with ammonia is known. Yes.

  In the present application, hereinafter, increasing the chemical or biochemical reactivity by the pretreatment, especially the reactivity to saccharification by an enzyme is referred to as “modification”, and the reactivity is enhanced by the pretreatment. Biomass is sometimes referred to as “modified plant biomass”. In addition, a substance such as ammonia used for pretreatment may be referred to as a “modifier”.

  As reforming of plant biomass with ammonia, a method in which plant biomass is brought into contact with liquid or gaseous ammonia under pressure and then reduced to atmospheric pressure in a short time to explode plant biomass (ammonia explosion method, for example, A method of treating with ammonia in a supercritical state (see, for example, Patent Literature 2), a method of treating with ammonia water (see, for example, Patent Literature 3), and the like are known. In addition, the improvement of the reactivity of the cellulose accompanying the modification | reformation by ammonia is not only the effect by removing the lignin strongly couple | bonded with the cellulose which comprises lignocellulose, but the crystal | crystallization of a cellulose is transformed from I type to III type. The effect by doing is also known (for example, refer to patent documents 4).

  In the above-mentioned patent documents, reforming using ammonia is performed using a batch-type apparatus. However, in order to implement the reforming industrially, a continuous or semi-continuous apparatus is used. Increasing efficiency is preferred from an economic point of view. The plant biomass used as a raw material is generally provided in the form of cut and / or pulverized particles. On the other hand, ammonia has a vapor pressure exceeding atmospheric pressure at room temperature, is toxic, and is a substance that requires attention in handling to form an explosive mixture with air. Supplying solid particles of plant biomass raw material continuously or semi-continuously to a container for performing a reforming treatment in which ammonia under pressure is accommodated without leaking such ammonia, and Extracting the modified plant biomass particles continuously or semi-continuously from the container for quality treatment requires advanced techniques.

  As a method for continuously performing reforming using ammonia, for example, Patent Document 5 discloses a method using an apparatus including a barrel and a screw installed in the barrel and sealed between the barrel. The Patent Document 6 discloses an apparatus for continuous reforming using aqueous ammonia as a modifier.

US Pat. No. 4,600,590 U.S. Pat. No. 4,644,060 JP 2008-535664 A JP 2008-161125 A JP 2005-232453 A JP 2010-115162 A

  In the continuous reforming method disclosed in Patent Document 5, liquid ammonia is used as a modifier. On the other hand, the ammonia as a modifier is not limited to liquid ammonia, and it is preferable that gaseous ammonia can also be used. However, in the above method, when gaseous ammonia is used, it is difficult to maintain the airtightness between the barrel and the screw as compared with the case where liquid ammonia is used, and there is a possibility of leakage of ammonia.

  Further, the device for continuous reforming disclosed in Patent Document 6 performs reforming with ammonia water, and supplies plant biomass particles to a container containing pressurized liquid or gaseous ammonia. There is no process to do. On the other hand, in the modification using ammonia, as described above, in addition to the effect of removing lignin from lignocellulose, the effect of transforming cellulose crystals from type I to type III is also imparted. However, when ammonia water is used as a modifier, cellulose III type crystals once produced return to cellulose I type by the action of water coexisting in large quantities, and the effect due to the transformation of the crystals is reduced. Become. In addition, a large amount of energy is required to separate and recover ammonia from aqueous ammonia. Therefore, it is desired to develop a method for continuously or semi-continuously reforming a pressurized gas or liquid with ammonia, which does not contain an amount of water sufficient to return the cellulose crystal form from type III to type I. It was.

  Further, since the mixture of ammonia and air has an explosion limit (ammonia is 15 to 28% by volume), it is necessary to prevent air from being mixed into the apparatus that handles ammonia. However, the particulate plant biomass raw material stored in the atmosphere, especially the raw material with a low water content, contains a lot of air, and if this is supplied as it is to a device that handles ammonia, the air is mixed into the device. , May form a mixture with ammonia and explosion limits. Therefore, it is necessary to remove air contained in the raw material in the step before the plant biomass raw material and ammonia come into contact with each other.

  Furthermore, in the reforming with ammonia, it is preferable to recover and reuse the ammonia once used from an economical viewpoint.

  Conventionally, all the above-mentioned problems, that is, using not only liquid ammonia but also pressurized gaseous ammonia as a modifier, preventing air from being mixed into the ammonia, recovering and reusing ammonia once used. There has been no known method and apparatus for reforming plant biomass raw materials continuously or semi-continuously and safely after solving the use.

  The present invention has been made in view of the above circumstances, using pressurized gas and liquid ammonia as a modifier, recovering and reusing ammonia once used without mixing ammonia and air. The plant biomass raw material can be semi-continuously modified, and is produced by a safe and efficient method for producing modified plant biomass, an apparatus for producing the same, and the method for producing the modified plant biomass. An object of the present invention is to provide an efficient method for producing ethanol using a modified plant biomass.

  In order to achieve such an object, a method for producing a modified plant biomass according to the present invention includes a first step of supplying a particulate plant biomass raw material to a first container, a first step, After the second step of exhausting the air in one container and the second step, the first container is pressurized so that the pressure in the first container is equal to or higher than the pressure in the second container for reforming the plant biomass material. A third step of supplying gaseous or liquid ammonia to one container, a fourth step of transferring plant biomass material from the first container to the second container after the third step, and a fourth step After the step, a fifth step of discharging ammonia remaining in the first container as a gas, and a gaseous or liquid ammonia in which the plant biomass material transferred in the fourth step is pressurized in the second vessel In the sixth step of reforming by contacting with and the sixth step A seventh step of transferring at least a part of the modified plant biomass from the second container to the third container; and an eighth step of discharging ammonia from the third container as a gas after the seventh step. , After the eighth step, a ninth step for discharging and recovering the modified plant biomass from the third container, a tenth step for discharging air from the third container, And 11th step of recovering ammonia discharged in step 5 and / or 8th step and reusing it as ammonia supplied to the first container, and repeating steps 1 to 11 A cycle is characterized in that the next cycle is started after the end of the fifth step in one cycle.

  According to this method, after the air in the first container is discharged in the second step, the third step of supplying ammonia to the first container in which the plant biomass raw material exists is provided. And air can be prevented from mixing. Furthermore, after transferring the plant biomass raw material from the first container, it is provided with a fifth step of discharging ammonia remaining in the first container as a gas, and the next cycle starts after the fifth step. Therefore, even if air flows into the first container in the first step of the next cycle, mixing of ammonia and air can be prevented. That is, it is possible to reliably prevent air and ammonia from being mixed in the first container at the same time as reforming is performed semi-continuously. In addition, after the ammonia is discharged as a gas from the third container in the eighth step, the ninth step in which air can be mixed into the third container is performed, so that mixing of ammonia and air is prevented. it can. Furthermore, by discharging the air from the third container in the tenth step, the air and ammonia are mixed even if the modified plant biomass is transferred to the third container in the next cycle. Can be prevented. In this way, it is possible to reliably prevent air and ammonia from mixing in the third container. In addition, upstream and downstream of the second container for reforming are provided with a first container and a third container for supplying and discharging ammonia and supplying plant biomass raw materials or discharging modified plant biomass, respectively. As a result, leakage of ammonia from the second container can be prevented even when gaseous ammonia is used as a modifier. In the eleventh step, ammonia discharged from the first container and / or the third container can be recovered and reused. As described above, pressurized gas and liquid ammonia are used as a modifier, and once used ammonia is collected and reused without mixing ammonia and air, and plant biomass feedstock is reformed semi-continuously. It is possible to produce plant biomass that has been modified safely and efficiently.

  In the manufacturing method according to the present invention, it is preferable that the eleventh step further includes a twelfth step of liquefying and recovering gaseous ammonia and separating and removing the non-liquefied gas from the liquid ammonia. When ammonia mixed with gas (inert gas) that is not liquefied is recovered and continuously reused, the concentration of the inert gas in ammonia gradually increases, and the partial pressure of ammonia in the second container The plant biomass raw material may not be efficiently reformed. Therefore, such a situation can be prevented by providing the twelfth step.

  In the manufacturing method according to the present invention, the air is discharged from the first container in the second step, the ammonia is discharged from the first container in the fourth step, and the third container in the eighth step. It is preferable that the ammonia is discharged and the air is discharged from the third container in the tenth step by decompressing the container. From the viewpoint of efficiently removing the air contained in the plant biomass raw material particles and preventing the inert gas such as nitrogen gas from being mixed into the ammonia, discharge by reduced pressure is preferably employed.

  Further, in the production method according to the present invention, in the twelfth step, the gaseous ammonia is cooled and liquefied to reduce the vapor pressure of ammonia, so that the first container in the fifth step is used. The gaseous ammonia is preferably discharged and / or gaseous ammonia is preferably discharged from the third container in the eighth step.

  In the production method according to the present invention, it is preferable that in the eleventh step, the ammonia liquefied in the twelfth step is vaporized again and reused as ammonia supplied in the third step. Thereby, ammonia with high partial pressure without mixing of inert gas can be used as a modifier.

  An apparatus for producing a modified plant biomass according to the present invention includes a first container to which particulate plant biomass material is supplied, a plant biomass material supply unit that supplies plant biomass material to the first container, A first air discharge section for discharging air from one container, a first ammonia discharge section for discharging ammonia from the first container, and supplying pressurized gas or liquid ammonia to the first container; A plant biomass raw material is transferred from the ammonia supply unit, the first container, and the plant biomass raw material is brought into contact with the pressurized gas or liquid ammonia to be reformed, and the second container From the provided heating means, the third container to which the modified plant biomass is transferred from the second container, the second air discharge unit for discharging air from the third container, and the third container ammonia A second ammonia discharge portion for discharging, characterized in that it comprises a plant biomass recovery unit for recovering was drained plant biomass that has been modified from the third container, the.

  By using the production apparatus configured as described above, the production method of the modified plant biomass described above can be suitably realized, and the effect of the production method can be obtained.

  In the manufacturing apparatus according to the present invention, the plant biomass material supply unit connects the plant biomass material storage unit that stores the plant biomass material, the plant biomass material storage unit, and the first container, and a plurality of valves. It is preferable to include a first pipe arranged in series. As a result, it is possible to reliably prevent the ammonia in the apparatus from leaking into the atmosphere and the air flowing into the apparatus and being mixed with the ammonia with the valve closed.

  Moreover, the manufacturing apparatus according to the present invention preferably further includes a second pipe that connects the second container and the third container and in which a plurality of valves are arranged in series. Accordingly, it is possible to reliably prevent the ammonia in the second container from leaking and the air from flowing into the apparatus and mixed with the ammonia with the valve closed.

  In the manufacturing apparatus according to the present invention, it is preferable that the plurality of valves include at least one ball valve and at least one gate valve.

  Moreover, the manufacturing apparatus which concerns on this invention WHEREIN: It is preferable that a 2nd container is equipped with the stirring means which stirs a plant biomass raw material. Thereby, the plant biomass raw material and ammonia in the second container can have a uniform temperature distribution.

  Moreover, the manufacturing apparatus which concerns on this invention WHEREIN: It is preferable that a 2nd container is equipped with a screw conveyor inside. The screw conveyor functions as a stirring means for stirring the plant biomass material, and also functions as a means for moving the plant biomass material and the modified plant biomass in the direction from the upstream side to the downstream side in the second container.

  Further, in the production apparatus according to the present invention, an ammonia liquefying section that liquefies ammonia compressed and / or cooled from the first container and / or the third container, and liquefied by compression and / or cooling. It is preferable to further comprise a fourth container for separating and removing the gas that is not removed from the liquid ammonia. Thereby, the gas (inert gas) which is not liquefied can be reliably separated and removed from ammonia.

  Moreover, in the manufacturing apparatus which concerns on this invention, it is preferable to further provide the ammonia heating means for vaporizing the liquid ammonia transferred from the 4th container. Thereby, ammonia with high partial pressure without mixing of inert gas can be used as a modifier.

  The method for producing ethanol according to the present invention includes a saccharification step for saccharifying the modified plant biomass produced by the above-described production method with an enzyme, and a fermentation step for ethanol fermentation of the sugar liquid obtained in the saccharification step. Prepare. By using the modified plant biomass produced by the above production method, ethanol can be produced efficiently.

  According to the present invention, pressurized gas and liquid ammonia are used as a modifier, and once used ammonia is collected and reused without mixing ammonia and air, and the plant biomass raw material is semi-continuous. It is possible to produce plant biomass that has been safely and efficiently modified. Moreover, ethanol can be produced efficiently.

It is a schematic block diagram which shows an example of the manufacturing apparatus which performs the manufacturing method of the modified plant biomass which concerns on embodiment of this invention. It is a schematic block diagram which shows another example of the manufacturing apparatus which performs the manufacturing method of the modified plant biomass which concerns on embodiment of this invention.

  As shown in FIG.1 and FIG.2, the manufacturing apparatus 100 of the modified plant biomass which concerns on embodiment of this invention is the 1st container 110, the plant biomass raw material supply part 120, the 1st discharge part ( (First air discharge unit, first ammonia discharge unit) 130, ammonia supply unit 140, second container 150, heating unit (heating means) 160, third container 170, and second discharge Section (second air discharge section, second ammonia discharge section) 180, plant biomass recovery section 190, first ammonia liquefying section 200, second ammonia liquefying section 210, and fourth container 220 And an ammonia heating unit 230.

  The plant biomass raw material used in the present embodiment is not particularly limited as long as it is derived from a plant and contains cellulose. For example, grains, sugar solution, etc. are collected from plants such as wheat straw, rice straw, rice husk, bagasse and the like. Residues, thinned timber made of various conifers or hardwoods, waste materials, plant-derived waste such as waste paper, pulp, etc. are used. Used paper and pulp may be made of lignocellulose, or lignin may be removed from lignocellulose and cellulose may be the main component. Also, as a raw material for producing ethanol for plants that do not become food or feed, especially plants that can be cultivated efficiently even in climates and soils that are not suitable for the production of food plants, such as switchgrass, napiergrass, and Eliansus It may be a plant to be cultivated.

  These plant biomass raw materials are dried by sun drying, hot air drying, or the like, if necessary, and are supplied after being cut and / or pulverized into particles.

  The first container 110 is supplied with particulate plant biomass material. The plant biomass material supply unit 120 supplies plant biomass material to the first container 110. The first discharge unit 130 discharges air and ammonia from the first container 110. The ammonia supply unit 140 supplies pressurized gas or liquid ammonia to the first container 110. In the second container 150, plant biomass raw material is transferred from the first container, and the plant biomass raw material is contacted with pressurized gas or liquid ammonia to be reformed. The heating unit 160 is provided in the second container 150 and heats the plant biomass material and the gaseous or liquid ammonia in the second container 150. The third container 170 is for transferring the modified plant biomass from the second container 150. The second discharge unit 180 discharges air and ammonia from the third container 170. The plant biomass recovery unit 190 discharges and recovers the modified plant biomass from the third container 170. The first ammonia liquefying unit 200 is a unit that compresses and / or cools and liquefies ammonia discharged as a gas from the first container 110. The second ammonia liquefying unit 210 liquefies the ammonia discharged from the third container 170 as a gas by compression and / or cooling. The 4th container 220 isolate | separates and removes the gas which is not liquefied by compression and / or cooling mixed in ammonia from liquid ammonia. The ammonia heating unit 230 is for vaporizing the liquid ammonia transferred from the fourth container 220. In addition, the more specific structure and function in each component are performed in conjunction with the description of the method for producing the modified plant biomass described below.

  Next, a modified plant biomass production method and an ethanol production method according to an embodiment of the present invention will be described, and a more detailed configuration of the production apparatus 100 will also be described.

  In the first step of the method for producing a modified plant biomass according to this embodiment, a plant biomass material is supplied to the first container 110. A plant biomass material supply unit 120 for supplying plant biomass material is connected to the first container 110. The plant biomass material supply unit 120 may be, for example, a charging hole provided with an openable / closable lid, and in that case, a predetermined amount of plant conveyed from a plant biomass material storage facility by a conveying means such as a belt conveyor. Biomass raw material is charged into the first container 110 through the charging hole, and the first container 110 is sealed by closing the lid. In the example shown in FIGS. 1 and 2, the first container 110 is constituted by the charging tank 5. The plant biomass raw material supply unit 120 can be configured by making the lid of the charging tank 5 openable and closable and arranging the plant biomass storage facility and the conveying means.

  Moreover, the plant biomass raw material supply part 120 is the plant biomass raw material storage part 1 which stores plant biomass, the plant biomass raw material storage part 1, and the input tank 5 (1st container) so that FIG.1 and FIG.2 may illustrate. 110), and a first pipe 2 having a valve disposed in the middle thereof. In this case, by opening a valve, after introducing a predetermined amount of plant biomass material conveyed by a gas such as gravity or air into the first container 110, the first container 110 is sealed by closing the valve. The It is desirable that a plurality of valves are arranged in series in the middle of the first pipe 2. When a plurality of valves are provided, a valve suitable for closing the flow of powder such as at least one ball valve, air or gaseous ammonia such as at least one gate valve, etc. It is preferable to use in combination with a valve suitable for closing the gas flow. By arranging the valve in this way, it is possible to reliably prevent the ammonia in the apparatus from leaking into the atmosphere and that the air flows into the apparatus and mixes with the ammonia with the valve closed. it can.

  In the second step, the first discharge unit 130 discharges the air mixed in the first container 110 accompanying the plant biomass material supplied in the first step.

  The plant biomass raw material is in the form of particles, and the raw material stored in the atmosphere, particularly in the dry state or in a state containing a small amount of moisture, contains a large amount of air in and between the particles. For this reason, when the plant biomass raw material is brought into direct contact with ammonia, there is a risk that ammonia and air form an air-fuel mixture within the explosion limit. Therefore, in the first container 110, before the ammonia is introduced, the air contained in the supplied plant biomass material is removed. As a method of removing the air employed in the first discharge unit 130, nitrogen gas or the like is supplied to the first container 110 supplied with the plant biomass raw material by supply and discharge pipes connected to the container 110. Using a method of circulating an inert gas (sweeping), a pipe for pressurizing the first container 110 with an inert gas such as nitrogen gas connected to the first container 110 and a pipe for depressurization , A method of repeatedly pressurizing / depressurizing the container 110 several times (pressurizing purge), a method of depressurizing the container 110 using equipment for depressurization connected to the first container 110 (degassing) Etc. can be used. From the viewpoint that the air contained in the plant biomass raw material particles is efficiently removed, and that inert gas such as nitrogen gas is difficult to mix in the ammonia supplied in the third step described later. A method of depressurizing one container 110 is preferably employed. It is also preferable to combine decompression and introduction of inert gas, such as introducing an inert gas such as nitrogen gas after depressurizing the first container 110 and then depressurizing again, so that air can be reliably removed. it can. As equipment for depressurizing the first container 110 in deaeration, a vacuum pump, an ejector, or a compressor that sucks air in the first container 110 and pressurizes the exhaust side is used. The air discharged in the second step is discharged out of the system through the piping.

  In the example shown in FIGS. 1 and 2, the first discharge unit 130 includes at least a valve 7, a compressor 8, and an air vent pipe 3 (closed in ammonia discharge). While opening the valve 7, the air is extracted from the charging tank 5, which is the first container 110, using the compressor 8, and the air is discharged to the outside from the air vent pipe 3. Thereafter, a slight amount of inert gas such as nitrogen gas is introduced from the supply pipe 4 so that the oxygen concentration in the charging tank 5 is set to a predetermined amount or less. At this time, it is desirable to reduce the amount of inert gas introduced as much as possible from the economical viewpoint and from the viewpoint of reducing the amount of inert gas mixed into the ammonia introduced in the third step. Alternatively, after introducing the inert gas, the first container 110 may be decompressed again to discharge the inert gas.

  In the third step, the ammonia supply unit 140 supplies gaseous or liquid ammonia to the first container 110 from which air has been removed in the second step so that the pressure is equal to or higher than that of the second container 150. To do. Here, the plant biomass raw material stored in the first container 110 is smoothly transferred from the first container 110 to the second container 150 due to gravity and / or a pressure difference between the first container 110 and the second container 150. It is preferable that the pressure of the first container 110 is equal to or slightly higher than the pressure of the second container 150. Regarding the ammonia to be supplied, gaseous ammonia is preferable when the ammonia stored in the second container 150 is a gas, and when the ammonia stored in the second container 150 is liquid, it is gaseous or liquid ammonia. Is preferred. In the example shown in FIGS. 1 and 2, the ammonia supply unit 140 is configured by at least the ammonia introduction pipe 6. Using this ammonia introduction pipe 6, gaseous ammonia is introduced into the charging tank 5 constituting the first container 110, and the same pressure as the reforming tanks 12 </ b> A and 12 </ b> B constituting the second container 150, or a slightly higher pressure. Boosting.

  Subsequent to the third step, in the fourth step, the plant biomass material is transferred from the first container 110 to the second container 150. For the transfer, it is preferable to use a pipe provided with a valve in the middle and connecting the first container 110 and the second container 150. The valve is closed except when the plant biomass material is transferred from the first container 110 to the second container 150, and the first container 110 and the second container 150 are sealed. The transfer is preferably performed using gravity and / or differential pressure between the first container 110 and the second container 150. In the example shown in FIGS. 1 and 2, the charging tank 5 constituting the first container 110 and the reforming tanks 12A and 12B constituting the second container 150 are connected by piping, and reforming is performed on the piping. A tank introduction valve 10 is provided. When the plant biomass material is transferred, all the plant biomass materials in the charging tank 5 are transferred to the reforming tanks 12A and 12B by opening the reforming tank introduction valve 10. When the transfer of the plant biomass material is completed, the reforming tank introduction valve 10 is closed.

  In the fifth step, the first discharge unit 130 discharges the ammonia remaining in the first container 110 after the plant biomass material has been transferred to the second container 150. The method of discharging ammonia from the first container 110 is similar to the case of discharging the air in the first container 110 in the second step, and the equipment used at that time is used to remove nitrogen gas or the like. Methods such as sweeping with an active gas, pressurized purge with an inert gas, and degassing can be used (in the embodiment, the function of the first air discharge unit and the function of the first ammonia discharge unit are combined into one first function. However, the discharge unit may be divided for each function). From the viewpoint that inert gas such as nitrogen gas is difficult to mix in the recovered ammonia, a method of degassing (depressurizing) the first container 110 is preferably employed. It is also preferable to combine decompression and introduction of inert gas, such as introducing an inert gas such as nitrogen gas after reducing the pressure of the first container 110 once, and then reducing the pressure again, thereby reliably removing ammonia. be able to. In addition, when using inert gas, such as nitrogen gas, it is preferable to minimize the usage-amount from a viewpoint of reducing the quantity of the inert gas mixed in ammonia as much as possible.

  As one method of depressurizing the first container 110 in the fifth step, the ammonia is cooled and liquefied by a cooler connected to a pipe for discharging ammonia connected to the first container 110. A method of reducing the pressure of the first container 110 by utilizing the decrease in the vapor pressure of ammonia can be employed. In this case, a vacuum pump, an ejector, a compressor, etc., which are facilities for decompressing the first container 110, are bypassed. It is preferable that ammonia in the first container 110 is discharged by a method using a cooler, and further the pressure is reduced by a vacuum pump, an ejector, a compressor, or the like to reliably discharge ammonia.

  In the example shown in FIG. 1 and FIG. 2, the ammonia in the charging tank 5 is discharged by opening the valve 7 and starting the compressor 8 in order to discharge the ammonia in the charging tank 5 constituting the first container 110. Is done. The ammonia discharged as a gas may cause the cooler 9 constituting the first ammonia liquefying section 200 (the cooling function by the cooler 9 to function as a part of the first discharge section 130 for discharging ammonia). ) Is cooled to become a liquid and collected into the liquid ammonia tank 23.

  By discharging ammonia in the first container 110 in the fifth step, in supplying the plant biomass raw material to the first container 110 in the first step in the next cycle, along with the supply Mixing air is mixed with ammonia remaining in the first container 110, and ammonia is prevented from leaking from the first container 110 to the atmosphere. This completes the preparation for the first container 110 to start the next cycle.

  In the sixth step, the second container 150 contacts the plant biomass raw material transferred in the fourth step with pressurized gaseous or liquid ammonia under heating in the second container 150. And reforming is performed.

  The second container 150 is provided with a heating unit 160 for heating gaseous or liquid ammonia and plant biomass, and the plant biomass material is brought into contact with gaseous or liquid ammonia at a predetermined temperature, pressure, and residence time. Reforming is performed.

  For the heating unit 160, normal means such as a jacket and a heater provided outside the second container 150, inside the container wall, or inside the container are used. The jacket is heated by circulating steam, heating oil, or the like. In the example shown in FIGS. 1 and 2, the reforming tanks 12 </ b> A and 12 </ b> B constituting the second container 150 include a jacket disposed on the outer periphery of the reforming tanks 12 </ b> A and 12 </ b> B as the heating unit 160. . By introducing a heated heat medium from the heat medium pipe 14 of the jacket, the reforming tanks 12A and 12B are heated to a predetermined temperature.

  Although the conditions for the reforming treatment in the second container 150 are not limited, the temperature is 40 to 150 ° C., the pressure is 0.2 to 12 MPa, and the residence time is 0 from the viewpoint of efficiently modifying the plant biomass. .1-24 hours are preferred.

  The second container 150 preferably includes a stirring means so that the plant biomass and ammonia in the container have a uniform temperature distribution. It is preferable that the stirring means mainly performs circumferential stirring with respect to the rotation axis of the stirring means and does not actively perform stirring in a direction perpendicular to the circumferential direction.

  The second container 150 receives the plant biomass raw material from the first container 110 through the pipe and discharges the modified plant biomass to the third container 170. For this purpose, it is necessary to move the plant biomass material from the upstream side to the downstream side in the second container 150 with time. That is, the 2nd container 150 goes to the connection part side of piping connecting between the 3rd container 170 from the connection part side of piping connecting between the 1st container 110 and plant biomass raw materials. Need to move in the direction. The supply amount per unit time of the plant biomass raw material supplied from the first container 110 to the second container 150 and the (modified) per unit time extracted from the second container 150 to the third container The extraction amount of plant biomass should be approximately equal.

  FIG. 1 shows a vertical gravity transfer type reforming tank 12A provided with a mixer, that is, a stirring blade (stirring means) 13A. The plant biomass material supplied from the charging tank 5 constituting the first container 110 is stirred by the stirring blade 13A, and the temperature distribution in the circumferential direction is kept uniform with respect to the heating from the outside of the container by the heating unit 160. . The stirring blade 13A is driven by the power unit 11 outside the reforming tank 12A. The plant biomass and ammonia that have been intermittently modified are extracted from the bottom of the reforming tank 12A, and the plant biomass material and the modified plant biomass in the reforming tank 12A move downward with time due to this extraction and gravity. I will do it. Further, the plant biomass material and ammonia are intermittently supplied from the charging tank 5 into the gap formed in the upper part of the reforming tank 12A.

  FIG. 2 shows a horizontal reforming tank 12B provided with a screw conveyor 13B inside the container. Here, the screw conveyor 13B functions as a stirring means for stirring the plant biomass material, and also functions as a means for moving the plant biomass material in the direction from the upstream side to the downstream side in the reforming tank 12B. Here, although the reforming tank 12B and the screw conveyor 13B disposed therein are shown as horizontal examples, they may be vertical.

  In the seventh step, part of the modified plant biomass obtained in the sixth step is transferred from the second container 150 to the third container 170 through the second pipe 15. The second pipe 15 connects the second container 150 and the third container 170, and a valve is disposed in the middle. During the transfer, the valve is opened intermittently, and after the transfer is completed, the valve is closed.

  In order to reliably prevent ammonia leakage, it is desirable that the second pipe 15 has a plurality of valves arranged in series. In this case, a valve suitable for closing the flow of powder such as at least one ball valve may be combined with a valve suitable for closing the flow of air or gaseous ammonia such as at least one gate valve. preferable. In the example shown in FIG.1 and FIG.2, the discharge valve provided in the 2nd piping 15 is opened and closed intermittently for every predetermined time. After the discharge valve is opened and a certain amount of plant biomass in the reforming tanks 12A and 12B constituting the second container 150 flows into the discharge tank 17 constituting the third container 170, the discharge valve is closed.

  In the seventh step, since ammonia is mixed into the third container 170 accompanying the transfer of the modified plant biomass to the third container 170, the third container 170 is opened to the atmosphere as it is. When trying to recover the modified plant biomass, ammonia and air may form an air-fuel mixture within the explosion limit. In addition, ammonia may leak into the atmosphere. Therefore, in the eighth step, the second discharge unit 180 discharges ammonia accompanying the transfer of the modified biomass from the second container 150 from the third container 170.

  In the eighth step, the method used by the second discharge unit 180 to discharge ammonia in the third container 170 and the equipment used therefor can be the same as those of the first discharge unit 130. . That is, methods such as sweeping with an inert gas, pressurized purge with an inert gas, and deaeration can be used. Among these, a method of degassing (reducing pressure) the third container 170 is preferably employed from the viewpoint that inert gas such as nitrogen gas is difficult to be mixed into the recovered ammonia. It is also preferable to combine decompression and introduction of inert gas, such as introducing an inert gas such as nitrogen gas after depressurizing the third container 170, and then reducing the pressure again, so that ammonia is reliably removed. Can do. Again, it is preferable to minimize the amount of inert gas used.

  Also in the method of discharging ammonia in the third container 170 in the eighth step, a method of cooling ammonia to lower the vapor pressure of ammonia is preferably used, as in the fifth step.

  In the example shown in FIGS. 1 and 2, the second discharge unit 180 includes at least a valve 20, a compressor 21, and an air vent pipe 27 (closed when ammonia is discharged). The ammonia in the discharge tank 17 is discharged by opening the valve 20 and starting the compressor 21 in order to discharge the ammonia in the discharge tank 17 constituting the third container 170. The ammonia discharged as a gas may cause the cooler 22 constituting the second ammonia liquefying section 210 (the cooling function by the cooler 22 to function as a part of the second discharge section 180 for discharging ammonia). ) Is cooled to become a liquid and collected into the liquid ammonia tank 23.

  In the ninth step, the plant biomass recovery unit 190 discharges and recovers the modified plant biomass from the third container 170 from which ammonia has been discharged in the eighth step. Examples of the equipment constituting the plant biomass recovery unit 190 include a discharge hole provided with an openable / closable lid or a pipe provided with a valve. The modified plant biomass in the third container 170 can be recovered by opening a lid that can be opened and closed, or by opening a valve disposed in the pipe. In addition, when the plant biomass collection | recovery part 190 is comprised by piping by which the valve | bulb was arrange | positioned, in order for the collect | recovered modified biomass to use the equipment for storage, or this modified biomass for a saccharification process It can also be supplied to other equipment. In the example shown in FIGS. 1 and 2, the plant biomass 19 whose modification has been completed is taken out by opening the discharge valve 18 provided in the piping constituting the plant biomass recovery unit 190.

  Since air is mixed in the third container 170 from which the modified biomass is discharged, the second discharge unit 180 discharges air from the third container 170 in the tenth step. Here, the method of exhausting the air employed by the second exhaust unit 180 and the equipment used therefor can be the same as those used in the second step. In addition, in embodiment, although it is set as the structure which can exhibit the function of a 2nd air discharge part and the function of a 2nd ammonia discharge part with one 2nd discharge part 180, even if it divides a discharge part for every function, Good. The third container 170 from which air has been exhausted in the tenth step can receive the modified biomass from the second container 150 in the seventh step of the next cycle. The tenth step may be executed at any stage as long as it is a previous stage in which the seventh step is executed in the next cycle. For example, the tenth step may be executed immediately after air is mixed into the container 170 in the ninth step, or just before the seventh step (or to discharge the air mixed in the previous cycle (or The tenth step may be executed at an earlier stage). In the example shown in FIGS. 1 and 2, the valve 20 is opened, the air is extracted from the discharge tank 17 constituting the third container 170 using the compressor 21, and the air is released to the outside from the air vent pipe 27. . Thereafter, a slight amount of inert gas such as nitrogen gas is introduced from the supply pipe 16 to reduce the oxygen concentration in the discharge tank 17 to a predetermined amount or less. At this time, it is desirable to reduce the amount of inert gas introduced as much as possible from the economical viewpoint and from the viewpoint of reducing the amount of inert gas mixed into the ammonia introduced in the third step. Alternatively, after introducing the inert gas, the first container 110 may be decompressed again to discharge the inert gas.

  In the eleventh step, the ammonia discharged in the fifth step and / or the eighth step is recovered and reused as ammonia supplied to the first container 110. In order to carry out the production of modified plant biomass using ammonia as a modifier with economic rationality, the ammonia discharged from the first container 110 and / or the third container 170 is recovered and reused. It is necessary. Ammonia discharged from the first container 110 and the third container 170 is preferably discharged in a gaseous state from the viewpoint of separation from plant biomass. In the method for producing a modified biomass of the present embodiment, when gaseous ammonia is used as the modifier, the gaseous ammonia discharged from the first container and / or the third container is used as it is in the eleventh embodiment. In the process, the first container can be supplied and reused. The recovery of ammonia in the eleventh step is performed at a predetermined timing when ammonia is discharged from the first container 110 and the third container 170, and reuse is performed by supplying ammonia to the first container 110. Is appropriately executed at a predetermined timing.

  On the other hand, when liquid ammonia is used as a modifier, it is necessary to convert gaseous ammonia discharged from the first container 110 and the third container 170 into liquid ammonia by compressing and / or cooling.

  Further, even when gaseous ammonia is used as the modifier, the discharged gaseous ammonia is mixed with an inert gas such as nitrogen gas when discharged from the first container 110 and / or the third container 170. In some cases, it is not preferable to reuse it as it is. That is, when ammonia mixed with an inert gas is recovered and continuously reused, the concentration of the inert gas in the ammonia gradually increases and the partial pressure of ammonia in the second container 150 decreases. However, there is a possibility that the plant biomass raw material is not efficiently reformed. Therefore, in these cases, when recovering gaseous ammonia in the eleventh step, this is liquefied by compression and / or cooling and is not liquefied in the fourth container 220 (mainly inert gas). It is preferable to further include a twelfth step of separating / removing.

  When liquid ammonia is used as the modifier, the liquid ammonia from which the inert gas obtained in the twelfth step is removed is supplied to the first container 110 and reused.

  On the other hand, when gaseous ammonia is used as the modifier, the liquid ammonium obtained in the twelfth step is vaporized by being heated by the ammonia heating unit 230 and supplied to the first container 110. Thereby, ammonia with high partial pressure without mixing of inert gas can be used as a modifier.

  In the example shown in FIGS. 1 and 2, the ammonia recovered from the charging tank 5 and liquefied by the cooler 9 and the ammonia recovered from the discharge tank 17 and liquefied by the cooler 22 are stored in the fourth container 220. The liquid ammonia tank 23 is stored. In the liquid ammonia tank 23, a gas that is not condensed (mainly an inert gas such as nitrogen) is separated and discharged from the non-condensed gas discharge pipe 24. The liquid ammonia is heated and vaporized by an ammonia heating section (ammonia heating means) 230 constituted by the ammonia evaporation tank 26 and the heat medium 25. Gaseous ammonia is supplied to the charging tank 5 through the ammonia introduction pipe 6.

  When the first to eleventh steps and the twelfth step are repeated, the next cycle can be started after the end of the fifth step in one cycle. This makes it possible to reform plant biomass semi-continuously. In addition, unless the context of the process is functionally limited (for example, the third process is performed after the second process so that ammonia and air are not mixed), the order of each process within one cycle. May be changed as appropriate.

  According to such a modified method for producing plant biomass, after the air in the first container 110 is discharged in the second step, ammonia is supplied to the first container 110 in which the plant biomass material is present. Since the third step is provided, mixing of ammonia and air can be prevented. Furthermore, after transferring the plant biomass raw material from the first container 110, it has a fifth step of discharging ammonia remaining in the first container 110 as a gas, and the next cycle starts after the fifth step. Therefore, even if air flows into the first container 110 in the next cycle, mixing of ammonia and air can be prevented. That is, reforming can be performed semi-continuously, and at the same time, mixing of air and ammonia in the first container 110 can be reliably prevented. In addition, after the ammonia is discharged as a gas from the third container in the eighth step, the ninth step in which air can be mixed into the third container 170 is performed, so that mixing of ammonia and air is prevented. it can. Furthermore, by discharging air from the third container 170 in the tenth step, air and ammonia are mixed even if the modified plant biomass is transferred to the third container 170 in the next cycle. Can be prevented. Thus, it is possible to reliably prevent air and ammonia from mixing in the third container 170. Further, upstream and downstream of the second container 150 for reforming, the first container 110 and the third container for supplying and discharging ammonia and supplying the plant biomass material or discharging the modified plant biomass, respectively. By providing 170, leakage of ammonia from the second container 150 can be prevented even when not only liquid but also gaseous ammonia is used as a modifier. In the eleventh step, ammonia discharged from the first container 110 and / or the third container 170 can be recovered and reused. As described above, pressurized gas and liquid ammonia are used as a modifier, and once used ammonia is collected and reused without mixing ammonia and air, and plant biomass feedstock is reformed semi-continuously. It is possible to produce plant biomass that has been modified safely and efficiently.

  Next, a method for producing ethanol using the modified biomass will be described. The modified plant biomass obtained by the above method is hydrolyzed to monosaccharides by a saccharification process, and the sugar solution obtained by saccharification is converted to ethanol by a fermentation process. Hereinafter, it demonstrates in detail along preferable embodiment.

(Saccharification process)
First, the modified plant biomass produced by the above method is hydrolyzed (saccharified) into monosaccharides in a saccharification step. The saccharification method is not particularly limited, and a known method, that is, a chemical method using concentrated sulfuric acid or the like as a catalyst, a biochemical method using an enzyme, or the like can be used. Of these, when chemical methods are used, the yield of monosaccharides tends to decrease due to excessive decomposition, and substances that have an inhibitory action tend to be easily produced in the fermentation process that follows saccharification. There are problems such as the occurrence of discharge of environmentally hazardous substances such as sulfuric acid. Therefore, these problems are unlikely to occur, and mild conditions can be selected, so that enzymatic saccharification is preferably employed. The enzyme used in this case is not limited, and known enzymes such as cellulase and cellobiase (β-glucosidase) can be used. An immobilized enzyme in which these enzymes are immobilized on an appropriate carrier or matrix can also be used.

  There is no restriction | limiting in particular as the usage-amount of the enzyme in the saccharification by the said enzyme, Although it can select suitably, For example, 0.0001-10 mass parts is preferable with respect to 100 mass parts of modified plant biomass, 0 0.001 to 1 part by mass is more preferable, and 0.01 to 0.1 part by mass is particularly preferable. If the amount of the enzyme used is less than 0.0001 part by mass, saccharification may be insufficient, and if it exceeds 10 parts by mass, inhibition of saccharification may occur and the cost associated with the enzyme increases. On the other hand, when the amount of the enzyme used is within the preferred range, it is advantageous in that the yield of monosaccharide obtained relative to the amount of enzyme used is large.

  There is no restriction | limiting in particular as temperature in the saccharification by the said enzyme, Although general conditions can be selected, For example, 10-70 degreeC is preferable, 20-60 degreeC is more preferable, and 30-50 degreeC is especially preferable. If the temperature is lower than 10 ° C, saccharification may not proceed, and if it exceeds 70 ° C, the enzyme may be deactivated. On the other hand, when the temperature is within the preferred range, it is advantageous in that the yield of monosaccharide obtained with respect to the amount of enzyme used is large.

  There is no restriction | limiting in particular as pH in the saccharification by the said enzyme, Although general conditions can be selected, For example, 3.0-8.0 are preferable, 3.5-7.0 are more preferable, 4. 0 to 6.0 is particularly preferable. If the pH is less than 3.0 or more than 8.0, the enzyme may be deactivated. On the other hand, when the pH is within the preferable range, it is advantageous in that the yield of monosaccharide obtained with respect to the amount of enzyme used is large.

  By the saccharification by the enzyme, glucose is obtained from cellulose contained in the modified biomass as a monosaccharide. When the modified biomass contains hemicellulose, hexoses such as glucose, galactose, and mannose derived from hemicellulose and pentoses such as xylose and arabinose are produced.

  The sugar solution containing the monosaccharide obtained by the above saccharification may be used for the fermentation process as it is, but for example, a sugar solution suitable for fermentation by adjusting the pH of the sugar solution, adjusting the sugar concentration, etc. It is good.

(Fermentation process)
Next, ethanol fermentation is performed by adding an ethanol fermentation microorganism to the sugar solution obtained in the saccharification step.

  Although it is not limited as an ethanol fermentation microorganism, yeast or bacteria of the genus Zymomonas such as Zymomonas mobilis is preferably used, and yeast is more preferable.

  Although it does not specifically limit as yeast, Saccharomyces yeasts, such as Saccharomyces cerevisiae, are preferable. However, when the plant biomass as a raw material contains lignocellulose, pentoses such as xylose and arabinose are produced by saccharification from the hemicellulose constituting the lignocellulose, but the yeast of the genus Saccharomyces assimilates the pentose sugar to produce ethanol. Has no ability to generate. Therefore, in order to effectively use not only hexose but also pentose derived from hemicellulose and convert it to ethanol, yeast that has the ability to assimilate pentose and produce ethanol (pentose-utilizing yeast) Is preferably used. As the pentose assimilating yeast, Pichia stippitis or Candida shihatae is preferably used. In order to efficiently convert hexose sugar and pentose sugar to ethanol, a method of using a yeast of the genus Saccharomyces and the aforementioned pentose assimilating yeast is also preferably employed. In this case, the yeast of the genus Saccharomyces and the above-mentioned pentose-assimilating yeast may be fermented, or glucose in the sugar solution is first assimilated by the yeast of the genus Saccharomyces, and then the above-mentioned pentose-assimilating yeast The pentose can be assimilated.

The yeast used for fermentation may be a natural yeast or a genetically modified yeast. In particular, saccharides derived from cellulose and hemicellulose can be efficiently converted to ethanol by using a genetically modified yeast having the ability to assimilate both hexose and pentose.

  The conditions such as the amount of yeast used in the fermentation process, additives other than sugar, fermentation temperature, pH, fermentation time and the like are not particularly limited, and known conditions can be used, but the pH is 4 to 7, and the fermentation temperature is 20. A temperature of about ~ 37 ° C is preferred.

  In addition, by performing fermentation at a temperature higher than usual using heat-resistant yeast, it is possible to perform fermentation efficiently without the need for cooling equipment and suppressing the growth of various bacteria. Examples of the heat-resistant yeast include heat-resistant yeasts belonging to the genus Kloyveromyces such as Kloyveromyces marxianas. When using these heat-resistant yeasts, the temperature of fermentation can be about 37 ° C to 50 ° C.

(Purification process)
In the manufacturing method of ethanol of this invention, it is preferable to provide the process of isolate | separating and producing | generating ethanol from the culture medium containing ethanol obtained in the fermentation process. By this step, ethanol is separated / purified from various substances contained in the fermentation medium and concentrated. The separation / purification method is not particularly limited, but for example, distillation is preferably employed.

  According to the ethanol production method of the present embodiment, ethanol can be efficiently produced by using the plant biomass modified by the production method as described above.

  As mentioned above, although the manufacturing method of the modified plant biomass of this invention, its manufacturing apparatus, and the manufacturing method of ethanol using the modified plant biomass manufactured by the said method were demonstrated along preferable embodiment. The present invention is not limited to the above-described embodiment without departing from the spirit of the present invention.

  In addition, the modified plant biomass obtained by the method of the present invention can be used not only for the production of ethanol but also as a raw material for the production of other substances. For example, lactic acid can be produced by subjecting a sugar solution obtained by saccharification of the modified plant biomass obtained by the method of the present invention to lactic acid fermentation by lactic acid bacteria or the like. The lactic acid thus obtained can be used as a raw material for biodegradable polymers such as polylactic acid.

  DESCRIPTION OF SYMBOLS 1 ... Plant biomass storage part, 2 ... 1st piping, 3 ... Air vent piping, 4 ... Supply piping, 5 ... Feeding tank, 6 ... Ammonia introduction piping, 7 ... Valve, 8 ... Compressor, 9 ... Cooler, 10 ... reforming tank introduction valve, 11 ... power unit, 12A, 12B ... reforming tank, 13A ... stirring blade (stirring means), 13B ... screw conveyor (stirring means), 14 ... heat medium piping, 15 ... second piping , 16 ... supply piping, 17 ... discharge tank, 18 ... discharge valve, 19 ... modified plant biomass, 20 ... valve, 21 ... compressor, 22 ... cooler, 23 ... liquid ammonia tank, 24 ... non-condensable gas discharge Piping, 25 ... Heat medium, 26 ... Ammonia evaporation tank, 27 ... Air venting pipe, 100 ... Production apparatus for modified plant biomass, 110 ... First container, 120 ... Plant biomass raw material supply unit, 130 ... First Discharge section (first air discharge section, first ammonia discharge section), 140 ... ammonia supply section, 150 ... second container, 160 ... heating section (heating means), 170 ... third container, 180 ... first 2 discharge parts (second air discharge part, second ammonia discharge part), 190 ... plant biomass recovery part, 200 ... first ammonia liquefaction part, 210 ... second ammonia liquefaction part, 220 ... fourth Container, 230 ... ammonia heating part (ammonia heating means).

Claims (14)

A first step of supplying particulate plant biomass raw material to the first container;
A second step of exhausting air in the first container after the first step;
After the second step, gas or liquid ammonia is supplied to the first container so that the pressure of the first container is equal to or higher than the pressure of the second container for reforming the plant biomass raw material. A third step;
After the third step, a fourth step of transferring the plant biomass material from the first container to the second container;
After the fourth step, a fifth step of discharging ammonia remaining in the first container as a gas;
A sixth step of reforming the plant biomass material transferred in the fourth step by bringing it into contact with gas or liquid ammonia pressurized in the second container;
A seventh step of transferring at least a part of the plant biomass modified in the sixth step from the second container to a third container;
After the seventh step, an eighth step of discharging ammonia as a gas from the third container;
After the eighth step, a ninth step of discharging and recovering the modified plant biomass from the third container;
A tenth step of discharging air from the third container;
An eleventh step of recovering the ammonia discharged in the fifth step and / or the eighth step and reusing it as ammonia supplied to the first container,
A method for producing a modified plant biomass, wherein the first to eleventh steps are repeated, and the next cycle is started after the end of the fifth step in one cycle.   The modified plant according to claim 1, further comprising a twelfth step of liquefying and recovering gaseous ammonia in the eleventh step and separating and removing the non-liquefied gas from the liquid ammonia. A method for producing biomass.   Air discharge from the first container in the second step, ammonia discharge from the first container in the fifth step, ammonia discharge from the third container in the eighth step 3. The method for producing modified plant biomass according to claim 1, wherein the air is discharged from the third container in the tenth step by decompressing the container.   In the twelfth step, the gaseous ammonia is discharged from the first container in the fifth step by utilizing the fact that the vapor pressure of ammonia is lowered by cooling and liquefying the gaseous ammonia. 4. The method for producing modified plant biomass according to claim 2, wherein gaseous ammonia is discharged from the third container in the eighth step.   5. The method according to claim 2, wherein in the eleventh step, the ammonia liquefied in the twelfth step is vaporized again and reused as ammonia supplied in the third step. A method for producing the modified plant biomass according to claim 1. A first container to which particulate plant biomass material is supplied;
A plant biomass material supply unit for supplying the plant biomass material to the first container;
A first air discharger for discharging air from the first container;
A first ammonia discharge part for discharging ammonia from the first container;
An ammonia supply section for supplying pressurized gaseous or liquid ammonia to the first container;
A second container for transferring the plant biomass raw material from the first container and bringing the plant biomass raw material into contact with a pressurized gas or liquid ammonia for reforming;
Heating means provided in the second container;
A third container in which the modified plant biomass is transferred from the second container;
A second air exhaust for exhausting air from the third container;
A second ammonia discharge part for discharging ammonia from the third container;
An apparatus for producing modified plant biomass, comprising: a plant biomass recovery unit that discharges and recovers the modified plant biomass from the third container. The plant biomass raw material supply unit
A plant biomass material storage section for storing the plant biomass material;
The modified plant according to claim 6, further comprising: a first pipe that connects the plant biomass raw material storage unit and the first container and in which a plurality of valves are arranged in series. Plant biomass production equipment.   8. The modified device according to claim 6, further comprising a second pipe that connects the second container and the third container and in which a plurality of valves are arranged in series. Production equipment for quality plant biomass.   9. The apparatus for producing modified plant biomass according to claim 7 or 8, wherein the plurality of valves includes at least one ball valve and at least one gate valve.   The said 2nd container is equipped with the stirring means to stir the said plant biomass raw material, The manufacturing apparatus of the modified plant biomass of any one of Claims 6-9 characterized by the above-mentioned.   The said 2nd container equips an inside with a screw conveyor, The manufacturing apparatus of the modified plant biomass of any one of Claims 6-10 characterized by the above-mentioned. An ammonia liquefying section for compressing and / or cooling and liquefying ammonia discharged as a gas from the first container and / or the third container;
The modified container according to any one of claims 6 to 11, further comprising a fourth container for separating and removing gas that is not liquefied by compression and / or cooling from liquid ammonia. Plant biomass production equipment.   The apparatus for producing modified plant biomass according to claim 12, further comprising ammonia heating means for vaporizing liquid ammonia transferred from the fourth container. A saccharification step of saccharifying the modified plant biomass produced by the production method according to any one of claims 1 to 5 with an enzyme,
A fermentation step of ethanol fermentation of the sugar solution obtained in the saccharification step;
A method for producing ethanol.

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