JP2015150528A - Saccharification pretreatment method of lignocellulose-based biomass and apparatus using for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pretreatment method of lignocellulose-based biomass and an apparatus for the same capable of quickly servicing an ammonia separation saccharification pretreated product to an enzymatic saccharifying reaction and suppressing the reduction of treatment efficiency.SOLUTION: A saccharification pretreatment method performing saccharification pretreatment using a reaction vessel 2 enzymatically saccharifying lignocellulose-based biomass comprises: a step discharging hot water from a jacket 14 to a hot water tank 16 after stopping the supply of the hot water to the jacket 14; and a step supplying substrate concentration adjusted water to the reaction vessel 2 after discharging the hot water from the jacket 14.

Description

  The present invention relates to a saccharification pretreatment method for lignocellulosic biomass used for bioethanol production and an apparatus used therefor.

  In recent years, it has been studied to use a gasoline-ethanol mixed fuel as a fuel for automobiles. For use in the gasoline-ethanol mixed fuel, a technique for producing ethanol using lignocellulosic biomass has been studied.

  The lignocellulosic biomass contains cellulose, and it can be decomposed into sugars such as glucose by subjecting the cellulose to a saccharification treatment using a saccharifying enzyme, and the resulting sugar can be fermented to obtain ethanol.

  However, the lignocellulosic biomass mainly contains hemicellulose and lignin in addition to cellulose, and usually the cellulose and the hemicellulose are firmly bound to the lignin. It is difficult to carry out the reaction. Therefore, when enzymatically saccharifying the cellulose, it is desirable that the lignocellulosic biomass is pretreated in advance so that the enzymatic saccharification reaction is possible.

  Conventionally, a saccharification pretreatment method for performing saccharification pretreatment using a reaction vessel for enzymatic saccharification treatment of the lignocellulosic biomass is known (for example, see Patent Document 1).

  In the pretreatment method, first, lignocellulosic biomass as a substrate is accommodated in a batch-type and sealable reaction vessel, and ammonia water is mixed to obtain a substrate mixture.

  Next, by heating the substrate mixture at a predetermined temperature for a predetermined time, an ammonia-containing saccharification pretreatment product that dissociates lignin from the substrate or swells the substrate is obtained.

  Thereafter, the ammonia-containing saccharification pretreatment product is cooled to an optimum temperature of the saccharification enzyme used for the enzyme saccharification reaction, and water (hereinafter referred to as substrate concentration-adjusted water) is supplied to the reaction vessel to perform the ammonia separation saccharification pretreatment Adjust the substrate concentration of the product.

  In addition, in this application, dissociation means cut | disconnecting at least one part coupling | bonding among the binding sites of lignin couple | bonded with cellulose etc. Swelling means that voids are formed in cellulose or the like constituting crystalline cellulose by the ingress of liquid, or the voids are generated inside the cellulose fibers to expand.

JP 2013-059716 A

  However, in the conventional pretreatment method, since it takes a long time for the temperature of the ammonia separation saccharification pretreatment product in the reaction vessel to decrease to the optimum temperature, the ammonia separation saccharification pretreatment product is quickly removed. There is an inconvenience that it cannot be used for the enzyme saccharification reaction.

  Therefore, it is conceivable that a large amount of substrate concentration adjusted water is supplied into the reaction vessel to lower the temperature of the ammonia separation saccharification pretreatment product. However, if the substrate concentration adjustment water is supplied in a large amount, the ammonia separation saccharification is performed. There is an inconvenience that the pretreatment product is excessively diluted and the processing efficiency is lowered.

  The present invention eliminates such inconveniences, and can quickly subject the ammonia-separated saccharification pretreatment product to an enzymatic saccharification reaction, and can suppress a decrease in the treatment efficiency, and a pretreatment method for lignocellulosic biomass and the same It aims at providing the apparatus to be used.

  In order to achieve such an object, the present invention is a saccharification pretreatment method in which pretreatment for saccharification is performed using a reaction vessel for enzymatic saccharification treatment of lignocellulosic biomass in a batch system, and the reaction vessel is a substrate. A step of containing lignocellulosic biomass and mixing ammonia water to obtain a substrate mixture, and a heating medium heated by heating means, and a jacket disposed outside the reaction vessel from the heating means by circulation means The substrate mixture is heated at a predetermined temperature for a predetermined time to obtain an ammonia-containing saccharification pretreatment product, and the heating medium heated by the heating unit is supplied to the heating means. The circulating means supplies the heating means to a jacket disposed outside the reaction vessel, circulates from the jacket to the heating means, and contains the ammonia. Separating ammonia from the pre-saccharification product to obtain ammonia-separated saccharification pre-treatment product, discharging the heat medium in the jacket to a heat medium storage tank, and discharging the heat medium from the jacket; And a step of supplying substrate concentration adjustment water to the reaction vessel.

  In the pretreatment method of the present invention, first, lignocellulosic biomass as a substrate is accommodated in a sealable reaction vessel, and ammonia water is mixed to obtain a substrate mixture.

  Next, the heating medium heated by the heating means is supplied to the jacket from the heating means to the jacket disposed outside the reaction vessel and circulated from the jacket to the heating means. To heat the substrate mixture. As a result, lignin can be dissociated from the substrate or the substrate can be swollen to obtain an ammonia-containing saccharification pretreatment product.

  Next, the heating medium heated by the heating unit is supplied from the heating unit to a jacket disposed outside the reaction vessel, and is supplied to the jacket through a circulation unit that circulates from the jacket to the heating unit. Thus, ammonia is separated from the ammonia-containing saccharification pretreatment product in the reaction vessel to obtain an ammonia separation saccharification pretreatment product.

  Next, the heat medium in the jacket is discharged into a heat medium storage tank. Here, in the pretreatment method of the present invention, since the heat medium storage tank is configured to be able to accommodate the heat medium in the jacket, the heat medium discharged from the jacket can be accommodated. . Thereby, the heat capacity (so-called heat mass) of the reaction vessel can be reduced as compared with the case where the heat medium stays in the jacket of the conventional pretreatment method.

  Next, the temperature of the ammonia separation saccharification pretreatment product is lowered by supplying substrate concentration adjusted water to the reaction vessel. At this time, since the heat capacity of the ammonia-separated saccharification pre-processed product is reduced as the heat medium is discharged from the jacket, the heat medium stays in the jacket of the conventional pre-treatment method. Sometimes, the supply amount of the substrate concentration adjustment water can be reduced as compared with the case where the substrate concentration adjustment water is supplied to the reaction vessel.

  Therefore, according to the pretreatment method of the present invention, as compared with the conventional pretreatment method, the ammonia-separated saccharification pretreatment product is cooled in a short time to the optimum temperature of the saccharification enzyme used for the enzyme saccharification reaction. The ammonia-separated saccharification pretreatment product can be subjected to the enzyme saccharification reaction in a short time. In addition, since the supply amount of the substrate concentration adjustment water can be reduced as compared with the conventional pretreatment method, it is possible to prevent the ammonia separation saccharification pretreatment product from being excessively diluted to lower the treatment efficiency. Can do.

  Further, the pretreatment apparatus of the present invention is a saccharification pretreatment apparatus for performing saccharification pretreatment using a reaction vessel for enzymatic saccharification treatment of lignocellulosic biomass, wherein the lignocellulosic biomass and ammonia water as a substrate are batch-wise. A sealable reaction vessel to obtain a substrate mixture, a jacket disposed outside the reaction vessel and through which a heat medium for heating the substrate mixture to a predetermined temperature is circulated, and the heat medium is heated A heating means; a circulation means for supplying the heat medium heated by the heating means to the jacket and circulating the heat medium from the jacket to the heating means; and a heat medium storage tank capable of storing the heat medium in the jacket A heat medium discharge means for discharging the heat medium from the jacket to the heat medium storage tank, and a substrate concentration adjustment water supply means for supplying substrate concentration adjustment water to the reaction vessel. And features. The pretreatment method of the present invention can be carried out by the pretreatment apparatus of the present invention.

  Further, in the pretreatment apparatus of the present invention, the heating means is a heat pump, and ammonia recovery means for cooling and condensing the ammonia gas and water vapor released to the outside of the reaction vessel and dissolving them in water and recovering them as ammonia water. The heat pump is configured to exchange heat with a heat medium for heating the heat medium having the heat of condensation when the ammonia gas and water vapor are condensed and the heat of dissolution when dissolved in the water as the heat source. It is preferable to heat the heating medium for heating.

  The ammonia recovery means can cool and condense the ammonia gas and water vapor released to the outside of the reaction vessel and dissolve them in water to obtain ammonia water. The ammonia water can be reused for mixing with the substrate. Can be used. Further, by using the heat pump as the heating means, the heat of condensation when the ammonia gas and water vapor are condensed and the heat of dissolution when the ammonia gas and water vapor are dissolved in the water are used for heating the heat medium for heating. The heat of dissolution can be cooled.

  Furthermore, in the pretreatment apparatus of the present invention, it is preferable that the heat medium storage tank is provided in the middle of a path that causes the circulation means to circulate from the jacket to the heating means. The heat medium in the heat medium storage tank is refluxed to the heating means through the circulation means, and the heat medium can be used in a pretreatment step to be performed next. As a result, the time required for the entire pretreatment can be shortened and the energy input to the pretreatment can be reduced.

  In the pretreatment apparatus of the present invention, it is preferable that the heat medium discharge unit includes a compressed air supply unit that supplies compressed air to the jacket. By forcibly discharging the heated heat medium staying in the jacket with the compressed air supplied to the jacket to the compressed air supply means, the discharge speed of the heat medium can be increased, and the time required for the entire process Can be further shortened.

The system block diagram which shows the apparatus structure which implements the pre-processing method of this embodiment. Explanatory drawing which shows schematically an example of the line of the binary system heat pump shown in FIG.

  Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

  In the present embodiment, as a pretreatment, a substrate mixture obtained by mixing a substrate and aqueous ammonia is heated to obtain an ammonia-containing saccharification pretreatment product, and then ammonia is removed from the ammonia-containing saccharification pretreatment product to separate ammonia saccharification. A pre-treatment product is obtained. Further, the substrate / saccharifying enzyme mixture obtained by adding a solution containing saccharifying enzyme to the ammonia separation saccharification pre-treated product is subjected to enzymatic saccharification treatment.

  The pretreatment method of this embodiment can be implemented using the pretreatment apparatus 1 shown in FIG.

  The pretreatment device 1 includes a reaction vessel 2, an ammonia water condenser 3, an ammonia water absorption tower 4, and an ammonia water tank 5.

  The reaction vessel 2 is provided with a substrate supply conduit 6, an ammonia water supply conduit 7, a saccharification enzyme solution supply conduit, an acid aqueous solution supply conduit, and an ion exchange water supply conduit (not shown) at the top, and ammonia gas. A first exhaust pipe 8 that discharges water vapor and guides it to the ammonia water condenser 3 is disposed via an exhaust valve 9 and a bag filter 10.

  The substrate supply conduit 6 supplies lignocellulosic biomass as a substrate, such as rice straw, to the reaction vessel 2, and the ammonia water supply conduit 7 supplies ammonia water to the reaction vessel 2 from an ammonia water tank (not shown). The saccharifying enzyme solution supply conduit supplies a solution containing saccharifying enzyme (hereinafter abbreviated as saccharifying enzyme solution) to the reaction vessel 2, and the acid aqueous solution supply conduit supplies an acid aqueous solution such as dilute sulfuric acid to the reaction vessel 2. To supply.

  In addition, the reaction vessel 2 includes a motor 11 disposed in the upper portion, a rotary shaft 12 hanging from the motor 11 into the reaction vessel 2, and a stirring blade 12 a extending from the rotary shaft 12 in the horizontal direction. .

  Further, a pressure sensor 13 for detecting pressure is provided inside the reaction vessel 2.

  A jacket 14 through which a heat medium is circulated is disposed outside the reaction vessel 2, and a hot water conduit 15 is connected to the jacket 14.

  The hot water conduit 15 supplies hot water derived from the upper part of the jacket 14 as a heating heat medium through a hot water tank 16, a hot water pump 17, an air cooling fan 18, a two-way heat pump 19, a check valve 20, and an on-off valve 21. The bottom of the jacket 14 is circulated.

  The hot water conduit 15 includes a hot water bypass conduit 22 that branches from between the check valve 20 and the on-off valve 21. The hot water bypass conduit 22 is connected to the hot water tank 16 via the on-off valve 23. A flow meter 24 is provided downstream of the on-off valve 23 of the hot water bypass conduit 22.

  The hot water conduit 15 includes an opening / closing valve 25 at a position near the upper portion of the reaction vessel 2 between the reaction vessel 2 and the hot water tank 16, and an air supply conduit 26 is connected to the upstream side of the opening / closing valve 25. The other end of the air supply conduit 26 is connected to a high pressure gas tank 27 that supplies compressed air, and includes a regulator 28 and an air supply valve 29 on the downstream side of the high pressure gas tank 27. The air supply conduit 26, the high-pressure gas tank 27, the regulator 28, and the air supply valve 29 constitute compressed air supply means.

  The hot water tank 16 has an internal volume larger than the internal volume of the jacket 14. The warm water tank 16 is provided with a first makeup water conduit 16a, and the first makeup water conduit 16a is connected to the first makeup water tank 16c via a first water supply valve 16b.

  The ammonia water condenser 3 cools at least a part of the ammonia gas and water vapor introduced from the first exhaust pipe 8 to condense the ammonia gas and water vapor into ammonia water. Is provided with a first drainage conduit 30. The first drainage conduit 30 is connected to the ammonia water tank 5 via a condensed water tank 31 and a first drainage pump 32 for further cooling the condensed ammonia water.

  Further, the ammonia water condenser 3 includes a second exhaust conduit 33 that discharges ammonia gas and water vapor that have not been condensed and guides them to the ammonia water tank 5. The second exhaust conduit 33 is connected via an on-off valve 34. The ammonia water tank 5 is connected. The second exhaust conduit 33 branches from the third exhaust conduit 35 upstream of the on-off valve 34, and the third exhaust conduit 35 includes a vacuum pump 36 on the way and joins the second exhaust conduit 33 downstream of the on-off valve 34. doing.

  The ammonia water absorption tower 4 communicates with the top surface of the ammonia water tank 5 at the bottom, and absorbs (dissolves) ammonia gas and water vapor guided to the ammonia water tank 5 by the second exhaust conduit 33 in the ammonia water. For this reason, the ammonia water absorption tower 4 is provided with a showering device 39 for showering the ammonia water supplied from the ammonia water tank 5 via the ammonia water circulation conduit 38 at the top.

  The ammonia water circulation conduit 38 is connected from the ammonia water tank 5 to the showering device 39 via the circulation pump 40, the ammonia water heat exchanger 41, and the ammonia water concentration sensor 42. The ammonia water heat exchanger 41 has a function of cooling the ammonia water circulated through the ammonia water circulation conduit 38. The ammonia water absorption tower 4 is provided with a second makeup water conduit 43, and the second makeup water conduit 43 is connected to a second makeup water tank 45 via a second water supply valve 44.

  The ammonia water tank 5 includes a second drainage conduit 46 that discharges ammonia water, and the second drainage conduit 46 is connected to an ammonia water tank (not shown) via a second drainage pump 47. Note that an ammonia water supply conduit 7 for supplying ammonia water to the reaction vessel 2 is connected to the ammonia water tank.

  The ammonia water condenser 3 is connected to a low temperature water conduit 48 for cooling ammonia gas and water vapor introduced from the first exhaust conduit 8. The low-temperature water conduit 48 is a low-temperature water primary tank 49, a low-temperature water primary pump 50, a two-way heat pump 19, a first switching valve 51, ammonia, The ammonia water condenser 3 is circulated through the water heat exchanger 41 and the condensed water tank 31.

  A low temperature water bypass conduit 52 is connected to the first switching valve 51, and the other end of the low temperature water bypass conduit 52 is connected to the low temperature water primary tank 49 via the second switching valve 53. A cold water conduit 55 is connected to the second switching valve 53, and the other end of the cold water conduit 55 is connected to the low temperature water secondary tank 56. The first switching valve 51 and the second switching valve 53 can switch the flow path of the low-temperature water.

  The low temperature water secondary tank 56 is provided with a cold water supply conduit 57, and the cold water supply conduit 57 is connected to the low temperature water conduit 48 downstream of the first switching valve 51 via the low temperature water secondary pump 58. Yes. The low temperature water primary tank 49 is provided with a third make-up water conduit 59, and the third make-up water conduit 59 is connected to the third make-up water tank 61 through the third water supply valve 60.

  Next, the operation of the pretreatment device 1 of this embodiment will be described.

  In the pretreatment apparatus 1, first, the saccharification product obtained in the previous treatment is discharged from a discharge port (not shown) at the bottom of the reaction vessel 2 and transferred to the next step.

  Next, after the lignocellulosic biomass, for example, rice straw, as a new substrate starts to be supplied from the substrate supply conduit 6 to the reaction vessel 2, the operation of the binary heat pump 19 is started. Further, hot water as a heating heat medium is supplied from the hot water conduit 15 to the jacket 14, and circulation is started between the jacket 14 and the binary heat pump 19, and the temperature of the warm water itself and the jacket 14 as the heat medium is increased. To do. At this time, since the hot water collected in the previous step of obtaining the pretreatment product for ammonia separation and stored in the hot water tank 16 is used, the heating time can be shortened as compared with the case of supplying water to the jacket 14. it can.

  Next, after ammonia water is supplied to the reaction vessel 2 from the ammonia water supply conduit 7, the rotary shaft 12 is driven to rotate by the motor 11, and the rice straw and ammonia water are stirred and mixed by the stirring blade 12a. Thus, a substrate mixture is prepared.

  In the present embodiment, the operation corresponds to a step of obtaining a substrate mixture.

  The substrate mixture is heated to a predetermined temperature, for example, in the range of 80 to 85 ° C., in the reaction vessel 2 by the hot water supplied from the hot water conduit 15 to the jacket 14. The stirring by the stirring blade 12a is continued until the substrate mixture reaches the predetermined temperature.

  Next, after the temperature of the substrate mixture is raised to the predetermined temperature, the stirring and hot water pump 17 and the binary heat pump 19 are stopped, heating is terminated, and the substrate mixture is heated to the predetermined temperature at a predetermined temperature. Hold for a time, for example 1-6 hours. As a result, it is possible to obtain an ammonia-containing saccharification pretreatment product in which lignin is dissociated from the substrate or the substrate is swollen so that rice straw as the substrate can be enzymatically saccharified. In this embodiment, the said operation | movement corresponds to the process of obtaining an ammonia containing saccharification pre-processing thing.

  Next, in the pretreatment device 1, in order to start the step of obtaining the ammonia separation saccharification pretreatment product, the operation of the binary heat pump 19 is restarted and the circulation with the jacket of the heat medium is further started. By opening the exhaust valve 9, the ammonia water contained in the ammonia-containing saccharification pretreatment product is diffused as ammonia gas and water vapor, and is guided from the first exhaust pipe 8 to the ammonia water condenser 3 through the bag filter 10. To do. At this time, the pressure in the reaction vessel 2 is higher than the atmospheric pressure due to the heating, and by opening the exhaust valve 9, ammonia gas and water vapor can be easily released from the ammonia-containing saccharification pretreatment product. it can.

  The ammonia gas and water vapor are cooled by low-temperature water supplied from the low-temperature water conduit 48 to the ammonia water condenser 3 as a cooling heat medium, and a part of the ammonia gas and water vapor is condensed and liquefied to become ammonia water. It is discharged to the condensed water tank 31 through 30. The ammonia water is further cooled by the low temperature water supplied from the low temperature water conduit 48 in the condensed water tank 31, and then sent to the ammonia water tank 5 via the first drain pump 32.

  The remaining ammonia gas and water vapor are introduced into the ammonia water tank 5 through the second exhaust conduit 33 by opening the on-off valve 34. The pressure of the ammonia gas and water vapor decreases as it is diffused, and when it becomes equal to the atmospheric pressure, it becomes difficult to dissipate further.

  Therefore, when the pressures of the ammonia gas and water vapor become equal to the atmospheric pressure, the on-off valve 34 is closed and the vacuum pump 36 is operated to suck the ammonia gas and water vapor in the reaction vessel 2 and 2 is introduced into the ammonia water tank 5 through the exhaust pipe 33 and the third exhaust pipe 35.

  The ammonia gas and water vapor introduced into the ammonia water tank 5 are then introduced into the ammonia water absorption tower 4 communicating with the ammonia water tank 5. In the ammonia water absorption tower 4, the ammonia gas circulated by the circulation pump 40 through the ammonia water circulation conduit 38 is showered by the showering device 39, thereby absorbing (dissolving) the ammonia gas and water vapor in the ammonia water and Condense.

  In the present embodiment, the condensation of the ammonia gas and water vapor in the ammonia water condenser 3 and the absorption in the ammonia water absorption tower 4 correspond to a process of recovering the diffused ammonia gas and water vapor as ammonia water.

  At this time, the heat and latent heat generated when the ammonia water and water vapor are absorbed (dissolved) and condensed in the ammonia water by the ammonia water heat exchanger 41 provided in the middle of the ammonia water circulation conduit 38 are converted into the low temperature water conduit. The ammonia water is cooled while being recovered by the low-temperature water flowing through 48.

  The ammonia water stored in the ammonia water tank 5 is, for example, in the range of 15 to 20 ° C. as a result of condensation and cooling in the ammonia water condenser 3 and the condensed water tank 31 and dissolution in the ammonia water in the ammonia water absorption tower 4. Is cooled to a temperature of The ammonia water cooled to the temperature in the above range is taken out by the second drainage pump 47 through the second drainage conduit 46 and reused for the preparation of the substrate mixture in the reaction vessel 2.

  In the reaction vessel 2, the ammonia-separated saccharification pretreatment product from which ammonia has been separated can be obtained as a result of the ammonia water being diffused from the ammonia-containing saccharification pretreatment product as described above.

  Next, the acid aqueous solution is supplied to the reaction vessel 2 via the acid aqueous solution supply conduit and stirred, and the saccharification enzyme solution is supplied and stirred via the saccharification enzyme solution supply conduit. As a result, a substrate / saccharifying enzyme mixture in which the ammonia separation saccharification pretreatment product and the saccharifying enzyme solution are mixed can be obtained.

  Next, by performing an enzymatic saccharification treatment in the reaction vessel 2, at least a part of the substrate / saccharifying enzyme mixture is saccharified, and the resulting saccharification treatment product is discharged from the bottom of the reaction vessel 2 as described above. It is discharged from (not shown) and transferred to the next process. Then, the next process is prepared in the reaction vessel 2.

  Next, the heating of the substrate mixture for obtaining the ammonia-containing saccharification pretreatment product in the reaction vessel 2 will be described in more detail.

  First, the heating of the substrate in the reaction vessel 2 will be described. After the substrate starts to be supplied to the reaction vessel 2 through the substrate supply conduit 6, hot water is supplied to the jacket 14 of the reaction vessel 2 through the hot water conduit 15. As a result, heating of the heat medium (warm water) itself and the jacket 14 is started. Thereafter, ammonia water is supplied through the ammonia water supply conduit 7, and the substrate and the ammonia water are stirred and mixed by the stirring blade 12a to prepare a substrate mixture.

  In the pretreatment method of the present embodiment, heating of the heating medium and the jacket 14 is started before the substrate mixture is prepared, and an ammonia separation pretreatment product is obtained in the hot water tank 16 during the previous pretreatment. Since the hot water recovered during the process can be used, the time required for the substrate mixture to rise to the predetermined temperature can be shortened. In addition, stirring is performed by the stirring blade 12a until the temperature of the substrate mixture is raised to the predetermined temperature, but the stirring time can be shortened and energy required for stirring can be reduced.

  Next, the circulation route of the low temperature water stored in the low temperature water primary tank 49 is shown. When obtaining the ammonia-containing pre-saccharification product, the first switching valve 51 is operated to switch the low-temperature water conduit 48 and the low-temperature water bypass conduit 52 to be connected.

  In this way, the low-temperature water stored in the low-temperature water primary tank 49 passes through the low-temperature water primary pump 50, and the low-temperature water primary pump 50, It is circulated through a path returning to the low-temperature water primary tank 49 through the original heat pump 19, the first switching valve 51, and the second switching valve 53.

  At this time, the low-temperature water circulated through the low-temperature water conduit 48 exchanges heat with the carbon dioxide in the first heat exchanger 74 of the binary heat pump 19 as described above, so that the ammonia water condenser 3 The target is cooled to a temperature at which ammonia gas can be condensed, for example, a temperature in the range of 10 to 15 ° C. However, since it is higher than the temperature at the time of start-up, it is circulated through a path returning to the low-temperature water primary tank 49.

  Next, when the temperature of the low-temperature water detected by the temperature sensor 54 is cooled to a target temperature in the range of 10 to 15 ° C., the second switching valve 53 is connected to the low-temperature water bypass conduit 52 and the cold water conduit 55. Can be switched to connect. As a result, low-temperature water having a temperature in the range of 10 to 15 ° C. or lower (hereinafter referred to as cold water) is stored in the low-temperature water secondary tank 56 and used in the step of obtaining the ammonia separation saccharification pretreatment product.

  Next, the binary heat pump 19 will be described in detail. The two-way heat pump 19 is a heat pump using two types of heat medium, and includes two types of heat medium circulation systems of a first circulation conduit 71 and a second circulation conduit 72 as shown in FIG. ing. As the two types of heat medium, for example, carbon dioxide is circulated through the first circulation conduit 71 and trifluoroethanol is circulated through the second circulation conduit 72.

  The first circulation conduit 71 is circulated to the expansion valve 73 and the first heat exchanger 74 that exchanges heat with the low-temperature water circulated to the low-temperature water conduit 48, the compressor 75, and the second circulation conduit 72. A second heat exchanger 76 that exchanges heat with fluoroethanol is provided. The second circulation conduit 72 is circulated to the expansion valve 77, the second heat exchanger 76 that exchanges heat with the carbon dioxide circulated to the first circulation conduit 71, the compressor 78, and the hot water conduit 15. A third heat exchanger 79 for exchanging heat with warm water is provided.

  The low-temperature water is heated to a temperature at which ammonia gas and water vapor can be condensed in the ammonia water condenser 3 by exchanging heat with carbon dioxide in the first heat exchanger 74 of the binary heat pump 19, for example, 10 to 15 ° C. To be cooled. The carbon dioxide is heated by exchanging heat with the low-temperature water in the first heat exchanger 74 of the binary heat pump 19.

  In the binary heat pump 19, the trifluoroethanol circulated through the second circulation conduit 72 exchanges heat with the carbon dioxide supplied through the first circulation conduit 71 in the second heat exchanger 76. Heated. The trifluoroethanol is cooled by exchanging heat with hot water supplied by the hot water conduit 15 in the third heat exchanger 79. As a result, the hot water supplied to the third heat exchanger 79 through the hot water conduit 15 is heated to a temperature at which the substrate mixture can be heated in the reaction vessel 2.

  Next, cooling and condensation of ammonia gas and water vapor by the ammonia water condenser 3 will be described in more detail.

  In the pretreatment device 1, first, in the normal time except for the initial stage of obtaining the ammonia separation pretreatment product, the first switching valve 51 connects the upstream and downstream of the low temperature water conduit 48, and the low temperature water primary pump 50. Is activated.

  As a result, the low-temperature water stored in the low-temperature water primary tank 49 is taken out by the low-temperature water conduit 48, and the low-temperature water primary pump 50, the two-way heat pump 19, the first switching valve 51, the ammonia water heat exchanger. 41, the condensed water tank 31, and the ammonia water condenser 3, and then circulated through a path returning to the low temperature water primary tank 49.

  At this time, the low-temperature water is cooled by exchanging heat with the hot water as the heating heat medium via the binary heat pump 19. The low-temperature water is heat-exchanged with ammonia water by the ammonia water heat exchanger 41 and the condensed water tank 31 to cool the ammonia water, and heat-exchanged with ammonia gas and water vapor by the ammonia water condenser 3. Cool ammonia gas and water vapor. On the other hand, the low-temperature water itself is heated by the ammonia water, the ammonia gas, and water vapor.

  Next, the initial stage of the process for obtaining the ammonia separation pretreatment product will be described. When the exhaust valve 9 is opened and ammonia gas and water vapor diffused from the ammonia-containing saccharification pretreatment product in the reaction vessel 2 are introduced into the ammonia water condenser 3, the second switching valve 53 The low temperature water secondary pump 58 is operated in a state where the low temperature water bypass conduit 52 and the cold water conduit 55 are connected. In this way, the cold water stored in the low temperature water secondary tank 56 is condensed with the ammonia water via the cold water supply conduit 57 and the low temperature water conduit 48, via the ammonia water heat exchanger 41 and the condensed water tank 31. Is supplied to the vessel 3.

  Since the pretreatment method of the present embodiment is a batch (batch) type, when ammonia gas and water vapor are condensed in the ammonia water condenser 3, a high concentration is obtained from the ammonia-containing saccharification pretreatment product in the initial stage of the emission. A large amount of ammonia gas and a small amount of water vapor are diffused, and a high concentration ammonia gas and a small amount of water vapor are introduced into the ammonia water condenser 3. For this reason, in the initial stage, large cooling heat energy is required to cool the high concentration ammonia gas and a small amount of water vapor. Therefore, as described above, by supplying the cold water stored in the low temperature water secondary tank 56 to the ammonia water condenser 3, the high concentration ammonia gas and a small amount of water vapor are efficiently cooled, Can be fully condensed.

  Thereafter, if it is detected by a water level sensor (not shown) that the water level of the cold water stored in the low temperature water secondary tank 56 has reached the lower limit, the first switching valve 51 is moved to the low temperature water as described above. It is switched to connect the upstream and downstream of the conduit 48.

  Then, the low-temperature water derived from the ammonia water condenser 3 is transferred to the low-temperature water primary tank 49, the low-temperature water primary pump 50, the two-way heat pump 19, the first switching valve 51, the ammonia water heat exchange by the low-temperature water conduit 48. Transition to the normal cooling state circulated to the ammonia water condenser 3 via the condenser 41 and the condensed water tank 31. At this time, since the concentration and amount of the ammonia gas diffused have already been reduced, the ammonia gas and water vapor can be sufficiently cooled and condensed by the low-temperature water in the normal cooling state.

  Furthermore, in the pretreatment method of the present embodiment, after the step of obtaining the ammonia separation saccharification pretreatment product, the heat capacity around the jacket 14 including the ammonia separation saccharification pretreatment product is reduced as follows.

  First, the on-off valve 25 is closed, the on-off valve 21 and the on-off valve 23 are opened, and then the air supply valve 29 is opened. As a result, compressed air is introduced from the high-pressure gas tank 27 to the jacket 14 via the air supply conduit 26, and the hot water staying in the jacket 14 is discharged from the bottom of the jacket 14 to the hot water conduit 15 by the compressed air.

  The warm water discharged to the warm water conduit 15 is accommodated in the warm water bypass conduit 22 via the on-off valve 23 and then stored in the warm water tank 16 via the flow meter 24. After confirming the completion of discharge of the hot water from the jacket 14 based on the total amount of flow detected by the flow meter 24, the on-off valve 21 is closed.

  As a result, the heat capacity of the jacket 14 from which the warm water has been discharged is reduced as compared with the conventional pretreatment method in which the warm water is retained. Thereby, the temperature of the said ammonia separation saccharification pre-processing thing accommodated in the reaction container 2 can be lowered | hung with a smaller amount of substrate concentration adjustment water.

  Next, the acid aqueous solution and the saccharifying enzyme solution are supplied to the reaction vessel 2 and substrate concentration adjusted water as cooling water is supplied through the ion exchange water supply conduit. Thereby, the temperature of the ammonia separation saccharification pretreatment product can be lowered and adjusted. At this time, since the heat capacity of the ammonia-separated saccharification pre-treatment product decreases as the hot water is discharged from the jacket 14, the hot water is retained in the jacket 14 of the conventional pre-treatment method. Compared with the case where the substrate concentration adjustment water is supplied to the reaction vessel 2, the supply amount can be reduced, and the degree of freedom of adjustment is improved.

  Therefore, according to the pretreatment method of the present embodiment, the temperature of the ammonia separation saccharification pretreatment product can be lowered in a short time to the optimum temperature of the saccharification enzyme used for the enzyme saccharification reaction. The treated product can be subjected to the enzyme saccharification reaction in a short time. In addition, since the supply amount of the substrate concentration adjustment water can be reduced as compared with the conventional pretreatment method, it is possible to prevent the ammonia separation saccharification pretreatment product from being excessively diluted to lower the treatment efficiency. Can do.

  Further, in the pretreatment method of the present embodiment, since the hot water tank 16 is provided, the heat medium stored and heated in the hot water tank 16 is used in the step of obtaining the next ammonia-containing saccharification pretreatment product. As a result, it is possible to reduce the time required for the entire pretreatment and reduce the input energy.

  DESCRIPTION OF SYMBOLS 1 ... Pretreatment apparatus, 2 ... Reaction container, 3, 4 ... Ammonia collection | recovery means, 14 ... Jacket, 15 ... Circulation means, 16 ... Heat-medium storage tank, 19 ... Heating means, heat pump.

Claims (5)

A saccharification pretreatment method for performing saccharification pretreatment using a reaction vessel for enzymatic saccharification treatment of lignocellulosic biomass in a batch system,
A step of containing lignocellulosic biomass as a substrate in the reaction vessel and mixing ammonia water to obtain a substrate mixture;
The heating medium heated by the heating means is supplied from the heating means to the jacket disposed outside the reaction vessel by the circulation means and circulated from the jacket to the heating means, and the substrate mixture is predetermined at a predetermined temperature. A step of obtaining an ammonia-containing pre-saccharified product by heating for a period of time;
The heating medium heated by the heating means is supplied from the heating means to a jacket disposed outside the reaction vessel by the circulation means, and is circulated from the jacket to the heating means, whereby the ammonia-containing saccharification pretreatment A step of separating ammonia from the product to obtain a pre-treated ammonia separation saccharification product,
Discharging the heat medium in the jacket to a heat medium storage tank;
And a step of supplying substrate concentration-adjusted water to the reaction container after discharging the heat medium from the jacket. A method for pre-saccharification of lignocellulosic biomass, A saccharification pretreatment apparatus for performing saccharification pretreatment using a reaction vessel for enzymatic saccharification treatment of lignocellulosic biomass,
A sealable reaction vessel that mixes lignocellulosic biomass and aqueous ammonia as a substrate in a batch system to obtain a substrate mixture;
A jacket disposed outside the reaction vessel and through which a heat medium for heating the substrate mixture to a predetermined temperature is circulated;
Heating means for heating the heat medium;
A circulation means for supplying the heating medium heated by the heating means to the jacket and circulating it from the jacket to the heating means;
A heat medium storage tank capable of accommodating the heat medium in the jacket;
A heat medium discharging means for discharging the heat medium from the jacket to the heat medium storage tank;
An apparatus for pre-saccharification of lignocellulosic biomass, comprising: substrate concentration adjusted water supply means for supplying substrate concentration adjusted water to the reaction vessel. In the lignocellulosic biomass saccharification pretreatment device according to claim 2,
The heating means is a heat pump;
Comprising ammonia recovery means for cooling and condensing ammonia gas and water vapor released to the outside of the reaction vessel and dissolving them in water and recovering them as ammonia water;
The heat pump heat-exchanges a heat medium having a heat source of condensation heat when condensing the ammonia gas and water vapor and heat of dissolution when dissolved in the water with the heat medium for heating. An apparatus for pre-saccharification of lignocellulosic biomass characterized by heating a heat medium. In the biomass pretreatment device according to claim 2 or claim 3,
The pretreatment for saccharification of lignocellulosic biomass, wherein the heat medium storage tank is provided in the middle of a path for circulation from the jacket to the heating means by the circulation means. In the lignocellulosic biomass saccharification pretreatment device according to any one of claims 2 to 4,
The pretreatment for saccharification of lignocellulosic biomass, wherein the heat medium discharge means includes compressed air supply means for supplying compressed air to the jacket.

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