JP2015142594A - Saccharification method and saccharification apparatus for cellulose-solubilized liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a saccharification method of cellulose-solubilized liquid, which enables saccharified liquid to be produced without using an acid catalyst when obtaining saccharified liquid from a cellulose-based biomass raw material, and which includes a small number of steps and can achieve reduction in production costs, and to provide a saccharification apparatus for cellulose-solubilized liquid.SOLUTION: The saccharification method of cellulose-solubilized liquid is provided which comprises: a first step of flowing cellulose-solubilized liquid obtained by converting a cellulose-containing biomass raw material, into a first inhibitor removal unit filled with a cation exchange substance; a second step of flowing effluent from the first inhibitor removal unit into a saccharification unit thereby converting the effluent to saccharified liquid; and a third step of flowing the saccharified liquid discharged from the saccharification unit into a second inhibitor removal unit filled with a cation exchange substance thereby obtaining saccharified liquid. After completion of the first to third steps, the cellulose-solubilized liquid is flowed in a direction reverse to the first to third steps, i.e., flowing the liquid from the second inhibitor removal unit to the first inhibitor removal unit via the saccharification unit to obtain the saccharified liquid.

Description

  The present invention relates to a saccharification method for a cellulose-based biomass raw material, which converts a biomass raw material containing cellulose into a saccharified solution under conditions where no catalyst is present.

  In recent years, biofuel has attracted attention as an alternative fuel for petroleum, and production of bioethanol using biomass such as sugarcane and corn has been put into practical use. However, when food is used as a raw material for bioethanol, there is a problem that the price fluctuates greatly due to competition with the food. For this reason, production of biofuels using cellulosic biomass, which is a non-food product such as wood, grass, and rice straw, as a raw material is desired.

However, it is not easy to hydrolyze a cellulosic biomass raw material into a saccharified solution. For this reason, a technique for saccharifying cellulose using a liquid strong acid such as sulfuric acid or a solid acid catalyst (for example, Non-Patent Document 1) has been known for a long time.
Moreover, after solubilizing a cellulosic biomass raw material by hydrothermal treatment (for example, Patent Document 1), saccharification treatment is also performed using a solid acid catalyst.

JP 2010-166831 A

M. Hara, et.al Nature, 438, (2005)

However, when using a liquid strong acid such as sulfuric acid, a large amount of alkali must be used as a post-treatment to neutralize the strong acid, and a large amount of gypsum is generated as waste. There's a problem.
On the other hand, when a solid acid catalyst is used, the solid acid catalyst can be recovered and reused after use. However, in order to recover and reuse the catalyst, a solid-liquid separation process is required, which increases the number of manufacturing processes and, consequently, increases the manufacturing cost.

  The present invention has been made in view of the above-described conventional situation, and in the case of obtaining a saccharified solution from a cellulosic biomass raw material, it is possible to produce a saccharified solution without using a liquid or solid acid catalyst. It is an object of the present invention to provide a saccharification method for a cellulose-based biomass raw material with a small number of steps and capable of reducing production costs.

  According to a first aspect of the present invention, there is provided a solubilization step of converting a biomass raw material containing cellulose into a solubilized mixture while controlling the temperature, pressure and moisture ratio and controlling the amount of organic acid generated, And a saccharification step of hydrolyzing the solubilized mixture to obtain a saccharified solution, wherein the pH of the solubilized mixture is controlled by controlling the temperature, pressure and water ratio, or It is a saccharification method of a cellulosic biomass raw material characterized in that the pH is controlled by the amount of water added to the solubilized mixture, followed by hydrolysis.

  In the solubilization step, by controlling the temperature, pressure, and water ratio, the biomass raw material containing cellulose becomes a water-soluble mixture, and organic acids such as lactic acid and acetic acid are by-produced. The organic acid generated in the solubilization step serves as an acid catalyst for the saccharification reaction by hydrolysis of cellulose in the saccharification step, and the cellulose is hydrolyzed to become a saccharified solution. Here, the pH of the solubilized mixture is controlled by controlling the temperature, pressure and moisture ratio, or the pH of the solubilized mixture is controlled by the amount of water added to the solubilized mixture. A suitable pH can be obtained. For this reason, in the saccharification method of the cellulose-based biomass raw material of the present invention, the saccharification step is performed only by using the organic acid procured from the biomass raw material as an acid catalyst without adding a liquid or solid acid catalyst from the outside. The manufacturing cost can be reduced. Further, unlike the method of adding a solid acid catalyst, it is not necessary to recover the solid acid catalyst, and the number of steps can be reduced.

  In the saccharification step in the present invention, if the pH is too high, the progress of hydrolysis of cellulose is delayed, and the reaction time to the solubilized saccharide solution is prolonged. On the other hand, if the pH is too low, a large amount of hyperdegradable products such as hydroxymethylfurfural (HMF) are generated, and the yield of monosaccharides may be deteriorated. For this reason, it is preferable to control the pH in the saccharification step to be in an optimal range. Therefore, in the second aspect of the present invention, the saccharified solution has a pH of 1 or more and less than 3.5. More preferably, it is 1.5 or more and less than 3.

  In the saccharification method of the present invention, an alkaline component such as calcium carbonate may be contained in a biomass raw material containing cellulose (for example, when calcium carbonate is contained as a filler in waste paper). The generated organic acid is neutralized by these alkali components, and the organic acid may not be able to exhibit the effect as an acid catalyst. In such a case, if the metal ion in the alkali component is converted to hydrogen ion by the cation exchange material and the pH is lowered, the organic acid is regenerated and can be used as an acid catalyst. Therefore, in the third aspect of the present invention, the saccharification step includes a solid-liquid separation step for solid-liquid separation of the solubilized mixture containing the organic acid, and removal of metal ions in the aqueous solution obtained by the solid-liquid separation. And a heating step of heating the aqueous solution from which the metal ions have been removed to obtain a saccharified solution.

As a method for this,
The saccharification step includes a first step of causing the aqueous solution obtained by the solid-liquid separation to flow into a first inhibitor removal unit filled with a cation exchange material;
A second step of heat-treating the effluent from the first inhibitor removal unit into a saccharification unit that is used as a saccharification solution to obtain a saccharification solution;
A third step of obtaining a saccharified solution by causing the saccharified solution flowing out of the saccharification unit to flow into a second inhibitor removing unit filled with a cation exchange material,
After completion of the first to third steps, the aqueous solution obtained by the solid-liquid separation is converted from the second inhibitor removal unit to the first inhibitor removal unit through the saccharification unit in the opposite direction to the first to third steps. A saccharified solution can be obtained by flowing.

  In this saccharification method, in the first step, after the metal ions contained in the aqueous solution obtained by solid-liquid separation are replaced with hydrogen ions by the cation exchange material filled in the first inhibitor removal unit, In the process, a saccharification reaction is performed in the saccharification unit. For this reason, a hydrogen ion flows into a saccharification unit instead of a metal ion, and it can prevent the catalyst activity fall by the raise of pH. For this reason, the saccharification reaction in a 2nd process is performed rapidly. Furthermore, in a 3rd process, after flowing into a 2nd inhibitor removal unit, it collect | recovers as a saccharified liquid.

  Thus, after the completion of the first to third steps, the aqueous solution obtained by solid-liquid separation is flowed from the second inhibitor removal unit through the saccharification unit to the first inhibitor removal unit in the opposite direction to the first to third steps. Thus, after the metal ions contained in the aqueous solution obtained by solid-liquid separation in the second inhibitor removal unit are captured by substitution with hydrogen ions, the aqueous solution from which the metal ions have been removed flows into the saccharification unit. The saccharification reaction proceeds rapidly to become a saccharified solution. Then, the saccharified solution that has flowed out of the saccharification unit flows into the first inhibitor removal unit, and the metal ions captured by the cation exchange material are replaced with hydrogen ions in the saccharification solution, so that the cation exchange material is returned again. It is regenerated so that it can capture cations. And the saccharified liquid which flowed out from the 1st inhibitor removal unit is collect | recovered.

  By repeating the above steps, the saccharification reaction can be carried out rapidly and continuously while repeating the capture and regeneration of metal ions by the cation exchange material in the inhibitor removal unit. Therefore, according to this saccharification method, it is possible to prevent a decrease in catalytic activity due to an alkali component containing a metal ion in an aqueous solution containing an organic acid, and the operating cost is reduced.

  The cation exchange material can be a cation exchange resin. Examples of such a cation exchange material include cation exchange resins such as Nafion (registered trademark).

The above saccharification method can be implemented by the following saccharification apparatus.
That is, the saccharification apparatus of the present invention is
A saccharification unit that heat-treats an aqueous solution obtained by solid-liquid separation into a saccharification solution, and first and second inhibitor removal units filled with a cation exchange substance,
A first flow path for flowing the aqueous solution from the first inhibitor removal unit via the saccharification unit to the second inhibitor removal unit;
A second flow path for flowing the aqueous solution from the second inhibitor removal unit via the saccharification unit to the first inhibitor removal unit;
Switching means for enabling switching between the first flow path and the second flow path is provided.

  In this saccharification device, a pH sensor and / or an electrical conductivity sensor is provided in the middle of the first flow path, upstream and midway and / or downstream of the first inhibitor removal unit, A pH sensor and / or an electrical conductivity sensor are provided in the middle of the second flow path, upstream and in the middle and / or downstream of the second inhibitor removal unit. Or it can be set as the apparatus provided with the control part which controls a switching means according to the output of each electrical conductivity sensor.

If it is like this, the metal ion adsorption amount of an obstruction removal unit can be grasped | ascertained by the output value of a pH sensor and / or an electrical conductivity sensor. That is, the adsorption of metal ions is performed by substitution with hydrogen ions present in the cation exchange material, and while the cation exchange capacity is maintained, the pH and electrical conductivity change due to the release of hydrogen ions. If the pH and electrical conductivity from the influent to the effluent are measured, the cation exchange saturation can be measured. Therefore, by controlling the switching unit by the control unit based on the output values of the pH sensor and / or the electrical conductivity sensor, it is possible to appropriately control the switching unit.
A fourth aspect of the present invention is a first step of causing a cellulose solubilized liquid obtained by converting a biomass raw material containing cellulose to flow into a first inhibitor removal unit filled with a cation exchange material; ,
A second step of flowing the effluent from the first inhibitor removal unit into the saccharification unit to obtain a saccharification solution;
A third step of obtaining a saccharified solution by causing the saccharified solution flowing out of the saccharification unit to flow into a second inhibitor removing unit filled with a cation exchange material,
After the completion of the first to third steps, the cellulose lysate is flowed from the second inhibitor removal unit through the saccharification unit to the first inhibitor removal unit in the opposite direction to the first to third steps. A method for saccharifying a cellulose-solubilized solution characterized in that
A fifth aspect of the present invention is a saccharification apparatus for cellulose solubilized liquid that obtains a saccharified liquid from a solubilized liquid obtained by converting a biomass raw material containing cellulose.
A saccharification unit and first and second inhibitor removal units filled with a cation exchange material,
A first flow path for flowing the lysate from the first inhibitor removal unit into the second inhibitor removal unit via the saccharification unit;
A second flow path for flowing the lysate from the second inhibitor removal unit via the saccharification unit to the first inhibitor removal unit;
A saccharification apparatus for a cellulose solubilizing liquid, comprising: a switching unit capable of switching between the first channel and the second channel.
In the saccharification apparatus for cellulose solubilized liquid defined in the fifth aspect, a pH sensor is provided in the middle of the first flow path, upstream, midway and / or downstream of the first inhibitor removal unit. And / or an electrical conductivity sensor is provided,
A pH sensor and / or an electrical conductivity sensor is provided in the middle of the second flow path, upstream and midway and / or downstream of the second inhibitor removal unit,
A control unit is provided for controlling the switching means in accordance with the output of each pH sensor and / or each electrical conductivity sensor.

It is process drawing which shows the saccharification method of the cellulose biomass raw material of embodiment of this invention. It is a figure which shows the state of the water accompanying a temperature and pressure change. In the saccharification apparatus of Embodiment 1, it is a schematic diagram which shows the state into which the cellulose solubilization liquid is flowing in into the 2nd inhibitor removal unit 12 via the saccharification unit 13 from the 1st inhibitor removal unit 11. FIG. In the saccharification apparatus of Embodiment 1, it is a schematic diagram which shows the state into which the cellulose solubilization liquid is flowing in into the 1st inhibitor removal unit 11 via the saccharification unit 13 from the 2nd inhibitor removal unit 12. FIG. It is a schematic diagram of the saccharification apparatus of Embodiment 2. It is a graph which shows the relationship between the pH after the solubilization process in Example 1 and the comparative example 1, and the yield of the monosaccharide after a saccharification process. It is a graph which shows the relationship between the pH after the solubilization process in Example 2 and the comparative example 2, and the yield of the monosaccharide after a saccharification process.

<Embodiment 1>
The saccharification method of the cellulose biomass raw material of Embodiment 1 of this invention is shown in FIG. This will be described in detail below.

(material)
The raw material containing cellulose is a plant-based raw material containing cellulose, and it can be used even if it contains polysaccharides other than cellulose, such as starch, hemicellulose, and pectin, in addition to cellulose. Specifically, grasses such as rice straw, wheat straw, bagasse, thinned timber such as bamboo and firewood, sawn wood, chips, wood chips such as wood chips, pruned roadside trees, wood construction waste, bark, driftwood, etc. Examples include woody biomass and biomass from cellulose products such as waste paper. In addition, sludge, livestock excrement, agricultural waste, municipal waste, etc. can be used as long as cellulose can be used as a raw material.

・ Rough grinding process (S1)
In order to promote solubilization of cellulose, these raw materials are preferably subjected to coarse pulverization as a pretreatment to reduce the crystallinity of cellulose. The pulverization method is not particularly limited, and an appropriate method may be appropriately selected according to the form of the raw material, but first, it is roughly pulverized to several to several tens of millimeters to be easily handled, and then further finely pulverized. Fine grinding can be performed efficiently. A general-purpose pulverizer such as a hammer mill or a cutter mill can be used for coarse pulverization. For fine pulverization, general-purpose pulverizers such as a vibration mill, ball mill, rod mill, roller mill, colloid mill, disc mill, jet mill, etc. can be used. Can be reduced. As the pulverization treatment, both dry and wet methods can be applied, but dry pulverization is desirable in terms of reducing the crystallinity of cellulose. When the water content of the raw material is large, the crystallinity of cellulose can be effectively reduced by dry pulverization after the water content is reduced to 30% or less in advance by centrifugal dehydration or hot air drying.

・ Moisture adjustment process (S2)
After measuring the moisture content of the raw material after the coarse pulverization, the moisture content is adjusted. If the water content is too high, dry it. If the water content is low, add water. An appropriate method for calculating the water content will be described in the next solubilization step.

・ Solubilization step (S3)
Then, the coarsely pulverized raw material with the adjusted water ratio is made into a solubilized mixture containing an organic acid by controlling the temperature and pressure. Examples of temperature and pressure control include 1) a control method for performing hydrothermal treatment, and 2) a control method at low temperature and low pressure.
Hydrothermal treatment is a treatment that makes a cellulose-containing biomass raw material water-soluble by pressurized hot water (high-temperature and high-pressure water that exists in a liquid state) pressurized to a saturation water vapor pressure or higher, and is a subcritical region shown in FIG. Or in the supercritical region. In the subcritical region, the total pressure is higher than the saturated water vapor pressure. In other words, water is a region where water stably coexists as liquid water in addition to water vapor. For this reason, it is presumed that the hydrolysis reaction of cellulose in the subcritical region proceeds with liquid water having a large ionic product. In addition, the hydrolysis reaction of cellulose in the supercritical region is a hydrolysis reaction with water in a special state called a supercritical state where gas-liquid cannot be distinguished. Pressurized hot water is thought to accelerate the hydrolysis reaction of cellulose due to an increase in ion product (see paragraph number [0024] in Patent Document 1). For this reason, the hydrothermal treatment method has the advantage that the cellulose raw material can be solubilized in a short time without using a special chemical, and is said to be a solubilizing method of the cellulose raw material with a small environmental load. be able to. Further, along with solubilization, organic acids such as lactic acid and acetic acid are also produced in addition to the solubilized sugar, and these organic acids can be used as catalysts in the saccharification step (S5) described later. The amount of organic acid produced can be controlled by controlling temperature, pressure and reaction time.

  On the other hand, the control method at low temperature and low pressure uses a temperature-pressure region which is completely different from that of hydrothermal treatment. That is, it is characterized in that the hydrolysis reaction is carried out in a high temperature-low pressure region where the total pressure is from 0.05 MPa to less than 10 MPa. Such a region is indicated by a hatched portion in FIG. 2 and is a region where the total pressure is smaller than the saturated water vapor pressure (that is, a region where water does not exist stably and only water vapor exists) or liquid water. Coexists with water vapor, but the total pressure is a small region of less than 10 MPa, which is completely different from the subcritical region and the supercritical region. Also in this method, organic acids such as lactic acid and acetic acid can be generated in addition to the solubilized sugar, and these organic acids can be used as a catalyst in the saccharification step (S5) described later. The amount of organic acid to be generated can be controlled by controlling the amount of water to be added, temperature, pressure, reaction time, and the like. This low temperature and low pressure control method produces less overdegradation products such as hydroxymethylfurfural (HMF) than the method using pressurized hot water, and can increase the final saccharification yield.

In the solubilization step (S3), a closed vessel with a lid can be used as the reaction vessel in order to control temperature and pressure. As such a container, a double-structure container such as an autoclave apparatus made of a corrosion-resistant metal or a metal pressure-resistant container that houses a lidded container made of a fluororesin such as PTFE can be used.
Then, a predetermined amount of the coarsely pulverized raw material and water adjusted in the water ratio are put into these containers, the lid is closed, and the temperature is set. As a result, the water originally contained in the raw material and the added water become water vapor and increase in volume. At this time, the finally reached pressure can be easily obtained by substituting the temperature, the amount of water, and the container volume into the state equation corrected for the actual gas. For this reason, the water | moisture content adjustment of the pulverized cellulose raw material performed prior to a solubilization process is performed so that it may become the quantity calculated | required by calculation. The heating method is not particularly limited, and an electric heater, high frequency, microwave, steam, or the like can be used. The coarsely pulverized raw material after the solubilization step (S3) is thus a solubilized mixture containing an organic acid such as lactic acid or acetic acid.

・ Extraction process (S4)
Water is added to dissolve the solubilized mixture thus obtained in an amount of 0.1 to 500 times to obtain a solubilized solution. This solubilized solution is acidic because it contains an organic acid such as lactic acid or acetic acid.

・ Saccharification process (S5)
Further, the solubilized solution is mixed and stirred, and hydrolyzed with an organic acid catalyst to obtain a saccharified solution containing a monosaccharide such as glucose as a main component. At this time, the reaction can be promoted by heating.

  As mentioned above, in the saccharification method of the cellulose biomass raw material of Embodiment 1, the organic acid produced | generated in the solubilization process (S3) is utilized as an acid catalyst, and a saccharified liquid is obtained in a saccharification process (S5). For this reason, it is not necessary to add a solid acid catalyst or a liquid acid from the outside, and the manufacturing cost can be reduced. Moreover, since a saccharification process (S5) can be performed without performing solid-liquid separation after an extraction process (S4), the number of manufacturing processes can be reduced.

<Saccharification equipment>
-Saccharification apparatus of Embodiment 1 The saccharification apparatus 10 of Embodiment 1 which can embody the saccharification method in this invention is shown in FIG. The saccharification apparatus 10 includes a first inhibitor removal unit 11, a second inhibitor removal unit 12, and a saccharification unit 13. Both inhibitor removal units 11 and 12 are filled with an acid-treated cation exchange resin.

Three-way valves V 1 and V 2 are attached to both ends of the first inhibitor removal unit 11, and three-way valves V 3 and V 4 are attached to both ends of the second inhibitor removal unit 12.
In addition, an inflow pipe 14 for allowing an aqueous solution containing an organic acid sent from a solid-liquid separator (not shown) to flow in is branched in the middle and connected to the three-way valves V1 and V3. Further, two pipes 15 and 16 for connecting the three-way valve V2 and the three-way valve V4 are provided. Further, a pipe 17 a branches from the middle of the pipe 15 and is connected to one end of the saccharification unit 13. One end of the pipe 17 b is connected to the other end of the saccharification unit 13, and the other end is in the middle of the pipe 16. It is connected.

Next, a method for using the saccharification apparatus 10 will be described.
An aqueous solution containing an organic acid sent from a solid-liquid separation device (not shown) flows from the inflow pipe 14 and is operated by the three-way valves V1 to V4 so as to pass through the following flow paths (flow paths indicated by bold lines in FIG. 3). Is done.
First, the aqueous solution containing the organic acid that has flowed from the inflow pipe 14 enters the first inhibitor removal unit 11 through the three-way valve V1. Here, metal ions such as Ca ions contained in the organic acid-containing aqueous solution are ion-exchanged with hydrogen ions of the cation exchange resin. The organic acid-containing aqueous solution in which metal ions are replaced with hydrogen ions in this way enters the saccharification unit 13 via the three-way valve V2, and a saccharification reaction is performed. Here, the organic acid-containing aqueous solution flowing into the saccharification unit 13 is replaced with hydrogen ions in the first inhibitor removal unit, so that the pH does not increase due to neutralization, and the saccharification reaction is performed quickly. proceed. The saccharified solution flowing out from the saccharification unit 13 enters the second inhibitor removal unit 12 via the three-way valve V4, and further collects the saccharified solution via the three-way valve V3.

After a predetermined time has elapsed, as shown in FIG. 4, an aqueous solution containing an organic acid flows from the second inhibitor removal unit 12 through the saccharification unit 13 to the first inhibitor removal unit 11 in the opposite direction to the above flow. Thus, the three-way valves V1 to V4 are operated.
That is, first, an aqueous solution containing an organic acid enters the second inhibitor removal unit 12 from the three-way valve V3. Here, metal ions contained in the organic acid-containing aqueous solution are exchanged and adsorbed with hydrogen ions of the cation exchange resin. The organic acid-containing aqueous solution from which the metal ions are removed in this way enters the saccharification unit 13 via the three-way valve V4, and a saccharification reaction is performed. Here, since the organic acid-containing aqueous solution flowing into the saccharification unit 13 does not contain metal ions, the metal ions do not decrease the activity of the organic acid as an acid catalyst, and the saccharification reaction proceeds rapidly. Then, the saccharified solution flowing out from the saccharification unit 13 enters the first inhibitor removal unit 11 via the three-way valve V2, and the metal ions captured by the cation exchange material are replaced with hydrogen ions in the saccharified solution. Then, the cation exchange material is regenerated so that the cation can be captured again. And the saccharified liquid which flowed out from the 1st obstruction removal unit 11 is collect | recovered from the three-way valve V1.

  By repeating the above steps, the saccharification reaction is carried out rapidly and continuously, while capturing and regenerating the metal ions by the cation exchange material in the inhibitor removal units 11 and 12 without consuming any drug. be able to. Therefore, according to the saccharification apparatus for an aqueous solution containing an organic acid according to Embodiment 1, saccharification of an aqueous solution containing an organic acid is performed at a low operating cost while preventing a decrease in catalytic activity due to metal ions in the aqueous solution containing the organic acid. be able to.

-The saccharification apparatus of Embodiment 2 As shown in FIG. 5, in the saccharification apparatus of Embodiment 2, the inhibitor removal unit 11 is divided into two parts of the inhibitor removal units 11a and 11b, and the inhibitor removal unit 12 is It is divided into two parts, the inhibitor removal units 12a and 12b. A first pH sensor P1 is provided in the middle of the inflow pipe 14, a second pH sensor P2 is provided between the inhibitor removal units 11a and 11b, and a third pH sensor P3 is provided between the inhibitor removal units 12a and 12b. The fourth pH sensor P4 is provided in the pipe 17a. The first to fourth pH sensors P1 to P4 are connected to a control unit 20 that controls the three-way valves V1 to V4 according to the output of the sensor. Other configurations are the same as those in the second embodiment, and the same components are denoted by the same reference numerals and description thereof is omitted.

  In the saccharification apparatus of Embodiment 2, the metal ion adsorption amount of the inhibitor removal units 11a, 11b, 12a, and 12b can be grasped from the output values of the first to fourth pH sensors. In other words, the adsorption of metal ions is performed by substitution with hydrogen ions present in the cation exchange material, and while the cation exchange capacity is maintained, the pH is lowered by the release of hydrogen ions. If the degree of decrease in pH to the effluent is measured, the degree of saturation of cation exchange can be measured. Therefore, it is possible to grasp in real time the metal adsorption rate of the cation exchange material in the inhibitor removal units 11a, 11b, 12a, and 12b based on the difference in pH between the influent and effluent of the inhibitor removal unit. It becomes possible. Then, the three-way valves V <b> 1 to V <b> 4 may be controlled by the control unit 20 so that the flow direction is reversed when the difference in pH becomes small. In addition, when it is flowing through the flow path shown by the thick line in FIG. 5, the pH sensor P2 installed in the middle of the inhibitor removal unit 11 can grasp the change in pH earlier than the pH sensor P4, and in the reverse direction. When flowing, the pH sensor P3 installed in the middle of the inhibitor removal unit 12 can grasp the change in pH faster than the pH sensor P4, so that the saturation degree of the inhibitor removal unit can be grasped quickly. It is preferable to install in the middle of the inhibitor removal unit.

  As a modification of the second embodiment, an electrical conductivity sensor may be used instead of the pH sensor or in addition to the pH sensor. Since the electrical conductivity changes due to the replacement of metal ions and hydrogen ions with a cation exchange material, grasping the saturation state of the cation exchange material by grasping the change in electrical conductivity instead of the change in pH This also allows the control unit 20 to control the three-way valves V1 to V4.

Example 1
・ Solubilization process Weighing 0.3 g of pulverized cellulose reagent (water content 7%), pressure-resistant PTFE container with double-structured lid (inner container is a 20 cm ³ capacity PTFE container, outer container is a stainless steel container) And capped without water. And the pressure | voltage resistant PTFE container was put into the electric heating furnace, and it heated at 200 degreeC for 3 hours. At this time, the total pressure inside the pressure-resistant PTFE container is calculated from the equation of state and becomes (partial pressure of air + partial pressure of water vapor) = 0.32 MPa. On the other hand, the saturated water vapor pressure at 200 ° C. is 1.56 MPa.
-Saccharification process After completion | finish of the solubilization process, the content was melt | dissolved with predetermined amount of water, the lid | cover was closed again, and the saccharification process for 6 hours was performed at 150 degreeC.

(Comparative Example 1)
In Comparative Example 1, after performing the same solubilization step as in Example 1, the content was dissolved in a predetermined amount of water as a saccharification step, and further 15 mg of sulfonated activated carbon was added as a solid acid catalyst and capped. The lid was closed again and a saccharification step was performed at 150 ° C. for 6 hours.

<Evaluation>
A solution obtained by dissolving the contents obtained in the solubilization step of Example 1 and Comparative Example 1 with a predetermined amount of water was analyzed by high performance liquid chromatography and a total organic carbon meter (TOC meter) to obtain a solubilization rate. . Further, the pH was measured with a pH meter. Furthermore, the solubilization rate was similarly obtained for the saccharified solution. The analysis results after the solubilization step and after the saccharification step are shown in Table 1. Further, FIG. 6 shows the pH after the solubilization step and the yield of monosaccharides after the saccharification step. From Table 1, it was found that the solubilization rate did not change much even when the amount of water added was changed, but the pH at the end of the solubilization step was lower as the amount of water added was lower. In addition, from Table 1 and FIG. 6, in the comparison of Example 1-1 and Comparative Example 1-1 in which the pH at the end of the solubilization process is 4.1, the monosaccharide after the saccharification process is better when the solid acid catalyst is present. Although the yield is high, a comparison between Example 1-3 and Comparative Example 1-3 in which the pH at the end of the process is 2.3, and Example 1-2 in which the pH at the end of the process is 2.8 and In the comparison of Comparative Example 1-2, it was found that the monosaccharide yield after the saccharification step was high regardless of the presence or absence of the solid acid catalyst.

(Example 2)
As a biomass raw material containing cellulose, a commercially available 100% cotton T-shirt was finely cut into a width of about 5 mm, and then pulverized with a blade mill to obtain a cotton-like sample. This was subjected to a solubilization step and a saccharification step under the same conditions as in Example 1.

(Comparative Example 2)
In Comparative Example 2, after performing the same solubilization step as in Example 1, the content was dissolved in a predetermined amount of water as a saccharification step, and further 15 mg of sulfonated activated carbon was added as a solid acid catalyst and capped. The lid was closed again and a saccharification step was performed at 150 ° C. for 6 hours.

<Evaluation>
The analysis results after the solubilization step and after the saccharification step are shown in Table 2. FIG. 7 shows the pH after the solubilization step and the yield of monosaccharides after the saccharification step.
From Table 2, it was found that the solubilization rate did not change much even when the amount of water added was changed, but the pH at the end of the solubilization step was lower as the amount of water added was lower. In addition, from Table 2 and FIG. 7, it can be seen from the comparison between Example 2-1 where the pH at the end of the process is 4.2 and Comparative Example 2-1 that the monosaccharide yield after the saccharification process is better without the solid acid catalyst. In comparison between Example 2-2 and Comparative Example 2-2 in which the pH at the end of the process is 3.1, the monosaccharide yield after the saccharification process is high regardless of the presence or absence of the solid acid catalyst. It was found that a yield was obtained.

  The present invention is not limited to the description of the embodiment of the invention. Various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the description of the scope of claims.

S1 ... Coarse grinding step, S2 ... Moisture adjustment step, S3 ... Solubilization step, S4 ... Extraction step, S5 ... Saccharification step, 10 ... Saccharification device, 13 ... Saccharification unit, 11 ... First inhibitor removal unit, 12 ... First 2 inhibitor removal unit, V1, V2, V3, V4 ... three-way valve (switching means), P1, P2, P3, P4 ... pH sensor, 20 ... control unit

Claims (3)

A first step of allowing a cellulose solubilized liquid obtained by converting a biomass raw material containing cellulose to flow into a first inhibitor removal unit filled with a cation exchange material;
A second step of flowing the effluent from the first inhibitor removal unit into the saccharification unit to obtain a saccharification solution;
A third step of obtaining a saccharified solution by causing the saccharified solution flowing out of the saccharification unit to flow into a second inhibitor removing unit filled with a cation exchange material,
After the completion of the first to third steps, the cellulose lysate is flowed from the second inhibitor removal unit through the saccharification unit to the first inhibitor removal unit in the opposite direction to the first to third steps. A method for saccharifying a cellulose-solubilized solution, A saccharification apparatus for a cellulose solubilizing liquid that obtains a saccharified liquid from a solubilized liquid obtained by converting a biomass raw material containing cellulose,
The saccharification unit, and first and second inhibitor removal units filled with a cation exchange material,
A first flow path for flowing the lysate from the first inhibitor removal unit into the second inhibitor removal unit via the saccharification unit;
A second flow path for flowing the lysate from the second inhibitor removal unit via the saccharification unit to the first inhibitor removal unit;
A saccharification apparatus for cellulose solubilized liquid, comprising: a switching means that enables switching between the first flow path and the second flow path. A pH sensor and / or an electrical conductivity sensor is provided in the middle of the first flow path, upstream and midway and / or downstream of the first inhibitor removal unit,
A pH sensor and / or an electrical conductivity sensor is provided in the middle of the second flow path, upstream and midway and / or downstream of the second inhibitor removal unit,
The saccharification apparatus for cellulose-solubilized liquid according to claim 2, further comprising a control unit that controls the switching unit according to the output of each of the pH sensors and / or the electrical conductivity sensors.

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