JP2020172455A - Method for producing c5+ compounds and c5+ compounds - Google Patents

Abstract

To obtain C5+ compounds in high yield from plant-derived biomass by suppressing catalyst poisoning in a catalytic reaction using a metal-based catalyst.SOLUTION: The method for producing C5+ compounds comprises: a component removal step of removing components derived from an enzyme used for saccharification from saccharified biomass obtained by saccharification of plant-derived biomass; a pH adjustment step of adjusting pH of saccharified biomass from which components derived from the enzyme have been removed; and a catalytic reaction step of producing C5+ compounds from the saccharified biomass, the pH of which has been adjusted, by a catalytic reaction using a metal-based catalyst.SELECTED DRAWING: Figure 3

Description

The present invention relates to a technique for producing a compound (C5 + compound) having 5 or more carbon atoms from plant-derived biomass by a catalytic reaction using a metal-based catalyst.

Plant-derived biomass mainly consists of a mixture (lignocellulose) of cellulose and hemicellulose, which are polysaccharides, and lignin, which is a high molecular compound. The liquid fuel is obtained by saccharifying (hydrolyzing) this polysaccharide component, decomposing it into monosaccharides, and using the decomposed monosaccharides as a raw material. For such saccharification and decomposition into monosaccharides, an acid saccharification method using sulfuric acid, an enzyme saccharification method using an enzyme, and the like are known. Since the structure of lignocellulose is very strong, in order to promote such decomposition, as a treatment for biomass, for example, a hydrothermal method using high temperature and high pressure water, or a mechano that is mechanically pulverized. The chemical method is adopted.

Patent Document 1 discloses that an aqueous phase modification (APR) catalyst, a hydrodeoxidation (HDO) catalyst, and the like are used as catalysts for producing liquid fuels and chemical substances from lignocellulosic biomass. Has been done. Patent Document 1 describes removing pollutants such as mineral salts, mineral acids, proteinaceous substances, ash and other organic substances from raw materials containing oxygenated hydrocarbons derived from water, pollutants and biomass.

Such contaminants can result in catalyst poisons that reduce the life and function of the catalyst, and therefore the contaminants may be removed as described above.

By the way, attempts have been made to use it as a fuel base material such as gasoline by obtaining hydrocarbons such as hexanol and pentanol, and dehydrated hexanol and pentene from plant-derived biomass while maintaining the carbon chain. ..

For example, Patent Document 2 discloses a method for selectively advancing the reaction using an Ir-Re (iridium-rhenium) -based catalyst in a method for obtaining hexanol and pentanol from cellulose and hemicellulose. Specifically, glucose and xylose are obtained by putting cellulosic biomass together with an Ir-Re catalyst in the aqueous phase and saccharifying them, and then hydrogenating them to obtain sorbitol and xylitol, respectively, by hydrocracking these. It is stated to obtain hexanol and pentanol.

Further, in Patent Document 3, a catalyst is used to modify a part of sorbitol or xylitol, which is a sugar alcohol having 5 or 6 carbon atoms, in an aqueous phase and hydrolyze and decompose the rest to maintain the number of carbon atoms and maintain hexanol. Alternatively, a method for obtaining pentanol is disclosed.

U.S. Pat. No. 9862893 Japanese Unexamined Patent Publication No. 2016-33129 JP-A-2017-7950

The present inventors have described the Ir-Re catalysts described in Patent Documents 2 and 3 in a method for producing a C5 + compound from a raw material containing an oxygen-containing hydrocarbon derived from lignocellulosic biomass as described in Patent Document 1. It was examined to use such a metal-based catalyst. In this case as well, the influence of the catalytic poison in performing hydrocracking can be considered.

An object of the present invention is to provide a technique for suppressing catalytic poisoning in a catalytic reaction using a metal-based catalyst from plant-derived biomass to obtain a C5 + compound in a high yield.

The method for producing a C5 + compound according to one aspect of the present disclosure includes a component removing step of removing a component derived from an enzyme used for saccharification and a component derived from the enzyme from the saccharified biomass obtained by saccharifying a plant-derived biomass. It includes a pH adjusting step of adjusting the pH of the saccharified biomass and a catalytic reaction step of producing a C5 + compound from the saccharified biomass whose pH has been adjusted by a catalytic reaction using a metal-based catalyst.

It is a figure which shows an example of a reaction process. It is a figure which shows an example of the process of hydrocracking among reaction steps. It is a flow chart which shows the manufacturing method of the C5 + compound.

Hereinafter, one embodiment of the method for producing a C5 + compound according to the present invention will be described in detail with reference to FIGS. 1 to 3.

In the method for producing a C5 + compound in the present embodiment, a C6 compound having 6 carbon atoms or a C5 having 5 carbon atoms is used as a starting material, starting from glycated biomass composed of monosaccharides obtained by hydrolyzing plant-derived biomass such as lignocellulosic biomass. A compound is produced by utilizing a catalytic reaction. Here, "C5 +" includes both C6 and C5, and "C5 + compound" mainly contains monoalcohol and alkane having such carbon atoms. Further, for example, hexanol, which is a C6 monoalcohol having 6 carbon atoms, has three types of 1-hexanol, 2-hexanol, and 3-hexanol depending on the position of the hydroxy group, but any of them may be included in the present embodiment. .. Similarly, pentanol, which is a C5 monoalcohol having 5 carbon atoms, may contain any of 1-pentanol, 2-pentanol, and 3-pentanol. The C6 alkane having 6 carbon atoms is hexane, and the C5 alkane having 5 carbon atoms is pentane.

FIG. 1 is a diagram showing an example of a reaction step for obtaining a C5 + compound in the present embodiment. As shown in FIG. 1, in the production of the C5 + compound in the present embodiment, in the reaction step, first, plant-derived biomass is saccharified by hydrolysis to obtain saccharified biomass which is a sugar solution containing monosaccharides. That is, monosaccharides such as glucose and xylose are obtained by saccharifying biomass such as lignocellulose. Here, it is preferable to use glucose and / or xylose as the main component of the saccharified biomass in order to obtain a C5 + compound having 6 or 5 carbon atoms. The monosaccharides of the obtained saccharified biomass are hydrogenated using a catalyst to become sugar alcohols, and further hydrolyzed and decomposed using a catalyst to produce monoalcohols having 6 or 5 carbon atoms, alkanes and the like. A C5 + compound consisting of is obtained.

Here, a metal-based catalyst is adopted as the catalyst used for the catalytic reaction in the hydrogenation step and the catalytic reaction in the hydrogenation decomposition step. Metallic catalysts, the metals and / or metal oxides are those obtained by supporting the catalyst carrier, for example, Ir and ReO _x silicon dioxide (SiO ₂₎ or titanium oxide Ir-Re which were supported on (TiO ₂₎ A system catalyst can be mentioned. The metal catalyst is not limited to this, and may be, for example, one in which Rh and MoO _x are supported on SiO ₂ or TiO ₂ . Further, the metal-based catalyst may be one in which a noble metal is further used. The metal-based catalyst may be, for example, one in which a noble metal such as Pt or Pd is supported on the Ir-Re-based catalyst. The catalyst used in the hydrogenation step and the catalyst used in the hydrocracking step may be the same or different, but at least the catalyst used in the hydrocracking step is , Ir-Re based catalyst is preferable. By using an Ir-Re based catalyst, the reaction efficiency of the catalytic reaction can be improved.

FIG. 2 is a diagram showing an example of a hydrogenation decomposition step among the reaction steps in the present embodiment. As shown in FIG. 2, in the catalytic reaction in the process of hydrocracking, hydrogen obtained by aqueous phase reforming (internal hydrogen) and hydrogen supplied from the outside (external hydrogen) are used to prepare a catalyst. It is used for hydrocracking. Specifically, in the process of hydrocracking, hydrogen is obtained by hydrogenating a part of the sugar alcohol obtained by hydrogenating the simple sugar contained in the saccharified biomass, and the hydrogen is obtained by the aqueous phase modification. The balance of sugar alcohol is hydrolyzed and decomposed using hydrogen. For example, when a C6 compound is produced from sorbitol as shown in the figure, hydrogen is obtained from a part of sorbitol by aqueous phase modification, and such hydrogen is used to obtain sorbitol (or glucose before being decomposed into sorbitol). (Including) is hydrolyzed to produce a C6 compound. When the monosaccharide is xylitol, although not shown, hydrogen obtained by partially modifying the aqueous phase can be used for hydrocracking. Here, in the process of hydrocracking including aqueous phase modification, it is preferable to use a catalyst in which a noble metal such as Pt or Pd is supported on the Ir-Re catalyst.

The hydrocracking step shown in FIG. 2 is an example, and the aqueous phase modification may not be performed in the hydrocracking step. In this case, hydrogen used for hydrocracking may be supplied from the outside. Further, hydrocracking may be carried out using both hydrogen obtained by aqueous phase reforming and hydrogen supplied from the outside.

FIG. 3 is a flow chart showing an example of a method for producing a C5 + compound. Referring to FIG. 3, the method for producing a C5 + compound according to the present embodiment is to produce saccharified biomass from plant-derived biomass (S1), and then remove components (S2) and adjust pH (S3) of the saccharified biomass. In this order, the catalytic reaction (S4) is carried out.

The production of saccharified biomass (S1) may be carried out by any method. In this embodiment, it is assumed that the production is performed by a known production method. Since the plant-derived biomass contains various impurities, the saccharified biomass obtained from the plant-derived biomass also contains impurities.

The inventors of the present application have observed that the Ir-Re catalyst, which is one of the metal catalysts, promotes the catalytic reaction satisfactorily under acidic conditions. Therefore, the inventors of the present application have found that the organic acid contained in the saccharide peroxide has little influence on the progress of the catalytic reaction. In addition, in a catalytic reaction test using a pulp sugar solution derived from eucalyptus that does not contain furfural, which is a saccharide peroxide, it has been observed that the catalytic reaction may not proceed. Therefore, the inventors of the present application considered that the progress of the catalytic reaction was hindered by substances other than the peroxidized saccharides. Substances other than saccharide peroxides contained in saccharified biomass include, for example, NaCl, sulfur (S), nitrogen (N) and the like. Of these, for example, NaCl may be contained in an amount of about several hundred ppm, but it has been observed that NaCl having a concentration of this degree does not affect the decrease in catalytic activity. Further, even if the ionicity was removed from the S and N components by ion exchange, a decrease in the activity of the catalyst was observed by the subsequent treatment. Therefore, the inventors of the present application considered that the ionic S and N components were not the cause of the decrease in catalytic activity. That is, the inventors of the present application have found that components containing at least one of S and N, which are not ionic, specifically, proteins and amino acids of protein constituents, such as methionine and cysteine, reduce the catalytic activity. Found to be the main cause.

If an enzyme, protein or amino acid used for saccharification remains in the obtained saccharified biomass, the catalyst may be poisoned so as to hinder the subsequent progress of the catalytic reaction of the monosaccharide in the saccharified biomass. Proteins and amino acids are components derived from enzymes (enzyme-derived components) mainly used in the production of saccharified biomass (S1). The present inventors have found that the poisoning of a catalyst can be suppressed by removing enzyme-derived components such as proteins and amino acids or enzyme components, which are considered to be the main causes of a decrease in catalytic activity.

Therefore, the enzyme-derived component used for saccharification is removed in the step of component removal (S2). Specifically, for example, an adsorbent is put into the saccharified biomass, and then the adsorbent is removed from the saccharified biomass to remove the enzyme component and the enzyme-derived component containing a protein and an amino acid. As the adsorbent, for example, "Mizuka Life" (registered trademark, manufactured by Mizusawa Industrial Chemicals Co., Ltd.) containing silicon dioxide and magnesium oxide as main components is suitable. The enzyme-derived components are, for example, proteins and amino acids, but are not limited thereto, and include components derived from other enzymes.

Further, in the step of pH adjustment (S3), the saccharified biomass that has become basic by using an adsorbent in the step of component removal (S2) is made neutral or acidic. The Ir-Re catalyst used for the catalytic reaction can obtain high activity in an acidic environment. Therefore, the pH is adjusted to maintain high activity. Specifically, ion removal or acid treatment is performed. Ion removal means, for example, putting an ion exchange resin into a saccharified biomass and then removing the ion exchange resin from the saccharified biomass to remove inorganic ions including metal ions, inorganic acid ions, and inorganic base ions. It is to be. Further, the acid treatment is to make the sugar solution acidic by, for example, adding an acid (for example, sulfuric acid) into the saccharified biomass.

By performing the component removal (S2) and pH adjustment (S3) in this order as described above, the catalytic poisoning of the metal-based catalyst is suppressed in the subsequent catalytic reaction (S4) to maintain high activity, and hydrogenation and hydrogenation and The C5 + compound can be obtained in high yield by advancing the catalytic reaction in the step of hydrocracking.

[C5 + compound production test]
Next, a production test of a C5 + compound using saccharified biomass will be described.

[Test 1]
A pulp sugar solution derived from eucalyptus was prepared as a saccharified biomass, and the pulp sugar solution was subjected to component removal (S2) and pH adjustment (S3). Then, the C5 + product produced was analyzed by a catalytic reaction using a metal-based catalyst. In the step of pH adjustment (S3), ion removal was performed.

As shown in Table 1, first, two types of pulp sugar solutions from which the components had been removed (S2) were prepared. That is, in the component removal (S2), one using Mizuka Life (registered trademark, manufactured by Mizusawa Industrial Chemicals Co., Ltd.) as an adsorbent (A: No. 1, 3) and one using a carbon adsorbent (B: No). .2, 4) was prepared. Of these, No. For 1 and 2, the ions were not removed, and No. For 3 and 4, ions were removed. In ion removal, 7.5 g of diaion (registered trademark, SMNUPB; manufactured by Mitsubishi Chemical Corporation) was added to 20 g of the sugar solution as an ion exchange resin, and then the ion exchange resin was removed from the sugar solution. In addition, No. For comparison, No. 5 used a purified glucose reagent as a sugar solution.

Here, the properties of each sugar solution were investigated. The Na ion concentration was quantitatively analyzed by an ICP emission spectrophotometer. The S component was quantitatively analyzed by the combustion tube oxygen method-ion chromatograph method. In addition, glucose (Glu) and xylose (Xyl) were quantitatively analyzed by high performance liquid chromatography.

Next, No. A catalytic reaction was carried out with each of the sugar solutions 1 to 5. For the catalytic reaction, a SUS316 autoclave (capacity: 100 mL) having a glass inner tube was used as a heating container. 5.0 g of water was placed in the heating container and 0.3 g of the Ir-ReO _x / SiO ₂ catalyst was reduced, and then 5.0 g of the sugar solution was stored in the heating container. In addition, No. For No. 5, 0.75 g of glucose reagent was contained instead of 5.0 g of sugar solution. Next, 20 mL of n-tridecane was added into the heating vessel, hydrogen gas was introduced so that the pressure in the heating vessel became 6.0 MPa at room temperature, and the heating vessel was heated to 180 ° C. and held for 3 hours.

The residual amounts of glucose (Glu) and xylose (Xyl) after the reaction were quantitatively analyzed in the same manner as described above to determine the conversion rate. In addition, C5 + alkane (hexane and pentane), C5 + monool (hexanol and pentanol), and C5 + diol (hexanediol and pentanediol) were quantitatively analyzed and collected as "C5 + product" using a gas chromatograph and a high performance liquid chromatograph. I asked for the rate. In the table, "ND" indicates that the target substance was not detected.

The conversion rate of monosaccharides (here, glucose and xylose) is the ratio of monosaccharides converted to other substances and is given by the following formula.
Conversion rate (%) = (amount of monosaccharide before reaction-amount of monosaccharide after reaction (residual amount)) / (amount of monosaccharide before reaction) × 100

The yield is the carbon yield of the product of interest, that is, the C5 + compound converted from monosaccharides (glucose and xylose), and is given by the following formula.
Yield (%) = (total number of moles of carbon of the product of interest) / (total number of moles of monosaccharide) x 100
For example, the "total number of carbon moles of the product of interest" can be calculated by multiplying the number of moles of the product of interest quantitatively analyzed by the number of carbon atoms of the product. Similarly, the "total number of moles of monosaccharides" can be calculated by multiplying the number of moles of monosaccharides charged in the heating container by the number of carbon atoms.

From the conversion rates of glucose and xylose, No. It is considered that almost all of glucose and xylose were hydrogenated by the catalytic reaction in all of the samples 1 to 5. However, No. 1 in which ion removal was not performed. It is probable that C5 + alkane and C5 + monool were not produced in 1 and 2, and the catalytic reaction in the process of hydrocracking did not proceed sufficiently due to the poisoning of the catalyst. In addition, No. 1 in which ions were removed. No. 3 and 4 using glucose reagent. A sufficient amount of C5 + alkane and C5 + monool was produced as compared with 5. As a result, by performing component removal (S2) and pH adjustment (S3; ion removal) in this order, poisoning of the Ir-Re catalyst in the process of hydrocracking can be reduced, and the C5 + compound can be produced in a high yield. I was able to manufacture it.

[Test 2]
Further, the production test of the C5 + compound was carried out in the same manner, and the product was analyzed.

As shown in Table 2, No. Items 3, 4 and 5 were the same samples as in Test 1, and the same test results were shown for comparison. No. In No. 6, a sugar solution in which neither component removal (S2) nor pH adjustment (S3, ion removal) was performed was prepared. In addition, No. In No. 7, No. In the same manner as in No. 3, Mizuka Life (registered trademark) was used as an adsorbent in the component removal (S2), and the sugar solution from which the ions had been removed was used, but the amount of the catalyst input was reduced to 0.1 g in the catalytic reaction. No. In No. 8, the amount of the catalyst charged was 0.1 g using the sugar solution obtained by performing the component removal (S2) and the ion removal in the reverse order. The catalytic reaction was also carried out in the same manner as in Test 1.

The properties of each sugar solution were quantitatively analyzed using the same method for the same items as in Test 1. The N content was quantitatively analyzed by the oxygen combustion-chemiluminescence method. The pH was measured by the glass thin film potentiometric method. In addition, No. For 7 and 8, the electric conductivity was measured by the AC bipolar method, and the Na ion column was coded and shown in the margin. No. In No. 8, the Na ion concentration was not measured.

No. 1 in which both component removal (S2) and pH adjustment (S3, ion removal) were omitted. In No. 6, the sugar solution used for the catalytic reaction had more S and N components than the others, and C5 + alkane and C5 + monool were not detected after the catalytic reaction. Therefore, the catalytic reaction was sufficiently due to the poisoning of the catalyst. It turns out that it did not progress. In particular, the conversion rates of glucose and xylose were lower than those of other samples including Test 1, and it is considered that the catalyst was poisoned with respect to the catalytic reaction in the hydrogenation step. It is considered that the main cause of such poisoning is that the sugar solution used for the catalytic reaction contained a large amount of enzyme-derived components containing S and N components.

No. In No. 7, the amount of catalyst was reduced, so No. Although the amount of C5 + alkane and C5 + monool produced was smaller than that of 3, it is considered that the catalytic reaction proceeded relatively well. On the other hand, No. was treated by changing the order so that the component removal (S2) was performed after the pH adjustment (S3, ion removal). At 8, the pH value increased, and C5 + alkane and C5 + monool were not detected as products. That is, the component removal (S2) and the pH adjustment (S3) need to be performed in this order. In addition, in the electric conductivity of the sugar solution used for the catalytic reaction, No. No. 7 rather than 7. No. 8 is significantly larger, and from this, it is considered that even if the ion removal is performed first, the basic environment is created by the subsequent removal of the components.

[Test 3]
Further, the production test of the C5 + compound was carried out in the same manner, and the product was analyzed. As shown in Table 3, No. No. 3 was the same sample as Tests 1 and 2, and the same test results were shown for comparison. No. In No. 9, after the component was removed (S2), acid treatment was performed as pH adjustment (S3). No. In 9, No. Mizuka Life (registered trademark) was used as an adsorbent in the component removal (S2) in the same manner as in 3. In the acid treatment, 123 mg of sulfuric acid was added to the sugar solution from which the components had been removed. The catalytic reaction was also carried out in the same manner as in Test 1.

No. The properties of the sugar solution of No. 9 were quantitatively analyzed using the same method as in Test 2 after the step of component removal (S2) was performed. The conversion rate and yield were quantitatively analyzed using the same method as in Test 2. In the step of pH adjustment (S3), the acid-treated No. In No. 9, S and N were contained in the solution, but the catalytic reaction proceeded sufficiently in the hydrocracking. Since the acid was added to the sugar solution, it can be seen that the solution became acidic and the reaction of the Ir-Re catalyst proceeded. As described above, by performing the acid treatment in the pH adjusting step, the poisoning of the Ir-Re catalyst could be reduced, and the C5 + compound could be produced in a high yield.

Although the examples according to the present disclosure have been described above, the present disclosure is not necessarily limited to this, and those skilled in the art can use various methods without departing from the gist of the present disclosure or the scope of the attached claims. Alternative and modified examples could be found.

S1 Production of saccharified biomass S2 Component removal S3 pH adjustment S4 Catalytic reaction

Claims (9)

A component removal step that removes components derived from enzymes used for saccharification from saccharified biomass that is saccharified from plant-derived biomass.
A pH adjusting step for adjusting the pH of the saccharified biomass from which the components derived from the enzyme have been removed, and
A catalytic reaction step of producing a C5 + compound from the saccharified biomass whose pH has been adjusted by a catalytic reaction using a metal-based catalyst, and
A method for producing a C5 + compound, which comprises. The method for producing a C5 + compound according to claim 1, wherein the pH adjusting step is an acid treatment of adding an acid to the saccharified biomass. The method for producing a C5 + compound according to claim 1, wherein the pH adjusting step is based on ion removal for removing ions from the saccharified biomass. The method for producing a C5 + compound according to claim 3, wherein the ion removal is a treatment for removing inorganic ions with an ion exchange resin. The method for producing a C5 + compound according to any one of claims 1 to 4, wherein the metal-based catalyst is an Ir-Re-based catalyst in which Ir and ReOx are supported on a catalyst carrier. The C5 + compound according to any one of claims 1 to 5, wherein the component removing step is a step of removing at least one of a protein and an amino acid containing at least one of sulfur and nitrogen. Manufacturing method. The method for producing a C5 + compound according to one of claims 1 to 6, wherein the catalytic reaction step hydrogenates the saccharified biomass whose pH has been adjusted, and hydrolyzes and decomposes the obtained sugar alcohol. The method for producing a C5 + compound according to any one of claims 1 to 7, wherein the main component of the saccharified biomass is at least one of glucose and xylose. A C5 + compound produced by the production method according to any one of claims 1 to 8.

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