JP2018080122A - Method for producing c5+ monoalcohol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method that makes it possible to obtain Cmonoalcohol from a C5-6 sugar alcohol with high selectivity, in a single container with a catalyst put in.SOLUTION: In a method for producing C5+ monoalcohol, a catalyst comprises a catalyst grain in which a metal selected from Pt, Pd, and Rh and a metal/metal oxide selected from Ir-ReOx and Rh-MoOx are co-supported on SiOor TiO. The method is characterized by putting hydrogen into a container from outside and heating it so that a selectivity of the Cmonoalcohol to a compound having 5 or more carbon atoms is 40% or more.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method for producing C 5 ₊ monoalcohol as a fuel base from a sugar alcohol having 5 or 6 carbon atoms, and in particular, a sugar alcohol having 5 or 6 carbon atoms in a single container containing a catalyst. The present invention relates to a method for producing C ₅₊ monoalcohol by hydrocracking while generating hydrogen by reforming an aqueous phase.

  Various proposals have been made on methods for producing a fuel base material from biomass or a biomass-derived raw material as a renewable energy source.

  For example, Patent Document 1 discloses a method for producing oxygen-containing compounds such as polyols, diols, ketones, aldehydes, carboxylic acids, and alcohols from water-soluble oxygen-containing hydrocarbons such as biomass-derived polyols and sugars. Here, an aqueous solution of a water-soluble oxygen-containing hydrocarbon having 2 or more carbon atoms is used as a raw material aqueous solution, the hourly weight space velocity per weight of the catalyst material is adjusted, and a part of the raw aqueous solution is present in the presence of the aqueous phase reforming catalyst. Hydrogen is produced from the hydrogen, and this hydrogen is introduced to produce an oxygen-containing compound from the remainder of the raw material aqueous solution in the presence of the hydrogenation catalyst. Most preferably, the reaction temperature at this time is 150 to 270 ° C. in the aqueous phase reforming reaction and 200 to 270 ° C. in the hydrocracking reaction. Further, the water phase reforming catalyst and the hydrogenation catalyst are mixed and the water phase reforming reaction and the hydrocracking reaction are allowed to proceed simultaneously or in parallel in a single chamber, or obtained by water phase reforming. In addition to hydrogen, a very small amount of hydrogen (for example, less than 1 bar in the raw material aqueous solution) is also supplied from the outside.

In addition, alcohol having a larger carbon number may be required in the process of producing a fuel substrate from cellulosic biomass. For example, glucose obtained by hydrolyzing cellulose is represented by a molecular formula of C ₆ H ₁₂ O ₆ , and the monoalcohol having the largest carbon number obtained therefrom is hexanol represented by C ₆ H ₁₄ O.

  For example, in Patent Document 2, as a method for obtaining hexanol and pentanol, which are monoalcohols having a larger carbon number, from saccharides and cellulose in cellulose-based biomass in the presence of a catalyst in a high yield, Ir— A method using a Re-based catalyst is disclosed. The process of hydrolyzing and saccharifying a raw material consisting of cellulose or xylan to obtain a saccharide, and the process of hydrolyzing a sugar alcohol obtained by hydrogenating a saccharide with hydrogen introduced from the outside to obtain a monoalcohol Can proceed in a container. Here, it is said that monoalcohol (hexanol or pentanol) maintaining the carbon number can be obtained by hydrogenolysis at a relatively low temperature so as to suppress the cleavage of the carbon chain of the saccharide obtained by hydrolysis.

Patent Documents 3 and 4 also disclose methods for producing hydrocarbons, ketones and alcohols from biomass-derived oxygenated hydrocarbons. Specifically, biomass, a cyclic sugar molecule derived from biomass, is converted to a linear polyhydric alcohol such as sorbitol by hydrogenation reaction or hydrogenolysis reaction, and this is defunctionalized by deoxygenation reaction. , Ketones, aldehydes, furans, diols, triols, hydroxycarboxylic acids, carboxylic acids and the like. Further, a condensation reaction is performed on the condensation catalyst under conditions of a predetermined temperature and pressure, and a compound having a larger number of carbon atoms, for example, alcohols having 4 or more carbon atoms, ketones, alkanes, alkenes, having 5 or more carbon atoms. It is said that cycloalkanes, cycloalkenes, aryls, fused aryls, and mixtures thereof (C ₄₊ compounds) can be produced. It is stated that the hydrogen used in the hydrocracking at this time is preferably obtained in situ from the above-described polyhydric alcohol, such as sorbitol, using aqueous phase reforming.

JP 2009-536648 A JP 2006-033129 A JP 2014-1559597 A JP 2014-167004 A

As described above, the monoalcohol having the largest carbon number obtained from glucose obtained by hydrolyzing cellulose is hexanol represented by C ₆ H ₁₄ O. However, if it is fragmented in the reaction process, it is an organic acid having a small carbon number. Therefore, it becomes alcohol and hydrocarbon, and hexanol cannot be obtained efficiently. In particular, as disclosed in Patent Document 2, when a plurality of reactions are allowed to proceed in a single container, it is not simple to increase efficiency by reaction competition.

In addition, using externally introduced hydrogen derived from fossil fuel (for example, when producing by natural gas steam reforming, about 11 kg of CO ₂ is discharged per kg of hydrogen) in a single container containing the catalyst. , C ₅₊ monoalcohol (in this specification, C ₆ monoalcohol (hexanol) and C ₅ monoalcohol (pentanol) together with C _{5 +} monoalcohol) _In the case of producing ₅₊ monoalcohol), a large amount of CO ₂ (greenhouse gas) associated therewith is emitted.

The present invention has been made in view of the situation as described above. The object of the present invention is to suppress the emission of greenhouse gases while keeping the number of carbon atoms in a single container containing a catalyst and 5 carbon atoms. _Another object of the present invention is to provide a method for producing C ₅₊ monoalcohol from 6 sugar alcohols with high selectivity.

The method for producing C 5 ₊ monoalcohol according to the present invention comprises hydrocracking while producing hydrogen by reforming a sugar alcohol having 5 and / or 6 carbon atoms in an aqueous phase in a single vessel containing a catalyst. A method for producing C ₅₊ monoalcohol, wherein the catalyst is selected from SiO ₂ or TiO ₂ selected from Pt, Pd, and Rh, and Ir—ReO _x and Rh—MoO _x Hydrogen is externally introduced into the vessel and heated so that the selectivity of the C 5 ₊ monoalcohol with respect to the compound having 5 or more carbon atoms is 40% or more, comprising catalyst particles co-supported with metal / metal oxide. It is characterized by.

According to this invention, the reaction temperature can be set to a relatively low temperature, so that the carbon chain can be prevented from being broken, and the hydrogen decomposition reaction of the sugar alcohol is controlled by controlling the hydrogen pressure introduced outside while generating hydrogen by aqueous phase reforming. Production of alkane can be suppressed while C ₅ is proceeding, and C 5 ₊ monoalcohol can be produced with high selectivity. Moreover, a part of hydrogen used for hydrocracking can be obtained by aqueous phase reforming, and greenhouse gas emissions can be suppressed.

  In the above-described invention, the container may be a batch-type reaction container, and hydrogen may be introduced into the outside in advance before heating. According to this invention, the hydrogen pressure at the reaction temperature can be predicted, and the pressure of hydrogen introduced outside can be easily controlled.

The vessel may be a continuous reaction vessel, and hydrogen may be continuously introduced to the outside. According to this invention, it is possible to produce C 5 ₊ monoalcohol with a high selectivity by continuously introducing hydrogen into a continuous reaction vessel.

  In the above-described invention, hydrogen may be externally introduced so as to have a pressure within a range of 0.6 to 2.0 MPa at room temperature. According to this invention, the reaction system can be controlled to a pressure at a predetermined reaction temperature corresponding to a pressure range of 0.6 to 2.0 MPa at room temperature, and the amount of hydrogen introduced externally can be controlled by the pressure.

In the above-described invention, the sugar alcohol is sorbitol, and the heating temperature of the container may be 170 ° C. or higher and 190 ° C. or lower. According to this invention, when the sugar alcohol is sorbitol, C ₅₊ monoalcohol can be produced with high selectivity.

It is a figure which shows the reaction process in this invention. It is a figure which shows the elementary reaction of the reaction process in this invention. It is a figure which shows the reaction process in this invention. It is a figure which shows the elementary reaction of the reaction process in this invention. It is sectional drawing of the container which shows the reaction process in this invention typically.

Below, the Example demonstrates the detail about one Example of the manufacturing method of C5 ₊ monoalcohol by this invention.

The method for producing C 5 ₊ monoalcohol according to the present invention maintains the carbon number from sorbitol, which is a sugar alcohol having 6 carbon atoms derived from cellulosic biomass, or xylitol, which is a sugar alcohol having 5 carbon atoms, that is, each having 6 carbon atoms. This is a method for producing hexanol, which is a C ₆ monoalcohol, or pentanol, which is a C ₅ monoalcohol having 5 carbon atoms, with high selectivity while suppressing emission of greenhouse gases. Here, although hexanol becomes three types, 1-hexanol, 2-hexanol, and 3-hexanol, depending on the position of the hydroxy group, any of them may be included in the present invention. Similarly, pentanol may include any of 1-pentanol, 2-pentanol, and 3-pentanol.

FIG. 1 is a diagram showing an example of the reaction in the present invention. First, hydrogen is obtained from a part of sorbitol by aqueous phase reforming. The largest carbon number that can be obtained by hydrocracking sorbitol (or sorbitol containing cellulose and glucose before decomposition) using hydrogen obtained internally and also using hydrogen introduced externally generating a _{C 6} monoalcohols. In addition, sorbitol can be obtained, for example, by hydrogenating glucose obtained by hydrolyzing cellulose in cellulosic biomass and saccharifying it.

Specifically, referring also to FIG. 2, carbon dioxide (CO ₂ ) and hydrogen can be obtained from sorbitol and water by using a Pt-based catalyst in the aqueous phase reforming. Since CO ₂ produced here is derived from biomass, carbon neutral is applied and it is not counted as a greenhouse gas. In such an aqueous phase reforming reaction, the higher the temperature, the more the reaction can proceed and the amount of hydrogen produced can be increased. The ideal reaction temperature is 200 ° C. or higher. On the other hand, in the hydrocracking reaction, for example, an Ir-Re catalyst can be used, and hexanol and water can be obtained from sorbitol and hydrogen. In such a hydrocracking reaction, the lower the temperature, the higher the selectivity for breaking the C—O bond without breaking the C—C bond. That is, the reaction can proceed while suppressing the breakage of the carbon chain, and the ideal reaction temperature is about 140 ° C.

Moreover, FIG. 3 is a figure which shows another example of reaction in this invention. First, hydrogen is obtained from a part of xylitol by water phase reforming. The largest number of carbons obtained by hydrogenolysis of xylitol (or xylitol containing hemicellulose and xylose before decomposition) using not only hydrogen obtained inside but also hydrogen introduced externally generating a _{C 5} monoalcohols. Xylitol can be obtained, for example, by hydrogenating xylose hydrolyzed and saccharified from hemicellulose in cellulosic biomass.

Specifically, referring also to FIG. 4, in the aqueous phase reforming, a Pt-based catalyst can be used, and carbon dioxide (CO ₂ ) and hydrogen can be obtained from xylitol and water. Since CO ₂ produced here is derived from biomass, carbon neutral is applied and it is not counted as a greenhouse gas. In such an aqueous phase reforming reaction, the higher the temperature, the more the reaction can proceed and the more hydrogen can be produced. The preferred reaction temperature is 200 ° C. or higher. On the other hand, in the hydrocracking reaction, for example, an Ir—Re catalyst can be used, and pentanol and water can be obtained from xylitol and hydrogen. In such a hydrocracking reaction, the lower the temperature, the higher the selectivity for breaking the C—O bond without breaking the C—C bond. That is, the reaction can proceed while suppressing the breakage of the carbon chain, and the preferred reaction temperature is about 140 ° C.

Referring to FIG. 5, in the present invention, such an aqueous phase reforming reaction and hydrocracking reaction are allowed to proceed in a single aqueous phase 2 of a single vessel 4, that is, in the same environment. For this purpose, it is considered to use a combination of catalysts having high catalytic activity for each of the aqueous phase reforming reaction and hydrocracking reaction. Such catalysts, catalyst particle 1 by _{Pt / Ir-ReO x / SiO} 2 catalysts were co carrying Pt and Ir-ReO _x to SiO ₂ is preferable. In such a Pt / Ir—ReO _x / SiO ₂ catalyst, hydrogen generation and hydrocracking reaction in the aqueous phase reforming reaction can proceed simultaneously as compared with the case where the Pt catalyst and the Ir—ReO _x catalyst are respectively provided. C ₅₊ monoalcohol can be produced efficiently. Further, the catalyst carrier may be TiO ₂ . Further, Pd or Rh may be used instead of Pt, and Rh—MoO _x may be used instead of Ir—ReO _x . Here, _x in ReO _x and MoO _x represents the number of oxygen and is an arbitrary real number.

The catalyst particles 1 are put into an aqueous phase (raw material solution) 2 containing sorbitol or xylitol, heated after external introduction of hydrogen, and the aqueous phase reforming reaction and hydrocracking reaction proceed in the same environment. Let Here, in the catalyst, Pt and Ir—ReO _x are co-supported on SiO ₂ so that the active point of the aqueous phase reforming reaction and the active point of the hydrocracking reaction are adjacent to each other, and hydrogen generated by the aqueous phase reforming reaction is generated. Is efficiently consumed in the hydrocracking reaction. With such a co-supported catalyst, the reaction temperature can be made relatively low, and the carbon chain scission due to the hydrocracking reaction can be suppressed.

Further, the surface of the aqueous phase 2 stored in the container 4 is covered with an oil phase 3 made of an organic solvent. Then, only the produced C ₅₊ compound containing C ₅₊ monoalcohol (in this specification, the C ₆ compound having ₆ carbon atoms and the C ₅ compound having ₅ carbon atoms are collectively referred to as a C ₅₊ compound). Can be moved to the oil phase 3 to recover the C ₅₊ compound from the oil phase 3 relatively easily. Here, C ₅₊ monoalcohol may be separated by such a C ₅₊ compounds such as distillation, but efficiently C ₅₊ monoalcohols higher C ₅₊ monoalcohol selectivity to total C ₅₊ compounds produced by hydrogenolysis Can be recovered.

  In the above, the container 4 needs to have an inner surface that can withstand the temperature and pressure of the reaction conditions described later and does not impair the catalytic activity. For example, a glass reaction vessel or a metal reaction vessel can be used. In the case of a metal reaction vessel, it is preferable that the content of Fe or Ni is small without impairing the catalytic activity. The container 4 is a batch-type reaction container, and hydrogen is externally introduced before heating, but is pressurized so as to have a predetermined hydrogen partial pressure. Although the container 4 can be a continuous reaction container, in this case, hydrogen introduced externally is also continuously supplied to maintain the same temperature and pressure as in the case of a batch reaction container.

Moreover, the solvent which forms the oil phase 3 does not inhibit the above-described aqueous phase reforming reaction and hydrocracking reaction. For example, when ether is used as a solvent, the ether itself is decomposed, so that the function as the oil phase 3 for dissolving the alcohol can be impaired. In addition, alcohol having an OH group is adsorbed on the catalyst and covers the active site, so that the catalytic ability may be impaired. In addition, unsaturated hydrocarbons, such as olefinic hydrocarbons, may themselves be hydrogenated in the presence of a metal catalyst, in which case the hydrogen used in the hydrocracking of sorbitol or xylitol is consumed and C The yield of ₅₊ monoalcohol is reduced. Aromatic hydrocarbons can also be hydrogenated, but they can also be used as solvents because the hydrogenation reaction rate is slow.

  Furthermore, the solvent forming the oil phase 3 needs to be a liquid phase (liquid) at the temperature and pressure as the reaction conditions described above. Typically, the preferable reaction conditions are 170 ° C. to 190 ° C., and the pressure at room temperature in the reaction vessel is 0.6 MPa to 2 MPa (described later). For example, the boiling point of the solvent is 170 ° C. or higher at 0.6 MPa. The temperature is preferably 190 ° C. or higher, more preferably 200 ° C. or higher at 0.6 MPa. Moreover, since it will become difficult to collect | recover a product if it will become a solid phase when taking out the oil phase 3, it is preferable to maintain a liquid phase also at normal temperature normal pressure. As such a saturated hydrocarbon, for example, n-tridecane, n-dodecane, n-decane and the like can be used. Moreover, you may use the solvent which forms the oil phase 3 in mixture of 2 or more types.

  By the way, as mentioned above, the ideal reaction temperature differs between the water phase reforming reaction and the hydrocracking reaction. However, since the aqueous phase reforming reaction and the hydrocracking reaction are advanced in a single vessel, the reaction temperatures must be the same. Therefore, for example, when a raw material solution containing sorbitol is used, it is preferably a low temperature from the viewpoint of suppressing carbon chain scission in the hydrocracking reaction, and the reaction temperature can be, for example, 200 ° C. or less, preferably 190 It is below ℃. On the other hand, the temperature is preferably high from the viewpoint of the aqueous phase reforming reaction, and the reaction temperature can be 160 ° C. or higher, preferably 170 ° C. or higher, in order to ensure the necessary amount of hydrogen generation.

When such temperature and pressure are set, the hydrogen is not sufficiently supplied to the hydrocracking reaction only by the hydrogen produced in the aqueous phase reforming reaction because of the relatively low temperature. Therefore, when hydrogen is introduced externally, an amount of hydrogen necessary for the hydrocracking reaction can be supplied, and the yield of C 5 ₊ monoalcohol can be improved. However, if hydrogen is supplied in excess, C5 ₊ monoalcohol is further hydrocracked to produce alkane. Even if the yield of C ₅₊ monoalcohol can be improved by increasing the supply amount of hydrogen, but the yield of C ₅₊ compounds other than monoalcohols such as alkanes is also increased, it is not intended. A large amount of raw materials are used for the production of the product, and the efficiency is poor even considering the trouble of separating them. That is, it is important to improve the selectivity of C ₅₊ monoalcohol relative to the entire C ₅₊ compound among the products produced by the hydrocracking reaction.

  By the way, in order to efficiently consume the supplied hydrogen in the hydrocracking reaction, the reaction atmosphere is set to a pressurized environment. On the other hand, as described above, when hydrogen is externally introduced, it is introduced under pressure. However, if the hydrogen pressure is too high, the amount of hydrogen produced in the aqueous phase reforming reaction is reduced. Furthermore, there is an upper limit to the hydrogen pressure in order to avoid excessive hydrogen supply as described above. Therefore, for example, when a raw material solution containing sorbitol is used, hydrogen is externally introduced so that the pressure before heating is 0.6 to 2.0 MPa.

Thus, despite the fact that the reaction temperature is lower than the ideal temperature for aqueous phase reforming alone, the above-mentioned co-supported catalyst can be used to efficiently supply the supplied hydrogen in the hydrocracking reaction. Can be consumed. Moreover, although the amount of hydrogen produced by the aqueous phase reforming is reduced by lowering the temperature, the amount of hydrogen necessary for the hydrocracking reaction can be secured by introducing hydrogen externally. On the other hand, excessive hydrogenolysis that further generates alkane from C 5 ₊ monoalcohol can be suppressed by adjusting the pressure for introducing hydrogen so as not to supply excessive hydrogen. By controlling the pressure of hydrogen introduced outside in this way, the selectivity of C 5 ₊ monoalcohol relative to a C 5 ₊ compound having 5 or more carbon atoms can be increased. Typically, for example, when a raw material solution containing sorbitol is used, the selectivity of C ₅₊ monoalcohol relative to the C ₅₊ compound can be 40% or more under the predetermined environmental conditions described above. Moreover, a part of hydrogen used for hydrocracking is obtained by aqueous phase reforming of biomass-derived raw materials, and greenhouse gas emissions can be suppressed.

One specific example of the present invention described above will be further described below. Here, for the purpose of obtaining C 5 ₊ monoalcohol using a raw material solution containing sorbitol, a test was carried out to produce C 5 ₊ monoalcohol under the conditions shown in Table 1 with room temperature pressure accompanying external introduction of hydrogen. It was.

[Preparation of catalyst]
First, an aqueous solution of iridium nitrate (Ir (NO ₃ ) ₄ ) is added dropwise to silicon dioxide (SiO ₂ ) (“CariACT G-6” manufactured by Fuji Silysia Chemical Ltd.), and the whole is wetted and dried at about 90 ° C. . Such wetting and drying steps were repeated so that Ir was 4% by mass with respect to the whole catalyst, and further drying was performed at 110 ° C. for about half a day. Next, the same wetting and drying steps were repeated with an aqueous ammonium perrhenate (NH ₄ ReO ₄ ) solution, and the molar ratio of Re to Ir, that is, [Re] / [Ir] was supported to be 2. Thereafter, firing was performed at 500 ° C. for 3 hours in an air atmosphere to obtain Ir—ReO _x / SiO ₂ . Further, a chloroplatinic acid (H ₂ PtCl ₆ ) aqueous solution is added dropwise to Ir—ReO _x / SiO ₂ to wet the whole and dried at about 90 ° C. By repeating such wetting and drying steps, Pt is supported on the entire catalyst so as to be 5% by mass, calcined in an air atmosphere at 500 ° C. for 3 hours, and Pt and Ir—ReO _{x on} SiO _2. Thus, a Pt / Ir—ReO _x / SiO ₂ catalyst was obtained.

[Reduction treatment]
A SUS316 autoclave (capacity: 100 mL) having a glass inner tube was used as a reaction vessel. An electric furnace is arranged around the reaction vessel so that the inside can be heated. Further, a stirring blade provided with a Teflon (registered trademark) coating is provided inside the reaction vessel so that the inside can be stirred. 0.3 g of the catalyst prepared as described above and 9.5 g of water are put in a reaction vessel, and hydrogen substitution is repeated three times or more. Hydrogen was introduced so that the total pressure was 5.0 MPa at room temperature, and then the reaction vessel was heated and held at 200 ° C. for 1 hour to reduce the catalyst. A reaction vessel containing the catalyst after the reduction treatment was prepared corresponding to each of Examples and Comparative Examples described later.

[Product yield and selectivity]
The yield is the carbon molar yield of the product of interest converted from sorbitol, ie, C ₅₊ monoalcohol (hexanol and pentanol), other C ₅₊ compounds and carbon dioxide, and is given by:
Yield (%) = (Total number of moles of carbon in the product of interest) / (Total number of moles of carbon in sorbitol) × 100
For example, “the total number of moles of carbon of the product of interest” can be calculated by multiplying the number of moles of the product of interest analyzed by a gas chromatograph or the like and the number of carbons of the product. Similarly, the “total number of moles of carbon in sorbitol” can be calculated by multiplying the number of moles of sorbitol charged in the reaction vessel by the number of carbon atoms.

Moreover, the selectivity calculated the ratio of C5 ₊ monoalcohol (hexanol + pentanol) with respect to the whole C5 ₊ compound produced _| generated by reaction from the yield, respectively.

[Production of C 5 ₊ monoalcohol]
As shown in Table 1, in each of the tests of Examples 1 to 3 and Comparative Examples 1 to 4, hydrogen (Comparative Example 1 is nitrogen) was introduced externally so as to have each “pressure at room temperature”, and C 5 ₊ monoalcohol Attempted to generate First, 0.5 g of sorbitol was added into the reaction vessel in which the catalyst was reduced as described above. Next, 20 mL of n-tridecane as oil phase 3 is added to the reaction vessel, and hydrogen gas is introduced at room temperature so that the pressure at room temperature shown in Table 1 is the total pressure (external introduction), heated to 180 ° C. and held for 3 hours. did. In Comparative Example 1, nitrogen gas is introduced instead of hydrogen gas as described above. Table 1 shows the results of analyzing the product after the reaction. In addition, the gas chromatograph, the gas chromatograph mass spectrometer, the high performance liquid chromatograph, and the liquid chromatograph mass spectrometer were used for the analysis.

[Test results]
In Table 1, “hexanol” represents 1-hexanol, 2-hexanol, 3-hexanol, “pentanol” represents 1-pentanol, 2-pentanol, 3-pentanol, and “C ₅₊ monoalcohol”. Indicates the total of hexanol and pentanol. The _{"C 5+} monoalcohol _{/ C 5+" is} a selectivity of _{C 5+} monoalcohols for _{C 5+ compounds,} among the _{C 5+} compound, as the _{C 6} compounds, besides hexanol, n- hexane, hexanone, hexanoic acid etc. are detected, the C ₅ compounds, besides pentanol, n- pentane, pentanone, etc. pentanoic acid was detected. As for the evaluation of selectivity, when C 5 ₊ monoalcohol is obtained at 40% or more, it is evaluated as high selectivity and “◯” is written, and less than 40% is evaluated as low selectivity. "X" was described. Furthermore, since CO ₂ is produced as a by-product when hydrogen is generated by aqueous phase reforming, those with CO ₂ detected were evaluated as having a greenhouse gas reduction effect and indicated with “◯”.

By the way, referring to FIG. 2 and FIG. 4, the carbon dioxide produced by the aqueous phase reforming reaction is not used in a hydrocracking reaction or the like that is a subsequent reaction step. Therefore, the yield of carbon dioxide obtained with respect to the amount of sorbitol is proportional to the amount of hydrogen generated by the aqueous phase reforming reaction. That is, the amount of hydrogen obtained by the aqueous phase reforming reaction is estimated from the yield of CO ₂ .

As shown in Table 1, in Examples 1 to 3 in which the pressure at room temperature by externally introduced hydrogen was 0.6 to 2.0 MPa, the selectivity of C 5 ₊ monoalcohol relative to the C _{5 +} compound (hereinafter simply “selection”) In some cases, the ratio was 40.1-70.6%, which was 40% or more. Moreover, it is considered that hydrogen was obtained by water phase reforming reaction in any of the examples from the yield of CO ₂ and used for hydrocracking reaction together with hydrogen introduced externally. C5 ₊ monoalcohol is obtained while suppressing the above.

In contrast, in Comparative Example 1 in which nitrogen was introduced instead of hydrogen, the selectivity was as low as 13.7%. From the CO ₂ yield, the amount of hydrogen obtained by the aqueous phase reforming reaction was the largest compared to other examples and comparative examples, but the hydrogen required for the hydrocracking reaction because there was no external introduction of hydrogen. It is probable that a sufficient amount was not secured.

In Comparative Examples 2 to 4 in which the pressure at room temperature by external introduction of hydrogen was 2.5 to 6.0 MPa, the yield of C 5 ₊ monoalcohol was obtained to the same extent as in Examples 1 to 3, but was selected. The rate is 18.3 to 35.3%, and less than 40%. Since the hydrogen partial pressure was high, it is considered that the hydrocracking reaction proceeded excessively and C 5 ₊ monoalcohol was decomposed to produce a large amount of alkane and the like. In particular, although not shown, the yield of alkanes (n-hexane and n-pentane) is about 40% in Comparative Example 2 and more than that in other Comparative Examples, and the selectivity is low. Moreover, it is thought that there was almost no water phase reforming reaction from the viewpoint of the yield of CO ₂ .

Even when xylitol is used as a raw material, C ₅₊ monoalcohol can be produced with high selectivity.

As described above, C ₅₊ monoalcohol is produced by hydrocracking a sugar alcohol having 5 and / or 6 carbon atoms in a single container containing a catalyst to produce hydrogen by reforming the water phase. In this case, by introducing hydrogen externally, it is possible to produce C 5 ₊ monoalcohol with high selectivity while suppressing the emission of greenhouse gases. In particular, so that the selectivity is 40% or more, specifically, when sorbitol is used as a raw material, hydrogen is externally introduced so that the room temperature pressure is 0.6 to 2.0 MPa, C5 ₊ monoalcohol can be produced with high selectivity while suppressing the emission of greenhouse gases.

As mentioned above, although the Example by this invention and the modification based on this were demonstrated, this invention is not necessarily limited to this, A person skilled in the art will deviate from the main point of this invention, or the attached claim. Various alternative embodiments and modifications could be found without doing so.

Claims (5)

A method for producing C 5 ₊ monoalcohol by hydrocracking while producing hydrogen by reforming an aqueous phase of a sugar alcohol having 5 and / or 6 carbon atoms in a single container containing a catalyst,
The catalyst is a catalyst particle in which a metal selected from Pt, Pd, and Rh and a metal / metal oxide selected from Ir—ReO _x and Rh—MoO _x are co-supported on SiO ₂ or TiO _2. A method for producing C ₅₊ monoalcohol, comprising introducing hydrogen into the vessel and heating the mixture so that the selectivity of the C ₅₊ monoalcohol to the compound having 5 or more carbon atoms is 40% or more. The method for producing C5 ₊ monoalcohol according to claim 1, wherein the vessel is a batch type reaction vessel, and hydrogen is introduced into the outside in advance before heating. The method for producing C 5 ₊ monoalcohol according to claim 1, wherein the vessel is a continuous reaction vessel, and hydrogen is continuously introduced to the outside. The method for producing C5 ₊ monoalcohol according to any one of claims 1 to 3, wherein hydrogen is externally introduced so as to have a pressure within a range of 0.6 to 2.0 MPa at room temperature. The sugar alcohol is sorbitol,
5. The method for producing C ₅₊ monoalcohol according to claim 1, wherein the heating temperature of the container is 170 ° C. or higher and 190 ° C. or lower.

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