JP2012188390A - Method for producing 1,2-propanediol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing 1,2-propanediol by which a targeted compound is produced in a mild condition with an excellent selectivity.SOLUTION: In the method for producing 1,2-propanediol, glycerol is hydrocracked in the presence of hydrogen and a catalyst obtained by subjecting hydrotalcite containing at least a copper component as a metal component to reduction treatment and containing a zero valent copper component, and thus 1,2-propanediol is obtained. The hydrotalcite preferably contains an aluminum component and/or a magnesium component as the other metal component.

Description

  The present invention relates to a process for producing 1,2-propanediol that can efficiently hydrocrack glycerol to obtain 1,2-propanediol.

  As fossil fuel supply insecurity and global warming problems due to carbon dioxide emissions become more serious, the use of biodiesel fuel derived from biological resources is becoming popular. As the use of biodiesel fuel increases, glycerol produced as a by-product in the production process is becoming excessively supplied. Therefore, effective use of glycerol is required.

  Glycerol is known to be used as an additive for foods, pharmaceuticals, cosmetics and the like, and as a raw material for alcohols having 3 carbon atoms such as 1,3-propanediol and 1,2-propanediol. In particular, alcohols having 3 carbon atoms such as 1,3-propanediol and 1,2-propanediol are very useful as humectants, emulsifiers, solvents, plastic raw materials, and the like. The production of alcohols 3 has attracted worldwide attention.

  Patent Document 1 describes a method for producing 1,2-propanediol using copper-platinum-supporting silica as a catalyst. However, there is a problem in that the distribution conditions are severe under a hydrogen pressure of 2 MPa (5 L / min), and the selectivity of 1,2-propanediol remains at about 90%.

JP 2010-111618 A

Accordingly, an object of the present invention is to provide a method for producing 1,2-propanediol, which can produce a target compound with excellent selectivity under mild conditions.
Another object of the present invention is to provide a process for producing 1,2-propanediol using a reusable catalyst.

  As a result of intensive studies to solve the above problems, the present inventors, as a metal component, obtained by reducing hydrotalcite containing at least a copper component, a catalyst containing a zero-valent copper component and the presence of hydrogen It has been found that 1,2-propanediol can be obtained with excellent selectivity under mild conditions by hydrogenolysis of glycerol. Further, the present inventors have found that the catalyst can be easily reused, and that the action does not decrease even after repeated use-regeneration. The present invention has been completed based on these findings.

  That is, the present invention is obtained by hydrocracking glycerol in the presence of a catalyst containing a zero-valent copper component and hydrogen obtained by reducing hydrotalcite containing at least a copper component as a metal component. A method for producing 1,2-propanediol to obtain 2-propanediol is provided.

  The hydrotalcite preferably contains an aluminum component and / or a magnesium component as another metal component, and the copper component and the other metal component have a former / latter (metal atom molar ratio) of 10/1 to 1/1 /. It is preferable to contain in the ratio used as ten.

  The present invention also provides a catalyst containing zero-valent and monovalent copper components obtained by reducing hydrotalcite containing at least a copper component as a metal component.

  The present invention further provides a method for producing the catalyst, the method comprising the step of reducing hydrotalcite containing at least a copper component as a metal component in a state of being dispersed in water.

  The method for producing 1,2-propanediol according to the present invention uses a catalyst containing a zero-valent copper component, which is obtained by reducing hydrotalcite containing at least a copper component. 1,2-propanediol can be selectively produced in an extremely high yield by hydrogenolysis of glycerol even under mild conditions. According to the method for producing 1,2-propanediol according to the present invention, useful 1,2-propanediol can be efficiently produced from glycerol produced as a by-product in the production process of biodiesel fuel. By effectively using it, it is possible to further reduce the amount of carbon dioxide that causes global warming. Furthermore, the catalyst used in the present invention can be reused, and the high catalytic action can be maintained even when used repeatedly. Therefore, the cost can be reduced, which is advantageous for industrialization, and useful 1,2-propanediol can be provided at low cost.

Cu-Al-hydrotalcite obtained in Production Example 1 (Cu / Al = 2.0 / 1.0: catalyst (1)) and the catalyst (1) used once-regenerated catalyst ( It is an X-ray-diffraction result of a catalyst (catalyst (5)) after repeating use-regeneration | regeneration of catalyst (2)) and this catalyst (1) 4 times.

[catalyst]
In the present invention, a compound containing a zero-valent copper component obtained by reducing hydrotalcite containing at least a copper component as a metal component is used as a catalyst.

  The copper component content of the hydrotalcite is, for example, about 0.1 to 10% by weight, preferably about 1 to 10% by weight, and particularly preferably about 3 to 10% by weight. When the copper component content is below the above range, the catalytic action tends to decrease. On the other hand, when the copper component content exceeds the above range, aggregation of the copper component tends to occur.

Hydrotalcite is, for example, the following formula (1)
[M ^II _1-X M ^III _X (OH) ₂ ] [A ²⁻ _{x / 2} ] · nH ₂ O (1)
(In the formula, M ^II is one or more selected from Mg ²⁺ , Fe ²⁺ , Zn ²⁺ , Ca ²⁺ , Li ²⁺ , Ni ²⁺ , Co ²⁺ , Cu ²⁺ , and Mn ^2+. And at least Cu ²⁺ M ^III is at least one trivalent metal selected from Al ³⁺ , Fe ³⁺ , Mn ³⁺ , Ru ³⁺ , x is 0 or more and less than 1. A ²⁻ represents a divalent anion, and n represents an integer of 0 to 30)
It is represented by

A ^2- in formula (1) includes, for example, carbonate anion, chlorine anion, acetate anion, sulfate anion, terephthalate anion, 1,5-naphthalenedisulfonate anion, dodecyl sulfate anion or sebacate anion. Can do.

As the hydrotalcite in the present invention, the inclusion of an aluminum component and / or a magnesium component as a metal component other than the copper component is excellent in the selectivity of 1,2-propanediol and the stability of the catalyst. In particular, in the above formula (1), M ^II is Cu ²⁺ , or Cu ²⁺ and Mg ²⁺ (particularly Cu ²⁺ is preferable), M ^III is Al ³⁺ , and A ²⁻ is a carbonate anion ( CO ₃ ^2- ) is preferred. As a content ratio of the copper component and the other metal component, for example, the former / the latter (metal atom molar ratio) is about 10/1 to 1/10, preferably about 5/1 to 1/8.

Further, when Cu ²⁺ and Mg ²⁺ are combined as M ^II , the ratio of Cu ²⁺ and Mg ²⁺ is, for example, the former / the latter (metal atom molar ratio) is 1/10 to 3/1. The degree is preferably about 1/8 to 1/1. In the present invention, in particular, hydrotalcite represented by Cu ₄ Al ₂ (OH) ₁₂ CO ₃ .nH ₂ O can be suitably used.

The hydrotalcite includes, for example, an aqueous solution of a copper compound such as Cu (NO ₃ ) ₂ , Cu (OAc) ₂ , CuCl ₂ , CuSO ₄ , aluminum nitrate, magnesium nitrate, aluminum chloride, magnesium chloride, aluminum sulfate, sulfuric acid One or more aqueous solutions selected from magnesium and the like, and an alkali (for example, a basic aqueous solution of NaOH, Na ₂ CO _3, etc.) are simultaneously added dropwise, followed by aging treatment (for example, 1 at a temperature of 60 to 80 ° C.). It can be manufactured by a method (simultaneous dripping method) of applying the solution to about 5 hours.

  In the simultaneous dropping method, it is preferable to adjust the reaction solution during dropping to about pH 8-9.

  The hydrotalcite obtained by the above production method is preferably subjected to a washing treatment (washing with water or an organic solvent), a drying treatment (drying by vacuum drying or the like) and the like thereafter.

The catalyst of the present invention is obtained by reducing the hydrotalcite. By subjecting hydrotalcite to a reduction treatment, the contained copper component (Cu: divalent) is reduced to become a monovalent copper component (Cu ⁺ ) and / or a zero-valent copper component (Cu (0)). .

The catalyst in the present invention contains a zero-valent copper component (Cu (0)). In the present invention, it is particularly preferable to contain both a zero-valent copper component (Cu (0)) and a monovalent copper component (Cu ⁺ ). When both the zero-valent copper component (Cu (0)) and the monovalent copper component (Cu ⁺ ) are contained, the selectivity of the desired 1,2-propanediol can be further improved. -Even if regeneration is repeated, the monovalent copper component (Cu ⁺ ) can be prevented from sintering and aggregation (sintering) of the zero-valent copper component (Cu (0)), and the degradation (catalytic activity) Reduction) can be suppressed.

Further, when both a zero-valent copper component (Cu (0)) and a monovalent copper component (Cu ⁺ ) are contained, as the content ratio, for example, the former / the latter (metal atom molar ratio) is 90 / About 10-60 / 40 is preferable. The content ratio of the zero-valent copper component (Cu (0)) and the monovalent copper component (Cu ⁺ ) can be determined by, for example, an X-ray diffraction method.

  In the reduction treatment of hydrotalcite, hydrotalcite containing at least a copper component as a metal component is preferably reduced in a state dispersed in water. The amount of water for dispersing hydrotalcite is preferably in the range where the hydrotalcite concentration is about 5 to 20% by weight, preferably about 10 to 20% by weight.

Examples of the reducing agent used for the reduction treatment of hydrotalcite include borohydride complex compounds such as sodium borohydride (NaBH ₄ ), lithium borohydride (LiBH ₄ ), and potassium borohydride (KBH ₄ ). Examples include hydrazine, hydrogen (H ₂ ), silane compounds such as dimethylphenylsilane, and hydroxy compounds. Examples of the hydroxy compound include alcohol compounds such as a primary alcohol and a secondary alcohol. The hydroxy compound may have a plurality of hydroxyl groups, and may be any of monohydric alcohol, dihydric alcohol, polyhydric alcohol and the like.

In the present invention, hydrogen (H ₂ ) and a borohydride complex compound are preferable, and hydrogen (H ₂ ) is particularly preferable. When hydrogen (H ₂ ) is used as a reducing agent, the reducing power is relatively weak, so the copper component contained in the hydrotalcite is a zero-valent copper component (Cu (0)) and a monovalent copper component (Cu ⁺ ) Can coexist. When hydrogen (H ₂ ) is used as the reducing agent, for example, the reduction reaction can be performed by bubbling hydrogen gas into the dispersion.

The reduction treatment temperature and time are, for example, 80 to 120 ° C. (preferably 100 to 120 ° C.) and about 1 to 8 hours (preferably 4 to 8 hours). By adjusting the reduction treatment temperature and time within the above ranges, a state in which a zero-valent copper component (Cu (0)) and a monovalent copper component (Cu ⁺ ) coexist can be formed.

[Method for producing 1,2-propanediol]
The method for producing 1,2-propanediol according to the present invention is obtained by reducing a hydrotalcite containing at least a copper component as a metal component, in the presence of a catalyst containing a zero-valent copper component and hydrogen. Glycerol is hydrocracked to obtain 1,2-propanediol.

  In addition, the catalyst may be obtained in advance by reducing the hydrotalcite containing at least a copper component as a metal component, and by reducing the hydrotalcite in the reaction system. A catalyst may be produced and used.

  The amount of the catalyst used (in terms of copper component) is, for example, about 0.0001 to 50 mol% (particularly about 0.01 to 50 mol%, more preferably about 0.1 to 50 mol%) with respect to glycerol. , Most preferably about 1.0 to 50 mol%).

  Examples of the hydrogen supply method include a method of performing a reaction in hydrogen (that is, under a hydrogen atmosphere), a method of bubbling hydrogen gas, and the like. When the reaction is performed in hydrogen, the pressure during the reaction is not particularly limited and may be normal pressure or increased pressure, but is preferably 0.1 to 15 MPa (particularly 5 to 14 MPa).

  The above reaction can be carried out by a conventional method such as batch, semi-batch or continuous.

  Moreover, it is preferable to perform the said reaction in presence of a solvent. This is because, when the reaction is carried out in the absence of a solvent, glycerol as a substrate is adsorbed on the catalyst and becomes lumped and the progress of the reaction may be inhibited. Examples of the solvent include water; fluorinated solvents such as trifluorotoluene, fluorobenzene, and fluorohexane; aromatic hydrocarbons (eg, benzene, toluene, xylene, chlorobenzene, nitrobenzene, etc.) and aliphatic hydrocarbons (eg, pentane). , Hexane, heptane, octane, cyclohexane, methylcyclohexane, etc.); ethers such as 1,2-dioxane, 1,3-dioxane, 1,4-dioxane, tetrahydrofuran, tetrahydropyran, diethyl ether, dimethyl ether; Examples include amides such as acetamide, dimethylacetamide, dimethylformamide, diethylformamide, and N-methylpyrrolidone; esters such as ethyl acetate, propyl acetate, and butyl acetate; and mixtures thereof. Among these, ethers are preferable as the solvent, and 1,4-dioxane is particularly preferable. The amount of the solvent used is preferably within the range where the initial concentration of glycerol is about 0.5 to 5% by weight when the reaction is carried out batchwise.

  The method for producing 1,2-propanediol according to the present invention allows the reaction to proceed smoothly even under mild conditions. As reaction temperature, it is 50-250 degreeC, for example, Preferably it is about 100-220 degreeC, Most preferably, it is about 150-200 degreeC. The reaction time can be appropriately adjusted according to the reaction temperature and pressure, and is, for example, about 30 minutes to 10 hours, preferably about 1 hour to 8 hours, and particularly preferably about 3 hours to 8 hours.

  After completion of the reaction, the reaction product can be separated and purified by, for example, separation means such as filtration, concentration, distillation, extraction and the like, or a separation means combining these.

  According to the method for producing 1,2-propanediol of the present invention, the hydrocracking reaction of glycerol can be performed under mild conditions, and 1,2-propanediol is selectively produced with excellent conversion. can do.

  Furthermore, the catalyst used in the reaction can maintain a high catalytic activity because the zero-valent copper component that is a catalytically active component hardly aggregates even after repeated use-regeneration. On the other hand, when the catalytically active component is agglomerated, the surface area is reduced, so that the catalytic activity is reduced. In addition, since the copper component, which is a catalytically active component, has a structure in which hydrotalcite is contained, the copper component is difficult to elute in the reaction solution even in an organic synthesis reaction, and the physical reaction such as filtration and centrifugation from the reaction solution It can be easily recovered by a simple separation method. The recovered catalyst is reused as it is or after being washed and dried. The washing treatment can be performed by a method of washing several times (for example, 2 to 3 times) with an appropriate solvent (for example, water).

  The recovered catalyst can exhibit almost the same catalytic ability as an unused catalyst, and the catalyst can be used-regenerated several times (for example, used five times-recycled). The performance hardly decreases. Therefore, according to the method for producing 1,2-propanediol according to the present invention, an expensive catalyst can be recovered and repeatedly used, so that the production cost can be greatly reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples.

Production Example 1
(Preparation of hydrotalcite)
In a 1 L 4-necked eggplant type flask, 200 mL of deionized water was added and stirred at 25 ° C. There, Cu (NO ₃ ) ₂ .3H ₂ O (24.16 g, 0.1 mol), Al (NO ₃ ) ₃ .9H ₂ O (18.76 g, 0.0499 mol), and deionized water (140 mL) Was added dropwise. At that time, a basic aqueous solution [mixture of sodium hydroxide (17.5 g, 0.44 mol), sodium carbonate (11.91 g, 0.112 mol) and deionized water (140 mL)] was added dropwise at the same time to prepare a reaction solution. The pH inside was adjusted to the range of 8-9.
After completion of dropping, the mixture was aged at 65 ° C. for 2 hours. Then, it is filtered, washed with deionized water to wash away the basic aqueous solution, vacuum dried at 65 ° C. for 8 hours, and hydrotalcite containing a divalent copper component and an aluminum component (Cu ²⁺ -Al-hydro). Talsite; Cu / Al = 2.0 / 1.0) was obtained.

(Reduction process)
Disperse 5 g of the obtained Cu ²⁺ -Al-hydrotalcite (Cu / Al = 2.0 / 1.0) in 50 mL of water to obtain a dispersion, and adjust the obtained dispersion to 110 ° C. Then, hydrogen gas was bubbled with a bubble meter at 1 bubble / second for 5 hours.
Thereafter, suction filtration, washing with 1 L of deionized water, and vacuum drying for 24 hours, Cu-Al-hydrotalcite (Cu / Al = 2.0 / 1.0) as a gray powder (Cu content: 7% by weight) was obtained.

Production Example 2
In a 50 mL eggplant-shaped flask, water (50 mL) was added to and dissolved in KBH ₄ (5.5 mmol), and the Cu ²⁺ -Al-hydrotalcite obtained by the preparation of the hydrotalcite of Production Example 1 ( 5 g of Cu / Al = 2.0 / 1.0) was added, and the mixture was stirred at room temperature for 1 hour under an argon atmosphere.
After stirring, suction filtration, washing with 1 L of deionized water, and vacuum drying for 24 hours to obtain a black powder of Cu-Al-hydrotalcite (Cu / Al = 2.0 / 1.0) (Cu content) : 7% by weight).

Production Example 3
Cu—Al— was prepared in the same manner as in Production Example 1 except that the amount of Cu (NO ₃ ) ₂ .3H ₂ O used was changed from (24.16 g, 0.1 mol) to 36.24 g (0.15 mol mol). Hydrotalcite (Cu / Al = 3.0 / 1.0) was obtained.

Production Example 4
Cu—Al— was prepared in the same manner as in Production Example 2 except that the amount of Cu (NO ₃ ) ₂ .3H ₂ O was changed from (24.16 g, 0.1 mol) to 36.24 g (0.15 mol mol). Hydrotalcite (Cu / Al = 3.0 / 1.0) was obtained.

Production Example 5
Cu—Al— was prepared in the same manner as in Production Example 1 except that the amount of Cu (NO ₃ ) ₂ .3H ₂ O was changed from (24.16 g, 0.1 mol) to 12.08 g (0.05 mol). Hydrotalcite (Cu / Al = 1.0 / 1.0) was obtained.

Production Example 6
Cu—Al is the same as Production Example 2 except that the amount of Cu (NO ₃ ) ₂ .3H ₂ O used is changed from (24.16 g, 0.1 mol) to 12.08 g (0.05 mol). -Hydrotalcite (Cu / Al = 1.0 / 1.0) was obtained.

Production Example 7
Cu—Al is the same as Production Example 1 except that the amount of Cu (NO ₃ ) ₂ .3H ₂ O used is changed from (24.16 g, 0.1 mol) to 6.04 g (0.025 mol). -Hydrotalcite (Cu / Al = 0.5 / 1.0) was obtained.

Production Example 8
Instead of Cu (NO ₃ ) ₂ .3H ₂ O (24.16 g, 0.1 mol), Al (NO ₃ ) ₃ .9H ₂ O (18.76 g, 0.0499 mol), Cu (NO ₃ ) _2. 3H ₂ O (6.04 g, 0.025 mol), Al (NO ₃ ) ₃ .9H ₂ O (18.76 g, 0.0499 mol), and Mg (NO ₃ ) ₂ .6H ₂ O (32.05 g, 0 Cu-Mg-Al-hydrotalcite (Cu / Mg / Al = 0.5 / 2.5 / 1.0) was obtained in the same manner as in Production Example 1, except that .125 mol) was used.

Production Example 9
_{Cu (NO 3) 2 · 3H} 2 O (24.16g, 0.1mol), in place of _{Al (NO 3) 3 · 9H} 2 O (18.76g, 0.0499mol), Al (NO 3) 3 · 9H ₂ O (18.76 g, 0.0499 mol), Mg (NO ₃ ) ₂ .6H ₂ O (38.46 g, 0.15 mol) was used, and the same procedure as in Production Example 1 was performed except that no reduction step was provided. Thus, Mg—Al / HT (Mg / Al = 3.0 / 1.0) was obtained.

Production Example 10
Cu (NO ₃ ) ₂ .3H ₂ O (1.78 g, 0.01 mol) and silica (SiO ₂ : trade name “CALiACT”, manufactured by Fuji Silysia Chemical Co., Ltd.) 9.0 g were stirred, and Cu ^{2 +} Supported silica (Cu ²⁺ / SiO ₂ ) (Cu supported amount: 7% by weight) was obtained.

Production Example 1 except that the obtained Cu ²⁺ -supporting silica (Cu ²⁺ / SiO ₂ ) was used instead of Cu ²⁺ -Al-hydrotalcite (Cu / Al = 2.0 / 1.0) The reduction treatment was performed in the same manner as described above to obtain Cu / SiO ₂ (Cu loading: 7% by weight).

Production Example 11
Instead of using silica (SiO ₂ : trade name “CariACT”, manufactured by Fuji Silysia Chemical Co., Ltd.), magnesia (MgO: trade name “magnesium oxide”, manufactured by Wako Pure Chemical Industries, Ltd.) 9.0 g was used. Obtained Cu / MgO (Cu supported amount: 7% by weight) in the same manner as in Production Example 10.

Example 1
In a stainless steel pressure-resistant reaction tube containing a Teflon (registered trademark) inner cylinder, 25 mg of Cu-Al-hydrotalcite (Cu / Al = 2.0 / 1.0) obtained in Production Example 1 (Cu: 7) 0.05%), 0.35 mmol of glycerol, and 3.0 mL of 1,4-dioxane were added, and the mixture was stirred under a hydrogen atmosphere (10 atm) at 180 ° C. for 5 hours to obtain 1,2-propanediol (conversion rate: 98.0%, selectivity: 98.0%, yield: 96.0%). In addition, the standard measuring method by a gas chromatography was used for the measurement of a conversion rate, a selectivity, and a yield.

Examples 2-8, Comparative Examples 1-3
Instead of the Cu-Al-hydrotalcite obtained in Production Example 1 (Cu / Al = 2.0 / 1.0), the same procedure as in Example 1 was conducted except that the catalysts described in the following table were used. 1,2-propanediol was obtained. In addition, Example 2 is Production Example 2, Example 3 is Production Example 3, Example 4 is Production Example 4, Example 5 is Production Example 5, Example 6 is Production Example 6, Example 7 is Production Example 7, In Example 8, the catalyst obtained in Production Example 8, Comparative Example 1 in Production Example 9, Comparative Example 2 in Production Example 10, and Comparative Example 3 in Production Example 11 were used.

Example 9
After completion of the reaction in Example 1, the reaction solution was filtered to separate the residue, washed twice with water, and then dried under reduced pressure at room temperature (25 ° C.) to obtain a catalyst (2). As a result of analyzing the catalyst (2) with an ICP emission spectroscopic analyzer (ICP-AES), 7.0% by weight of a copper component was detected from the residue.

  Cu-Al-hydrotalcite obtained in Production Example 1 (Cu / Al = 2.0 / 1.0) (Cu: 7.0 wt%) (hereinafter sometimes referred to as “catalyst (1)”) ) Was used in the same manner as in Example 1 except that the catalyst (2) was used to obtain 1,2-propanediol (conversion rate: 97.8%).

Example 10
After completion of the reaction of Example 9, the reaction solution was filtered to separate the residue, washed twice with water, and then dried under reduced pressure at room temperature (25 ° C.) to obtain a catalyst (3). 1,2-propanediol was obtained in the same manner as in Example 1 except that the catalyst (3) was used in place of the catalyst (1) (conversion rate: 98.0%).

Example 11
After completion of the reaction in Example 10, the reaction solution was filtered to collect a residue, washed twice with water, and then dried under reduced pressure at room temperature (25 ° C.) to obtain a catalyst (4). 1,2-propanediol was obtained in the same manner as in Example 1 except that the catalyst (4) was used in place of the catalyst (1) (conversion rate: 98.0%).

Example 12
After completion of the reaction of Example 11, the reaction solution was filtered to separate the residue, washed twice with water, and then dried under reduced pressure at room temperature (25 ° C.) to obtain a catalyst (5). 1,2-propanediol was obtained in the same manner as in Example 1 except that the catalyst (5) was used in place of the catalyst (1) (conversion rate: 98.0%).

  From Examples 1 to 8 and Comparative Examples 1 to 3, according to the method for producing 1,2-propanediol according to the present invention, 1,2-propanediol can be selectively produced with an excellent yield. I understood. In addition, from Examples 9 to 12, the catalyst used in the present invention does not elute the catalytically active component in the reaction solution, and can be easily recovered by filtering the solution after the reaction. Even with this, it was found that high catalytic activity can be maintained.

  The reusability of the catalyst in the present invention was further evaluated by the following method.

Catalyst (1) 25 mg (Cu: 7.0 wt%), glycerol 0.35 mmol, 1,4-dioxane 3.0 mL were added to a stainless steel pressure-resistant reaction tube containing a Teflon (registered trademark) inner cylinder, and hydrogen The mixture was stirred at 180 ° C. for 2 hours and 30 minutes under an atmosphere (10 atm) to obtain 1,2-propanediol (conversion rate: 50.0%).
Thereafter, the reaction solution was filtered, and the filtrate was stirred at 180 ° C. for 2 hours and 30 minutes, but the hydrogenolysis reaction did not proceed. Moreover, as a result of analyzing a filtrate with an ICP emission-spectral-analysis apparatus (ICP-AES), the copper component was not detected.

  Furthermore, X-ray diffraction measurement was performed on the catalyst (1), the catalyst (2), and the catalyst (5) (see FIG. 1). The diffraction peaks 2θ appearing at 43.3, 50.5, and 74.1 are attributable to the zero-valent copper component, and the diffraction peaks 2θ appearing at 36.51, 61.39 are attributable to the monovalent copper component. . That is, the peaks of the zero-valent copper component that is a catalytically active component and the monovalent copper component that has catalytic activity and has an action of preventing the sintering of the zero-valent copper component appeared clearly. This result is obtained from Card No. of Joint Committee for Power Diffraction Standards (JCPDS). 4-036, and 5-0667.

  Furthermore, when the said catalyst (1) and the catalyst (5) were observed using the field emission type | mold scanning electron microscope (FE-SEM), aggregation of the copper component did not occur.

  From these results, the catalyst in the present invention can retain the copper component, which is a catalytically active component, in the hydrotalcite even after repeated use-regeneration. It has been found that excellent catalytic activity can be maintained because the surface area does not decrease.

Claims (5)

  In the presence of hydrogen and a catalyst containing a zero-valent copper component obtained by reducing hydrotalcite containing at least a copper component as a metal component, glycerol is hydrocracked to give 1,2-propanediol. A process for producing the obtained 1,2-propanediol.   The method for producing 1,2-propanediol according to claim 1, wherein the hydrotalcite contains an aluminum component and / or a magnesium component as other metal components.   The 1,2-propanediol according to claim 2, wherein the hydrotalcite contains a copper component and another metal component at a ratio of the former / the latter (metal atom molar ratio) of 10/1 to 1/10. Manufacturing method.   A catalyst containing zero-valent and monovalent copper components obtained by reducing hydrotalcite containing at least a copper component as a metal component.   The method for producing a catalyst according to claim 4, comprising a step of reducing hydrotalcite containing at least a copper component as a metal component in a state dispersed in water.

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