Hydrotalcite-based catalyst for producing 1,2-hexanediol and method for producing 1,2-hexanediol in presence of catalyst

Abstract

The present invention relates to a hydrotalcite-based catalyst for producing 1,2-hexanediol and a method for producing 1,2-hexanediol in the presence of the catalyst. More specifically, the present invention relates to: a catalyst having a specific combination of catalytically active metals supported on a hydrotalcite support, so as to convert methylfurfural, which is a reactant, into 1,2-hexanediol with high yield; and a method for producing 1,2-hexanediol using the catalyst.

Description

Hydrotalcite-based catalyst for producing 1,2-hexanediol and method for producing 1,2-hexanediol in the presence of the catalyst

[0001] The present invention relates to a hydrotalcite-based catalyst for producing 1,2-hexanediol and a method for producing 1,2-hexanediol in the presence of the catalyst, and more particularly, to a catalyst for selectively producing 1,2-hexanediol from methyl furfural as a reactant, wherein hydrotalcite is used as a support, and a catalyst having a catalytically active metal of a specific metal combination supported thereon, and a method for producing 1,2-hexanediol in a high yield using the same.

[0002] 1,2-hexanediol (1,2-hexanediol, C6H 12 O2) is a colorless, water-soluble solid with hydroxyl groups at adjacent carbons 1 and 2 in the main chain of 6 carbon atoms in its structure. It is a high value-added compound used in various fields such as polyester raw materials and cross-linking agents in the polymer industry, and moisturizers, antibacterial agents, and preservatives in cosmetics and personal care products.

[0003] Recently, 1,2-hexanediol has been produced by reacting 1-hexene with hydrogen peroxide (Patent Documents 1, 2, and 3). This method boasts the advantage of being economical and capable of producing 1,2-hexanediol in high yield using the inexpensive oxidizing agent hydrogen peroxide.

[0004] However, the above 1-hexene is a compound obtained mainly from petrochemical raw materials, and has the advantage of easy supply. However, due to recent concerns about climate change and the strengthening of carbon neutrality policies, there is a growing need for research and development of technology to manufacture it using biomass platform compounds as raw materials instead of petrochemical raw materials. For example, a method for manufacturing 1,2-pentanediol using biomass-derived furfural as a raw material in the presence of a Rh / OMS-2 catalyst has been reported (Non-patent Document 1).

[0005] Currently, the hydrogenation of biomass-derived methyl furfural to produce 1,2-hexanediol is being researched and developed as a key technology for utilizing biomass, and a catalyst for this process is currently under development. However, the development of a novel catalyst with higher reaction selectivity for 1,2-hexanediol and a method for producing 1,2-hexanediol using such a catalyst have not been reported, necessitating further technological development.

[0006] The inventor of the present invention has conducted research to explore a catalyst system capable of producing 1,2-hexanediol in high yield from biomass-derived raw materials, and has confirmed that the reaction selectivity of 1,2-hexanediol increases when a catalyst system including a catalytically active metal of a specific metal combination and a hydrotalcite support is used, thereby completing the present invention.

[0007] The present invention aims to provide a hydrotalcite catalyst capable of producing 1,2-hexanediol in high yield using biomass-derived methyl furfural as a reactant, and a method for producing 1,2-hexanediol in the presence of the catalyst.

[0008] In order to solve the above problem, in the catalyst for producing 1,2-hexanediol used for producing 1,2-hexanediol from the reaction of methyl furfural and hydrogen of the present invention, the catalyst for producing 1,2-hexanediol is a catalyst in which a catalytically active metal is supported on a hydrotalcite of the following chemical formula 1,

[0009] [Mg 1-x Al x (OH)2][(CO3 2- ) x / 2 ]·nH2O [chemical formula 1]

[0010] (In the above chemical formula 1, x is 0.2≤x≤0.33, and n is 0.33≤n≤1.)

[0011] The above catalytically active metal may be characterized by including a metal selected from the group consisting of ruthenium and nickel; and tin (Sn).

[0012] As an example of the present invention, the methyl furfural may be derived from biomass.

[0013] The content of tin supported on the catalyst may be 20 wt% or less, preferably 10 wt% or less, more preferably 5 wt% or less, and most preferably 1 to 5 wt%.

[0014] As an example of the present invention, the catalyst can be used by reduction without calcination in an oxidizing atmosphere.

[0015] In addition, the present invention can provide a method for producing 1,2-hexanediol in the presence of the hydrotalcite catalyst.

[0016] The above 1,2-hexanediol manufacturing method may be characterized by manufacturing 1,2-hexanediol through a liquid phase reaction of methyl furfural and hydrogen in the presence of a hydrotalcite catalyst for manufacturing 1,2-hexanediol, wherein methyl furfural is diluted in any one solvent selected from 1-propanol, isopropanol, 1-butanol, 2-butanol, and mixtures thereof, and reacted in a liquid phase.

[0017] The temperature during the reaction in the presence of the above hydrotalcite catalyst may be 120 to 200°C, preferably 120 to 140°C, and the reaction pressure may be 20 to 40 bar, preferably 20 to 30 bar.

[0018] According to the present invention, when a catalyst system including a catalytically active metal of a specific metal combination and a hydrotalcite support is used, biomass-derived methyl furfural is used as a reactant, and there is an effect that 1,2-hexanediol can be produced in a high yield.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In general, the nomenclature used herein is well known and commonly used in the art.

[0020] Throughout this specification, whenever a part is said to “include” a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise stated.

[0021] Hereinafter, the hydrotalcite catalyst for producing 1,2-hexanediol of the present invention and the method for producing 1,2-hexanediol in the presence of the catalyst will be examined.

[0022] The catalyst used for producing 1,2-hexanediol from the reaction of methyl furfural and hydrogen according to the present invention is a catalyst in which a specific combination of catalytically active metals is supported on hydrotalcite of the following chemical formula 1.

[0023] [Mg 1-x Al x (OH)2][(CO3 2- ) x / 2 ]·nH2O [chemical formula 1]

[0024] (In the above chemical formula 1, x is 0.2≤x≤0.33, and n is 0.33≤n≤1.)

[0025] The above catalytically active metal is characterized by including a metal selected from the group consisting of ruthenium and nickel; and tin (Sn).

[0026] Methyl furfural can be produced through a one-step direct hydrogenation reaction to produce 1,2-hexanediol and a mixture containing the same, and the reaction yield of 1,2-hexanediol can be controlled depending on the activity of the catalyst component used.

[0027] The above methyl furfural may be a compound derived from biomass, and specifically, may be derived from hemicellulose. The substance that makes up the majority of hemicellulose is xylan, and the xylan is decomposed into the pentose xylose through hydrolysis, and furfural can be easily obtained by dehydrating the xylose.

[0028] The content of tin supported on the catalyst may be 20 wt% or less, preferably 10 wt% or less, more preferably 5 wt% or less, and most preferably in the range of 1 to 5 wt%.

[0029] The above catalytically active metal is preferably a heterogeneous catalyst system supported on a support, and in the present invention, the support is characterized in that a hydrotalcite having the following chemical formula 1 is used.

[0030] [Mg 1-x Al x (OH)2][(CO3 2- ) x / 2 ]·nH2O [chemical formula 1]

[0031] (In the above chemical formula 1, x is 0.2≤x≤0.33, and n is 0.33≤n≤1.)

[0032] It is preferable that the catalytically active metal be supported on the above hydrotalcite support at 8 to 12 wt%, preferably 9 to 11 wt%, and when the supported amount of the catalytically active metal is within the above range, an optimal effect is exhibited between the catalytic activity and the supported amount.

[0033] The method for manufacturing a catalyst system in which the above catalytically active metal is supported on a hydrotalcite support may be to form hydrotalcite in advance and support the precursor of the active metal by an impregnation method or the like, or to support the catalyst system by using a method in which a material used for manufacturing hydrotalcite and a precursor of the catalytically active metal are simultaneously co-precipitated.

[0034] The tin precursor as the above catalytically active metal is not particularly limited in type, and examples thereof include Sn(NO3)2, SnCl2, SnBr2, SnI2, Sn(OH)2, SnSO4, Sn(CH3COO)2, Sn(CH3COCHCOCH3). 2, One or more components selected from SnO, SnO2, and Sn3(PO)4 can be used.

[0035] The ruthenium precursor and nickel precursor as the above catalytically active metal are not particularly limited in type, and for example, one or more selected from halogen salts, nitrate salts, carbonates, sulfates, nitrosyl acetate salts, and nitrosyl nitrate salts can be used.

[0036] Meanwhile, the present invention can provide a method for producing the catalyst for producing 1,2-hexanediol. In the method for producing a catalyst for producing 1,2-hexanediol, wherein a catalytically active metal including a metal selected from the group consisting of ruthenium and nickel; and tin (Sn); is supported on a hydrotalcite of the chemical formula 1, the method comprising the steps of: a) dispersing the hydrotalcite support in water or an organic solvent to produce a hydrotalcite support dispersion solution; b) adding a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor; and a tin precursor as active ingredients to the hydrotalcite support dispersion solution and stirring the same; c) drying the solution stirred in step b) to obtain a dried product; d) calcining the dried product to obtain a calcined product; e) reducing the calcined product to obtain a metal selected from the group consisting of ruthenium and nickel as a catalytically active metal; And a step of obtaining a catalyst for producing 1,2-hexanediol, in which tin (Sn) is supported on the hydrotalcite of the above chemical formula 1;

[0037] As an example of the present invention, step a) is a step a') of preparing a solution in which a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor used as a catalytically active metal; and a tin precursor; are dissolved, and step b) is a step b') of dispersing a hydrotalcite support of the chemical formula 1 prepared in advance in a solution in which a precursor selected from the group consisting of the main ruthenium precursor and a nickel precursor; and a tin precursor; are dissolved, so that the order of introduction of the hydrotalcite support and the catalytically active metal can be changed.

[0038] In addition, as another example of the present invention, steps a) and b) may be performed simultaneously to administer the support and the precursor of the active ingredient metal simultaneously.

[0039] Meanwhile, as an example of the present invention, the precursors of steps b) and b') may be directly added to the solutions of steps a) and a'), or the precursors of steps b) and b') may be separately dissolved in separate solvents and the dissolved solutions may be added to the solutions of steps a) and a').

[0040] In addition, as another example of the present invention, the firing in step d) may be omitted and the process may proceed directly to step e).

[0041] In addition, the method for preparing a catalyst for producing 1,2-hexanediol of the present invention can be implemented through a co-precipitation method in addition to the impregnation method described above. As another example of the method for preparing a catalyst of the present invention, the method includes: i) preparing a support and a catalytically active metal precursor solution by quantitatively dissolving a precursor used for preparing the hydrotalcite of the chemical formula 1, a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor used as a catalytically active metal component; and a tin precursor in a solvent; ii) adjusting the pH of the support and the catalytically active metal precursor solution; iii) aging the solution after the pH adjustment in step ii) at a predetermined temperature; iv) filtering and optionally washing the precipitate from the solution after the aging in step iii) and drying it; v) calcining the dried precipitate; vi) reducing the calcined product after the calcination.

[0042] As an example of the present invention, in step i), a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor used as a catalytically active metal and a precursor used for producing the hydrotalcite of the chemical formula 1; and a tin precursor; may be simultaneously introduced into a solvent, or solutions in which each precursor is individually dissolved may be mixed together to prepare a support and a catalytically active metal precursor solution. At this time, the mixing order may be such that the precursor selected from the group consisting of a ruthenium precursor and a nickel precursor used as a catalytically active metal; and a tin precursor; are mixed first, and then the precursor used for producing the hydrotalcite of the chemical formula 1 is mixed, or the mixing order may be reversed.

[0043] In addition, as another example of the present invention, a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor; and a precursor used for producing the hydrotalcite of the above chemical formula 1; may be mixed first, and then a tin precursor; may be mixed thereto, or the precursor used for producing the hydrotalcite of the above chemical formula 1; and a tin precursor; may be mixed first, and then a precursor selected from the group consisting of a ruthenium precursor and a nickel precursor; may be mixed thereto, and there may also be other variations in the mixing order. However, when step i) is not a single step but sequential mixing, the pH adjustment of step ii) is performed after the sequential mixing, and the aging of step iii) may be performed after the final mixing, or may be performed after mixing at each step.

[0044] Meanwhile, as another example of the present invention, the firing step of v) may be omitted and the reduction step of vi) may be performed directly.

[0045] The aging in step ⅲ) above can be done by leaving it in a state where temperature is applied or by leaving it in a state where it is left without separate heating.

[0046] The pH of the above step ⅱ) can be adjusted using a basic substance or an acidic substance, and NaOH is preferably used.

[0047] In addition, the reduction step of the above step ⅳ) is a reduction process in a liquid phase using a reducing agent such as hydrazine or NaBH4, or a hydrogen atmosphere heat treatment process. This is for controlling the dispersion and specific surface area of ​​the catalytically active metal, removing impurities in the catalyst itself, and enhancing the bonding strength between the catalytically active metal and the support, and it is preferable to treat at a temperature range from room temperature to 500°C.

[0048] In the reduction step of the above step ⅵ), all of the metals existing as catalytically active metals may be reduced, or only a portion of them may be reduced. For example, when ruthenium and tin are used as active metals, ruthenium is reduced to a metal, but some of the tin is not reduced to a metal, but is combined with oxygen, etc. Sn 2+ , Sn 4+ It can exist in the state of etc. In addition, tin and a metal selected from the group consisting of ruthenium and nickel as catalytically active metals can form an alloy with each other.

[0049] In addition, the method for producing 1,2-hexanediol according to the present invention is characterized by producing it by reacting methyl furfural with hydrogen in the presence of a catalyst in which a catalytically active metal including a metal selected from the group consisting of ruthenium and nickel; and tin; is supported on a hydrotalcite support.

[0050] The above methyl furfural may be a compound derived from biomass, and specifically, may be derived from hemicellulose. The substance that makes up the majority of hemicellulose is xylan, and the xylan is decomposed into the pentose sugar xylose through hydrolysis, and methyl furfural can be easily obtained by dehydrating the xylose.

[0051] The amount of the hydrotalcite catalyst used for producing the above 1,2-hexanediol is preferably 1 to 15 wt% with respect to methyl furfural. If the content of the catalyst is less than 1 wt%, sufficient catalytic activity effect is not exhibited, and if the content of the catalyst exceeds 15 wt%, it may be uneconomical in terms of the synergistic effect of catalytic activity according to the catalyst content.

[0052] The reaction in the presence of the above catalyst may proceed in a liquid phase or a gas phase, and preferably in a liquid phase.

[0053] For example, the reaction in the presence of the catalyst may be carried out at a reaction temperature of 120 to 200°C, preferably 120 to 140°C, and a hydrogen pressure of 20 to 40 bar, preferably 20 to 30 bar. If the hydrogen pressure is less than 20 bar, a problem of slow reaction rate may occur, and if the hydrogen pressure exceeds 40 bar, a problem of low reaction yield of 1,2-hexanediol may occur as the reaction yield of by-products increases.

[0054] The reaction of the present invention can be carried out in a liquid phase, and at this time, the reaction is carried out under conditions in which methyl furfural is maintained in a liquid phase.

[0055] The above methyl furfural can be used by diluting it in a solvent capable of dissolving methyl furfural, and it is preferable that the solvent is included in an amount of 25 to 1000 wt% based on the methyl furfural. Without limitation, the solvent may be alcohol, GBL (gamma butyl lactone), water, and a mixture thereof. Preferably, the solvent may be alcohol, and more preferably, 1-propanol, isopropanol, 1-butanol, 2-butanol, or a mixture thereof.

[0056] The above alcohol solvent has high solubility in methyl furfural and does not contain highly reactive reaction sites, so it does not cause changes in functional groups or rapid changes in chemical properties due to reaction with hydrogen, and thus can provide constant reaction conditions during the reaction process.

[0057] When a reaction between methyl furfural and hydrogen is carried out using the catalyst of the present invention, in which a catalytically active metal including a metal selected from the group consisting of ruthenium and nickel and tin (Sn) is supported on the hydrotalcite support of the above chemical formula 1, the reaction yield of 1,2-hexanediol increases.

[0058] The reaction yield of the above 1,2-hexanediol is preferably 75% or more, more preferably 85% or more, and most preferably 90% or more.

[0059] Hereinafter, preferred embodiments of the present invention will be described. It should be noted that the following examples are provided to illustrate one or more preferred embodiments of the present invention, but the present invention is not limited to these embodiments. Numerous modifications to the following examples may be made within the scope of the present invention.

[0060] <Example 1: Preparation of 10 wt% 1Ni-1Sn / Hydrotalcite catalyst>

[0061] Hydrotalcite was purchased from Sigma-Aldrich and used. Ni(NO3)2·6H2O and SnCl4·5H2O were quantitatively added to hydrotalcite by impregnation so that the molar ratio of Ni and Sn was 1:1 and the total mass of Ni and Sn was 10 wt%, thereby obtaining 1Ni-1Sn / Hydrotalcite.

[0062] <Example 2: Preparation of 4.66 wt% 1Ru-1Sn / Hydrotalcite Catalyst>

[0063] 1Ru-1Sn / Hydrotalcite was prepared in the same manner as in Example 1, except that RuCl3 was used instead of Ni(NO3)2.6H2O.

[0064] <Comparative Example 1: Preparation of 10 wt% 1Ni-1Sn / ZnO catalyst>

[0065] 1Ni-1Sn / ZnO was manufactured using the same method as in Example 1 above, except that ZnO was used instead of hydrotalcite.

[0066] <Comparative Example 2: Preparation of 4.66 wt% 1Ru-1Sn / ZnO catalyst>

[0067] 1Ru-1Sn / ZnO was manufactured using the same method as in Comparative Example 1 above, except that RuCl3 was used instead of Ni(NO3)2·6H2O.

[0068] <Experimental Example: Production of 1,2-hexanediol using Example and Comparative Example catalysts>

[0069] A 20 mL batch reactor system equipped with a temperature controller, a pressure controller, and a magnetic stirrer was prepared, and then 1.5 g of the Hydrotalcite-based catalyst of Examples 1 and 2 or the ZnO-based catalyst of Comparative Examples 1 and 2 (10 wt% of the feed) that had been reduced at 500 ° C. for 6 hours before the reaction was introduced into the reactor containing 15 g of feed (solvent IPA) with an MF concentration of 10%. The reactor system was sealed and heated to a temperature of 120 to 140 ° C. at a H2 pressure of 20 to 30 bar, and the reaction was started while stirring at 500 rpm. The reaction was confirmed to be complete when the MF peak disappeared, and the yield of the product as a result of the reaction was measured by GC chromatography and is shown in Table 1 below.

[0070] Catalyst H2 Pressure (bar) Temperature (℃) Time (hr) Conversion (%) Yield (%) DMF * 1,2-HDO ** 1,5-HDO *** Others **** Example 1 (Ni-Sn / HT) 20120721005.082.15.87.1130591005.282.65.17.1140481005.581.55.57.530130531003.683.25.77.5 Example 2 (Ru-Sn / HT) 30130411005.981.74.88.7 Comparative Example 1 (Ni-Sn / ZnO) 30130571006.175.68.310.0 Comparative Example 2 (Ru-Sn / ZnO) 30130431008.575.36.59.7 * DMF: Dimethylfuran, ** 1,2-HDO: 1,2-hexanediol, *** 1,5-HDO: 1,5-hexanediol ****Others: Oligomers + Unknown Ingredients

[0071] Referring to Table 1 above, when the methyl furfural conversion reaction was performed in the presence of the Ni-Sn / Hydrotalcite catalyst of Example 1, the maximum 1,2-HDO yield was obtained when the reaction was performed at a temperature of 130°C under a constant pressure condition of 20 bar. In addition, when the methyl furfural conversion reaction was performed by increasing the pressure to 30 bar in the presence of the Ni-Sn / Hydrotalcite catalyst of Example 1, the time required for the completion of the reaction was shortened by 11%, but the yield was recorded at a level equal to or higher (0.6%p increase).

[0072] Meanwhile, in order to compare the catalytic activity according to the type of hydrotalcite support, a conversion reaction was performed under constant conditions of 130°C and 30 bar in the presence of any one of the catalysts of Examples 1 and 2 and Comparative Examples 1 and 2. As a result, the catalysts of Examples 1 and 2 adopting a hydrotalcite support recorded a superior 1,2-HDO yield than those of Comparative Examples 1 and 2 adopting a conventional ZnO-based support. In addition, the catalyst of Example 1 adopting Ni-Sn as the active metal was found to have a higher 1,2-HDO yield than the catalyst of Example 2 using Ru-Sn.

[0073] In addition, under the above reaction conditions, the H2 pressure was set to a constant 20 bar, and then the temperature was increased to a range of 120 to 200°C to perform the reaction. The GC measurement results are shown in Table 2 below.

[0074] Catalyst H2 Pressure (bar) Temperature (℃) Time (hr) Conversion (%) Yield (%) Reactor DMF * 1,2-HDO ** 1,5-HDO *** Others ****Example 1 (Ni-Sn / HT) 20120721005.082.15.87.120mL130591005.282.65.17.1140481005.581.55.57.5150441007.278.35.78.8160381006.975.26.311.6180311005.973.38.212.6200301008.365.037.818.87 * DMF: Dimethylfuran, ** 1,2-HDO: 1,2-hexanediol, *** 1,5-HDO: 1,5-hexanediol **** Others: Oligomers + Unknown Ingredients

[0075] Referring to Table 2 above, when the reaction was performed by expanding the temperature range from 120 to 200°C under a constant H2 pressure of 20 bar using the catalyst of Example 1, the maximum 1,2-HDO was recorded at a temperature of 130°C, and as the reaction temperature increased from 130°C, the reaction time shortened, but the 1,2-HDO yield showed a tendency to gradually decrease.

[0076] While the present invention has been described above with reference to the embodiments described herein and illustrated in the accompanying drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent embodiments are possible. Accordingly, the technical protection scope of the present invention should be defined by the following claims.

Claims

1. A catalyst for producing 1,2-hexanediol used to produce 1,2-hexanediol from the reaction of methyl furfural and hydrogen, The above catalyst for producing 1,2-hexanediol is a catalytically active metal supported on hydrotalcite of the following chemical formula 1, [Mg 1-x Al x (OH)2][(CO3 2- ) x / 2 ]·nH2O [chemical formula 1] (In the above chemical formula 1, x is 0.2≤x≤0.33, and n is 0.33≤n≤1.) The above catalytically active metal is characterized by including a metal selected from the group consisting of ruthenium and nickel; and tin (Sn). Hydrotalcite catalyst for producing 1,2-hexanediol.

2. In paragraph 1, The above methyl furfural is characterized in that it is derived from biomass. Hydrotalcite catalyst for producing 1,2-hexanediol.

3. In paragraph 1, The content of tin supported on the catalyst is characterized by being 1 to 5 wt%. Hydrotalcite catalyst for producing 1,2-hexanediol.

4. In paragraph 1, The above catalyst is characterized in that it is used by reduction without calcination in an oxidizing atmosphere. Hydrotalcite catalyst for producing 1,2-hexanediol.

5. In the presence of a hydrotalcite catalyst for producing 1,2-hexanediol as described in any one of paragraphs 1 to 4, A method for producing 1,2-hexanediol by a liquid phase reaction between methyl furfural and hydrogen, characterized in that methyl furfural is diluted in any one solvent selected from 1-propanol, isopropanol, 1-butanol, 2-butanol, and mixtures thereof and reacted in a liquid phase. A method for producing 1,2-hexanediol in the presence of a hydrotalcite catalyst.

6. In paragraph 5, The reaction temperature is 120 to 200 ℃, and the reaction pressure is 20 to 40 bar, A method for producing 1,2-hexanediol in the presence of a hydrotalcite catalyst.

7. In paragraph 6, The reaction temperature is 120 to 140 ℃, and the reaction pressure is 20 to 30 bar, A method for producing 1,2-hexanediol in the presence of a hydrotalcite catalyst.