Ester compound hydrogenation method

Abstract

The present invention relates to the field of hydrogenation reactions, and discloses an ester compound hydrogenation method, which comprises that: in the presence of a copper catalyst, an ester compound is subjected to a hydrogenation reaction, the copper catalyst contains a Cu element, a Mn element and an Al element, and the total weight of the copper catalyst is adopted as a reference, the content of the Cu element in the copper catalyst is 32 wt%-60 wt%, the content of the Mn element is 3 wt%-16 wt%, and the content of the Al element is 10 wt%-32 wt%. The hydrogenation reaction has the advantages of high reactant conversion rate, high target product selectivity and long catalyst service life.

Description

Technical Field

[0001] The invention relates to the field of hydrogenation reaction, and in particular to a method for hydrogenating ester compounds. Background Art

[0002] Catalytic hydrogenation is one of the most important reactions in organic reactions. The process of producing high value-added alcohol products through ester hydrogenation has the advantages of high atomic economy, green environmental protection, and high selectivity. At present, gas-phase ester hydrogenation has been widely studied, but the gas-phase hydrogenation process requires the gasification of reactants and an excessively high hydrogen-ester ratio, which leads to its high energy consumption. How to reduce the energy consumption of ester hydrogenation is the focus of current research. The catalysts used for ester hydrogenation mainly include Pt-based catalysts, Pd-based catalysts, Ni-based catalysts, Cu-based catalysts, etc. Among them, Cu-based catalysts have many advantages, such as high selectivity for CO bond cleavage, inactivity for CC bond cleavage, excellent activation ability for hydrogen molecules, high designability, and relatively low price. In the 1990s, people conducted in-depth research on Cu-Cr catalysts, but with the development of the economy and the emphasis on "green chemical industry", chromium, as a highly toxic material, is no longer accepted. People have turned their attention to chromium-free catalysts, and Cu-Zn system ester hydrogenation catalysts have been developed. The catalyst has high catalytic activity but poor stability.

[0003] With the development of the process of synthesizing sec-butyl acetate by adding n-butene to acetic acid and the commissioning of industrialized equipment, the cost of sec-butyl acetate has been greatly reduced. Therefore, the process of producing sec-butyl alcohol by hydrogenating sec-butyl acetate has become a hot research topic. Although most processes are still in the laboratory stage, due to its mild reaction conditions, high conversion rate and selectivity, and environmental friendliness, it will be the development direction of preparing sec-butyl alcohol in the future. Among them, the hydrogenation of sec-butyl acetate is a very promising green process. It can use the saturated market of sec-butyl acetate to co-produce sec-butyl alcohol with higher added value and clean fuel ethanol with a broad market.

[0004] The advantages of using sec-butyl acetate hydrogenation to produce sec-butyl alcohol are as follows:

[0005] (1) The raw material can be directly industrial sec-butyl acetate, which can be directly fed without pre-treatment;

[0006] (2) The catalytic hydrogenation reaction process is simple, has low energy consumption, does not require strong acid, and the catalyst is easy to recover, which is more in line with the "green chemical industry requirements";

[0007] (3) The main by-product is ethanol, which has high economic value, and there are almost no other by-products;

[0008] (4) The hydrogenation products are mainly sec-butyl alcohol and ethanol, which have a large difference in boiling points and are easy to separate;

[0009] (5) Copper-based catalysts are relatively cheap and readily available, and have excellent catalytic performance.

[0010] Since sec-butyl acetate and sec-butyl alcohol form azeotropes, it takes a lot of energy to separate sec-butyl acetate and sec-butyl alcohol directly by distillation. The purity of the raw material sec-butyl acetate for preparing butanone by dehydrogenation is required to be higher than 99.5%, so the conversion rate of preparing sec-butyl alcohol by hydrogenation of sec-butyl acetate needs to be continuously higher than 99%, which puts higher requirements on the catalyst used. The catalysts used for ester hydrogenation reactions mainly include Pd catalysts, Ni-based catalysts, Cu-based catalysts, etc. Among them, Cu-based catalysts have many advantages, such as high reaction activity, high designability, and relatively low price.

[0011] CN105618062A discloses a supported Cu-Zr / CaO-SiO2 catalyst, which is used for the reaction of sec-butyl acetate at 200-250°C, 2MPa and a liquid hourly space velocity of 1h -1 , under the hydrogen ester molar ratio of 100, the conversion rate of sec-butyl acetate is about 99.6%, and the selectivity of sec-butyl alcohol is above 99%. The hydrogenation reaction using this catalyst has a low reaction pressure, but has the disadvantages of high hydrogen ester molar ratio and high production energy consumption.

[0012] CN103172492A discloses a Cu / Al2O3 catalyst prepared by an impregnation method, wherein sec-butyl acetate is hydrogenated to prepare sec-butyl alcohol under the joint action of Cu-Cr and Cu-Zn commercial catalysts. In this method, the conversion rate of sec-butyl acetate can be greater than 96% only at a low liquid hourly space velocity or a reaction pressure greater than 6.0 MPa, and the product contains 1-3% of isobutyl alcohol as a by-product, and the generation of the by-product will be unfavorable for the separation of subsequent products.

[0013] CN101934228A discloses the use of a Cu-SiO2 / Al2O3 catalyst in the hydrogenation reaction of sec-butyl acetate. At 180-260°C, 1.0-10MPa, the liquid hourly space velocity of sec-butyl acetate is 0.2-0.3h -1 , when the hydrogen-ester molar ratio is 70-100, the conversion rate of sec-butyl acetate is greater than 85%, and the selectivity of ethanol is greater than 90%. The defects of this method are that the required hydrogen-ester molar ratio is high and the conversion rate of sec-butyl acetate is low, thereby increasing the circulation and recovery cost of sec-butyl acetate.

[0014] Therefore, it is necessary to develop a method for hydrogenating ester compounds with low reaction energy consumption, high catalyst catalytic activity, long catalyst service life, and high reactant conversion rate and target product selectivity. Summary of the invention

[0015] The purpose of the present invention is to solve the problems of high energy consumption and low conversion rate of ester compound in the prior art hydrogenation reaction of ester compound.

[0016] In order to achieve the above object, the present invention provides a method for hydrogenating an ester compound, the method comprising: subjecting the ester compound to a hydrogenation reaction in the presence of a copper catalyst;

[0017] The copper catalyst contains Cu, Mn and Al elements. Based on the total weight of the copper catalyst, the content of Cu in the copper catalyst is 32wt%-60wt%, the content of Mn in the copper catalyst is 3wt%-16wt%, and the content of Al in the copper catalyst is 10wt%-32wt%.

[0018] The copper catalyst contains CuO crystal phase and / or CuAl2O4 spinel phase.

[0019] Through the above technical solution, the present invention has at least the following advantages:

[0020] (1) When the catalyst obtained by the present invention is used for ester hydrogenation reaction, the required hydrogen circulation amount is small and the production energy consumption is low.

[0021] (2) The catalyst obtained by the present invention is suitable for low-temperature reaction when used for ester hydrogenation, and the conversion rate of reactants is high, the selectivity of target products is high, and the catalyst activity is high under low-temperature reaction.

[0022] (3) The hydrogenation reaction of the present invention is applicable to a low reaction temperature, and the target product, sec-butyl alcohol, will not undergo isomerization, which is beneficial to the separation of subsequent products.

[0023] (4) In the hydrogenation reaction described in the present invention, the copper catalyst exhibits excellent stability and a long catalyst service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the X-ray diffraction pattern of copper catalyst A1.

[0025] Figure 2 It is a schematic diagram of the stability test results of copper catalyst A1. DETAILED DESCRIPTION

[0026] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0027] As mentioned above, the present invention provides a method for hydrogenating an ester compound, the method comprising: subjecting the ester compound to a hydrogenation reaction in the presence of a copper catalyst;

[0028] The copper catalyst contains Cu, Mn and Al elements. Based on the total weight of the copper catalyst, the content of Cu in the copper catalyst is 32wt%-60wt%, the content of Mn in the copper catalyst is 3wt%-16wt%, and the content of Al in the copper catalyst is 10wt%-32wt%.

[0029] The copper catalyst contains CuO crystal phase and / or CuAl2O4 spinel phase.

[0030] Preferably, the ester compound is an organic carboxylic acid ester generated by transesterification of C2-C12 monocarboxylic acid and / or polycarboxylic acid with C1-C12 monohydric alcohol.

[0031] More preferably, the ester compound is at least one selected from dimethyl succinate, dimethyl 1,4-cyclohexanedicarboxylate, sec-butyl acetate, cyclohexyl acetate, isopropyl acetate, and methyl isononanoate.

[0032] Particularly preferably, the ester compound is sec-butyl acetate.

[0033] Preferably, the copper catalyst has a Cu content of 34wt%-56wt%, a Mn content of 3.2wt%-12wt%, and an Al content of 12wt%-30wt%. The inventors of the present invention have found that in this preferred case, the CuO crystal phase and / or CuAl2O4 spinel phase in the obtained copper catalyst has better crystallinity.

[0034] Preferably, the specific surface area of ​​the copper catalyst is 20-100 m 2 / g, pore volume is 0.1-2.0cm 3 The inventors of the present invention have found that in this preferred case, the obtained copper catalyst has better catalytic activity.

[0035] More preferably, the bulk density of the copper catalyst is 1.0-1.5 g / mL.

[0036] Further preferably, the sodium content in the copper catalyst is 500-5000 ppm.

[0037] Specifically, in the present invention, the specific surface area and pore volume of the copper catalyst are measured by Anton Paar's specific surface and pore size analyzer Nova600; the bulk density of the copper catalyst is measured by a tap density tester; and the sodium content is measured by an inductively coupled plasma emission spectrometer.

[0038] According to a specific embodiment, the preparation steps of the copper catalyst include:

[0039] (1) Under the condition of pH 8-9, an aqueous solution containing copper salt, manganese salt and aluminum salt is subjected to a coprecipitation reaction at a temperature not lower than 40° C. to obtain an intermediate I;

[0040] (2) subjecting the intermediate I to an aging treatment to obtain an intermediate II;

[0041] (3) calcining the intermediate II to obtain the copper catalyst;

[0042] The conditions are controlled so that the content of Cu element in the copper catalyst is 32wt%-60wt%, the content of Mn element is 3wt%-16wt%, and the content of Al element is 10wt%-32wt%; the copper catalyst contains CuO crystal phase and / or CuAl2O4 spinel phase.

[0043] Wherein, in step (1), the present invention has no particular requirements on the specific type of the alkaline solution for adjusting the pH value of the precipitation reaction process, and the alkaline solution can be selected from at least one of sodium carbonate and sodium hydroxide.

[0044] The copper salt, manganese salt and aluminum salt described in the present invention are soluble metal salts containing copper, manganese and aluminum elements respectively or together.

[0045] Preferably, the copper salt is selected from at least one of copper nitrate, copper sulfate and copper chloride.

[0046] Preferably, the manganese salt is selected from at least one of manganese nitrate, manganese sulfate and manganese chloride.

[0047] Preferably, the aluminum salt is selected from at least one of sodium aluminate, aluminum sulfate and aluminum trichloride.

[0048] Preferably, the coprecipitation reaction conditions include: a temperature of 70-90° C. and a time of 2.5-4 hours. The inventors of the present invention have found that in this preferred case, the CuO crystal phase and / or CuAl2O4 spinel phase in the obtained copper catalyst has better crystallinity.

[0049] According to a specific embodiment, the co-precipitation reaction uses a peristaltic pump to contact and mix the raw materials in a parallel flow manner. The present invention has no special requirements on the dripping rate of each raw material. Those skilled in the art can appropriately adjust the dripping rate of the peristaltic pump according to actual conditions to control the precipitation reaction time to be about 3 hours.

[0050] More preferably, the aging treatment conditions include: a temperature of 25-30° C. and a time of 2-3 hours. The inventors of the present invention have found that under this preferred condition, the obtained copper catalyst has better catalytic activity.

[0051] Further preferably, the conditions of the calcination treatment include: a calcination temperature of 400-600° C. and a calcination time of 5-10 h.

[0052] More preferably, the calcination treatment is performed in an air atmosphere.

[0053] According to a specific embodiment, in step (3), before the intermediate II is calcined, the intermediate II is also washed, filtered and dried, and then ground. The ground powder is mixed with graphite and then sliced ​​into 3x3mm cylindrical particles. The particles obtained above are then calcined to obtain the copper catalyst.

[0054] The present invention has no particular requirement on the particle size of the powder obtained by the grinding. Those skilled in the art can make the ground powder and graphite be mixed and dispersed evenly according to actual needs.

[0055] Preferably, the amount of graphite used is 2-4 parts by weight relative to 100 parts by weight of the ground powder. Particularly preferably, the amount of graphite used is 3 parts by weight relative to 100 parts by weight of the ground powder.

[0056] It should be noted that the precipitation reaction time of the present invention is measured from the time when the copper salt, the manganese salt, the aluminum salt and the alkaline solution begin to mix.

[0057] Preferably, the reaction temperature of the hydrogenation reaction is 150-250° C., and the reaction pressure is 3-9 MPa.

[0058] Further preferably, the reaction temperature of the hydrogenation reaction is 160-230° C., and the reaction pressure is 4-8 MPa.

[0059] Preferably, in the hydrogenation reaction, the molar ratio of hydrogen to ester compound is 5-70, and the liquid hourly space velocity of the ester compound is 0.2-2h -1 .

[0060] Further preferably, in the hydrogenation reaction, the molar ratio of hydrogen to ester compound is 10-60, and the liquid hourly space velocity of the ester compound is 0.2-1h -1 The inventors of the present invention have found that in this preferred case, in the hydrogenation reaction of ester compounds, the copper catalyst has a higher reaction activity and the conversion rate of the ester compounds is higher.

[0061] According to a specific implementation, before the obtained catalyst is applied to the reaction, the catalyst is first loaded into a tubular reactor, both ends of the catalyst bed are filled with porcelain balls, and reduced in a hydrogen atmosphere at, for example, 250° C. for, for example, 12 hours.

[0062] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the instruments, reagents, materials, etc. involved are all conventional instruments, reagents, materials, etc., which can be obtained through regular commercial channels. Among them, unless otherwise specified, the reagents used are all ordinary commercially available analytically pure products.

[0063] Graphite: The average particle diameter is 70-80 μm, purchased from Qingdao Mingrun Chenyue Graphite Co., Ltd.

[0064] Preparation Example 1: The content of the elements in the copper catalyst designed and prepared is Cu: 51.9wt%, Mn: 6.3wt%, Al: 13.2wt%

[0065] Weigh 1616.64 g of copper nitrate solution (the content of Cu element in the copper nitrate solution is 14 wt%) and put it into a beaker, add 179.44 g of manganese nitrate solution (the content of manganese nitrate in the manganese nitrate solution is 50 wt%) to the copper nitrate solution, stir and mix, and record it as solution 1.

[0066] Weigh 473.77 g of sodium aluminate solution (the content of sodium aluminate in the sodium aluminate solution is 37 wt %) and put it into a beaker. Add deionized water to dilute it to 720 mL and stir to mix. This is recorded as Solution 2.

[0067] Weigh 300 g of sodium carbonate and 300 g of sodium hydroxide and dissolve them in 3000 mL of deionized water to prepare a mixed solution with a mass ratio of sodium carbonate to sodium hydroxide of 1:1, which is recorded as Solution 3.

[0068] At 80°C and under continuous stirring, solution 1, solution 2 and solution 3 were added dropwise to a precipitation tank using a peristaltic pump for 3 hours. The pH value was controlled to be 8.5 during the entire precipitation reaction process. The solution was then aged at 25°C for 2 hours. The catalyst was washed and filtered and then dried at 120°C for 12 hours. The mixture was then ground and the powder obtained by grinding was mixed with graphite at a weight ratio of 100:3 and then tableted into 3x3mm cylindrical particles. The particles were then calcined at 500°C in an air atmosphere for 8 hours to obtain copper catalyst A1.

[0069] The composition of the copper catalyst A1 was detected by inductively coupled plasma emission spectrometry, and the results showed that the content of the elements in the copper catalyst A1 was Cu: 52 wt%, Mn: 6.2 wt%, and Al: 13.2 wt%.

[0070] Figure 1 The X-ray diffraction pattern of the copper catalyst A1 is shown. The XRD characteristic peaks of the copper catalyst A1 correspond to the characteristic peaks of CuO and CuAl2O4. Figure 1 It can be seen that the copper catalyst A1 contains CuO crystal phase and CuAl2O4 spinel phase.

[0071] Preparation Example 2: The content of the elements in the copper catalyst designed and prepared is Cu: 59.9wt%, Mn: 3.2wt%, Al: 10.6wt%

[0072] Weigh 1865.36 g of a copper nitrate solution (the content of Cu element in the copper nitrate solution is 14 wt%) and put it into a beaker, add 89.72 g of a manganese nitrate solution (the content of manganese nitrate in the manganese nitrate solution is 50 wt%) to the copper nitrate solution, stir and mix, and record it as Solution 1.

[0073] Weigh 379.01 g of sodium aluminate solution (the content of sodium aluminate in the sodium aluminate solution is 37 wt %) and put it into a beaker. Add deionized water to dilute it to 576 mL and stir to mix. This is recorded as Solution 2.

[0074] Weigh 300 g of sodium carbonate and 300 g of sodium hydroxide and dissolve them in 3000 mL of deionized water to prepare a mixed solution with a mass ratio of sodium carbonate to sodium hydroxide of 1:1, which is recorded as Solution 3.

[0075] The subsequent operations of this preparation example were carried out in the same manner as in Preparation Example 1. The process parameters of the precipitation reaction, aging and calcination treatment were consistent with those in Preparation Example 1, and copper catalyst A2 was obtained.

[0076] The composition of the copper catalyst A2 was detected by inductively coupled plasma emission spectrometry, and the results showed that the content of the elements in the copper catalyst A2 was Cu: 60wt%, Mn: 3.1wt%, and Al: 13wt%.

[0077] The copper catalyst A2 prepared in this preparation example has XRD characteristic diffraction peaks similar to those of the copper catalyst A1, that is, the copper catalyst A2 contains CuO crystal phase and CuAl2O4 spinel phase.

[0078] Comparative Preparation Example 1: The content of the elements in the designed copper catalyst is Cu: 28wt%, Mn: 1.9wt%, Al: 32.8wt%

[0079] Weigh 870.5 g of a copper nitrate solution (the content of Cu element in the copper nitrate solution is 14 wt%) and put it into a beaker, add 53.83 g of a manganese nitrate solution (the content of manganese nitrate in the manganese nitrate solution is 50 wt%) to the copper nitrate solution, stir and mix, and record it as Solution 1.

[0080] Weigh 1174.94 g of sodium aluminate solution (the content of sodium aluminate in the sodium aluminate solution is 37 wt %) and put it into a beaker. Add deionized water to dilute it to 1787 mL and stir to mix. This is recorded as Solution 2.

[0081] Weigh 300 g of sodium carbonate and 300 g of sodium hydroxide and dissolve them in 3000 mL of deionized water to prepare a mixed solution with a mass ratio of sodium carbonate to sodium hydroxide of 1:1.

[0082] The subsequent operations of this preparation example were carried out in the same manner as in Preparation Example 1. The process parameters of the precipitation reaction, aging and calcination treatment were consistent with those in Preparation Example 1, and copper catalyst D-A1 was obtained.

[0083] The composition of the copper catalyst D-A1 was detected by inductively coupled plasma emission spectrometry, and the results showed that the content of elements in the copper catalyst D-A1 was Cu: 28wt%, Mn: 2.0wt%, and Al: 33wt%.

[0084] Comparative Preparation Example 2

[0085] The designed copper catalyst contains 51.9 wt% Cu, 6.3 wt% Zn and 14.1 wt% Al.

[0086] 1616.64 g of a copper nitrate solution (the content of Cu element in the copper nitrate solution is 14 wt%) was weighed and placed in a beaker, 133.82 g of zinc nitrate hexahydrate was added to the copper nitrate solution, and the mixture was stirred and mixed, and the mixture was recorded as Solution 1.

[0087] Weigh 504.09 g of sodium aluminate solution (the content of sodium aluminate in the sodium aluminate solution is 37 wt %) and put it into a beaker. Add deionized water to dilute it to 766 mL and stir to mix. This is recorded as Solution 2.

[0088] Weigh 300 g of sodium carbonate and 300 g of sodium hydroxide and dissolve them in 3000 mL of deionized water to prepare a mixed solution with a mass ratio of 1:1, which is recorded as Solution 3.

[0089] The subsequent operations of this preparation example were carried out in the same manner as in Preparation Example A1. The process parameters of the precipitation reaction, aging and calcination treatment were consistent with those in Preparation Example 1, and copper catalyst D-A2 was obtained.

[0090] The composition of the copper catalyst D-A2 was detected by inductively coupled plasma emission spectrometry, and the results showed that the content of elements in the copper catalyst D-A2 was Cu: 52wt%, Zn: 6.3wt%, and Al: 14wt%.

[0091] For the copper catalysts obtained in all the above preparation examples, their specific surface area and pore volume were measured using Anton Paar's specific surface and pore size analyzer Nova600, their bulk density was measured using a tap density tester, and their sodium content was measured using an inductively coupled plasma emission spectrometer. The specific results are shown in Table 1.

[0092] Table 1

[0093] Preparation Example 1 Preparation Example 2 Comparative Preparation Example 1 Comparative Preparation Example 2 Copper Catalyst A1 A2 D-A1 D-A2 <![CDATA[Specific surface area / m 2 / g]]> 43.3 44.6 9.7 39.5 <![CDATA[Pore volume / cm 3 / g]]> 0.29 0.30 0.08 0.24 Bulk density / g / mL 1.35 1.36 1.50 1.35 Sodium content / ppm 1160 1390 1560 1280

[0094] Example 1

[0095] S1: 13 mL of copper catalyst A1 was loaded into a tubular reactor with an inner diameter of 10 mm, both ends of the catalyst bed were filled with porcelain balls, and reduced under pure hydrogen at 250°C for 12 hours.

[0096] S2: Using sec-butyl acetate as raw material, the reaction temperature is 180°C, the reaction pressure is 5.0 MPa, the molar ratio of hydrogen to the sec-butyl acetate is 30, and the liquid hourly space velocity of sec-butyl acetate is 0.3 h -1 The reaction is carried out under the conditions of to obtain sec-butanol.

[0097] Unless otherwise specified, the remaining examples are carried out with reference to the method of Example 1, except that the types of catalysts, reaction raw materials and process parameters used in Examples 2 to 5 are different from those in Comparative Examples 1 and 2, see Table 2 for details.

[0098] Table 2

[0099]

[0100]

[0101] The hydrogenated products obtained in all the above Examples 1 to 5 and Comparative Examples 1 and 2 were analyzed by gas chromatograph area normalization method, and the results are shown in Table 3.

[0102] The calculation formulas for the reactant conversion and target product selectivity in Table 3 are:

[0103] Reactant conversion rate % = [(amount of reactant before reaction - amount of reactant after equilibrium) / amount of reactant before reaction] × 100%

[0104] Selectivity of target product % = [amount of target product / (amount of reactant before reaction - amount of reactant after equilibrium)] × 100%

[0105] Table 3

[0106] Reactant conversion rate / % Selectivity of target product / % Example 1 99.9 99.6 Example 2 99.6 99.4 Example 3 99.5 99.3 Example 4 99.0 98.0 Example 5 97.3 98.5 Comparative Example 1 95.3 96.7 Comparative Example 2 97.0 98.5

[0107] Stability test

[0108] S1: 13 mL of copper catalyst A1 was loaded into a tubular reactor with an inner diameter of 10 mm, both ends of the catalyst bed were filled with porcelain balls, and reduced under pure hydrogen at 250°C for 12 hours.

[0109] S2: Using sec-butyl acetate as raw material, the reaction temperature is 180°C, the reaction pressure is 5.0 MPa, the molar ratio of hydrogen to the sec-butyl acetate is 30, and the liquid hourly space velocity of sec-butyl acetate is 0.3 h -1 The reaction was carried out under the conditions of .

[0110] After the catalyst was online for 2020 hours, the conversion rate of sec-butyl acetate was 99.8%, and the selectivity of sec-butyl alcohol was 99.5%. Figure 2 shown.

[0111] It can be seen from the results in Table 3 that the hydrogenation reaction still has the advantages of high catalyst activity, high reactant conversion rate and high target product selectivity under relatively mild conditions, that is, low reaction energy consumption.

[0112] At the same time, from Figure 2 From the stability test results of sec-butyl acetate hydrogenation on copper catalyst A1, it can be seen that when the catalyst online time reaches 2020h, the conversion rate of sec-butyl acetate (SBAc conversion rate) is 99.8% and the selectivity of sec-butyl alcohol is 99.5%, and the catalyst activity does not change significantly. This test result fully demonstrates that the copper catalyst provided by the present invention has the characteristics of long service life and extremely stable catalytic activity.

[0113] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for hydrogenating an ester compound, characterized in that: The method comprises: subjecting an ester compound to a hydrogenation reaction in the presence of a copper catalyst; The copper catalyst contains Cu, Mn and Al elements. Based on the total weight of the copper catalyst, the content of Cu in the copper catalyst is 32wt%-60wt%, the content of Mn in the copper catalyst is 3wt%-16wt%, and the content of Al in the copper catalyst is 10wt%-32wt%. The copper catalyst contains CuO crystal phase and / or CuAl2O4 spinel phase.

2. The method according to claim 1, wherein: The ester compound is an organic carboxylic acid ester generated by transesterification of a C2-C12 monocarboxylic acid and / or a polycarboxylic acid with a C1-C12 monohydric alcohol; Preferably, the ester compound is selected from at least one of dimethyl succinate, dimethyl 1,4-cyclohexanedicarboxylate, sec-butyl acetate, cyclohexyl acetate, isopropyl acetate, and methyl isononanoate; Preferably, the ester compound is sec-butyl acetate.

3. The method according to claim 1 or 2, wherein: The copper catalyst has a Cu content of 34wt%-56wt%, a Mn content of 3.2wt%-12wt%, and an Al content of 12wt%-30wt%.

4. The method according to claim 1 or 2, wherein: The specific surface area of ​​the copper catalyst is 20-100m 2 / g, pore volume is 0.1-2cm 3 / g.

5. The method according to claim 1 or 2, wherein: The bulk density of the copper catalyst is 1-1.5 g / mL; Preferably, the sodium content in the copper catalyst is 500-5000 ppm.

6. The method according to any one of claims 1 to 5, wherein: The method also includes the following steps of preparing the copper catalyst: (1) Under the condition of pH 8-9, an aqueous solution containing copper salt, manganese salt and aluminum salt is subjected to a coprecipitation reaction at a temperature not lower than 40° C. to obtain an intermediate I; (2) subjecting the intermediate I to an aging treatment to obtain an intermediate II; (3) calcining the intermediate II to obtain the copper catalyst.

7. The method according to claim 6, wherein: The coprecipitation reaction conditions include: temperature of 70-90°C and time of 2.5-4h; And / or, the aging treatment conditions include: aging temperature of 25-30° C., aging time of 2-3 h.

8. The method according to claim 6 or 7, wherein: The conditions of the calcination treatment include: a calcination temperature of 400-600° C. and a calcination time of 5-10 hours.

9. The method according to any one of claims 1 to 8, wherein: The reaction temperature of the hydrogenation reaction is 150-250°C and the reaction pressure is 3-9MPa; Preferably, the reaction temperature of the hydrogenation reaction is 160-230° C., and the reaction pressure is 4-8 MPa.

10. The method according to any one of claims 1 to 9, wherein: In the hydrogenation reaction, the molar ratio of hydrogen to ester compound is 5-70, and the liquid hourly space velocity of the ester compound is 0.2-2h -1 ; Preferably, in the hydrogenation reaction, the molar ratio of hydrogen to ester compound is 10-60, and the liquid hourly space velocity of the ester compound is 0.2-1h -1 .

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