A bio-based 1,4-butanediol and its preparation method

Abstract

This invention relates to a bio-based 1,4-butanediol and its preparation method, belonging to the field of chemical raw material synthesis technology. The preparation method of bio-based 1,4-butanediol in this invention includes the following steps: preparing a bio-based 1,4-succinic acid solution; continuously introducing the obtained bio-based 1,4-succinic acid solution and hydrogen gas into a fixed bed containing a first-stage nickel-copper catalyst for hydrogenation reaction to obtain a first-stage product; continuously introducing the obtained first-stage product and hydrogen gas into a fixed bed containing a second-stage nickel-copper catalyst for hydrogenation reaction to obtain a second-stage product; separating and purifying the obtained second-stage product in a separation tower to obtain bio-based 1,4-butanediol. This invention prepares polymer-grade bio-based 1,4-butanediol by continuous liquid-phase hydrogenation of bio-based 1,4-butanenic acid. The purity of the obtained polymer-grade bio-based 1,4-butanediol is ≥99.90%, and the product does not contain methyl-1,4-butanediol or 2-(4-hydroxybutoxy)-tetrahydrofuran.

Description

Technical Field

[0001] This invention relates to the field of chemical raw material synthesis technology, and in particular to a bio-based 1,4-butanediol and its preparation method. Background Technology

[0002] 1,4-Butanediol, abbreviated as BDO, is a basic raw material for the production of polyesters such as polybutylene terephthalate (PBT), polybutylene terephthalate-adipate-glycol (PBAT), and polybutylene succinate (PBS), and is an important organic and fine chemical raw material. Simultaneously, 1,4-Butanediol is a major raw material for the production of tetrahydrofuran. The polytetramethylene glycol ether (PTMEG) obtained after the polymerization of tetrahydrofuran is a basic raw material for the production of high-elasticity spandex (Lycra fiber), used in the production of high-elasticity knitwear such as high-end sportswear and swimwear.

[0003] There are over 17 different processes for producing 1,4-butanediol, but industrially, the main methods include the Reppe process (acetylene-aldehyde process) using formaldehyde and acetylene (calcium carbide gas) as raw materials, and the hydrogenation process using maleic anhydride, succinic acid, and their derivatives. While the acetylene-aldehyde process has relatively low production costs, calcium carbide is an energy-intensive raw material. The hydrogenation process can produce different products depending on the process conditions; however, its main drawbacks are the large number of hydrogenation byproducts, high separation costs, and the acidic reaction system. Generally, acid-sensitive systems can lead to poisoning of the active sites, making long-term production impossible. If 1,4-butanediol could be produced through targeted and highly selective hydrogenation by adjusting the catalytic active sites, it would have significant industrial potential.

[0004] Patent CN111018669A discloses a continuous preparation method for 1,4-butanediol, which requires two esterification reactions. This makes the existing mono-esterification-diesterification preparation process complex, requiring multiple supporting production facilities, large equipment investment, long production cycle, and high energy consumption. Furthermore, due to the special preparation process of bio-based succinic acid, trace impurities can affect the catalytic activity of the catalyst, resulting in unsatisfactory performance of the final product, 1,4-butanediol.

[0005] Therefore, there is an urgent need to provide a method for producing bio-based 1,4-butanediol with low production cost and high purity. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a bio-based 1,4-butanediol and its preparation method. The nickel-copper catalyst of this invention comprises an ordered composite porous carbon / molybdenum disulfide support, nickel and copper precursor compounds as active components, and a hydrophobic compound component. Specifically, in the first-stage hydrogenation catalyst, the nickel loading is 30wt%–60wt%, the copper loading is 1wt%–5wt%, and the hydrophobic compound is 0.01wt%–0.2wt%; in the second-stage hydrogenation catalyst, the nickel loading is 5wt%–10wt%, the copper loading is 30wt%–60wt%, and the hydrophobic compound is 0.01wt%–0.2wt%. This invention prepares polymer-grade bio-based 1,4-butanediol through continuous liquid-phase hydrogenation of bio-based 1,4-succinic acid. The purity of the obtained polymer-grade bio-based 1,4-butanediol is ≥99.90%, and the product does not contain methyl-1,4-butanediol.

[0007] This invention is achieved through the following technical solution:

[0008] The first objective of this invention is to provide a bio-based 1,4-butanediol, wherein the bio-based 1,4-butanediol has a purity ≥99.90%, is free of methyl-1,4-butanediol and 2-(4-hydroxybutoxy)-tetrahydrofuran, and the remainder consists of impurities; the main impurities are tetrahydrofuran, with a content ≤0.05%, and n-butanol, with a content ≤0.05%.

[0009] A second object of the present invention is to provide the method for producing bio-based 1,4-butanediol, comprising the following steps:

[0010] (1) Prepare a bio-based 1,4-succinic acid solution;

[0011] (2) The bio-based 1,4-succinic acid solution obtained in step (1) and hydrogen gas are continuously introduced into a fixed bed containing a nickel-copper catalyst to carry out a hydrogenation reaction, and a product is obtained.

[0012] (3) The first product obtained in step (2) and hydrogen are continuously fed into a fixed bed containing a two-stage nickel-copper catalyst to carry out a hydrogenation reaction to obtain a second product;

[0013] (4) The two-stage product obtained in step (3) is fed into a separation tower for separation and purification to obtain bio-based 1,4-butanediol;

[0014] In step (2), the nickel loading in the nickel-copper catalyst is 30wt% to 60wt%, the copper loading is 1wt% to 5wt%, and the content of hydrophobic compounds is 0.01wt% to 0.2wt%.

[0015] In step (3), the nickel loading in the two-stage nickel-copper catalyst is 5 wt% to 10 wt%, the copper loading is 30 wt% to 60 wt%, and the content of the hydrophobic compound is 0.01 wt% to 0.2 wt%.

[0016] In one embodiment of the present invention, in step (1), the bio-based 1,4-succinic acid solution contains a bio-based 1,4-succinic acid mass percentage of 5 wt% to 30 wt%.

[0017] In one embodiment of the present invention, in step (1), the solvent of the bio-based 1,4-succinic acid solution is selected from one or more of tetrahydrofuran, γ-butyrolactone, diethyl ether, ethyl acetate, ethyl formate and methyl acetate; preferably tetrahydrofuran or γ-butyrolactone.

[0018] In one embodiment of the present invention, in steps (2) and (3), the flow rate of the bio-based 1,4-succinic acid solution is 0 to 5 mL / min;

[0019] And / or, the flow rate of the product segment is 0–5 mL / min;

[0020] And / or, the flow rate of the hydrogen gas is 0 to 100 mL / min.

[0021] In one embodiment of the present invention, in step (2), the nickel-copper catalyst is obtained by the following preparation method:

[0022] S1. Stir and mix asphalt and molybdenum disulfide; heat-treat the resulting mixture under oxygen conditions to obtain a porous carbon / molybdenum disulfide material carrier;

[0023] S2. Dissolve the nickel precursor compound, copper precursor compound, hydrophobic compound, and acid solution in water to obtain a mixed solution; the mass ratio of the nickel precursor compound, copper precursor compound, and hydrophobic compound is 80-99:0.1-20:0.01-1.

[0024] S3. The porous carbon / molybdenum disulfide material support obtained in step S1 is impregnated in the mixed solution obtained in step S2 to obtain a catalyst intermediate;

[0025] S4. The catalyst intermediate obtained in step S3 is aged, dried and reduced to obtain the nickel-copper catalyst.

[0026] In one embodiment of the present invention, in step (3), the two-stage nickel-copper catalyst is obtained by the following preparation method:

[0027] S11. Stir and mix asphalt and molybdenum disulfide; heat-treat the resulting mixture under oxygen conditions to obtain a porous carbon / molybdenum disulfide material carrier.

[0028] S12. Dissolve the nickel precursor compound, copper precursor compound, hydrophobic compound, and acid solution in water to obtain a mixed solution; the mass ratio of the nickel precursor compound, copper precursor compound, and hydrophobic compound is 1-50:50-99:0.01-1.

[0029] S13. The porous carbon / molybdenum disulfide material support obtained in step S11 is impregnated in the mixed solution obtained in step S12 to obtain a catalyst intermediate;

[0030] S14. The catalyst intermediate obtained in step S13 is aged, dried and reduced to obtain the two-stage nickel-copper catalyst.

[0031] In one embodiment of the present invention, the mass-average molecular weight of the asphalt is 600-2000, and the molecular weight distribution is 1.2-1.4.

[0032] And / or, the molybdenum disulfide is a nanosheet structure with 5 to 20 layers.

[0033] In one embodiment of the present invention, the mass ratio of the asphalt to molybdenum disulfide is 1:5 to 5:1;

[0034] And / or, the heat treatment conditions are: heat treatment at 200℃~400℃ for 3h~8h.

[0035] In one embodiment of the present invention, the obtained porous carbon / molybdenum disulfide material carrier has a pore volume of 0.2 mL / g to 0.7 mL / g, a particle size of 3 mm to 5 mm, and a bulk density of 750 kg / m³. 3 ~1100kg / m 3 .

[0036] In one embodiment of the present invention, the nickel precursor compound is selected from one or more of nickel chloride, nickel nitrate, nickel sulfate, basic nickel carbonate, nickel acetylacetone, nickel oxalate, nickel acetate, nickel citrate, nickel hypophosphite, nickel phosphate, and nickel formate.

[0037] And / or, the copper precursor compound is selected from one or more of copper chloride, copper nitrate, and copper sulfate;

[0038] And / or, the structural formula of the hydrophobic compound is: Where n≥6.

[0039] In one embodiment of the present invention, the acid solution is a dilute nitric acid solution with a concentration of 1 mol / L to 6 mol / L.

[0040] In one embodiment of the present invention, in step S4, the reduction conditions are: reduction at 160°C to 200°C for 6 to 10 hours under hydrogen atmosphere and atmospheric pressure. ，This gives the nickel-copper catalyst hydrogenation activity.

[0041] In one embodiment of the present invention, in step S14, the reduction conditions are: reduction at 160°C to 200°C for 6 to 10 hours under hydrogen atmosphere and atmospheric pressure. ， This gives the nickel-copper catalyst hydrogenation activity.

[0042] In one embodiment of the present invention, in step (2), the pressure of the hydrogenation reaction is 1 MPa to 10 MPa; preferably 2 MPa to 5 MPa;

[0043] And / or, the temperature of the hydrogenation reaction is 25°C to 100°C; preferably 80°C to 100°C;

[0044] And / or, the system space velocity of the hydrogenation reaction is 0.6 hr. -1 ~6.0hr -1 .

[0045] In one embodiment of the present invention, in step (3), the pressure of the hydrogenation reaction is 3 MPa to 10 MPa; preferably 5 MPa to 8 MPa;

[0046] And / or, the temperature of the hydrogenation reaction is 100°C to 200°C; preferably 120°C to 150°C;

[0047] And / or, the system space velocity of the hydrogenation reaction is 0.6 hr. -1 ~6.0hr -1 .

[0048] The particle strength of the single-stage and two-stage nickel-copper catalysts prepared by this invention is ≥400 N / cm. Furthermore, the cluster sizes of both catalysts are: length 80 nm–150 nm, width approximately 30 nm–100 nm, and thickness approximately 10 nm–30 nm. The prepared bio-based 1,4-butanediol has a purity ≥99.90%, is free of methyl-1,4-butanediol and 2-(4-hydroxybutoxy)-tetrahydrofuran; the main impurities are tetrahydrofuran (≤0.05%) and n-butanol (≤0.05%).

[0049] The technical solution of this invention uses a high-strength molybdenum disulfide / porous carbon support, which can avoid the loss of non-precious metal nickel and copper catalytic centers into the product under pressurized hydrogenation conditions, thus preventing the catalyst activity from gradually decreasing and ensuring long-cycle production. In addition, the hydrophobic compound can enable the hydrogenated product to desorb quickly from the catalyst surface, and the degree of hydrogenation of the two C=O bonds of succinic acid can be controlled by adjusting the reaction pressure and temperature, thereby obtaining the target product.

[0050] The porous carbon / molybdenum disulfide support of this invention, due to the layered structure of molybdenum disulfide, allows the asphalt to extend along the layered voids during high-temperature treatment. Subsequently, under certain temperatures, processes such as dehydration and removal of organic matter result in a layered carbon structure that firmly bonds with molybdenum disulfide, creating numerous porous channels that facilitate the dispersion of active metal components. Simultaneously, this composite support structure naturally possesses high mechanical strength, easily achieving a particle strength ≥400 N / cm, which is difficult to achieve with traditional alumina particles; the mechanical strength of commercial catalyst support alumina particles typically reaches 100 N / cm.

[0051] The above technical solution has the following advantages compared with the existing technology:

[0052] (1) The catalyst used in this invention has an ultra-high strength of ≥400 N / cm, and the metal is not easily lost during the reaction, which plays a key role in the synthesis of high-purity bio-based 1,4-butanediol.

[0053] (2) The catalyst used in this invention uses porous carbon / molybdenum disulfide as a support. The catalyst support itself has a certain hydrogenation activity, which can promote the improvement of reaction activity, thereby reducing the reaction temperature, improving the reaction selectivity, and thus improving the purity of the product.

[0054] (3) The present invention uses bio-based 1,4-butanediol as the reaction raw material and uses hydrophobic compounds as additives as catalysts, which can make the product bio-based 1,4-butanediol desorb from the catalyst surface as soon as possible. On the one hand, it can accelerate the reaction rate, and on the other hand, it can avoid further reaction of the product on the catalyst surface, thereby achieving the final goal of the product purity reaching the polymerization level. Detailed Implementation

[0055] The present invention will be further described below with reference to specific embodiments, so that those skilled in the art can better understand and implement the present invention, but the embodiments are not intended to limit the present invention.

[0056] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.

[0057] Product purity and impurity content were determined by gas chromatography (GC). An HP-5 (30m × 320μm × 0.25μm) GC column with an FID detector was used. Column temperature conditions were: initial temperature 60℃, first-order termination temperature 90℃, heating rate 15℃ / min, hold time 2 min, second-order termination temperature 230℃, heating rate 10℃ / min, injection port temperature 260℃, split ratio 100:1, injection volume 0.2μL, hydrogen flow rate 30mL / min, and nitrogen flow rate 25mL / min. Standard curves were established using acetone as the solvent for 1,4-succinic acid, tetrahydrofuran, methyl-1,4-butanediol, 2-(4-hydroxybutoxy)-tetrahydrofuran, γ-butyrolactone, n-butanol, and 1,4-butanediol.

[0058] The strength of the hydrogenation catalyst was tested in accordance with the HG / T 2782 standard.

[0059] Example 1

[0060] This embodiment provides a method for preparing bio-based 1,4-butanediol, the specific steps of which are as follows:

[0061] (1) Carrier preparation: Asphalt and molybdenum disulfide were mixed at a mass ratio of 1:1 and heat-treated at 300℃ for 4 hours under oxygen conditions to prepare a porous carbon / molybdenum disulfide carrier with a pore volume of 0.5 mL / g and a particle size of 5 mm.

[0062] (2) Preparation of a single-stage nickel-copper catalyst: Weigh 50.00g of basic nickel carbonate (molecular weight 376.17), 159.5mL (5mol / L) dilute nitric acid solution, 4.58g of copper nitrate, 0.30g of sodium dodecyl sulfonate, and 500.00g of deionized water. Stir at 45℃ until all solids are dissolved to obtain a nickel-copper solution. Impregnate the obtained porous carbon / molybdenum disulfide support in the nickel-copper solution. Under stirring conditions, age the resulting mixture at 60℃ for 14h, then dry it at 120℃ for 12h. After filling it into a tube, reduce it at 200℃ under hydrogen conditions for 6h to obtain a single-stage nickel-copper catalyst.

[0063] Preparation of the two-stage nickel-copper catalyst: 9.16 g of basic nickel carbonate (molecular weight 376.17), 29.2 mL (5 mol / L) dilute nitric acid solution, 50.00 g of copper nitrate, 0.30 g of sodium dodecyl sulfonate, and 500.00 g of deionized water were weighed and stirred at 45 °C until all solids dissolved to obtain a nickel-copper solution; the obtained porous carbon / molybdenum disulfide support was impregnated in the nickel-copper solution; under stirring conditions, the mixture was aged at 60 °C for 14 h, then dried at 120 °C for 12 h, packed into a tube, and reduced under hydrogen conditions at 200 °C for 6 h to obtain the two-stage nickel-copper catalyst.

[0064] (3) Prepare a γ-butyrolactone solution of bio-based 1,4-succinic acid with a mass percentage of 5 wt%; mix the γ-butyrolactone solution of bio-based 1,4-succinic acid with hydrogen gas at a flow rate of 200 mL / min and continuously introduce it into a 50 mL hydrogenation tube reactor containing a nickel-copper catalyst. The reaction temperature is 96 °C and the reaction pressure is 2.8 MPa (A) to obtain the γ-butyrolactone solution.

[0065] A solution of γ-butyrolactone at a flow rate of 0.5 mL / min was mixed with hydrogen at a flow rate of 200 mL / min and continuously fed into a 50 mL hydrogenation tubular reactor containing a two-stage nickel-copper catalyst. The reaction temperature was 130 °C and the reaction pressure was 5.2 MPa (A). The mixture was then continuously fed into a distillation column to separate and obtain bio-based 1,4-butanediol.

[0066] Example 2

[0067] This embodiment provides a method for preparing bio-based 1,4-butanediol, which is similar to Example 1, except that:

[0068] In step (2), the basic nickel carbonate in the two-stage nickel-copper catalyst preparation process is replaced with nickel nitrate;

[0069] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0070] Example 3

[0071] This embodiment provides a method for preparing bio-based 1,4-butanediol, which is similar to Example 1, except that:

[0072] In step (2), copper nitrate in the two-stage nickel-copper catalyst preparation process is replaced with copper chloride;

[0073] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0074] Example 4

[0075] This embodiment provides a method for preparing bio-based 1,4-butanediol, which is similar to Example 1, except that:

[0076] During the catalytic hydrogenation process, a 10 wt% solution of γ-butyrolactone in bio-based 1,4-succinic acid was prepared and catalytically hydrogenated to obtain bio-based 1,4-butanediol.

[0077] Example 5

[0078] This embodiment provides a method for preparing bio-based 1,4-butanediol, which is similar to Example 1, except that:

[0079] In the catalytic hydrogenation process, a 5 wt% tetrahydrofuran solution of bio-based 1,4-butanediol was prepared and catalytically hydrogenated to obtain bio-based 1,4-butanediol.

[0080] Comparative Example 1

[0081] This comparative example provides a method for preparing bio-based 1,4-butanediol, similar to Example 1, except that:

[0082] Copper nitrate is not added during the preparation of either the first-stage or second-stage nickel-copper catalyst.

[0083] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0084] Comparative Example 2

[0085] This comparative example provides a method for preparing bio-based 1,4-butanediol, similar to Example 1, except that:

[0086] Sodium dodecyl sulfonate is not added during the preparation of both the first-stage and second-stage nickel-copper catalysts.

[0087] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0088] Comparative Example 3

[0089] This comparative example provides a method for preparing bio-based 1,4-butanediol, similar to Example 1, except that:

[0090] Neither copper nitrate nor sodium dodecyl sulfonate is added during the preparation of the first-stage and second-stage nickel-copper catalysts.

[0091] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0092] Comparative Example 4

[0093] This comparative example provides a method for preparing bio-based 1,4-butanediol, similar to Example 1, except that:

[0094] Molybdenum disulfide is not added during the preparation of both the first-stage and second-stage nickel-copper catalysts.

[0095] The obtained two-stage nickel-copper catalyst was subjected to catalytic hydrogenation to prepare bio-based 1,4-butanediol.

[0096] Test case

[0097] The strength of the catalysts prepared in the examples and comparative examples was tested according to the HG / T 2782 standard. The test results are shown in Table 1 below:

[0098] Table 1

[0099] Catalyst strength (N / cm) Two-stage catalyst strength (N / cm) Example 1 453.3 450.9 Example 2 451.8 453.2 Example 3 457.2 451.0 Example 4 453.3 450.9 Example 5 453.3 450.9 Comparative Example 1 453.8 450.6 Comparative Example 2 454.6 451.2 Comparative Example 3 451.5 450.4 Comparative Example 4 205.1 201.3

[0100] As can be seen from Table 1, the strength of the supported catalyst prepared in the examples exceeds 450 N / cm. By combining high-strength molybdenum disulfide with porous carbon, the strength of the supported catalyst can be greatly improved.

[0101] The purity and impurity content of the product were tested by gas chromatography. The conversion rate of the hydrogenation process after 1000 hours of continuous experiment is shown in Table 2 below:

[0102] Table 2

[0103]

[0104] As can be seen from Table 2, the catalyst of the present invention still has high catalytic activity and selectivity after 1000 hours of continuous hydrogenation, which means that it can prepare high-purity 1,4-butanediol under certain pressure and temperature conditions.

[0105] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for the production of a biobased 1,4-butanediol, characterized in that, The method comprises the following steps: (1) preparing a bio-based 1,4-succinic acid solution; (2) continuously feeding the bio-based 1,4-succinic acid solution obtained in step (1) and hydrogen into a fixed bed containing a first-stage nickel-copper catalyst to perform a hydrogenation reaction to obtain a first-stage product; (3) continuously feeding the first-stage product obtained in step (2) and hydrogen into a fixed bed containing a second-stage nickel-copper catalyst to perform a hydrogenation reaction to obtain a second-stage product; (4) feeding the second-stage product obtained in step (3) into a separation tower to perform separation and purification to obtain bio-based 1,4-butanediol; In step (2), the first-stage nickel-copper catalyst has a nickel loading of 30 wt% to 60 wt%, a copper loading of 1 wt% to 5 wt%, and a content of hydrophobic compound of 0.01 wt% to 0.2 wt%; In step (3), the second-stage nickel-copper catalyst has a nickel loading of 5 wt% to 10 wt%, a copper loading of 30 wt% to 60 wt%, and a content of hydrophobic compound of 0.01 wt% to 0.2 wt%; In step (2), the first-stage nickel-copper catalyst is prepared by the following method: S1, stirring and mixing pitch and molybdenum disulfide; heat treating the obtained mixture under oxygen to obtain a porous carbon / molybdenum disulfide material carrier; S2, dissolving a nickel precursor compound, a copper precursor compound, a hydrophobic compound, and an acid solution in water to obtain a mixed solution; the mass ratio of the nickel precursor compound, the copper precursor compound, and the hydrophobic compound is 80 to 99: 0.1 to 20: 0.01 to 1; S3, immersing the porous carbon / molybdenum disulfide material carrier obtained in step S1 in the mixed solution obtained in step S2 to obtain a catalyst intermediate; S4, aging, drying, and reducing the catalyst intermediate obtained in step S3 to obtain the first-stage nickel-copper catalyst; In step (3), the second-stage nickel-copper catalyst is prepared by the following method: S11, stirring and mixing pitch and molybdenum disulfide; heat treating the obtained mixture under oxygen to obtain a porous carbon / molybdenum disulfide material carrier; S12, dissolving a nickel precursor compound, a copper precursor compound, a hydrophobic compound, and an acid solution in water to obtain a mixed solution; the mass ratio of the nickel precursor compound, the copper precursor compound, and the hydrophobic compound is 1 to 50: 50 to 99: 0.01 to 1; S13, immersing the porous carbon / molybdenum disulfide material carrier obtained in step S11 in the mixed solution obtained in step S12 to obtain a catalyst intermediate; S14, aging, drying, and reducing the catalyst intermediate obtained in step S13 to obtain the second-stage nickel-copper catalyst; The hydrophobic compound is sodium dodecyl sulfonate.

2. The production method according to claim 1, characterized by, In step (1), the mass percentage of bio-based 1,4-succinic acid in the bio-based 1,4-succinic acid solution is 5 wt% to 30 wt%.

3. The production method according to claim 1, characterized by, In step (1), the solvent of the bio-based 1,4-succinic acid solution is selected from one or more of tetrahydrofuran, gamma-butyrolactone, diethyl ether, ethyl acetate, ethyl formate, and methyl acetate.

4. The method of claim 1, wherein, In step (2) and step (3), the flow rate of the bio-based 1,4-succinic acid solution is 0-5 mL / min; And / or, the flow rate of the one-stage product is 0-5 mL / min; And / or, the flow rate of the hydrogen is 0-100 mL / min.

5. The preparation method according to claim 1, characterized in that, The nickel precursor compound is selected from one or more of nickel chloride, nickel nitrate, nickel sulfate, nickel carbonate basic, nickel acetylacetone, nickel oxalate, nickel acetate, nickel citrate, nickel hypophosphite, nickel phosphate, and nickel formate; And / or, the copper precursor compound is selected from one or more of copper chloride, copper nitrate, and copper sulfate.

6. The method of claim 1, wherein, In step (2), the pressure of the hydrogenation reaction is 1-10 MPa; And / or, the temperature of the hydrogenation reaction is 25-100°C; and / or the system reaction space velocity of the hydrogenation reaction is 0.6 hr -1 ~6.0 hr -1 .

7. The preparation method according to claim 1, characterized in that, In step (3), the pressure of the hydrogenation reaction is 3-10 MPa; And / or, the temperature of the hydrogenation reaction is 100-200°C; and / or the system reaction space velocity of the hydrogenation reaction is 0.6 hr -1 ~6.0 hr -1 .

Images