Bio-based gamma-butyrolactone and production method thereof

Abstract

The invention relates to bio-based gamma-butyrolactone and a production method thereof. The production method of the bio-based gamma-butyrolactone comprises the following steps: preparing a bio-based succinic acid solution; continuously feeding the obtained bio-based succinic acid solution and hydrogen into a fixed bed containing a nickel-copper catalyst, and carrying out hydrogenation reaction to obtain a crude product; the obtained crude product enters a separation tower to be separated and purified, and bio-based gamma-butyrolactone is obtained; in the nickel-copper catalyst, the loading amount of nickel is 30wt%-60wt%, the loading amount of copper is 1wt%-5wt%, and the content of the hydrophobic compound is 0.01 wt%-0.2 wt%. According to the method, 5-30 wt% of a diluted bio-based 1, 4-succinic acid solution continuously enters a fixed bed hydrogenation reactor to prepare a bio-based gamma-butyrolactone liquid, and the bio-based gamma-butyrolactone liquid continuously enters a rectification separation tower to be separated, so that a bio-based gamma-butyrolactone product with the purity being greater than or equal to 99.99% can be prepared, and the balance is impurities; the impurities comprise tetrahydrofuran and 1, 4-butanediol; the content of tetrahydrofuran is less than or equal to 0.004%; the content of the 1, 4-butanediol is less than or equal to 0.005%.

Description

Technical Field

[0001] The invention relates to the technical field of chemical raw material synthesis, in particular to bio-based gamma-butyrolactone and a production method thereof. Background Art

[0002] γ-Butyrolactone is an important chemical raw material, mainly used in the production of important raw materials and medicines such as cyclopropylamine, pyrrolidone, acetylbutyrolactone and vitamin B1, and is also used as an industrial solvent, extractant, electrolyte solution, etc. At present, the main production process of γ-butyrolactone is the dehydrogenation cyclization method of 1,4-butanediol, which will produce a large amount of 2-(4-hydroxybutoxy)tetrahydrofuran high-boiling by-product, resulting in the precipitation of solid by-products on the inner wall of the reactor and piping, and even blockage, which makes it impossible to produce continuously for a long time. In addition, the hydrogenation method is to prepare tetrahydrofuran, γ-butyrolactone and 1,4-butanediol mixture by hydrogenation of maleic anhydride, succinic acid and its derivatives, and then prepare γ-butyrolactone by distillation separation. Maleic anhydride has one C=C bond and two C=O bonds in the molecule or two C=O bonds in succinic acid. Under certain catalytic conditions, hydrogenation will produce succinic anhydride, γ-butyrolactone, 1,4-butanediol and tetrahydrofuran in turn. The characteristic of this technology is that it can produce tetrahydrofuran, γ-butyrolactone and 1,4-butanediol at the same time according to different process conditions. The main disadvantages are that there are many hydrogenation by-products, the separation cost is high, and the maleic anhydride hydrogenation acidic reaction system, generally the acid-resistant system will lead to active center poisoning, and long-term production cannot be achieved. By adjusting the catalytic active center, γ-butyrolactone can be prepared by directional and highly selective hydrogenation, which has great industrialization potential. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a bio-based γ-butyrolactone and a production method thereof. The present invention uses a 5wt% to 30wt% bio-based 1,4-succinic acid dilute solution to continuously enter a fixed bed hydrogenation reactor to prepare a bio-based γ-butyrolactone liquid, which is continuously separated by a distillation separation tower to prepare a bio-based γ-butyrolactone product with a purity of ≥99.99%.

[0004] The present invention is achieved through the following technical solutions:

[0005] The first object of the present invention is to provide a bio-based γ-butyrolactone, wherein the purity of the bio-based γ-butyrolactone is ≥99.99%, and the rest is impurities; the impurities include tetrahydrofuran and 1,4-butanediol; the content of the tetrahydrofuran is ≤0.004%; the content of the 1,4-butanediol is ≤0.005%.

[0006] The second object of the present invention is to provide a method for producing the bio-based γ-butyrolactone, comprising the following steps:

[0007] (1) preparing a bio-based succinic acid solution;

[0008] (2) continuously introducing the bio-based succinic acid solution obtained in step (1) and hydrogen into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain a crude product;

[0009] (3) the crude product obtained in step (2) is placed in a separation tower for separation and purification to obtain bio-based γ-butyrolactone;

[0010] 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 the hydrophobic compound is 0.01wt% to 0.2wt%.

[0011] In one embodiment of the present invention, in step (1), the mass percentage of bio-based succinic acid in the bio-based succinic acid solution is 5 wt % to 30 wt %.

[0012] In one embodiment of the present invention, in step (1), the solvent of the bio-based succinic acid solution is selected from one or more of tetrahydrofuran, γ-butyrolactone, diethyl ether, ethyl acetate, ethyl formate and methyl acetate; preferably tetrahydrofuran and γ-butyrolactone.

[0013] In one embodiment of the present invention, in step (2), the flow rate of the bio-based succinic acid solution is 0 to 5 mL / min;

[0014] And / or, the flow rate of the hydrogen is 0 to 100 mL / min.

[0015] In one embodiment of the present invention, in step (2), the nickel-copper catalyst is obtained by the following preparation method:

[0016] S1, stirring and mixing asphalt and molybdenum disulfide; heat-treating the obtained mixture under oxygen conditions to obtain a porous carbon / molybdenum disulfide material carrier;

[0017] S2, dissolving the nickel precursor compound, the copper precursor compound, the hydrophobic compound and the acid solution in water to obtain a mixed solution;

[0018] S3, impregnating the porous carbon / molybdenum disulfide material carrier obtained in step S1 into the mixed solution obtained in step S2 to obtain a catalyst intermediate;

[0019] S4, aging and drying the catalyst intermediate obtained in step S3 to obtain the nickel-copper catalyst.

[0020] In one embodiment of the present invention, the mass average molecular weight of the asphalt is 600 to 2000, and the molecular weight distribution is 1.2 to 1.4;

[0021] And / or, the molybdenum disulfide is a nanosheet structure with 5 to 20 layers.

[0022] In one embodiment of the present invention, the mass ratio of the asphalt to molybdenum disulfide is 1:5 to 5:1;

[0023] And / or, the heat treatment conditions are: heat treatment at 200°C to 400°C for 3h to 8h.

[0024] In one embodiment of the present invention, the 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 / m 3 ~1100kg / m 3 .

[0025] 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 acetylacetonate, nickel oxalate, nickel acetate, nickel citrate, nickel hypophosphite, nickel phosphate and nickel formate;

[0026] and / or, the copper precursor compound is selected from one or more of copper chloride, copper nitrate and copper sulfate;

[0027] And / or, the structural formula of the hydrophobic compound is Where n≥6.

[0028] In one embodiment of the present invention, the mass ratio of the nickel precursor compound, the copper precursor compound and the hydrophobic compound is 80-99:0.1-20:0.01-1.

[0029] In one embodiment of the present invention, in step S4, the reduction conditions are: reduction at 160°C to 200°C for 6h to 10h under hydrogen and normal pressure. ， This makes the nickel-copper catalyst have hydrogenation activity.

[0030] 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;

[0031] And / or, the temperature of the hydrogenation reaction is 25°C to 100°C, preferably 80°C to 100°C;

[0032] And / or, the system reaction space velocity of the hydrogenation reaction is 0.6 hr -1 ~6.0hr -1 .

[0033] In one embodiment of the present invention, in step (3), the purity of the bio-based γ-butyrolactone is ≥ 99.99%.

[0034] The particle strength of the nickel-copper catalyst prepared by the present invention is ≥400N / cm. In addition, the size of the catalytic active center cluster is: 80nm-150nm in length, about 30nm-100nm in width, and about 10nm-30nm in thickness.

[0035] The technical solution of the present invention adopts a high-strength molybdenum disulfide / porous carbon carrier, which can avoid the problem of non-precious metal nickel and copper catalytic centers being lost into the product under pressurized hydrogenation conditions, thereby causing the catalyst activity to gradually decrease, thereby ensuring long-term production; in addition, the hydrophobic compound can make the hydrogenation product quickly desorb from the catalyst surface, and then by adjusting the reaction pressure and temperature, the degree of hydrogenation of the two C=O bonds in the succinic acid molecule can be controlled to obtain the target product.

[0036] The porous carbon / molybdenum disulfide carrier of the present invention, due to the layered structural characteristics of molybdenum disulfide, when the carrier is subjected to high temperature treatment, the asphalt will extend along the layered voids, and then undergo dehydration, de-organic matter and other processes at a certain temperature to form a layered carbon structure, which is firmly combined with molybdenum disulfide and produces a large number of pore structures, which is conducive to the dispersion of active metal components. At the same time, this composite carrier structure naturally has a very high mechanical strength, and it is easy to achieve a particle strength of ≥400N / cm, while the particle strength of traditional alumina is difficult to achieve this. The mechanical strength of alumina particles of commercial catalyst carriers can generally reach 100N / cm.

[0037] Compared with the existing technology, it has the following advantages:

[0038] (1) The catalyst used in the present 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 succinic anhydride.

[0039] (2) The catalyst used in the present invention uses porous carbon / molybdenum disulfide as a carrier. The catalyst carrier itself has a certain hydrogenation activity, which can promote the improvement of reaction activity, thereby reducing the reaction temperature, improving the reaction selectivity, and further improving the purity of the product.

[0040] (3) The catalyst used in the present invention uses a hydrophobic compound as an additive, which can make the target product desorb from the catalyst surface as quickly 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 goal of high-purity product. DETAILED DESCRIPTION

[0041] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0042] The invention provides a bio-based gamma-butyrolactone, wherein the purity of the bio-based gamma-butyrolactone is ≥99.99%, and the remainder is impurities; the impurities include tetrahydrofuran and 1,4-butanediol; the tetrahydrofuran is ≤0.004%; and the 1,4-butanediol is ≤0.005%.

[0043] Also provided is a method for producing bio-based γ-butyrolactone, comprising the following steps:

[0044] (1) preparing a bio-based succinic acid solution;

[0045] (2) continuously introducing the bio-based succinic acid solution obtained in step (1) and hydrogen into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain a crude product;

[0046] (3) the crude product obtained in step (2) is placed in a separation tower for separation and purification to obtain bio-based γ-butyrolactone;

[0047] 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 the hydrophobic compound is 0.01wt% to 0.2wt%.

[0048] Furthermore, the nickel-copper catalyst is composed of an ordered composite porous carbon / molybdenum disulfide material carrier, a nickel precursor compound, a copper precursor compound active component, and a hydrophobic compound component. The nickel loading in the nickel-copper catalyst is 30wt% to 60wt%, the copper loading is 1wt% to 5wt%, and the hydrophobic compound is 0.01wt% to 0.2wt%.

[0049] Furthermore, the porous carbon / molybdenum disulfide carrier is prepared by mixing asphalt and molybdenum disulfide in a mass ratio of 1:1, and heat treating at 200°C to 400°C for 3h to 8h under oxygen conditions, and has a pore volume of 0.2mL / g to 0.7mL / g, a particle size of 3mm to 5mm, and a bulk density of 750kg / m 3 ~1100kg / m 3 The molybdenum disulfide has a nanosheet structure of 5 to 20 layers. In addition, the size of the catalytic active center cluster is: 80nm to 150nm in length, about 30nm to 100nm in width, and about 10nm to 30nm in thickness.

[0050] Furthermore, the nickel precursor compound is one or more of nickel chloride, nickel nitrate, nickel sulfate, basic nickel carbonate, nickel acetylacetonate, nickel oxalate, nickel acetate, nickel citrate, nickel hypophosphite, nickel phosphate and nickel formate.

[0051] Furthermore, the copper precursor compound is one or more of copper chloride, copper nitrate and copper sulfate.

[0052] Furthermore, the hydrophobic compound is Where n≥6.

[0053] Furthermore, in step S2, the concentration of the acid solution is 1 mol / L to 6 mol / L; and the acid in the acid solution is selected from nitric acid.

[0054] Furthermore, the nickel-copper catalyst preparation method includes the following steps: performing an impregnation operation on the carrier so that the carrier is immersed in a mixture solution containing nickel, copper and a hydrophobic compound, and then rinsing and drying the porous carbon / molybdenum disulfide structure to obtain a nickel-copper catalyst.

[0055] Furthermore, the particle strength of the nickel-copper catalyst is ≥400N / cm.

[0056] Furthermore, the bio-based succinic acid good solvent is one or more of tetrahydrofuran, γ-butyrolactone, ether, ethyl acetate, ethyl formate, and methyl acetate, preferably tetrahydrofuran and γ-butyrolactone.

[0057] Furthermore, the reduction temperature of the nickel-copper catalyst is 160° C. to 200° C., the pressure is normal pressure, the heating rate is 10° C. / h to 20° C. / h, and the constant temperature is 6h to 10h.

[0058] Furthermore, the reaction pressure of the hydrogenation system is 1MPa to 10MPa, preferably 2MPa to 5MPa; the hydrogenation reaction temperature is 25°C to 100°C, preferably 80°C to 100°C; the reaction space velocity of the system is 0.6hr -1 ~6.0hr -1 .

[0059] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0060] The purity and impurity content of the product were tested by gas chromatography, with a gas chromatography column HP-5 (30m×320μm×0.25μm) and a FID detector. The column temperature conditions were initial temperature 60℃, first-order termination temperature 90℃, heating rate 15℃ / min, and holding for 2min, 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, nitrogen flow rate: 25mL / min. Using acetone as the solvent, the standard curves of 1,4-succinic acid, tetrahydrofuran, γ-butyrolactone and 1,4-butanediol were established.

[0061] The strength test of nickel-copper catalyst was carried out according to HG / T 2782 standard.

[0062] Example 1

[0063] This embodiment provides a method for producing bio-based γ-butyrolactone, and the specific steps are as follows:

[0064] (1) The preparation method of nickel-copper catalyst is as follows: weigh 50.00g of basic nickel carbonate, 159.5mL (5mol / L) of dilute nitric acid solution, 4.58g of copper nitrate, 0.30g of sodium dodecyl sulfate, and 500.00g of deionized water, and stir at 45°C until all solids are dissolved to obtain a nickel-copper solution; stir and mix asphalt and molybdenum disulfide in a mass ratio of 1:1, and heat treat at 300°C for 4h under oxygen conditions to prepare a porous carbon / molybdenum disulfide carrier with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon / molybdenum disulfide carrier in the nickel-copper solution, and age the mixture at 60°C for 14h under stirring, and then dry at 120°C for 12h, and reduce it under 200°C hydrogen conditions for 6h to obtain a nickel-copper catalyst.

[0065] (2) preparing a tetrahydrofuran solution of bio-based succinic acid with a mass percentage of 5 wt%; mixing the tetrahydrofuran solution of bio-based succinic acid with a flow rate of 0.5 mL / min and hydrogen with a flow rate of 200 mL / min, and then continuously entering a 50 mL nickel-copper catalyst hydrogenation tubular reactor at a reaction temperature of 96° C. and a reaction pressure of 2.8 MPa(A), and continuously entering a distillation separation tower to separate and obtain the product bio-based γ-butyrolactone.

[0066] Example 2

[0067] This example provides a method for producing bio-based γ-butyrolactone, which is similar to Example 1, except that:

[0068] During the preparation of the nickel-copper catalyst, basic nickel carbonate is replaced with nickel nitrate;

[0069] The obtained catalyst is subjected to catalytic hydrogenation to obtain the product bio-based γ-butyrolactone.

[0070] Example 3

[0071] This example provides a method for producing bio-based γ-butyrolactone, which is similar to Example 1, except that:

[0072] During the preparation of nickel-copper catalyst, copper nitrate is replaced with copper chloride;

[0073] The obtained catalyst is subjected to catalytic hydrogenation to obtain the product bio-based γ-butyrolactone.

[0074] Example 4

[0075] This example provides a method for producing bio-based γ-butyrolactone, which is similar to Example 1, except that:

[0076] During the catalytic hydrogenation process, a tetrahydrofuran solution containing 10 wt% of bio-based succinic acid is prepared, and catalytic hydrogenation is performed to obtain the product bio-based gamma-butyrolactone.

[0077] Example 5

[0078] This example provides a method for producing bio-based γ-butyrolactone, which is similar to Example 1, except that:

[0079] During the catalytic hydrogenation process, a γ-butyrolactone solution containing 5 wt% of bio-based succinic acid is prepared and catalytically hydrogenated to obtain the product bio-based γ-butyrolactone.

[0080] Comparative Example 1

[0081] This comparative example provides a method for producing bio-based γ-butyrolactone, and the specific steps are as follows:

[0082] (1) Preparation of nickel-based catalyst: 50.00 g of basic nickel carbonate, 159.5 mL (5 mol / L) of dilute nitric acid solution, 0.30 g of sodium dodecyl sulfate, and 500.00 g of deionized water were weighed and stirred at 45° C. until all solids were dissolved to obtain a nickel solution; asphalt and molybdenum disulfide were stirred and mixed in a mass ratio of 1:1, and heat treated at 300° C. for 4 h under oxygen conditions to obtain a porous carbon / molybdenum disulfide carrier with a pore volume of 0.5 mL / g and a particle size of 5 mm; the obtained porous carbon / molybdenum disulfide carrier was impregnated in the nickel solution, and the mixture was aged at 60° C. for 14 h under stirring, and then dried at 120° C. for 12 h, and reduced under hydrogen conditions at 200° C. for 6 h to obtain a catalyst.

[0083] (2) preparing a 5 wt% tetrahydrofuran solution of bio-based succinic acid; mixing the tetrahydrofuran solution of bio-based succinic acid at a flow rate of 0.5 mL / min with hydrogen at a flow rate of 200 mL / min, and then continuously entering a 50 mL hydrogenation tubular reactor containing a nickel-copper catalyst, the reaction temperature is 96° C., the reaction pressure is 2.8 MPa(A), and continuously entering a distillation separation tower to separate and obtain the product bio-based γ-butyrolactone.

[0084] Comparative Example 2

[0085] This comparative example provides a method for producing bio-based γ-butyrolactone, and the specific steps are as follows:

[0086] (1) Preparation of nickel-copper catalyst: 50.00 g of basic nickel carbonate, 159.5 mL (5 mol / L) of dilute nitric acid solution, 4.58 g of copper nitrate, and 500.00 g of deionized water were weighed and stirred at 45° C. until all solids were dissolved to obtain a nickel-copper solution; asphalt and molybdenum disulfide were stirred and mixed in a mass ratio of 1:1, and heat treated at 300° C. for 4 h under oxygen conditions to obtain a porous carbon / molybdenum disulfide carrier with a pore volume of 0.5 mL / g and a particle size of 5 mm; the obtained porous carbon / molybdenum disulfide carrier was impregnated in the nickel-copper solution, and the mixture was aged at 60° C. for 14 h under stirring, and then dried at 120° C. for 12 h, and reduced under hydrogen conditions at 200° C. for 6 h to obtain a nickel-copper catalyst.

[0087] (2) Prepare a 5 wt% tetrahydrofuran solution of bio-based succinic acid; mix the tetrahydrofuran solution of bio-based succinic acid at a flow rate of 0.5 mL / min with hydrogen at a flow rate of 200 mL / min, and then continuously enter a 50 mL hydrogenation tubular reactor containing a nickel-copper catalyst at a reaction temperature of 96° C. and a reaction pressure of 2.8 MPa(A), and continuously enter a distillation separation tower to separate and obtain the product bio-based γ-butyrolactone.

[0088] Comparative Example 3

[0089] This comparative example provides a method for producing bio-based γ-butyrolactone, and the specific steps are as follows:

[0090] (1) The method for preparing a nickel-based catalyst is as follows: weigh 50.00 g of basic nickel carbonate, 159.5 mL (5 mol / L) of dilute nitric acid solution, and 500.00 g of deionized water, and stir at 45°C until all solids are dissolved to obtain a nickel solution; stir asphalt and molybdenum disulfide in a mass ratio of 1:1, and heat treat at 300°C for 4 h 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; immerse the obtained porous carbon / molybdenum disulfide carrier in the nickel solution, and age the mixture at 60°C for 14 h under stirring, and then dry at 120°C for 12 h, and reduce it under hydrogen conditions at 200°C for 6 h to obtain a catalyst.

[0091] (2) preparing a 5 wt% tetrahydrofuran solution of bio-based succinic acid; mixing the tetrahydrofuran solution of bio-based succinic acid at a flow rate of 0.5 mL / min with hydrogen at a flow rate of 200 mL / min, and then continuously entering a 50 mL nickel-based catalyst hydrogenation tubular reactor, the reaction temperature is 96° C., the reaction pressure is 2.8 MPa (A), and continuously entering a distillation separation tower to separate and obtain the product bio-based γ-butyrolactone.

[0092] Comparative Example 4

[0093] This comparative example provides a method for producing bio-based γ-butyrolactone, and the specific steps are as follows:

[0094] (1) The nickel-copper catalyst is prepared as follows: 50.00 g of basic nickel carbonate, 159.5 mL (5 mol / L) of dilute nitric acid solution, 4.58 g of copper nitrate, 0.30 g of sodium dodecyl sulfate, and 500.00 g of deionized water are weighed and stirred at 45°C until all solids are dissolved to obtain a nickel-copper solution; asphalt is heat treated at 300°C for 4 h under oxygen conditions to obtain porous carbon with a pore volume of 0.5 mL / g and a particle size of 5 mm; the obtained porous carbon support is impregnated in the nickel-copper solution, and the mixture is aged at 60°C for 14 h under stirring, then dried at 120°C for 12 h, and reduced under hydrogen conditions at 200°C for 6 h to obtain a nickel-copper catalyst.

[0095] (2) preparing a 5 wt% tetrahydrofuran solution of bio-based succinic acid; mixing the tetrahydrofuran solution of bio-based succinic acid at a flow rate of 0.5 mL / min with hydrogen at a flow rate of 200 mL / min, and then continuously entering a 50 mL hydrogenation tubular reactor containing a nickel-copper catalyst, the reaction temperature is 96° C., the reaction pressure is 2.8 MPa(A), and continuously entering a distillation separation tower to separate and obtain the product bio-based γ-butyrolactone.

[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) Example 1 453.3 Example 2 451.8 Example 3 457.2 Example 4 453.3 Example 5 453.3 Comparative Example 1 453.8 Comparative Example 2 454.6 Comparative Example 3 451.5 Comparative Example 4 205.1

[0100] It can be seen from Table 1 that the strength of the supported catalyst prepared in the example 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 product purity and impurity content were tested by gas chromatography. The conversion rate of the hydrogenation process after 1000h of continuous experiment is shown in Table 2 below:

[0102] Table 2

[0103]

[0104] It can be seen from Table 2 that the catalyst of the present invention still has high catalytic activity and selectivity after long-term continuous hydrogenation for 1000 hours, which is manifested in that high-purity γ-butyrolactone can be prepared under certain pressure and temperature conditions.

[0105] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A bio-based γ-butyrolactone, characterized in that: The purity of the bio-based γ-butyrolactone is ≥99.99%, and the rest is impurities; the impurities include tetrahydrofuran and 1,4-butanediol; the content of the tetrahydrofuran is ≤0.004%; the content of the 1,4-butanediol is ≤0.005%.

2. The method for producing bio-based γ-butyrolactone according to claim 1, characterized in that: The following steps are involved: (1) preparing a bio-based succinic acid solution; (2) continuously introducing the bio-based succinic acid solution obtained in step (1) and hydrogen into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain a crude product; (3) the crude product obtained in step (2) is placed in a separation tower for separation and purification to obtain bio-based γ-butyrolactone; 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 the hydrophobic compound is 0.01wt% to 0.2wt%.

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

4. The production method according to claim 2, characterized in that: In step (1), the solvent of the bio-based succinic acid solution is selected from one or more of tetrahydrofuran, γ-butyrolactone, ether, ethyl acetate, ethyl formate and methyl acetate.

5. The production method according to claim 2, characterized in that: In step (2), the flow rate of the bio-based succinic acid solution is 0 to 5 mL / min; And / or, the flow rate of the hydrogen is 0 to 100 mL / min.

6. The production method according to claim 2, characterized in that: In step (2), the nickel-copper catalyst is obtained by the following preparation method: S1, stirring and mixing asphalt and molybdenum disulfide; heat-treating the obtained mixture under oxygen conditions to obtain a porous carbon / molybdenum disulfide material carrier; S2, dissolving the nickel precursor compound, the copper precursor compound, the hydrophobic compound and the acid solution in water to obtain a mixed solution; S3, impregnating the porous carbon / molybdenum disulfide material carrier obtained in step S1 into 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 nickel-copper catalyst.

7. The production method according to claim 6, characterized in that: In step S2, the nickel precursor compound is selected from one or more of nickel chloride, nickel nitrate, nickel sulfate, basic nickel carbonate, nickel acetylacetonate, 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; And / or, the structural formula of the hydrophobic compound is Where n≥6.

8. The production method according to claim 6, characterized in that: In step S2, the mass ratio of the nickel precursor compound, the copper precursor compound and the hydrophobic compound is 80-99:0.1-20:0.01-1.

9. The production method according to claim 6, characterized in that: In step S4, the reduction conditions are: reduction at 160° C. to 200° C. for 6 h to 10 h.

10. The production method according to claim 2, characterized in that: In step (2), the pressure of the hydrogenation reaction is 1 MPa to 10 MPa; And / or, the temperature of the hydrogenation reaction is 25°C to 100°C; And / or, the system reaction space velocity of the hydrogenation reaction is 0.6 hr -1 ~6.0hr -1 .

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