A bio-based gamma-butyrolactone and a method for producing the same
By using a bio-based 1,4-succinic acid dilute solution in a fixed-bed hydrogenation reaction and distillation separation on a nickel-copper catalyst, the problems of numerous byproducts and easy catalyst poisoning in the production of γ-butyrolactone were solved, achieving high-purity and long-cycle production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- JIANGNAN UNIV
- Filing Date
- 2024-11-20
- Publication Date
- 2026-05-29
AI Technical Summary
Existing γ-butyrolactone production processes suffer from problems such as numerous byproducts, high separation costs, easy poisoning of catalyst active sites, and inability to achieve long-term production cycles.
High-purity γ-butyrolactone was prepared by reacting a 5wt%–30wt% bio-based 1,4-succinic acid dilute solution with a nickel-copper catalyst in a fixed-bed hydrogenation reactor, followed by separation in a distillation column. The catalyst was composed of a porous carbon/molybdenum disulfide support and a hydrophobic compound, and the reaction conditions were controlled.
This method enables the production of γ-butyrolactone with high purity (≥99.99%), reduces byproducts, extends the production cycle, and improves the mechanical strength and reaction selectivity of the catalyst.
Smart Images
Figure BDA0005142598620000101
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical raw material synthesis technology, and in particular to a bio-based γ-butyrolactone and its production method. Background Technology
[0002] γ-Butyrolactone is an important chemical raw material, mainly used in the production of important pharmaceutical raw materials such as cyclopropylamine, pyrrolidone, acetylbutyrolactone, and vitamin B1. It is also used as an industrial solvent, extractant, and electrolyte solution. Currently, the main production process for γ-butyrolactone is the 1,4-butanediol dehydrogenation cyclization method. This method generates a large amount of high-boiling-point byproduct 2-(4-hydroxybutoxy)tetrahydrofuran, leading to the precipitation of solid byproducts on the inner walls of the reactor and piping, and even blockage, making long-term continuous production impossible. Alternatively, the hydrogenation method involves hydrogenating maleic anhydride, succinic acid, and their derivatives to prepare a mixture of tetrahydrofuran, γ-butyrolactone, and 1,4-butanediol, followed by distillation to obtain γ-butyrolactone. Maleic anhydride molecules have one C=C bond and two C=O bonds, or succinic acid has two C=O bonds. Under certain catalytic conditions, hydrogenation sequentially produces succinic anhydride, γ-butyrolactone, 1,4-butanediol, and tetrahydrofuran. This technology is characterized by its ability to simultaneously produce tetrahydrofuran, γ-butyrolactone, and 1,4-butanediol, depending on the process conditions. Its main drawbacks include a higher number of hydrogenation byproducts, higher separation costs, and the acidic reaction system of maleic anhydride hydrogenation. Generally, acid-sensitive systems can lead to active site poisoning, making long-term production impossible. By adjusting the catalytic active site, γ-butyrolactone can be prepared through targeted and highly selective hydrogenation, demonstrating significant industrialization potential. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a bio-based γ-butyrolactone and its production method. This invention uses a 5wt%–30wt% dilute solution of bio-based 1,4-succinic acid continuously fed into a fixed-bed hydrogenation reactor to prepare a liquid bio-based γ-butyrolactone. This liquid is then continuously fed into a distillation column for separation, yielding a bio-based γ-butyrolactone product with a purity ≥99.99%.
[0004] This invention is achieved through the following technical solution:
[0005] The first objective of this invention is to provide a bio-based γ-butyrolactone, wherein the bio-based γ-butyrolactone has a purity ≥99.99%, with the remainder being impurities; the impurities include tetrahydrofuran and 1,4-butanediol; the content of the tetrahydrofuran is ≤0.004%; and the content of the 1,4-butanediol is ≤0.005%.
[0006] A second objective of this invention is to provide a method for producing the bio-based γ-butyrolactone, comprising the following steps:
[0007] (1) Prepare a bio-based succinic acid solution;
[0008] (2) The bio-based succinic acid solution obtained in step (1) and hydrogen gas are continuously introduced into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain crude product;
[0009] (3) The crude product obtained in step (2) is fed into a separation tower for separation and purification to obtain bio-based γ-butyrolactone;
[0010] In step (2), the nickel-copper catalyst has a nickel loading of 30wt% to 60wt%, a copper loading of 1wt% to 5wt%, and a hydrophobic compound content of 0.01wt% to 0.2wt%.
[0011] In one embodiment of the present invention, in step (1), the bio-based succinic acid solution contains a bio-based succinic acid mass percentage of 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 or γ-butyrolactone.
[0013] In one embodiment of the present invention, in step (2), the flow rate of the bio-based succinic acid solution is 0-5 mL / min;
[0014] And / or, the flow rate of the hydrogen gas 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. Stir and mix asphalt and molybdenum disulfide; heat-treat the resulting mixture under oxygen conditions to obtain a porous carbon / molybdenum disulfide material carrier;
[0017] S2. Dissolve the nickel precursor compound, copper precursor compound, hydrophobic compound, and acid solution in water to obtain a mixed solution;
[0018] 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;
[0019] S4. The catalyst intermediate obtained in step S3 is aged and dried to obtain the nickel-copper catalyst.
[0020] In one embodiment of the present invention, the asphalt has a mass-average molecular weight of 600 to 2000 and a molecular weight distribution of 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℃~400℃ for 3h~8h.
[0024] 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 .
[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 acetylacetone, 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 6 to 10 hours under hydrogen atmosphere and atmospheric pressure. ， This gives the nickel-copper catalyst 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 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 nickel-copper catalyst prepared by this invention has a particle strength ≥400 N / cm. Furthermore, the size of the catalytic active center clusters is: length 80 nm–150 nm, width approximately 30 nm–100 nm, and thickness approximately 10 nm–30 nm.
[0035] 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 in the succinic acid molecule can be controlled by adjusting the reaction pressure and temperature, thereby obtaining the target product.
[0036] 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.
[0037] Compared with existing technologies, it has the following advantages:
[0038] (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 succinic anhydride.
[0039] (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.
[0040] (3) The catalyst used in this invention uses hydrophobic compounds as additives, which can enable the target product to 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 goal of high-purity product. Detailed Implementation
[0041] 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.
[0042] This invention provides a bio-based γ-butyrolactone, wherein the purity of the bio-based γ-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] A method for producing bio-based γ-butyrolactone is also provided, comprising the following steps:
[0044] (1) Prepare a bio-based succinic acid solution;
[0045] (2) The bio-based succinic acid solution obtained in step (1) and hydrogen gas are continuously introduced into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain crude product;
[0046] (3) The crude product obtained in step (2) is fed into a separation tower for separation and purification to obtain bio-based γ-butyrolactone;
[0047] In step (2), the nickel-copper catalyst has a nickel loading of 30wt% to 60wt%, a copper loading of 1wt% to 5wt%, and a hydrophobic compound content of 0.01wt% to 0.2wt%.
[0048] Furthermore, the nickel-copper catalyst is composed of an ordered composite porous carbon / molybdenum disulfide material support, nickel precursor compounds, copper precursor compounds as active components, and hydrophobic compound components. Specifically, the nickel loading in the nickel-copper catalyst is 30 wt%–60 wt%, the copper loading is 1 wt%–5 wt%, and the hydrophobic compound is 0.01 wt%–0.2 wt%.
[0049] Furthermore, the porous carbon / molybdenum disulfide carrier is prepared by mixing asphalt and molybdenum disulfide at a mass ratio of 1:1 and then heat-treating at 200℃~400℃ for 3h~8h under oxygen conditions. It has a pore volume of 0.2mL / g~0.7mL / g, a particle size of 3mm~5mm, and a bulk density of 750kg / m³. 3 ~1100kg / m 3 The molybdenum disulfide has a 5-20 layer nanosheet structure. Furthermore, the size of the catalytic active center clusters is: length 80 nm-150 nm, width approximately 30 nm-100 nm, and thickness approximately 10 nm-30 nm.
[0050] Furthermore, the nickel precursor compound is 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.
[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] Further, in step S2, the concentration of the acid solution is 1 mol / L to 6 mol / L; the acid in the acid solution is selected from nitric acid.
[0054] Furthermore, the method for preparing the nickel-copper catalyst includes the following steps: impregnating the support in a solution containing a mixture of nickel, copper, and a hydrophobic compound, followed by rinsing and drying the porous carbon / molybdenum disulfide structure to obtain the nickel-copper catalyst.
[0055] Furthermore, the particle strength of the nickel-copper catalyst is ≥400 N / cm.
[0056] Furthermore, the good solvent for the bio-based succinic acid is one or more of tetrahydrofuran, γ-butyrolactone, diethyl ether, ethyl acetate, ethyl formate, and methyl acetate, preferably tetrahydrofuran or γ-butyrolactone.
[0057] Furthermore, the reduction temperature of the nickel-copper catalyst is 160℃~200℃, the pressure is atmospheric pressure, the heating rate is 10℃ / h~20℃ / h, and the temperature is held for 6h~10h.
[0058] Furthermore, the hydrogenation system reaction pressure is 1 MPa to 10 MPa, preferably 2 MPa to 5 MPa; the hydrogenation reaction temperature is 25°C to 100°C, preferably 80°C to 100°C; and the system reaction space velocity is 0.6 hr. -1 ~6.0hr -1 .
[0059] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available.
[0060] 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 for 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 for 1,4-succinic acid, tetrahydrofuran, γ-butyrolactone, and 1,4-butanediol were established using acetone as the solvent.
[0061] The strength of the nickel-copper catalyst was tested in accordance with the HG / T 2782 standard.
[0062] Example 1
[0063] This embodiment provides a method for producing bio-based γ-butyrolactone, the specific steps of which 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) dilute nitric acid solution, 4.58g of copper nitrate, 0.30g of sodium dodecyl sulfonate, and 500.00g of deionized water and stir at 45℃ until all solids are dissolved to obtain a nickel-copper solution; mix asphalt and molybdenum disulfide at a mass ratio of 1:1 and heat-treat at 300℃ for 4h under oxygen conditions to prepare a porous carbon / molybdenum disulfide support with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon / molybdenum disulfide support in the nickel-copper solution, age the mixture at 60℃ for 14h under stirring, dry at 120℃ for 12h, and reduce under hydrogen conditions at 200℃ for 6h to obtain the nickel-copper catalyst.
[0065] (2) Prepare a 5 wt% tetrahydrofuran solution of bio-based succinic acid; mix the 0.5 mL / min tetrahydrofuran solution of bio-based succinic acid with 200 mL / min hydrogen gas and continuously feed it into a 50 mL nickel-copper catalyst hydrogenation tube reactor. The reaction temperature is 96 °C and the reaction pressure is 2.8 MPa (A). The mixture is continuously fed into a distillation separation column to separate the product bio-based γ-butyrolactone.
[0066] Example 2
[0067] This embodiment provides a method for producing bio-based γ-butyrolactone, similar to Example 1, with the only difference being:
[0068] In the preparation of nickel-copper catalysts, basic nickel carbonate is replaced with nickel nitrate;
[0069] The obtained catalyst was subjected to catalytic hydrogenation to obtain the product bio-based γ-butyrolactone.
[0070] Example 3
[0071] This embodiment provides a method for producing bio-based γ-butyrolactone, similar to Example 1, with the only difference being:
[0072] In the preparation of nickel-copper catalysts, copper nitrate is replaced with copper chloride;
[0073] The obtained catalyst was subjected to catalytic hydrogenation to obtain the product bio-based γ-butyrolactone.
[0074] Example 4
[0075] This embodiment provides a method for producing bio-based γ-butyrolactone, similar to Example 1, with the only difference being:
[0076] In the catalytic hydrogenation process, a tetrahydrofuran solution containing 10 wt% bio-based succinic acid was prepared, and the product bio-based γ-butyrolactone was obtained by catalytic hydrogenation.
[0077] Example 5
[0078] This embodiment provides a method for producing bio-based γ-butyrolactone, similar to Example 1, with the only difference being:
[0079] In the catalytic hydrogenation process, a γ-butyrolactone solution of 5 wt% bio-based succinic acid was prepared and subjected to catalytic hydrogenation 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, the specific steps of which are as follows:
[0082] (1) Preparation of nickel-based catalyst: Weigh 50.00g of basic nickel carbonate, 159.5mL (5mol / L) dilute nitric acid solution, 0.30g of sodium dodecyl sulfonate, and 500.00g of deionized water and stir at 45℃ until all solids are dissolved to obtain a nickel solution; mix asphalt and molybdenum disulfide at a mass ratio of 1:1 and heat-treat at 300℃ for 4h under oxygen conditions to prepare a porous carbon / molybdenum disulfide support with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon / molybdenum disulfide support in the nickel solution, age the mixture at 60℃ for 14h under stirring, dry at 120℃ for 12h, and reduce under hydrogen conditions at 200℃ for 6h to obtain the catalyst.
[0083] (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 continuously feed 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). The mixture is continuously fed into a distillation column to separate the product bio-based γ-butyrolactone.
[0084] Comparative Example 2
[0085] This comparative example provides a method for producing bio-based γ-butyrolactone, the specific steps of which are as follows:
[0086] (1) Preparation of nickel-copper catalyst: Weigh 50.00g of basic nickel carbonate, 159.5mL (5mol / L) dilute nitric acid solution, 4.58g of copper nitrate, and 500.00g of deionized water and stir at 45℃ until all solids are dissolved to obtain a nickel-copper solution; mix asphalt and molybdenum disulfide at a mass ratio of 1:1 and heat-treat at 300℃ for 4h under oxygen conditions to prepare a porous carbon / molybdenum disulfide support with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon / molybdenum disulfide support in the nickel-copper solution, age the mixture at 60℃ for 14h under stirring, dry at 120℃ for 12h, and reduce under hydrogen conditions at 200℃ for 6h 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 continuously feed 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). The mixture is continuously fed into a distillation separation column to separate the product bio-based γ-butyrolactone.
[0088] Comparative Example 3
[0089] This comparative example provides a method for producing bio-based γ-butyrolactone, the specific steps of which are as follows:
[0090] (1) The preparation method of nickel-based catalyst is as follows: Weigh 50.00g of basic nickel carbonate, 159.5mL (5mol / L) dilute nitric acid solution, and 500.00g of deionized water and stir at 45℃ until all solids are dissolved to obtain a nickel solution; mix asphalt and molybdenum disulfide at a mass ratio of 1:1 and heat-treat at 300℃ for 4h under oxygen conditions to obtain a porous carbon / molybdenum disulfide support with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon / molybdenum disulfide support in the nickel solution, age the mixture at 60℃ for 14h under stirring, dry at 120℃ for 12h, and reduce under hydrogen conditions at 200℃ for 6h to obtain the catalyst.
[0091] (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 continuously feed it into a 50 mL hydrogenation tube reactor containing a nickel-based catalyst. The reaction temperature is 96 °C and the reaction pressure is 2.8 MPa (A). The mixture is continuously fed into a distillation column to separate the product bio-based γ-butyrolactone.
[0092] Comparative Example 4
[0093] This comparative example provides a method for producing bio-based γ-butyrolactone, the specific steps of which are as follows:
[0094] (1) The preparation method of nickel-copper catalyst is as follows: Weigh 50.00g of basic nickel carbonate, 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 and stir at 45℃ until all solids are dissolved to obtain a nickel-copper solution; heat-treat asphalt at 300℃ for 4h under oxygen conditions to prepare porous carbon with a pore volume of 0.5mL / g and a particle size of 5mm; impregnate the obtained porous carbon support in the nickel-copper solution, age the mixture at 60℃ for 14h under stirring, dry at 120℃ for 12h, and reduce it under hydrogen conditions at 200℃ for 6h to obtain the nickel-copper catalyst.
[0095] (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 continuously feed 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). The mixture is continuously fed into a distillation column to separate 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] 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 high-purity γ-butyrolactone can be prepared 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 producing bio-based γ-butyrolactone, characterized in that, Includes the following steps: (1) Prepare a bio-based succinic acid solution; (2) The bio-based succinic acid solution obtained in step (1) and hydrogen gas are continuously introduced into a fixed bed containing a nickel-copper catalyst for hydrogenation reaction to obtain crude product; (3) The crude product obtained in step (2) is fed into a separation tower for separation and purification to obtain bio-based γ-butyrolactone; In step (2), the nickel-copper catalyst has a nickel loading of 30 wt%~60 wt%, a copper loading of 1 wt%~5 wt%, and a hydrophobic compound content of 0.01 wt%~0.2 wt%. In step (2), the nickel-copper catalyst is obtained by the following preparation method: 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; S2. Dissolve the nickel precursor compound, copper precursor compound, hydrophobic compound, and acid solution in water to obtain a mixed solution; 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; S4. The catalyst intermediate obtained in step S3 is aged, dried and reduced to obtain the nickel-copper catalyst. The hydrophobic compound is sodium dodecyl sulfonate.
2. The production method according to claim 1, characterized in that, In step (1), the bio-based succinic acid in the bio-based succinic acid solution has a mass percentage of 5 wt% to 30 wt%.
3. The production method according to claim 1, 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, diethyl ether, ethyl acetate, ethyl formate and methyl acetate.
4. The production method according to claim 1, characterized in that, In step (2), the flow rate of the bio-based succinic acid solution is 0~5 mL / min, and the flow rate of the bio-based succinic acid solution is not 0; And / or, the flow rate of the hydrogen gas is 0~100 mL / min, and the flow rate of the hydrogen gas is not 0.
5. The production method according to claim 1, 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 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 production method according to claim 1, 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.
7. The production method according to claim 1, characterized in that, In step S4, the reduction conditions are: 160℃~200℃ for 6 h~10 h.
8. The production method according to claim 1, 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 space velocity of the hydrogenation reaction is 0.6 hr. -1 ~6.0 hr -1 .