A cobalt-based catalyst, its preparation method and use

Abstract

The application discloses a cobalt-based catalyst and a preparation method and application thereof. The catalyst comprises an oxide and a nitride, wherein the oxide is CoO and the nitride is Co2N. The application further discloses a preparation method of the catalyst, which comprises the following steps: preparing a CoO / Co2N mixture by using an ammonia nitriding method, and obtaining the catalyst. The application further discloses a method for preparing 1,3-butanediol by using the catalyst to perform a 3-hydroxybutyraldehyde hydrogenation reaction.

Description

Technical Field

[0001] This application relates to a cobalt-based catalyst, its preparation method, and its application, and belongs to the field of chemical engineering. Background Technology

[0002] 1,3-Butanediol is an organic compound mainly used in the preparation of polyester resins, polyurethane resins, and plasticizers. It is also used as a humectant and softener in textiles, paper, and tobacco. Because it contains two hydroxyl groups, it is chemically reactive and has relatively low toxicity, making it a widely used fine chemical in the chemical, pharmaceutical, and cosmetic industries.

[0003] Publicly available patents and other literature report several different processes for synthesizing 1,3-butanediol: ① Direct synthesis of 1,3-butanediol by KrF laser irradiation of ethanol containing H2O2 and N2 saturated; ② Carbonylation synthesis of 1,3-butanediol and acetaldehyde using epoxides and syngas as raw materials under rhodium and phosphine catalyst conditions; ③ Obtaining 1,3-butanediol from acrolein and 2,2-dimethyl-1,3-propanediol through a series of reactions including carbonylation, hydrolysis, and hydrogenation; ④ Biosynthesis of 1,3-butanediol by bio-fermentation of sugarcane using specific microorganisms (Japan Ko...). (kyuAlcohol Company); ⑤ Condensation hydrolysis method using propylene and formaldehyde as raw materials; ⑥ Production of 3-hydroxybutyraldehyde from acetaldehyde in alkaline solution or with an alkaline catalyst, followed by direct hydrogenation of the condensation liquid, whereby the 3-hydroxybutyraldehyde is hydrogenated to synthesize 1,3-butanediol, which is then purified to obtain the product. This method is called acetaldehyde condensation hydrogenation method; some have also considered trying other hydrogenation methods, such as CN111116340A which discloses the use of distillation to first separate 3-hydroxybutyraldehyde; however, 3-hydroxybutyraldehyde is extremely heat-sensitive, resulting in a low yield, and it is extremely difficult to achieve commercialization. The above process routes ①~④ cannot be carried out in continuous industrial production due to factors such as limited raw material sources or limited production capacity. Process route ⑤ is a typical Prins addition reaction, which requires polar solvents and acidic catalysts. Therefore, the current main industrial production route is ⑥, which not only has readily available raw materials and high product quality, but also produces a natural product when the raw material acetaldehyde comes from fermented alcohol, meeting people's health needs for natural products. Summary of the Invention

[0004] The catalyst prepared in this patent is used in the hydrogenation reaction to prepare 1,3-butanediol. The catalyst has good activity, high conversion rate of 3-hydroxybutyraldehyde and selectivity of 1,3-butanediol, and good stability.

[0005] According to one aspect of this application, a cobalt-based catalyst is provided, the cobalt-based catalyst comprising oxides and nitrides;

[0006] The oxide is CoO;

[0007] The nitride is Co2N.

[0008] The cobalt-based catalyst can be applied to the hydrogenation reaction of 3-hydroxybutyraldehyde to prepare 1,3-butanediol, and improves the conversion rate of 3-hydroxybutyraldehyde and the selectivity of 1,3-butanediol.

[0009] According to another aspect of this application, a method for preparing the above-mentioned cobalt-based catalyst is provided, comprising the following steps:

[0010] The cobalt-based catalyst is obtained by nitriding a raw material containing cobalt tetroxide.

[0011] The atmosphere for the nitriding treatment is an ammonia atmosphere;

[0012] The nitriding treatment temperature is 250–350°C;

[0013] Optionally, the nitriding temperature is any value or a range between 250°C, 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, 340°C, and 350°C.

[0014] The nitriding treatment time is 1 to 4 hours.

[0015] Optionally, the nitriding treatment time is any value among 1h, 2h, 3h, and 4h, or a range between any two.

[0016] The nitriding treatment is carried out in a high-temperature calcining furnace.

[0017] According to another aspect of this application, a method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde is provided, comprising the following steps:

[0018] In a reactor, a material containing an aqueous solution of 3-hydroxybutyraldehyde and hydrogen is introduced into contact with a catalyst and reacted to obtain a product containing 1,3-butanediol.

[0019] The catalyst is selected from the cobalt-based catalysts described above or the cobalt-based catalysts prepared by the preparation method described above.

[0020] The reactor is a fixed-bed reactor.

[0021] The mass fraction of 3-hydroxybutyraldehyde in the aqueous solution of 3-hydroxybutyraldehyde is 20-50 wt%.

[0022] Optionally, the mass fraction of 3-hydroxybutyraldehyde in the aqueous solution of 3-hydroxybutyraldehyde is any value among 20wt%, 30wt%, 40wt%, and 50wt%, or any range between two.

[0023] The mass hourly space velocity of the hydrogen gas is 80–120 h⁻¹. -1 .

[0024] Optionally, the mass hourly space velocity of the hydrogen gas is 80 h⁻¹. -1 90h -1 100h -1 110h -1 120h -1 Any value in the range or any value between the two.

[0025] The mass hourly space velocity (MSV) of the 3-hydroxybutyraldehyde aqueous solution was 2–4 h⁻¹. -1 .

[0026] Optionally, the mass hourly space velocity (MSV) of the 3-hydroxybutyraldehyde aqueous solution is 2 h⁻¹. -1 3h -1 4h -1 Any value in the range or any value between the two.

[0027] The reaction temperature is 70–110°C;

[0028] Optionally, the temperature of the reaction is any value among 70°C, 80°C, 90°C, 100°C, and 110°C, or a range between any two.

[0029] The reaction time is 1–4 hours;

[0030] Optionally, the reaction time is any value among 1h, 2h, 3h, and 4h, or a range between any two.

[0031] The reaction is carried out at a pressure of 2–5 MPa.

[0032] Optionally, the pressure of the reaction is any value of 2 MPa, 3 MPa, 4 MPa, 5 MPa, or a range between any two.

[0033] The beneficial effects that this application can produce include:

[0034] 1) The catalyst provided in this application can be applied to the hydrogenation of 3-hydroxybutyraldehyde to prepare 1,3-butanediol, and improves the conversion rate of acetaldehyde and the selectivity of the generated 3-hydroxybutyraldehyde.

[0035] 2) The preparation method of the catalyst provided in this application is stable, controllable, and reproducible.

[0036] 3) The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutanal provided in this application uses the catalyst provided in this application, which has a fast reaction rate and high yield and can be applied to large-scale production. Attached Figure Description

[0037] Figure 1 Catalyst 1 # X-ray powder diffraction pattern. Detailed Implementation

[0038] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0039] Unless otherwise specified, the raw materials and catalysts used in the embodiments of this application were all purchased commercially. The gas chromatograph used was an Agilent 7890B gas chromatograph.

[0040] Example 1

[0041] Preparation of catalysts

[0042] Taking item 1 in Table 1 as an example, cobalt tetroxide was placed in a high-temperature calcining furnace and nitrided in an ammonia atmosphere at a nitriding temperature of 250°C for 2 hours. The resulting CoO / Co2N mixture was designated as catalyst 1. # .

[0043] Following the steps below, adjust the type and amount of each raw material and the reaction parameters to obtain a series of catalysts numbered 2 to 28, denoted as catalyst 2. # ~Catalyst 28 # As shown in Table 1 below:

[0044] Table 1

[0045]

[0046]

[0047] XRD characterization

[0048] Catalyst 1 was analyzed using a Miniflex 600 X-ray diffractometer with a Cu target. # Powder diffraction yielded catalyst 1. # The diffraction peaks conform to the characteristic peaks of CoO / Co2N (e.g. Figure 1 (As shown).

[0049] Gas chromatography characterization

[0050] The composition of the hydrogenation products of 3-hydroxybutyraldehyde was analyzed using an Agilent 7890B gas chromatograph (FID detector, HP-5 capillary column).

[0051] The conversion rate and selectivity calculation formulas in the embodiments of this application are as follows (using 3-hydroxybutyraldehyde conversion rate as the evaluation index):

[0052] 3-Hydroxybutyraldehyde conversion rate = (Initial carbon number of 3-hydroxybutyraldehyde - Carbon number of 3-hydroxybutyraldehyde in the product) * 100 / Initial molar number of 3-hydroxybutyraldehyde

[0053] 1,3-Butanediol selectivity = (number of carbon atoms in 1,3-butanediol) * 100 / ∑(number of carbon atoms in 1,3-butanediol + number of carbon atoms in other products)

[0054] Example 2

[0055] The catalyst is used in the hydrogenation reaction to prepare 1,3-butanediol.

[0056] Catalysts 1 to 28 prepared in Example 1 # ~Catalyst 28 # The catalyst is used for the hydrogenation preparation of 1,3-butanediol, and is packed in a fixed-bed reactor. H2 and a feedstock, wherein the feedstock is a 40 wt% aqueous solution of 3-hydroxybutyraldehyde, are introduced. The reaction is carried out at a temperature of 100°C for 2 hours, with a mass hourly space velocity (MHSV) of 3 h⁻¹. -1 The mass space velocity of H2 is 100 h⁻¹ -1 The reaction pressure is 3 MPa, and the hydrogenation reaction produces 1,3-butanediol.

[0057] After the reaction stabilized (i.e., when the reaction chromatogram data showed no abnormalities), both the reactants and products were analyzed using online gas chromatography. The reaction results are shown in Table 2.

[0058] Table 2

[0059]

[0060]

[0061] As can be seen from the table, the catalyst is applied to the hydrogenation reaction to prepare 1,3-butanediol, and the selectivity for 1,3-butanediol is high.

[0062] Example 3

[0063] Catalyst 1 prepared in Table 2 # The hydrogenation reaction to prepare 1,3-butanediol was carried out. After the reaction parameters were varied and the reaction stabilized (i.e., when the chromatographic data showed no abnormalities), both the reactants and products were analyzed using online gas chromatography. The reaction results are shown in Table 3.

[0064] Table 3

[0065]

[0066]

[0067] The table shows that the reaction temperature has a significant impact on the selectivity of 1,3-butanediol.

[0068] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde, characterized in that, Includes the following steps: In a reactor, a material containing an aqueous solution of 3-hydroxybutyraldehyde and hydrogen is introduced and reacted with a cobalt-based catalyst to obtain a product containing 1,3-butanediol. The cobalt-based catalyst comprises oxides and nitrides; The oxide is CoO; The nitride is Co2N; The reaction temperature is 90~110℃.

2. A method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The preparation method of the cobalt-based catalyst includes the following steps: The cobalt-based catalyst is obtained by nitriding a raw material containing cobalt tetroxide.

3. The method according to claim 2, characterized in that, The atmosphere for the nitriding treatment is an ammonia atmosphere; The nitriding treatment temperature is 250~350℃; The nitriding treatment time is 1 to 4 hours.

4. The method according to claim 2, characterized in that, The nitriding treatment is carried out in a high-temperature calcining furnace.

5. The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The reactor is a fixed-bed reactor.

6. The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The mass fraction of 3-hydroxybutyraldehyde in the aqueous solution of 3-hydroxybutyraldehyde is 20~50wt%.

7. The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The mass hourly space velocity of the hydrogen gas is 80-120 h⁻¹. -1 .

8. The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The mass hourly space velocity (MSV) of the 3-hydroxybutyraldehyde aqueous solution is 2-4 h⁻¹. -1 .

9. The method for preparing 1,3-butanediol by hydrogenation of 3-hydroxybutyraldehyde according to claim 1, characterized in that, The reaction time is 1-4 hours; The reaction is carried out at a pressure of 2-5 MPa.

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