Industrial preparation method of 1, 3-butanediol

Abstract

The invention discloses an industrial preparation method of 1, 3-butanediol, and the preparation method comprises the following steps: taking a mixed solution of 3-hydroxybutyraldehyde generated by condensation of acetaldehyde as a raw material, introducing the raw material into a fixed bed reactor filled with a catalyst, introducing hydrogen, and reacting to obtain the 1, 3-butanediol. According to the method, a mixed solution of 3-hydroxybutyraldehyde generated by condensation of acetaldehyde is not separated and is directly hydrogenated, so that high-quality 1, 3-butanediol is obtained. The preparation method is simple, the product is high in purity and few in impurities, and the smell, chromaticity and the like meet high-quality index requirements.

Description

Technical Field

[0001] The present application relates to an industrial preparation method of 1,3-butanediol, belonging to the field of 1,3-butanediol preparation. Background Art

[0002] 1,3-Butanediol is an important chemical raw material, referred to as 1,3-BDO, which has the characteristics of good hygroscopicity, no odor, low toxicity, good water solubility, and the reactivity of diols. It is mainly used in the production of plasticizers, unsaturated polyester resins, industrial dehydrating agents, etc.; it can be used as a moisturizer in cosmetics, applied to lotions, creams, lotions, gels, toothpastes and other products; it can also be used as a humidifier and softener for textiles, tobacco and paper, and an antibacterial agent for cheese or meat, etc.

[0003] The main industrial production methods of 1,3-butanediol are acetaldehyde condensation hydrogenation, which is the mainstream process for the production of 1,3-butanediol. This method uses acetaldehyde as a raw material, condenses it in the presence of an alkaline catalyst (such as NaOH) to produce 3-hydroxybutyraldehyde, and then catalytically hydrogenates it to produce 1,3-butanediol. The first step of the acetaldehyde condensation reaction obtains a material liquid containing 3-hydroxybutyraldehyde and unreacted acetaldehyde. Usually, 3-hydroxybutyraldehyde must be separated for the next step of catalytic hydrogenation. Since the chemical properties of the intermediate 3-hydroxybutyraldehyde are relatively active, the separation is usually carried out under heating. Due to its instability, it is easy to dehydrate and hydrogenate to produce various by-products, which not only greatly reduces the yield of 1,3-butanediol, but also seriously affects the product's purity, odor, color and other quality indicators. Summary of the invention

[0004] In order to solve the above technical problems, the present application provides a new idea, that is, the material liquid containing 3-hydroxybutyraldehyde obtained in the first step is directly hydrogenated without separation to obtain high-quality 1,3-butanediol.

[0005] An industrial preparation method of 1,3-butanediol, the preparation method comprising:

[0006] The mixed liquid of 3-hydroxybutyraldehyde generated by condensation of acetaldehyde is used as raw material, the raw material is introduced into a fixed bed reactor filled with a catalyst, hydrogen is introduced, and the reaction is carried out to obtain the 1,3-butanediol.

[0007] Optionally, in the mixed solution obtained by condensing acetaldehyde to generate 3-hydroxybutyraldehyde, the content of trihydroxybutyraldehyde is 35-65%.

[0008] Optionally, the content of trihydroxybutyraldehyde is independently selected from any value of 35%, 40%, 45%, 50%, 55%, 60%, 65%, or any range therebetween.

[0009] Optionally, the mixed solution obtained by condensing acetaldehyde to generate 3-hydroxybutyraldehyde also contains acetaldehyde, crotonaldehyde, paraldehyde and heavy components.

[0010] Optionally, the catalyst is selected from at least one of Raney nickel, NiO, and Ni / Al2O3.

[0011] Optionally, the flow rate of the raw material is 1 to 3 kg / h.

[0012] Optionally, the flow rate of the raw material is independently selected from any value of 1 kg / h, 1.2 kg / h, 1.5 kg / h, 1.6 kg / h, 1.8 kg / h, 2 kg / h, 2.2 kg / h, 2.5 kg / h, 2.6 kg / h, 2.8 kg / h, 3 kg / h or any range therebetween.

[0013] Optionally, the mass space velocity of the reaction is 0.01 to 2 h -1 .

[0014] Optionally, the mass space velocity of the reaction is independently selected from 0.01h -1 、0.02h -1 , 0.05h -1 、0.06h -1 、0.08h -1 , 0.1h -1 、0.2h -1 , 0.5h -1 , 0.8h -1 , 1h -1 , 1.2h -1 , 1.5h -1 , 1.8h -1 , 2h -1 Any value in between or any range of values ​​between them.

[0015] Optionally, the pressure of hydrogen is 4-6 MPa.

[0016] Optionally, the pressure of hydrogen is independently selected from any value of 4 MPa, 4.2 MPa, 4.5 MPa, 4.8 MPa, 5 MPa, 5.2 MPa, 5.5 MPa, 5.8 MPa, 6 MPa, or any range therebetween.

[0017] Optionally, the flow rate of hydrogen is 2000-2500 L / h.

[0018] Optionally, the flow rate of hydrogen is independently selected from any value among 2000 L / h, 2050 L / h, 2100 L / h, 2150 L / h, 2200 L / h, 2250 L / h, 2300 L / h, 2350 L / h, 2400 L / h, 2450 L / h, 2500 L / h, or any range value therebetween.

[0019] Optionally, the temperature of the reaction is 72-75 degrees.

[0020] The beneficial effects of this application include:

[0021] The industrial preparation method of 1,3-butanediol provided in the present application is simple in preparation method, high in product purity, less in impurities, and odor, color, etc. meet high quality index requirements. DETAILED DESCRIPTION

[0022] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0023] Unless otherwise specified, the raw materials in the examples of this application were purchased through commercial channels.

[0024] Unless otherwise specified, conventional methods were used for testing and instrument settings were those recommended by the manufacturer.

[0025] catalyst

[0026] Commercial Raney nickel, denoted as catalyst 1.

[0027] 1 kg of nickel nitrate hexahydrate was dissolved in 12 kg of water. After it was completely dissolved, 1 kg of γ-Al2O3 was added and stirred for 3 hours. After aging at room temperature for 3 hours, it was dried in an oven at 100 degrees for 12 hours. The sample was taken out and placed in a crucible and calcined in air at 500 degrees for 4 hours. After hydrogen reduction, Ni / Al2O3 was obtained, which was recorded as catalyst 2.

[0028] 1kg nickel nitrate hexahydrate and 1.6kg aluminum nitrate were dissolved in 12kg water. After complete dissolution, 1mol / L NaOH and Na2CO3 mixed solution was added, stirred for 0.5 hours, aged at room temperature for 3 hours, filtered and washed, dried in an oven at 100 degrees for 12 hours, and the sample was taken out and placed in a crucible, and calcined in air at 500 degrees for 4 hours. After hydrogen reduction, Ni / Al2O3 was obtained, which was recorded as catalyst 3.

[0029] 1 kg of nickel nitrate hexahydrate was dissolved in 12 kg of water. After complete dissolution, a 1 mol / L mixed solution of NaOH and Na2CO3 was added, and the mixture was stirred for 0.5 hours. The mixture was aged at room temperature for 3 hours, filtered and washed, and dried in an oven at 100 degrees for 12 hours. The sample was taken out and placed in a crucible, and calcined in air at 500 degrees for 4 hours. After hydrogen reduction, NiO was obtained, which was recorded as catalyst 4.

[0030] Example 1

[0031] The mixed solution of 3-hydroxybutyraldehyde generated by condensation of acetaldehyde is used as the raw material, and the component contents of the reaction solution are shown in Table 1.

[0032] Table 1

[0033]

[0034]

[0035] 50kg of the above catalyst 1 (about 27L) was loaded into a fixed bed reactor, the bed was connected, 5MPa H2 was introduced, the hydrogen flow rate was 2300L / h, and the 3-hydroxybutyraldehyde reaction raw materials 1-5 were respectively introduced into the reactor at a flow rate of 2kg / h through a sampling pump to react, and the catalyst bed temperature was controlled at 72-75 degrees. When the reaction temperature was too high, it was cooled with coil circulating water. The reaction was stable for 2 hours, and sampling was tested. The results are shown in Table 2.

[0036] Table 2

[0037]

[0038] Example 2

[0039] The operation was the same as in Example 1, except that catalyst 1 was replaced by catalyst 2. The reaction was stabilized for 2 hours, and samples were taken for testing. The results are shown in Table 3.

[0040] Table 3

[0041]

[0042] Example 3

[0043] The operation was the same as in Example 1, except that catalyst 1 was replaced by catalyst 3. The reaction was stabilized for 2 hours, and samples were taken for testing. The results are shown in Table 4.

[0044] Table 4

[0045]

[0046] Example 4

[0047] The operation was the same as in Example 1, except that catalyst 1 was replaced by catalyst 4. The reaction was stabilized for 2 hours, and samples were taken for testing. The results are shown in Table 5.

[0048] Table 5

[0049]

[0050] Example 5

[0051] The product obtained by treating raw material 1 in Example 1 is a typical example and is analyzed.

[0052] The product obtained by treating the raw material 1 in Example 1 was separated to obtain 1,3-butanediol, and its quality indicators such as purity, odor, and color were as follows:

[0053] Colorless and odorless, the gas chromatography purity of 1,3-butanediol is over 99.6%.

[0054] The above are only a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application is disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with the profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. An industrial preparation method of 1,3-butanediol, characterized in that: The preparation method comprises: The mixed liquid of 3-hydroxybutyraldehyde generated by condensation of acetaldehyde is used as raw material, the raw material is introduced into a fixed bed reactor filled with a catalyst, hydrogen is introduced, and the reaction is carried out to obtain the 1,3-butanediol.

2. The preparation method according to claim 1, characterized in that: In the mixed solution generated by condensation of acetaldehyde to form 3-hydroxybutyraldehyde, the content of trihydroxybutyraldehyde is 35-65%.

3. The preparation method according to claim 1, characterized in that: The mixed solution generated by condensation of acetaldehyde to form 3-hydroxybutyraldehyde also contains acetaldehyde, crotonaldehyde, paraldehyde and heavy components.

4. The preparation method according to claim 1, characterized in that: The catalyst is selected from at least one of Raney nickel, NiO, and Ni / Al2O3.

5. The preparation method according to claim 1, characterized in that: The flow rate of the raw material is 1 to 3 kg / h.

6. The preparation method according to claim 1, characterized in that: The mass space velocity of the reaction is 0.01~2h -1 .

7. The preparation method according to claim 1, characterized in that: The pressure of hydrogen is 4-6 MPa.

8. The preparation method according to claim 1, characterized in that: The flow rate of hydrogen is 2000-2500 L / h.

9. The preparation method according to claim 1, characterized in that: The reaction temperature is 72-75 degrees.

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