Octanol production system and production method

Abstract

The present application relates to the technical field of octanol production, and discloses an octanol production system and a production method. The system comprises an aldol condensation device, an oil-water separation device, a dealkali tower and a hydrogenation device which are connected through pipelines. The aldol condensation device is used for aldol condensation reaction of n-butyraldehyde and sodium hydroxide to obtain an aldol condensation reaction product. The oil-water separation device is used for oil-water separation of the aldol condensation reaction product to obtain a dehydrated aldol condensation reaction product containing sodium hydroxide, and the content of sodium hydroxide in the dehydrated aldol condensation reaction product is higher than 5 ppm. The dealkali tower is arranged between the oil-water separation device and the hydrogenation device, and is used for dealkali treatment of the dehydrated aldol condensation reaction product to obtain a de-sodium-hydroxide aldol condensation reaction product. The hydrogenation device is used for hydrogenation reaction of the de-sodium-hydroxide aldol condensation reaction product. The system can ensure the purity of the target product while improving the colority of the target product.

Description

Technical Field

[0001] This invention relates to the technical field of octanol production, and specifically to an octanol production system and method. Background Technology

[0002] Octyl alcohol is a colorless, flammable liquid with a characteristic odor. It is primarily used in the production of plasticizers, extractants, and stabilizers, and serves as an intermediate in the production of solvents and fragrances. Octyl alcohol itself is also used as a fragrance ingredient, blending floral scents such as rose and lily, and as a flavoring agent in soaps.

[0003] The current mainstream production technology for octanol involves the low-pressure carbonylation synthesis of butyraldehyde using a rhodium catalyst, followed by the aldol condensation of butyraldehyde to obtain octenal, and then the hydrogenation purification of octenal to yield octanol. The aldol condensation reaction equation is as follows:

[0004]

[0005] Butyraldehyde and sodium hydroxide solution react in an aldol condensation reactor, and octenal and unreacted butyraldehyde are separated in an aldol condensation recycling column. Unreacted organic matter is recovered from the top of the aldol condensation recycling column, and crude octenal is obtained from the bottom. Crude octenal undergoes oil-water separation in a chromatography column. The dehydrated octenal is hydrogenated in a liquid-phase hydrogenation reactor to produce octanol; however, the target product, octanol, has poor color and purity, often resulting in substandard products. Summary of the Invention

[0006] The purpose of this invention is to overcome the problem of substandard octanol products due to poor color in existing technologies, and to provide an octanol production system and method. This system can reduce the sodium hydroxide content in the sodium hydroxide dehydrogenase aldol condensation reaction product to below 5 ppm, reduce the occurrence of side reactions, and improve the color of the target product octanol while ensuring the purity of the target product.

[0007] To achieve the above objectives, the first aspect of the present invention provides an octanol production system, wherein the system comprises: an alcohol-aldehyde condensation unit, an oil-water separation unit, a dealkali removal tower, and a hydrogenation unit connected by pipelines;

[0008] The aldol condensation apparatus is used to carry out an aldol condensation reaction between n-butyraldehyde and sodium hydroxide to obtain the aldol condensation reaction product.

[0009] The oil-water separation device is used to separate the oil and water of the alcohol-aldehyde condensation reaction product to obtain the dehydrated alcohol-aldehyde condensation reaction product, which contains sodium hydroxide and the sodium hydroxide content in the dehydrated alcohol-aldehyde condensation reaction product is higher than 5 ppm.

[0010] The dealkali removal tower is located between the oil-water separation unit and the hydrogenation unit. The dealkali removal tower is used to dealkali-react the dehydrated alcohol-aldehyde condensation reaction product to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product.

[0011] The hydrogenation device is used to hydrogenate the product of the sodium hydroxide dehydrogenation aldol condensation reaction to obtain octanol.

[0012] A second aspect of the present invention provides a method for producing octanol, wherein the method is carried out in the system described in the first aspect, the method comprising:

[0013] (1) Butyraldehyde and sodium hydroxide are subjected to an alcohol-aldol condensation reaction in an alcohol-aldol condensation apparatus to obtain the alcohol-aldol condensation reaction product.

[0014] (2) The aldol condensation reaction product is separated into oil and water in an oil-water separation device to obtain a dehydrated aldol condensation reaction product. The dehydrated aldol condensation reaction product contains sodium hydroxide, and the sodium hydroxide content in the dehydrated aldol condensation reaction product is higher than 5 ppm.

[0015] (3) The dehydrated alcohol-aldehyde condensation reaction product is subjected to dealkali treatment in a dealkali tower to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product.

[0016] (4) The product of the sodium hydroxide dehydrogenation aldol condensation reaction is hydrogenated in a hydrogenation device to obtain octanol.

[0017] Preferably, the conditions for the dealkalization treatment are such that the sodium hydroxide content in the product of the desodium hydroxide aldol condensation reaction is less than 5 ppm, and more preferably 1-4 ppm.

[0018] The inventors of this invention discovered during their research that the dehydrated aldol condensation reaction product contains dissolved water, which contains sodium hydroxide. When the untreated dehydrated aldol condensation reaction product is directly fed into the hydrogenation unit, the sodium hydroxide in the dehydrated aldol condensation reaction product will also enter the hydrogenation unit. When the sodium hydroxide content is higher than 5 ppm, a side reaction occurs in the hydrogenation unit to generate sodium isooctanoate, which affects the color of the octanol product and results in the product failing to meet standards. In addition, due to incomplete washing of the oil-water separation device, the byproduct sodium isooctanoate is commonly present in the octanol product, reducing the product purity. Based on this, the inventors of this invention introduced a dealkali tower into the octanol production system to dealkali-treat the dehydrated aldol condensation reaction product, reducing the sodium hydroxide content in the dehydrated aldol condensation reaction product to below 5 ppm, thereby reducing the occurrence of side reactions and improving the color of the target product octanol while ensuring the purity of the target product. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the production system of the present invention;

[0020] Figure 2 This is a schematic diagram of the production system of the embodiment;

[0021] Figure 3 This is a schematic diagram of a proportional production system.

[0022] Explanation of reference numerals in the attached figures

[0023] Figure 1 and Figure 2 middle,

[0024] 1-Butyraldehyde isomer tower; 2-Aldol condensation reactor;

[0025] 3-Aldol condensation circulation tower; 4-Oil-water separation unit;

[0026] 5-Dealkali removal tower; 6-Hydrogenation unit;

[0027] 7-Purification tower; 8-Distillation tower.

[0028] Figure 3 middle,

[0029] 1-Butyraldehyde isomer tower; 2-Aldol condensation reactor;

[0030] 3-Aldol condensation circulation tower; 4-Oil-water separation unit;

[0031] 5- Hydrogenation unit; 6- Purification tower;

[0032] 7-Distillation column. Detailed Implementation

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] The first aspect of the present invention provides a system for producing octanol, wherein, as Figure 1 As shown, the system includes: an alcohol-aldehyde condensation unit, an oil-water separation unit 4, an alkali removal tower 5, and a hydrogenation unit 6, all connected by pipelines.

[0035] The aldol condensation apparatus is used to carry out an aldol condensation reaction between n-butyraldehyde and sodium hydroxide to obtain the aldol condensation reaction product.

[0036] The oil-water separation device 4 is used to separate the oil and water of the alcohol-aldehyde condensation reaction product to obtain the dehydrated alcohol-aldehyde condensation reaction product. The dehydrated alcohol-aldehyde condensation reaction product contains sodium hydroxide, and the content of sodium hydroxide in the dehydrated alcohol-aldehyde condensation reaction product is higher than 5 ppm.

[0037] The dealkali removal tower 5 is located between the oil-water separation device 4 and the hydrogenation device 6. The dealkali removal tower 5 is used to dealkali-removing the dehydrated alcohol-aldehyde condensation reaction product to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product.

[0038] The hydrogenation device 6 is used to hydrogenate the product of the sodium hydroxide dehydrogenation aldol condensation reaction to obtain octanol.

[0039] The inventors of this invention discovered during their research that the dehydrated aldol condensation reaction product contains dissolved water, which contains sodium hydroxide. When the untreated dehydrated aldol condensation reaction product is directly fed into the hydrogenation unit, the sodium hydroxide in the product also enters the hydrogenation unit. When the sodium hydroxide content is higher than 5 ppm, a side reaction occurs in the hydrogenation unit to generate sodium isooctanoate, affecting the color of the octanol product and causing it to fail to meet standards. In addition, due to incomplete washing in the oil-water separation device, sodium isooctanoate is commonly present in the octanol product, reducing product purity. Based on this, the inventors of this invention introduced a dealkali tower into the octanol production system to dealkali-treat the dehydrated aldol condensation reaction product, reducing the sodium hydroxide content in the dehydrated aldol condensation reaction product to below 5 ppm, thereby reducing the occurrence of side reactions and improving the color of the target product octanol while ensuring the purity of the target product.

[0040] In this invention, preferably, the sodium hydroxide content in the dehydrated aldol condensation reaction product is 20-200 ppm. The system provided by this invention is particularly suitable for processing dehydrated aldol condensation reaction products with specific sodium hydroxide contents to obtain the target product octanol with high color and purity.

[0041] In this invention, preferably, the dealkali removal tower 5 is equipped with a tray, which is horizontally arranged inside the dealkali removal tower 5. By setting up the dealkali removal tower, sodium hydroxide can be extracted from the aldol condensation reaction product, a sodium hydroxide solution is obtained at the top of the dealkali removal tower, and the sodium hydroxide-dehydrated aldol condensation reaction product is obtained at the bottom of the tower.

[0042] In this invention, preferably, the number of trays in the dealkali removal tower 5 is 5-30, more preferably 5-15.

[0043] In this invention, preferably, the dealkali removal tower 5 is provided with a detergent inlet, which is located at the upper part of the dealkali removal tower 5. By placing the detergent inlet at the upper part of the dealkali removal tower, the detergent is introduced from the upper part of the dealkali removal tower, while the dehydration alcohol-aldehyde condensation reaction product is introduced from the lower part of the dealkali removal tower. The two streams come into countercurrent contact, which is more conducive to the dealkali removal process, reduces the sodium hydroxide content, avoids the occurrence of side reactions, and improves the color of the target product while ensuring the purity of the target product.

[0044] In this invention, preferably, the aldol condensation device includes an aldol condensation reactor 2 and an aldol condensation circulation tower 3 connected in series.

[0045] In this invention, preferably, the aldol condensation reactor 2 is used to carry out an aldol condensation reaction of n-butyraldehyde and sodium hydroxide to obtain an aldol condensation reaction product containing unreacted n-butyraldehyde.

[0046] In this invention, the specific type of alcohol-aldol condensation reactor is not particularly limited. It can be any alcohol-aldol condensation reactor conventionally defined in the art, as long as it can realize the alcohol-aldol condensation reaction. Those skilled in the art can choose according to actual needs.

[0047] In this invention, preferably, the aldol condensation circulation tower 3 is used to separate the aldol condensation reaction product containing unreacted butyraldehyde to obtain the aldol condensation reaction product (bottom of the tower) and the aqueous phase containing unreacted n-butanol (top of the tower).

[0048] In this invention, preferably, the top material outlet of the aldol condensation circulation tower 3 is connected to the detergent inlet of the dealkali removal tower 5. Through the connection between the aldol condensation circulation tower 3 and the dealkali removal tower, the aqueous phase containing unreacted n-butanol at the top of the aldol condensation circulation tower 3 is provided as a detergent to the dealkali removal tower 5 for dealkali removal treatment.

[0049] In this invention, the specific type of alcohol-aldehyde condensation circulation tower is not particularly limited. It can be any alcohol-aldehyde condensation circulation tower conventionally defined in the art, as long as it can remove unreacted n-butyraldehyde and recycle it while providing a detergent for dealkalization treatment. Those skilled in the art can choose according to actual needs.

[0050] In a preferred embodiment of the present invention, the system further includes a butanol isomer tower 1, which is used to obtain n-butanol.

[0051] In this invention, preferably, the butanol isomer tower 1 is connected in series with the aldol condensation reactor 2.

[0052] In a preferred embodiment, the n-butyraldehyde is provided by a mixture of butyraldehydes; more preferably, the n-butyraldehyde is provided by a mixture of butyraldehydes via an isomerization reaction.

[0053] In this invention, the specific type of oil-water separation device is not particularly limited, as long as it can achieve oil-water separation. Preferably, the oil-water separation device 4 is a chromatography apparatus and / or a coalescer, preferably a chromatography apparatus. The chromatography apparatus is used to separate the oil and water in the aldol condensation reaction product, removing the aqueous phase from the aldol condensation reaction product to obtain the dehydrated aldol condensation reaction product.

[0054] In this invention, preferably, the system further includes a purification device for purifying the hydrogenation reaction product obtained from the hydrogenation reaction to obtain octanol.

[0055] In this invention, preferably, the purification device includes a purification tower 7 and a distillation tower 8 connected in series.

[0056] In this invention, preferably, the purification tower 7 is used to purify the hydrogenation reaction products to obtain purified products.

[0057] In this invention, no particular type of purification tower is specified. Any reaction tower conventionally defined in the art that can achieve purification is applicable to this invention, and those skilled in the art can choose according to actual needs.

[0058] In this invention, preferably, the distillation column 8 is used to distill the purified product to obtain octanol.

[0059] In this invention, no particular type of distillation column is specified. Any distillation column conventionally defined in the art can be applied to this invention, and those skilled in the art can choose according to actual needs.

[0060] A second aspect of the present invention provides a method for producing octanol, wherein the method is carried out in the system described in the first aspect, the method comprising:

[0061] (1) Butyraldehyde and sodium hydroxide are subjected to an alcohol-aldol condensation reaction in an alcohol-aldol condensation apparatus to obtain the alcohol-aldol condensation reaction product.

[0062] (2) The aldol condensation reaction product is separated into oil and water in the oil-water separation device 4 to obtain the dehydrated aldol condensation reaction product. The dehydrated aldol condensation reaction product contains sodium hydroxide, and the content of sodium hydroxide in the dehydrated aldol condensation reaction product is higher than 5 ppm.

[0063] (3) The dehydrated alcohol-aldehyde condensation reaction product is dealkalized in the dealkalization tower 5 to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product.

[0064] (4) The product of the sodium hydroxide dehydrogenation aldol condensation reaction is hydrogenated in hydrogenation device 6 to obtain octanol.

[0065] The inventors of this invention discovered in their research that the dehydrated aldol condensation reaction product contains dissolved water, which contains sodium hydroxide. When the untreated dehydrated aldol condensation reaction product is directly subjected to subsequent hydrogenation, a side reaction occurs during hydrogenation when the sodium hydroxide content exceeds 5 ppm, generating sodium isooctanoate, which affects the color of the octanol product and leads to substandard quality. Furthermore, due to incomplete washing during oil-water separation, sodium isooctanoate is commonly present in the octanol product, reducing its purity. Therefore, the inventors of this invention introduce a dealkalization treatment into the octanol production method. This dealkalization treatment reduces the sodium hydroxide content in the dehydrated aldol condensation reaction product to below 5 ppm, thereby reducing side reactions, preventing the formation of sodium isooctanoate, and improving the color of the target octanol product while ensuring its purity.

[0066] In this invention, the conditions for the aldol condensation reaction in step (1) are not particularly limited, and those skilled in the art can select them according to actual needs. Preferably, the conditions for the aldol condensation reaction in step (1) include: a temperature of 90-130℃, a time of 0.1-2h, and a volume ratio of n-butyraldehyde to sodium hydroxide of 1-10, preferably 1-5.

[0067] In this invention, preferably, the sodium hydroxide is provided by a sodium hydroxide-containing solution. The concentration of the sodium hydroxide solution is not particularly limited in this invention; for example, it can be 0.1-3 wt%.

[0068] In this invention, the source of n-butyraldehyde in step (1) is not particularly limited. Preferably, the n-butyraldehyde is provided by mixed butyraldehyde. More preferably, the n-butyraldehyde is provided by mixed butyraldehyde through an isomerization reaction.

[0069] In this invention, preferably, step (1) further includes: n-butyraldehyde and sodium hydroxide undergo an aldol condensation reaction in aldol condensation reactor 2 to obtain an aldol condensation reaction product containing unreacted n-butyraldehyde;

[0070] In this invention, preferably, step (1) further includes: separating the alcohol-aldehyde condensation reaction product containing unreacted n-butyraldehyde in the alcohol-aldehyde condensation circulation tower 3 to obtain the alcohol-aldehyde condensation reaction product and an aqueous phase containing unreacted n-butanol.

[0071] In this invention, the conditions and operations for oil-water separation are not particularly limited, as they are conventional operations in the field. Those skilled in the art can adjust them according to the actual situation, as long as the separation of the oil phase and the water phase can be achieved.

[0072] In this invention, preferably, in step (2), the oil-water separation is carried out in a chromatography apparatus.

[0073] In this invention, preferably, in step (2), the sodium hydroxide content in the dehydrated aldol condensation reaction product is 20-200 ppm.

[0074] In this invention, preferably, in step (3), the dealkalization treatment is carried out in the presence of a detergent.

[0075] In this invention, the type of detergent is not particularly limited, and those skilled in the art can select the desired detergent based on the differences in the solubility of sodium hydroxide in different media. Preferably, the detergent is selected from at least one of water, an aqueous phase containing unreacted n-butyraldehyde, and steam condensate, and more preferably an aqueous phase containing unreacted n-butyraldehyde.

[0076] In this invention, the source of the detergent is not particularly limited. It can be provided by an external detergent supply device or by the system itself. Preferably, it is provided by the system itself, and more preferably by the aldol condensation circulation tower 3.

[0077] In this invention, preferably, in step (3), the feed volume flow rate of the detergent is 5-30% of the feed volume flow rate of the dehydrated aldol condensation reaction product.

[0078] In this invention, the method of dealkalization treatment in step (3) is not particularly limited; for example, it can be extraction.

[0079] In this invention, preferably, in step (3), the detergent is subjected to countercurrent contact with the dehydrated aldol condensation reaction product for dealkalization treatment. Countercurrent contact is more conducive to the dealkalization treatment, reduces the sodium hydroxide content in the dehydrated aldol condensation reaction product, avoids side reactions, and improves the color of the target product while ensuring product purity.

[0080] In this invention, preferably, in step (3), the conditions of the dealkalization treatment are such that the sodium hydroxide content in the dehydration aldol condensation reaction product is less than 5 ppm, preferably 1-4 ppm. By reducing the sodium hydroxide content in the dehydration aldol condensation reaction product through dealkalization treatment, side reactions are avoided, and the color of the target product is improved while ensuring product purity.

[0081] In this invention, preferably, in step (4), the hydrogenation reaction is carried out in the presence of a catalyst. The type of catalyst is not particularly limited in this invention; any hydrogenation catalyst conventionally defined in the art that is suitable for hydrogenation reactions is applicable to this invention, such as BASF's Cu / Cr hydrogenation catalyst.

[0082] In this invention, the conditions for the hydrogenation reaction are not particularly limited, and those skilled in the art can select them according to actual needs. Preferably, in step (4), the conditions for the hydrogenation reaction include: a temperature of 130-200℃, a pressure of 1-10 MPa, and a volume hourly space velocity of 0.1-0.9 h⁻¹. -1 .

[0083] In this invention, preferably, step (4) further includes: purifying the hydrogenation reaction product obtained from the hydrogenation reaction in a purification tower 7 to obtain a purified product, and then distilling the purified product in a distillation tower 8 to obtain octanol.

[0084] The present invention will be described in detail below through embodiments.

[0085] Example

[0086] In such Figure 2 The system shown is used for the production of octanol, specifically...

[0087] (1) 80 mL of n-butyraldehyde and 50 mL of 0.45 wt% sodium hydroxide solution in the butyraldehyde isomer tower 1 are subjected to an alcohol-aldol condensation reaction in the alcohol-aldol condensation reactor 2. The reaction conditions are: temperature 90℃, time 30 min, pressure 0.23 MPa. The alcohol-aldol condensation reaction product containing unreacted n-butyraldehyde (unreacted n-butyraldehyde, crude octenal) is obtained. The alcohol-aldol condensation reaction product containing unreacted n-butyraldehyde enters the alcohol-aldol condensation circulation tower 3 for separation. The top of the tower is the aqueous phase containing unreacted n-butyraldehyde, and the bottom of the tower is the alcohol-aldol condensation reaction product (crude octenal).

[0088] (2) The aldol condensation reaction product enters the oil-water separation device 4 (chromatograph) for oil-water separation to obtain the oil phase dehydrated aldol condensation reaction product and the water phase containing sodium hydroxide. The dehydrated aldol condensation reaction product contains sodium hydroxide, and the sodium hydroxide content in the dehydrated aldol condensation reaction product is 100 ppm.

[0089] (3) The aqueous phase (detergent) containing unreacted n-butanol obtained from the top of the aldol condensation circulation tower 3 enters the dealkali tower 5 (with 5 trays) through the detergent inlet at the top of the dealkali tower 5. The dehydrated aldol condensation reaction product enters from the bottom of the dealkali tower 5. The dehydrated aldol condensation reaction product and the aqueous phase containing unreacted n-butanol are in countercurrent contact in the dealkali tower 5 for dealkali treatment. The volume flow rate of the aqueous phase containing unreacted n-butanol is 5% of the volume flow rate of the dehydrated aldol condensation reaction product, and the desodium hydroxide aldol condensation reaction product is obtained. The dealkali treatment conditions make the sodium hydroxide content in the desodium hydroxide aldol condensation reaction product 3 ppm.

[0090] (4) In the presence of a catalyst (BASF's Cu / Cr hydrogenation catalyst), the product of the sodium hydroxide dehydration aldol condensation reaction is pumped from the top of the dealkali removal tower 5 into the hydrogenation unit 6 (liquid-phase hydrogenation converter) for hydrogenation reaction to obtain the hydrogenation product. The conditions for the hydrogenation reaction include: reaction temperature of 150℃, reaction pressure of 2.4MPa, and volume hourly space velocity of 0.6h. -1 The hydrogenation reaction product enters purification tower 7 for purification to obtain purified product, which then enters distillation tower 8 for distillation to obtain octanol.

[0091] The color of octanol was determined according to GB / T 3134, the method for determining the color of liquid chemicals. Specifically, the color of the sample was visually compared with the color of the standard platinum-cobalt colorimetric solution, and the result was expressed in Hazen (platinum-cobalt) color units. The color of octanol was measured to be 10.

[0092] The purity of octanol was determined to be 99.9% according to the GB / T 2013 standard for the determination of density of liquid petrochemical products.

[0093] Comparative Example

[0094] In such Figure 3 The system shown is used for the production of octanol, specifically...

[0095] (1) 80 mL of n-butyraldehyde and 50 mL of 0.45 wt% sodium hydroxide in the butyraldehyde isomer tower 1 were subjected to an alcohol-aldol condensation reaction in the alcohol-aldol condensation reactor 2. The reaction conditions were: temperature 90℃, time 30 min, and pressure 0.23 MPa. The alcohol-aldol condensation reaction product containing unreacted n-butyraldehyde was obtained. The alcohol-aldol condensation reaction product containing unreacted n-butyraldehyde was fed into the alcohol-aldol condensation circulation tower 3 for separation. The top of the tower was obtained as an aqueous phase containing unreacted n-butyraldehyde, and the bottom of the tower was obtained as the alcohol-aldol condensation reaction product.

[0096] (2) The aldol condensation reaction product enters the oil-water separation device 4 (chromatograph) for oil-water separation to obtain the oil phase dehydrated aldol condensation reaction product and the water phase containing sodium hydroxide. The dehydrated aldol condensation reaction product contains sodium hydroxide, and the sodium hydroxide content in the dehydrated aldol condensation reaction product is 100 ppm.

[0097] (3) In the presence of a catalyst (BASF's Cu / Cr hydrogenation catalyst), the dehydrated aldol condensation reaction product is hydrogenated in hydrogenation unit 5 (liquid-phase hydrogenation reactor) to obtain the hydrogenation reaction product. The hydrogenation reaction conditions include: reaction temperature of 150℃, pressure of 2.4MPa, and volume hourly space velocity of 0.6h. -1 The hydrogenation reaction product enters purification tower 6 for purification to obtain purified product, which then enters distillation tower 7 for distillation to obtain octanol.

[0098] Following the method in Example 1, the color of octanol was measured to be 35, and the purity of octanol was 99.9%.

[0099] As can be seen from the examples and comparative examples, the system provided by the present invention has an alkali removal tower, which optimizes the water washing process of the alcohol-aldehyde condensation reaction product. It can effectively reduce the amount of sodium hydroxide entering the hydrogenation reactor along with octenal, avoid the occurrence of side reactions between octanol and sodium hydroxide, and improve the color of octanol product while ensuring the purity of octanol product.

[0100] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A system for producing octanol, wherein, The system includes: an alcohol-aldehyde condensation unit, an oil-water separation unit (4), an alkali removal tower (5), and a hydrogenation unit (6) connected by pipelines; The aldol condensation apparatus is used to carry out an aldol condensation reaction between n-butyraldehyde and sodium hydroxide to obtain the aldol condensation reaction product. The oil-water separation device (4) is used to separate the oil and water of the alcohol-aldehyde condensation reaction product to obtain the dehydrated alcohol-aldehyde condensation reaction product. The dehydrated alcohol-aldehyde condensation reaction product contains sodium hydroxide, and the content of sodium hydroxide in the dehydrated alcohol-aldehyde condensation reaction product is higher than 5 ppm. The dealkali tower (5) is located between the oil-water separation device (4) and the hydrogenation device (6). The dealkali tower (5) is used to dealkali-treat the dehydrated alcohol-aldehyde condensation reaction product to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product. The hydrogenation device (6) is used to hydrogenate the product of the sodium hydroxide dehydrogenation aldol condensation reaction to obtain octanol.

2. The system according to claim 1, wherein, The sodium hydroxide content in the dehydrated aldol condensation product is 20-200 ppm.

3. The system according to claim 1 or 2, wherein, The dealkali removal tower (5) is provided with a tower plate, which is horizontally arranged inside the dealkali removal tower (5); Preferably, the number of trays in the dealkali removal tower (5) is 5-30, more preferably 5-15; Preferably, the dealkali removal tower (5) is provided with a detergent inlet, which is located at the top of the dealkali removal tower (5).

4. The system according to claim 3, wherein, The aldol condensation device includes an aldol condensation reactor (2) and an aldol condensation circulation tower (3) connected in series. Preferably, the aldol condensation reactor (2) is used to carry out an aldol condensation reaction of n-butyraldehyde and sodium hydroxide to obtain an aldol condensation reaction product containing unreacted n-butyraldehyde. Preferably, the aldol condensation circulation tower (3) is used to separate the aldol condensation reaction product containing unreacted n-butyraldehyde to obtain the aldol condensation reaction product and an aqueous phase containing unreacted n-butyraldehyde. Preferably, the top material outlet of the alcohol-aldehyde condensation circulation tower (3) is connected to the detergent inlet of the dealkali tower (5).

5. The system according to claim 1 or 2, wherein, The oil-water separation device (4) is a chromatography unit and / or a coalescer.

6. The system according to claim 1 or 2, wherein, The system also includes a purification device, which is used to purify the hydrogenation reaction product obtained from the hydrogenation reaction to obtain octanol; Preferably, the purification device includes a purification tower (7) and a distillation tower (8) connected in series; Preferably, the purification tower (7) is used to purify the hydrogenation reaction products to obtain purified products; Preferably, the distillation column (8) is used to distill the purified product to obtain octanol.

7. A method for producing octanol, wherein, The method is performed in the system described in any one of claims 1-6, and the method includes: (1) Butyraldehyde and sodium hydroxide are subjected to an alcohol-aldol condensation reaction in an alcohol-aldol condensation apparatus to obtain the alcohol-aldol condensation reaction product. (2) The aldol condensation reaction product is separated into oil and water in the oil-water separation device (4) to obtain the dehydrated aldol condensation reaction product. The dehydrated aldol condensation reaction product contains sodium hydroxide, and the content of sodium hydroxide in the dehydrated aldol condensation reaction product is higher than 5 ppm. (3) The dehydrated alcohol-aldehyde condensation reaction product is dealkalized in the dealkalization tower (5) to obtain the dehydrated sodium hydroxide alcohol-aldehyde condensation reaction product; (4) The product of the sodium hydroxide dehydrogenation aldol condensation reaction is hydrogenated in the hydrogenation device (6) to obtain octanol.

8. The method according to claim 7, wherein, In step (1), the conditions for the aldol condensation reaction include: 90-130℃, time of 0.1-2h, and volume ratio of n-butyraldehyde to sodium hydroxide of 1-10. Preferably, step (1) further includes: n-butyraldehyde and sodium hydroxide undergo an aldol condensation reaction in an aldol condensation reactor (2) to obtain an aldol condensation reaction product containing unreacted n-butyraldehyde; Preferably, step (1) further includes: separating the alcohol-aldehyde condensation reaction product containing unreacted n-butyraldehyde in an alcohol-aldehyde condensation circulation tower (3) to obtain the alcohol-aldehyde condensation reaction product and an aqueous phase containing unreacted n-butyraldehyde.

9. The method according to claim 7 or 8, wherein, In step (2), the sodium hydroxide content in the dehydrated aldol condensation reaction product is 20-200 ppm.

10. The method according to claim 8, wherein, In step (3), the dealkalization treatment is carried out in the presence of a detergent, preferably the detergent is selected from at least one of water, an aqueous phase containing unreacted n-butyraldehyde, and steam condensate; Preferably, in step (3), the feed volume flow rate of the detergent is 5-30% of the feed volume flow rate of the dehydrated aldol condensation reaction product; Preferably, in step (3), the detergent is subjected to dealkalization treatment by countercurrent contact with the dehydrated aldol condensation reaction product; Preferably, in step (3), the conditions of the dealkalization treatment are such that the sodium hydroxide content in the desodium hydroxide aldol condensation reaction product is less than 5 ppm, preferably 1-4 ppm.

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