Method and device for hydrolysis of succinic anhydride to produce succinic acid

Abstract

The application provides a method for hydrolyzing succinic anhydride to produce succinic acid, which comprises the following steps: spraying liquid succinic anhydride to form droplets, contacting the droplets with water vapor, and reacting to generate succinic acid; and drying the generated succinic acid to obtain a succinic acid product. The method shortens the process flow from succinic anhydride to the succinic acid product, and shortens the original process of hydrolysis-temperature reduction-crystallization-filtration-drying to hydrolysis-drying, greatly saves the equipment cost, and improves the production efficiency. The application can obtain a succinic acid product with more concentrated particle size. There is no problem of residual succinic acid in the mother liquor, and the one-way yield is high.

Description

Technical Field

[0001] This invention relates to the field of succinic acid production technology, specifically to a method and apparatus for producing succinic acid by hydrolysis of succinic anhydride. Background Technology

[0002] Succinic acid, also known as succinic acid, is an important chemical and pharmaceutical intermediate and a key monomer in the production of biodegradable materials PBS and PBSA. Furthermore, succinic acid is widely used in numerous industries, including food, pharmaceuticals, agriculture, coatings, dyes, plastics, rubber, photographic chemicals, surfactants, lubricants, and electroplating.

[0003] The main production methods for succinic acid include electrochemical reduction, bio-fermentation, and catalytic hydrogenation. Among these, catalytic hydrogenation is currently the only production method that can match the production capacity of PBS / PBSA due to its ease of scaling up production and its high conversion rate, selectivity, and product purity. This method uses maleic anhydride as a raw material, hydrogenating it to obtain succinic anhydride, which is then hydrolyzed and crystallized to obtain succinic acid. The hydrolysis and crystallization process of succinic anhydride generally involves reacting succinic anhydride with a large amount of water to form a succinic acid solution, which is then cooled and crystallized to obtain succinic acid crystals. CN217854643U provides a succinic anhydride hydrolysis crystallization apparatus, including a hydrolysis vessel and multiple crystallization vessels connected in series. Each crystallization vessel has a cooling jacket on its outer wall, with a cold water inlet and a hot water outlet at its top and bottom, respectively. A vertical shaft is positioned along the vertical axis of each crystallization vessel, with its upper end connected to a drive device mounted on the top of the vessel. Multiple stirring components are spaced vertically along the shaft, each component including a connecting disc and multiple stirring blades. The stirring blades are evenly distributed circumferentially on the connecting disc, and multiple guide plates are inclinedly arranged on the blades to guide the cooling water temperature within the cooling jackets of the crystallization vessels to gradually decrease. Using this apparatus for succinic anhydride hydrolysis crystallization requires a relatively long process flow. This involves multiple pieces of equipment, and only a small amount of water in the process water is used as a reactant in the hydrolysis reaction of succinic anhydride, while the vast majority of water is used as a solvent for the succinic acid solution. Cooling the solution during crystallization results in huge energy consumption, and there is a lot of succinic acid residue in the crystallization mother liquor, which leads to a low single-pass yield. In addition, the succinic acid product obtained by cooling crystallization has a relatively dispersed particle size. Summary of the Invention

[0004] To address the above shortcomings, this invention provides a method and apparatus for producing succinic acid by hydrolyzing succinic anhydride. The method involves dispersing succinic anhydride into droplets and then contacting them with water vapor, allowing the two to react rapidly under specific conditions to obtain succinic acid. This method eliminates the need for lengthy processes, requires minimal equipment investment, and facilitates large-scale production.

[0005] The technical objective of this invention is achieved through the following technical solution:

[0006] The first aspect of the present invention provides a method for producing succinic acid by hydrolysis of succinic anhydride, comprising: spraying liquid succinic anhydride to form droplets, contacting them with water vapor to react and generate succinic acid, and drying the generated succinic acid to obtain the succinic acid product.

[0007] Furthermore, the temperature of the liquid succinic anhydride should exceed its melting point, not less than 120°C, and preferably not less than 130°C.

[0008] Furthermore, the droplet size of succinic anhydride is 0.01-1.0 mm, preferably 0.1-0.5 mm, through spray treatment.

[0009] Furthermore, the temperature of the water vapor is 100-180℃, preferably 120-150℃.

[0010] Furthermore, the pressure of the water vapor is 0.1-1.0 MPa, preferably 0.1-0.5 MPa.

[0011] Furthermore, the mass ratio of water vapor to succinic anhydride is not less than 0.18, preferably (0.8-1):1.

[0012] Furthermore, the succinic anhydride droplets and water vapor are mixed in a counter-current contact manner to ensure more thorough contact and a faster and more complete reaction.

[0013] Furthermore, the contact time between the succinic anhydride droplets and water vapor is not less than 10 minutes, preferably 10-120 minutes.

[0014] To ensure sufficient contact time between succinic anhydride droplets and water vapor, the vertical height of the contact space between the droplets and water vapor must be maintained, or the contact time can be ensured by adjusting the pressure and flow rate of the water vapor. To further ensure the flow rate and pressure of the water vapor, inert gases such as nitrogen, argon, or helium can be added to the water vapor.

[0015] Furthermore, the water vapor from the reaction exhaust is collected, mixed with fresh water vapor, and reused as a reactant to react with succinic anhydride.

[0016] Furthermore, the succinic acid after the reaction is collected in solid form, and the drying can be performed using any industrially common drying method available in the prior art.

[0017] The second aspect of the present invention aims to provide an apparatus for producing succinic acid by hydrolysis of succinic anhydride, comprising a tank, a succinic anhydride feed pipeline at the top of the tank connected to a spray device at the top of the tank, a steam feed pipeline at the bottom of the tank connected to a gas distributor at the bottom of the tank, a tail gas discharge pipeline at the top of the tank, and a product storage space at the bottom of the tank where the succinic acid produced after the reaction falls and is collected through a succinic acid discharge pipeline.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] (1) The method of the present invention shortens the process flow from succinic anhydride to succinic acid product. The original process of hydrolysis-cooling crystallization-filtration-drying is shortened to hydrolysis-drying, which greatly saves equipment costs and improves production efficiency.

[0020] (2) The method of the present invention uses a spray device to form succinic anhydride droplets. By controlling the size of the liquid, the size of the succinic acid product can be controlled, resulting in a succinic acid product with more concentrated particle size.

[0021] (3) Compared with the traditional hydrolysis-cooling crystallization-filtration-drying route, in the present invention, succinic acid product is obtained directly after the hydrolysis reaction of succinic anhydride, without the problem of succinic acid residue in the mother liquor, so the single-pass yield is high.

[0022] (4) Compared with the traditional crystallization route, the method of the present invention does not require solution cooling, thus saving a lot of energy.

[0023] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the succinic anhydride hydrolysis reaction apparatus used in the method of the present invention.

[0025] The components include: 1. Tank body, 2. Succinic anhydride feed pipeline, 3. Spray device, 4. Steam feed pipeline, 5. Gas distributor, 6. Tail gas discharge pipeline, and 7. Succinic acid discharge pipeline. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example 1

[0028] Provide succinic anhydride hydrolysis reaction apparatus, such as Figure 1 As shown, the system includes a tank 1, which is a cylindrical tank with a certain height and a conical bottom. A succinic anhydride feed line 2 is installed at the top of the tank, connected to a spray device 3 installed at the top of the tank. A steam feed line 4 is installed at the bottom of the tank, connected to a gas distributor 5 installed at the bottom of the tank. A tail gas discharge line 6 is installed at the top of the tank. The bottom of the tank is a product storage space where the succinic acid produced after the reaction falls to the area and is collected through the succinic acid discharge line 7.

[0029] The process of hydrolyzing succinic anhydride using the above apparatus is as follows: Liquid succinic anhydride is fed into the succinic anhydride feed line 2 and formed into uniformly sized droplets through the spray device 3. Water vapor enters the tank 1 through the water vapor feed line 4 and the gas distributor 5, filling the tank 1 with water vapor. As the succinic anhydride droplets fall, they come into contact with the water vapor and undergo a hydrolysis reaction to generate succinic acid particles, which fall to the bottom of the reactor and are collected through the succinic acid discharge line 7.

[0030] Example 2

[0031] The succinic anhydride hydrolysis reaction was carried out using the apparatus described in Example 1. The liquid succinic anhydride temperature was 130°C, the feed rate was 5 kg / h, the steam temperature was 120°C, the pressure was 0.1 MPa, and the feed rate was 4 kg / h. The droplet size formed by the liquid succinic anhydride through the spray device was 0.1-0.2 mm. In addition to the relatively high tank height, nitrogen was added to the feed gas, and the gas flow rate was controlled to ensure that the droplets and steam were in contact for 30 minutes. The reaction product was collected and dried to obtain succinic acid, with a calculated yield of 90.5%. The particle size distribution (mass fraction) of succinic acid was as follows: <0.100 mm: 24.37%, 0.100-0.200 mm: 60.20%, 0.200-0.300 mm: 15.10%, >0.300 mm: 0.33%.

[0032] Example 3

[0033] The succinic anhydride hydrolysis reaction was carried out using the apparatus in Example 1. The temperature of the liquid succinic anhydride was 135°C, the feed rate was 10 kg / h, the water vapor temperature was 150°C, the pressure was 0.2 MPa, and the feed rate was 10 kg / h. The droplet size formed by the liquid succinic anhydride through the spray device was 0.3-0.5 mm. In addition to the high height of the tank, nitrogen was added to the feed gas. The reaction time between the droplets and the water vapor was controlled by controlling the gas flow rate to 60 min. The reaction product was collected and dried to obtain succinic acid, with a calculated yield of 91.6%. The particle size distribution (mass fraction) of succinic acid was as follows: <0.100mm: 1.57%, 0.100-0.200mm: 2.99%, 0.200-0.300mm: 7.31%, 0.300-0.500mm: 68.34%, 0.500-0.650mm: 19.21%, >0.650mm: 0.58%.

[0034] Example 4

[0035] The succinic anhydride hydrolysis reaction was carried out using the apparatus described in Example 1. The liquid succinic anhydride temperature was 120°C, the feed rate was 10 kg / h, the steam temperature was 130°C, the pressure was 0.1 MPa, and the feed rate was 9 kg / h. The droplet size formed by the liquid succinic anhydride through the spray device was 0.2-0.3 mm, and the contact time between the droplets and the steam was 10 min. The reaction product was collected and dried to obtain succinic acid, with a calculated yield of 84.3%. The particle size distribution (mass fraction) of succinic acid was as follows: <0.100 mm: 3.22%, 0.100-0.200 mm: 11.44%, 0.200-0.300 mm: 65.02%, 0.300-0.500 mm: 18.70%, >0.500 mm: 1.62%.

[0036] Example 5

[0037] The succinic anhydride hydrolysis reaction was carried out using the apparatus described in Example 1. The liquid succinic anhydride temperature was 150°C, and the feed rate was 10 kg / h. The steam temperature was 130°C, and the feed rate was 9 kg / h. The droplet size of the liquid succinic anhydride formed by the spray device was 0.1-0.2 mm. In addition to the relatively high height of the tank, nitrogen was added to the feed gas. The gas flow rate was controlled to ensure that the droplets and steam reacted for 20 minutes. The reaction product was collected and dried to obtain succinic acid. The yield was calculated to be 92.7%. The particle size distribution (mass fraction) of succinic acid was as follows:

[0038] <0.100mm: 20.24%, 0.100-0.200mm: 63.47%, 0.200-0.300mm: 16.01%, >0.300mm: 0.28%.

[0039] Comparative Example 1

[0040] Using existing conventional process routes, a hydrolysis reaction was carried out in a hydrolysis reactor with a feed rate of 10 kg / h of liquid succinic anhydride and 30 kg / h of water at 90°C and a reaction residence time of 30 min. The reaction was followed by three stages of continuous cooling crystallization at temperatures of 50°C, 35°C, and 20°C, with a residence time of 120 min at each stage. The obtained crystals were filtered and dried, with a single-pass yield of 68.6%. The particle size distribution (mass fraction) was as follows: <0.100 mm: 1.03%, 0.100-0.200 mm: 3.55%, 0.200-0.350 mm: 18.13%, 0.350-0.500 mm: 38.52%, 0.500-0.650 mm: 34.45%, 0.650-1.000 mm: 4.21%, >1.00 mm: 0.11%.

Claims

1. A method for producing succinic acid by hydrolysis of succinic anhydride, comprising: Liquid succinic anhydride is sprayed to form droplets, which then react with water vapor to produce succinic acid. The succinic acid is then dried to obtain the succinic acid product.

2. The method according to claim 1, characterized in that, The temperature of the liquid succinic anhydride is not less than 120°C.

3. The method according to claim 2, characterized in that, The temperature of the liquid succinic anhydride is not less than 130°C.

4. The method according to claim 1, characterized in that, The droplet size of succinic anhydride is 0.01-1.0 mm through spray treatment.

5. The method according to claim 4, characterized in that, The droplet size of succinic anhydride is 0.1-0.5 mm through spray treatment.

6. The method according to claim 1, characterized in that, The temperature of the water vapor is 100-180℃.

7. The method according to claim 6, characterized in that, The temperature of the water vapor is 120-150℃.

8. The method according to claim 1, characterized in that, The pressure of the water vapor is 0.1-1.0 MPa.

9. The method according to claim 1, characterized in that, The mass ratio of water vapor to succinic anhydride is not less than 0.

18.

10. The method according to claim 1, characterized in that, The mass ratio of water vapor to succinic anhydride is 0.8-1:

1.

11. The method according to claim 1, characterized in that, Succinic anhydride droplets mix with water vapor in an opposing contact manner.

12. The method according to claim 1, characterized in that, The contact time between succinic anhydride droplets and water vapor should not be less than 10 minutes.

13. An apparatus for producing succinic acid by hydrolysis of succinic anhydride, characterized in that, It includes a tank, with a succinic anhydride feed line at the top of the tank, connected to a spray device at the top of the tank, a steam feed line at the bottom of the tank, connected to a gas distributor at the bottom of the tank, a tail gas discharge line at the top of the tank, and a product storage space at the bottom of the tank where the succinic acid produced after the reaction falls and is collected through the succinic acid discharge line.

Images