CN114029006A

CN114029006A - Reaction device and method for preparing adiponitrile

Info

Publication number: CN114029006A
Application number: CN202111506506.6A
Authority: CN
Inventors: 耿海涛; 应国海
Original assignee: Beijing Daosike Mining Equipment Technology Co ltd
Current assignee: Beijing Daosike Mining Equipment Technology Co ltd
Priority date: 2021-12-10
Filing date: 2021-12-10
Publication date: 2022-02-11

Abstract

The invention discloses a reaction device for preparing adiponitrile, which comprises a shell, wherein a circulating device and a discharge hole are arranged on the shell, and a flow guide device and a heat conduction device are arranged in the shell. The flow guide device comprises a flow guide cylinder and a throat pipe; the heat conducting device is connected with a plurality of bayonet tubes; circulating device includes first pan feeding pipe, circulating pipe, second pan feeding pipe, third pan feeding pipe, material injection pipe and circulation force (forcing) pump, first pan feeding pipe, second pan feeding pipe and the circulation force (forcing) pump all sets up on the circulating pipe, the one end of circulating pipe with the material injection pipe is connected, the other end and the casing bottom of circulating pipe are connected, just third pan feeding pipe sets up on the material injection pipe, material injection pipe one end is run through the casing. According to the invention, through the design of the circulation reaction and the heat conduction device, the utilization rates of the raw materials and the catalyst can be effectively improved, and the method has a high popularization value.

Description

Reaction device and method for preparing adiponitrile

Technical Field

The invention relates to the technical field of chemical equipment, in particular to a reaction device and a method for preparing adiponitrile.

Background

Adiponitrile is an important chemical intermediate, particularly for the production of nylon 66, and is currently obtained primarily by double hydrocyanation of 1, 3-butadiene.

The chinese invention patent (publication No. CN1914155) discloses a method for preparing 3-pentenenitrile by hydrocyanating 1, 3-butadiene in the presence of a catalyst and an equipment system thereof, the main innovation of the equipment is that the combination of external circulation and internal jet circulation can strengthen the mass transfer process and keep the concentration of hydrogen cyanide in the reactor low enough, thereby ensuring the whole reaction rate and the stability (service life) of the catalyst. However, the reactor of this patent and the common reactors in the market generally adopt internal circulation formed by spraying fluid from the inside, which cannot completely achieve ideal dispersion degree of material components, and there still exists a problem that the material concentration in a local area is too high, so that the expensive catalyst is deactivated to affect the production efficiency, thereby causing certain loss.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: provides a reaction device for preparing adiponitrile, which solves the problems that the conventional reaction device has low material utilization rate and high catalyst waste rate.

The technical scheme adopted by the invention is as follows: the reaction device for preparing adiponitrile is characterized by comprising a shell, wherein a circulating device and a discharge hole are arranged on the shell, a heat conduction device and a plurality of bayonet tubes connected with the heat conduction device are arranged in the shell, and a third feeding tube is arranged at the top of the shell;

the circulating device comprises a circulating pipe, a first feeding pipe, a second feeding pipe, a material spraying pipe, a third feeding pipe and a circulating pressure pump, wherein the first feeding pipe and the second feeding pipe are communicated with the circulating pipe; the circulating pressurization pump is arranged on the circulating pipe; both ends of the circulating pipe are communicated with the inside of the shell.

According to the invention, through the arrangement of the circulating device, reactants are added through three feeding ports, so that the materials (1, 3-butadiene) added into the first feeding pipe and the materials (catalyst mixture) added into the second feeding pipe are subjected to preliminary reaction, then hydrogen cyanide is added into the third feeding pipe and enters the reaction system, the circulating pressure pump drives the materials to circularly move in the shell and the circulating pipe, so that sufficient reaction is carried out, and the heat conducting device and the bayonet pipe can timely absorb heat generated by the reaction and maintain the reaction temperature. The working principle of the device of the invention is as follows: the external circulation is formed by pumping the 1,3 butadiene and catalyst system from the external circulation system through a first inlet pipe, a second inlet pipe into the device system, and hydrogen cyanide from the bayonet tube loop reactor through a third inlet pipe into the device system. The material inside the shell is injected at high pressure through the material injection pipe, so that local negative pressure is formed in the reactor, and the material in the reaction system is circulated at high speed. And during the reaction, cooling water is introduced into the bayonet tube to remove reaction heat, so that the temperature in the reactor is kept constant to perform the reaction.

Preferably, the heat conducting device includes a heat transfer medium flowing chamber, a heat transfer medium outlet and a heat transfer medium inlet which are arranged at the bottom of the housing, the heat transfer medium outlet and the heat transfer medium inlet are arranged in the heat transfer medium flowing chamber, and the cross section of the heat transfer medium flowing chamber is circular. By adopting the design of the heat transfer medium flowing chamber, the heat transfer medium can be replaced in time after the heat exchange of the bayonet tube, thereby completing the function of heat conduction.

Preferably, the heat transfer medium outlet is disposed above the heat transfer medium inlet. The heat transfer medium outlet is disposed at an upper portion of the heat transfer medium inlet.

Preferably, the third feeding pipe is communicated with the inside of the shell through a material injection pipe, the material injection pipe vertically penetrates through the top of the shell, and the circulating pipe is communicated with the material injection pipe. The circulating pressurization pump is arranged at the middle part of the circulating pipe, so that the driving force of the circulating pipe can be ensured to be in the optimal state, and the problem that the driving force at the other end is insufficient due to the fact that the circulating pipe is arranged at one end is solved.

Preferably, a guide cylinder is arranged in the shell corresponding to the material injection pipe, and the top of the guide cylinder is higher than the bottom of the material injection pipe. The setting of draft tube can prevent that the reactant that jets in the material injection pipe from leading to the bottom of the housing to the lateral wall and the bayonet pipe of casing, causes the extravagant problem of reactant, with draft tube upper portion design in the bottom of material injection pipe, can improve the effect of sheltering from of guide plate, makes the material all flow in the casing bottom through the draft tube.

Preferably, a guide cylinder is arranged in the shell corresponding to the material injection pipe, and a throat is arranged at the upper part of the guide cylinder.

Preferably, a throat is arranged on the guide shell, and the height of the throat is the same as that of the bottom of the injection pipe. The arrangement of the throat pipe can guide the flow more uniformly and prevent the reactants from splashing.

Preferably, the bayonet tubes are arranged around the guide shell. The bayonet tube is arranged around the guide shell, so that the reactant guided by the guide shell can fully obtain the heat conduction effect and absorb heat.

Preferably, the number of the bayonet tubes is 10-500. The heat of the reactant can be maximally absorbed.

Preferably, the first feeding pipe, the second feeding pipe and the circulating pressure pump are arranged at one end of the circulating pipe close to the bottom of the shell.

Another technical problem to be solved by the present invention is to provide a method for preparing adiponitrile by using the reaction device, comprising the following steps:

s1: adding the dehydrated 1, 3-butadiene and catalyst mixture into a circulating pipe from a first feeding pipe and a second feeding pipe respectively, and circulating in a reaction device under the action of a circulating pressure pump;

s2: and (4) introducing hydrogen cyanide into the shell through a third feeding pipe, mixing the hydrogen cyanide with the mixture of the 1,3 butadiene and the catalyst in the circulation of the step S1, circulating, and obtaining adiponitrile at a discharge hole.

Preferably, in step S2, the circulation time is 48 hours, and the temperature of the hydrogen cyanide is 0 ℃.

According to the invention, through the arrangement of the circulating device and the design of the preparation method, materials can be subjected to circulating reaction in the device, and heat generated by the material reaction is continuously absorbed through the matching of the heat conduction device and the bayonet tube, so that the full reaction is carried out for a long time, the utilization rate of raw materials and a catalyst is improved, the occurrence of side reactions is reduced, the stability of the catalyst is ensured, the production efficiency is greatly improved, and the device has a certain popularization significance.

Drawings

FIG. 1 is a schematic front view of the present invention;

the reference numbers in the figures illustrate:

wherein 1, a shell; 2. a draft tube; 3. a throat; 4. a bayonet tube; 5. a material injection pipe; 6. a third feeding pipe; 7. a heat transfer medium flow chamber; 72. a heat transfer medium outlet; 73. a heat transfer medium inlet; 8. a circulating booster pump; 9. a circulation pipe; 10. a first feeding pipe; 11. a second feeding pipe; 12. and (4) a discharge port.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

example 1 provides the structure of a reaction apparatus for producing adiponitrile according to the present invention:

as shown in fig. 1, fig. 1 is a schematic front view of the present invention, the present invention comprises a housing 1, a circulation device and a discharge port 12 are disposed on the housing 1, the circulation device comprises a first material inlet pipe 10, a circulation pipe 9, a second material inlet pipe 11, a material injection pipe 5 and a circulation pressure pump 8, the first material inlet pipe 10 and the circulation pressure pump 8 are disposed on the circulation pipe 9, the material injection pipe 5 penetrates the top of the housing and is communicated with the interior of the housing 1, a third material inlet pipe is disposed on the material injection pipe 5, the first material inlet pipe 10 is used for adding 1,3 butadiene and the second material inlet pipe is used for adding a catalyst and a catalyst mixture, and the third material inlet pipe is used for adding hydrogen cyanide; one end of a circulating pipe 9 is connected and communicated with the bottom of the shell 1, the other end of the circulating pipe is communicated with a material injection pipe 5, specifically, an inlet of the circulating pipe 9 is communicated with the bottom of the shell, an outlet of the circulating pipe 9 is communicated with the top of the shell through the material injection pipe 5, one end of the material injection pipe 5 penetrates through the upper part of the shell 1 so as to form a closed circulation, materials pass through a first feeding pipe 10 and a second feeding pipe 11 and then are operated through a circulation pressure pump 8, after initial operation, hydrogen cyanide raw materials are added into a third feeding pipe 6, and the three materials are mixed and enter the shell 1 from the material injection pipe 4;

a guide shell 2 is arranged in the shell 1 corresponding to the position of the material injection pipe 5, the position of the guide shell 2 is generally slightly higher than the bottom of the material injection pipe 5, a throat pipe 3 is arranged on the guide shell 2, and the height of the throat pipe 3 is the same as that of the bottom of the injection pipe 5; the heat conduction device is arranged at the bottom of the shell 1 and is connected with a plurality of bayonet tubes 4, the heat conduction device specifically comprises a heat transfer medium flowing chamber 7, a heat transfer medium outlet 7-2 and a heat transfer medium inlet 7-1 which are arranged at the bottom of the shell 1, the heat transfer medium outlet 7-2 and the heat transfer medium inlet 7-1 are arranged in the heat transfer medium flowing chamber 7, and the cross section of the heat transfer medium flowing chamber 7 is circular.

In the embodiment, a shell 1 with the volume of 20L is used, the diameter ratio of the shell 1 to the guide shell 5 is 2:1, and the number of the bayonet tubes 3 in the reactor is 10-500; the catalysts used in the hydrocyanation of 1,3 butadiene are all zero-valent nickel Ni (0)/monodentate phosphorus ligand/1- (diphenylphosphino) -2- (ethyldiphenylphosphino) ferrocene in a molar ratio of 1: 2: 4.

The working principle of the device of the invention is as follows: the external circulation is formed by pumping the 1,3 butadiene and catalyst system from the external circulation system through a first inlet pipe 10, a second inlet pipe 11 into the apparatus system and hydrogen cyanide from the bayonet tube loop reactor through a third inlet pipe 6 into the apparatus system. The material inside the shell 1 is injected at high pressure through the material injection pipe 5, so that local negative pressure is formed in the reactor, and the material in the reaction system forms internal high-speed circulation. And during the reaction, the reaction heat is removed by introducing cooling water into the bayonet tube 4, thereby maintaining the temperature in the reactor constant to perform the reaction.

Example 2: example 2 provides a process of the present invention for the preparation of adiponitrile:

s1: respectively metering 20Kg/h and 15Kg/h to convey the dehydrated 1, 3-butadiene and catalyst mixed system into a circulating device from a first feeding pipe 10 and a second feeding pipe 11;

s2: hydrogen Cyanide (HCN) at 0 ℃ was fed into the interior of the housing 1 at 7.5Kg/h through the feed injection pipe 5 and circulated, giving a product stream of 42.5 Kg/h. After 48 hours of operation, a sample was taken at the outlet 12 and after absorption by aqueous sodium hydroxide, the content of hydrogen cyanide in the sample was determined by titration of the sodium hydroxide solution and essentially no residual HCN was detected in the product, indicating that in this example the conversion of hydrogen cyanide was essentially 100%.

Example 3: example 3 provides a process of the present invention for the preparation of adiponitrile:

s1: the mixed system of the dehydrated 1,3 butadiene and the catalyst is conveyed to a reaction device system for circulation by setting the metering at 20Kg/h and 15 Kg/h;

s2: HCN at 0 ℃ was fed to the reactor system at 8.5Kg/h through the feed injection line 4 to give a product stream of 43.5 Kg/h. After 48 hours of operation, a sample was taken at the outlet 12 and after absorption by aqueous sodium hydroxide, the content of hydrogen cyanide in the sample was determined by titration of the sodium hydroxide solution, and likewise essentially no residual HCN was detected in the product, indicating that in this example the conversion of hydrogen cyanide was essentially 100%.

Example 4: example 4 provides a process of the present invention for the preparation of adiponitrile:

s2: HCN at 0 ℃ was fed to the reactor system at 9.0Kg/h through the feed injection line 4 to give a product stream of 44 Kg/h. After 48 hours of operation, a sample was taken at the outlet 12 and after absorption by aqueous sodium hydroxide solution, the content of hydrogen cyanide in the sample was determined by titration of the sodium hydroxide solution, at which point the analysis gave an effluent stream with an HCN content of 60 ppm by weight.

The above examples also fully demonstrate that the present invention can increase the conversion of hydrogen cyanide, increase the utilization of the feedstock, and reduce catalyst waste.

The foregoing has described preferred embodiments of the present invention and is not to be construed as limiting the claims. The present invention is not limited to the above embodiments, and the specific structure thereof is allowed to vary, and various changes made within the scope of the independent claims of the present invention are within the scope of the present invention.

Claims

1. The reaction device for preparing adiponitrile, characterized in that it comprises a shell (1), a circulation device and a discharge port (12) are provided on the shell (1), and the shell (1) is internally provided with There is a heat conduction device (7) and a plurality of bayonet tubes (4) connected with the heat conduction device (7), and a third feeding tube (6) is arranged on the top of the casing;

The circulation device comprises a circulation pipe (9), a first feeding pipe (10), a second feeding pipe (11), a material injection pipe (5), a third feeding pipe (6) and a circulating pressure pump ( 8), the first feeding pipe (10) and the second feeding pipe (11) are all communicated with the circulation pipe (9); the circulation booster pump (8) is arranged in the circulation pipe (9); both ends of the circulation pipe (9) are communicated with the inside of the casing (1).

2. The reaction device for preparing adiponitrile according to claim 1, wherein the heat conducting device comprises a heat transfer medium flow chamber (7), a heat transfer medium outlet (7) arranged at the bottom of the shell (1) -2) and the heat transfer medium inlet (7-1), and the heat transfer medium outlet (7-2) and the heat transfer medium inlet (71) are arranged in the heat transfer medium flow chamber (7), the heat transfer medium The cross section of the medium flow chamber (7) is annular.

3. The reaction device for preparing adiponitrile according to claim 2, characterized in that: the heat transfer medium outlet (7-2) is arranged on the upper part of the heat transfer medium inlet (7-1).

4. The reaction device for preparing adiponitrile according to claim 1, wherein the third feed pipe (6) is communicated with the inside of the shell (1) through a material injection pipe (5). , and the material injection pipe (5) vertically penetrates the top of the casing (1), and the circulation pipe (9) communicates with the material injection pipe (5).

5. The reaction device for preparing adiponitrile according to claim 4, characterized in that: a guide tube (2) is provided at a position corresponding to the material injection pipe (5) in the housing (1), and The top of the guide tube (2) is higher than the bottom of the material injection pipe (5).

6. The reaction device for preparing adiponitrile according to claim 5, characterized in that: a throat pipe (3) is provided on the guide tube (2), and the height of the throat pipe (3) is the same as that of the The bottom of the spray pipe (5) is the same.

7. The reaction device for preparing adiponitrile according to claim 5, characterized in that: the plurality of bayonet tubes (4) are arranged around the guide tube (2), and the number of the bayonet tubes (4) is For 10-500 pieces.

8. The reaction device for preparing adiponitrile according to claim 1, characterized in that: the first feeding pipe (10), the second feeding pipe (11) and the circulating pressure pump ( 8) It is arranged at one end of the circulation pipe (9) close to the bottom of the casing (1).

9. a method utilizing the reaction device for preparing adiponitrile described in any one of claims 1-8 to prepare adiponitrile, is characterized in that, comprises the following steps:

S1: Add the dehydrated 1,3-butadiene and the catalyst mixture to the circulation pipe (9) from the first feeding pipe (10) and the second feeding pipe (11), respectively, and press the circulating pressure pump ( 8) under the action of circulating in the reaction device;

S2: hydrogen cyanide is passed into the inside of the shell (1) through the third feeding pipe (6), mixed with the 1,3 butadiene and the catalyst mixture in the cycle of step S1, and then circulated at the discharge port ( 12) Obtain adiponitrile.

10 . The method for preparing adiponitrile according to claim 9 , wherein, in the step S2 , the cycle time is 48 hours, and the temperature of the hydrogen cyanide introduced is 0° C. 11 .