A reaction system for preparing butyraldehyde by carbonylating propylene

Abstract

The present application relates to the technical field of chemical equipment, and particularly relates to a reaction system for preparing butyraldehyde by propylene carbonylation, which comprises a carbonyl synthesis reactor, a condenser and a circulating pump, the top of the carbonyl synthesis reactor is connected with the gas inlet pipeline of the condenser, the top gas outlet of the condenser is provided with a tail gas discharge pipeline, the bottom liquid outlet of the condenser is connected with the upper pipeline of the carbonyl synthesis reactor; the bottom of the carbonyl synthesis reactor is connected with the liquid inlet of the circulating pump, the liquid outlet of the circulating pump is connected with the upper pipeline of the carbonyl synthesis reactor, and the liquid outlet of the circulating pump is also provided with a propylene adding pipeline on the pipeline connected with the upper part of the carbonyl synthesis reactor; the carbonyl synthesis reactor is also provided with a carbonyl reaction tail gas inlet pipeline and a reactant flow pipeline, and the carbonyl reaction tail gas inlet pipeline is provided with a synthesis gas inlet pipeline. The device can quickly reduce the carbon monoxide partial pressure.

Description

Technical Field

[0001] This invention relates to the field of chemical equipment technology, and in particular to a reaction system for the carbonylation of propylene to prepare butyraldehyde. Background Technology

[0002] Carbonyl synthesis is the most important technology for producing butanol and octanol today. In the process of producing butanol and octanol by carbonyl synthesis of propylene, the hydroformylation of propylene yields n-butyraldehyde and isobutyraldehyde, which are then hydrogenated to obtain n-butanol and isobutanol.

[0003] In the hydroformylation of propylene, propylene and carbon monoxide react with hydrogen to produce butyraldehyde. In the existing synthesis process, the amount of carbon monoxide added is easily disordered, which leads to a significant increase in the partial pressure of carbon monoxide in the reaction system. However, the reaction system for the carbonylation of propylene to prepare butanol and octanol reduces the partial pressure of carbon monoxide too slowly, which seriously reduces the production efficiency. Summary of the Invention

[0004] The purpose of this invention is to solve the problems described in the background section. Here, a reaction system for the carbonylation of propylene to prepare butyraldehyde is proposed. This reaction system can rapidly reduce carbon monoxide to normal levels and quickly restore production.

[0005] The technical solution adopted by this invention to solve its technical problem is: a reaction system for the carbonylation of propylene to prepare butyraldehyde, the reaction system comprising a carbonyl synthesis reactor, a condenser, and a circulating pump.

[0006] The top of the carbonyl synthesis reactor is connected to the liquid inlet pipe of the condenser, the top outlet of the condenser is equipped with a tail gas exhaust pipe, and the bottom outlet of the condenser is connected to the upper pipe of the carbonyl synthesis reactor.

[0007] The bottom of the carbonyl synthesis reactor is connected to the inlet pipe of the circulating pump, and the outlet of the circulating pump is connected to the upper pipe of the carbonyl synthesis reactor. A propylene addition pipeline is also provided on the pipe connecting the outlet of the circulating pump to the upper part of the carbonyl synthesis reactor.

[0008] The carbonyl synthesis reactor is also equipped with a carbonyl reaction tail gas inlet pipeline and a reaction stream pipeline, and the carbonyl reaction tail gas inlet pipeline is equipped with a synthesis gas inlet pipeline.

[0009] Preferably, a carbon monoxide infrared detector and a pressure controller are installed on the pipe connecting the top of the carbonyl synthesis reactor to the air inlet of the condenser, and a first control valve is installed on the exhaust gas pipeline, with the pressure controller electrically connected to the first control valve.

[0010] Preferably, the reaction system further includes a temperature controller connected to the carbonyl synthesis reactor. A circulation loop is provided on the pipes on both sides of the outlet and inlet of the circulation pump. A second control valve is provided on the circulation loop, and a third control valve is provided at the outlet of the circulation pump. The temperature controller is electrically connected to the second and third control valves.

[0011] Preferably, the carbonyl synthesis reactor is a micro-interface reactor, and the micro-interface reactor is filled with a carbonyl synthesis catalyst.

[0012] Preferably, the amount of gas circulated by the circulating pump is 1 / 4 to 1 / 5 of the total amount of gas in the carbonyl synthesis reactor.

[0013] Preferably, the temperature inside the carbonyl synthesis reactor is 85-115°C.

[0014] Preferably, the reaction system further includes a mixing and inlet device, which connects the propylene addition pipeline and the outlet of the circulation pump to the pipeline connected to the upper part of the carbonyl synthesis reactor.

[0015] The mixing air intake device includes:

[0016] The housing has a circulating air inlet on one side and a propylene air inlet at the bottom.

[0017] A mixing unit, comprising a motor and a helical impeller, wherein the motor is fixed to the top of the housing, and the output end of the motor extends into the housing and is fixedly connected to the helical impeller;

[0018] A pressure control unit includes a cylinder, an extension tube, a first push plate, a second push plate, and an elastic element. The extension tube is connected to a housing. The cylinder is fixed to one side of the extension tube. The piston of the cylinder extends into the extension tube and is fixedly connected to the first push plate. The elastic element connects the first push plate and the second push plate. An air outlet is provided on the wall of the extension tube.

[0019] Preferably, the shell is a hollow cylinder, and a plurality of first baffles are equally spaced along the inner circumference of the shell, the first baffles being arc-shaped.

[0020] Preferably, the top of the inner wall of the housing is provided with a second baffle, which is arc-shaped.

[0021] Preferably, the second baffle is located above the propylene inlet.

[0022] Preferably, the extension tube has two air outlets on its wall, one of which is connected to the buffer tank.

[0023] The beneficial effects of this invention are:

[0024] 1. This invention can detect the carbon monoxide concentration in the exhaust gas at the top of the carbonyl synthesis reactor using a carbon monoxide infrared detector, thereby monitoring whether the carbon monoxide added to the reaction system is excessive. When the carbon monoxide is excessive, propylene is added to the carbonyl synthesis reactor through the propylene addition pipeline to consume the excess carbon monoxide and achieve the purpose of rapidly reducing the partial pressure of carbon monoxide in the carbonyl synthesis reactor.

[0025] 2. The present invention uses a mixing inlet device to mix the circulating gas with propylene in advance before adding it to the carbonyl synthesis reactor, so that the mixed propylene and circulating gas can fully contact and react with the catalyst in the reactor, further accelerating the reduction rate of carbon monoxide partial pressure.

[0026] 3. The present invention uses a first baffle to disperse and mix the gas driven by the spiral blade in a "horizontal" manner, and a second baffle to disperse and mix the gas in a "vertical" manner while controlling the impact of the propylene and circulating gas intake, so as to make the gas mixture more uniform.

[0027] 4. The present invention uses a cylinder to push the first push plate and the second push plate to provide a buffer space and prevent excessive addition of propylene. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the reaction system for preparing butyraldehyde by propylene carbonylation according to the present invention;

[0030] Figure 2 This is a schematic diagram of the structure of the mixing air intake device of the present invention;

[0031] Figure 3 This is a schematic diagram of the operation of the first spoiler of the present invention;

[0032] Figure 4 This is a schematic diagram of the operation of the second spoiler of the present invention.

[0033] Diagram Description: 1. Carbonyl Synthesis Reactor; 2. Condenser; 3. Circulating Pump; 4. Mixing Inlet Device; 5. Exhaust Gas Pipeline; 6. Carbonyl Reaction Tail Gas Inlet Pipeline; 7. Synthesis Gas Inlet Pipeline; 8. Reaction Flow Pipeline; 9. Propylene Addition Pipeline; 10. Carbon Monoxide Infrared Detector; 11. Pressure Controller; 12. First Control Valve; 13. Temperature Controller; 14. Circulation Loop; 15. Second Control Valve; 16. Third Control Valve; 401. Shell; 402. Circulating Gas Inlet; 403. Propylene Inlet; 404. Motor; 405. Spiral Impeller; 406. Cylinder; 407. Extension Pipe; 408. First Push Plate; 409. Second Push Plate; 410. Elastic Component; 411. Gas Outlet; 412. First Baffle Plate; 413. Second Baffle Plate. Detailed Implementation

[0034] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] The present invention will now be further illustrated with specific examples. The following embodiments are only for explaining the present invention and do not constitute a limitation thereof. The test samples and test procedures used in the following embodiments include the following (if the specific experimental conditions are not specified in the embodiments, they are usually performed according to conventional conditions or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following embodiments can be obtained commercially unless otherwise specified).

[0037] Example 1

[0038] A reaction system for the carbonylation of propylene to prepare butyraldehyde includes a carbonyl synthesis reactor 1, a condenser 2, and a circulating pump 3. The top of the carbonyl synthesis reactor is connected to the inlet pipe of the condenser. The top outlet of the condenser is equipped with a tail gas pipeline 5. The bottom outlet of the condenser is connected to the upper pipe of the carbonyl synthesis reactor. The condenser condenses the unreacted gas phase and inert gas in the carbonyl synthesis reactor and returns them to the carbonyl synthesis reactor. The remaining gas is sent to a flare or a recovery system for treatment through the tail gas pipeline.

[0039] The bottom of the carbonyl synthesis reactor is connected to the inlet pipe of the circulating pump, and the outlet of the circulating pump is connected to the upper pipe of the carbonyl synthesis reactor. A propylene addition line 9 is also installed on the pipe connecting the outlet of the circulating pump to the upper part of the carbonyl synthesis reactor. The addition of propylene to the carbonyl synthesis reactor is controlled by the propylene addition line to consume excess carbon monoxide and reduce the partial pressure.

[0040] The carbonyl synthesis reactor is also equipped with a carbonyl reaction tail gas inlet pipeline 6 and a reaction stream pipeline 8. A syngas inlet pipeline 7 is provided on the carbonyl reaction tail gas inlet pipeline. It should be noted that the reaction system of the present invention includes a multi-stage carbonyl synthesis reactor for carbonyl synthesis reaction. The carbonyl synthesis reactor of the present invention is one of them. The carbonyl reaction tail gas inlet pipeline is used to transport the reaction tail gas of the previous stage carbonyl synthesis reactor into the carbonyl synthesis reactor of the present invention. A portion of the syngas is transported through the syngas inlet pipeline to mix with the reaction tail gas of the previous stage carbonyl synthesis reactor and enter the carbonyl synthesis reactor of the present invention for carbonyl synthesis reaction. In this embodiment, the amount of syngas used is controlled to be 18%-25% of the total amount of syngas used.

[0041] In this embodiment, the carbonyl synthesis reactor is a micro-interface reactor, which is filled with a carbonyl synthesis catalyst capable of catalyzing the reaction of propylene with syngas to produce butyraldehyde. The micro-interface reactor can "break up" carbon monoxide gas, allowing the gas to fully mix with the catalyst and propylene. The aforementioned carbonyl synthesis catalyst is prior art and will not be described in detail here.

[0042] In this embodiment, the amount of liquid circulated by the circulating pump is 1 / 4 to 1 / 5 of the total amount of liquid in the carbonyl synthesis reactor.

[0043] In this embodiment, the reaction system is also equipped with a temperature controller, and a circulation loop is provided on the pipes on both sides of the outlet and inlet of the circulation pump. A second control valve is provided on the circulation loop, and a third control valve is provided at the outlet of the circulation pump. The temperature controller is electrically connected to the second control valve and the third control valve. The above structure is used to control the temperature of the micro-interface reactor.

[0044] In this embodiment, the temperature inside the micro-interface reactor is 85-115°C.

[0045] Example 2

[0046] A reaction system for the carbonylation of propylene to prepare butyraldehyde is provided. The structure of the reaction system is the same as that of the reaction system described in Example 1. The difference is that a carbon monoxide infrared detector 10 and a pressure controller 11 are provided on the pipe connecting the top of the carbonyl synthesis reactor to the gas inlet of the condenser. A first control valve 12 is provided on the exhaust gas pipeline. The pressure controller is electrically connected to the first control valve.

[0047] In this embodiment, a carbon monoxide infrared detector is used to monitor the carbon monoxide concentration in the system. The normal concentration is 0.5-4%. When the carbon monoxide infrared detector monitors a change in concentration, the external flow control system can add propylene through the propylene addition pipeline to keep the carbon monoxide partial pressure at a normal level.

[0048] The pressure controller is used to detect gas pressure. When the pressure is high, the first control valve is opened, and the exhaust gas is discharged through the control valve; when the pressure is low, the control valve is closed.

[0049] Example 3

[0050] like Figure 2 As shown, a reaction system for the carbonylation of propylene to prepare butyraldehyde is described. The structure of this reaction system is the same as that in Example 2, except that the reaction system is further equipped with a mixing and gas inlet device 4. The mixing and gas inlet device is connected to the propylene addition pipeline and the outlet of the circulation pump, which is connected to the pipeline at the top of the carbonyl synthesis reactor.

[0051] The mixing air intake device consists of a housing 401, a mixing unit, and a pressure control unit. The housing has a circulating air inlet 402 on the right side and a propylene air inlet 403 at the bottom.

[0052] The mixing unit consists of a motor 404 and a spiral impeller 405. The motor is fixed to the top of the housing, and the output end of the motor extends into the housing and is fixedly connected to the spiral impeller.

[0053] The pressure control unit consists of a cylinder 406, an extension tube 407, a first push plate 408, a second push plate 409, and an elastic element 410. The extension tube is connected to the left side of the housing. The cylinder is fixed to one side of the extension tube. The piston part of the cylinder extends into the extension tube and is fixedly connected to the first push plate. The elastic element connects the first push plate and the second push plate. The extension tube wall is provided with two air outlets 411. The two air outlets are located on opposite sides of the extension tube wall. One air outlet can be connected to the carbonyl synthesis reactor through a pipeline, and the other air outlet is connected to the buffer tank.

[0054] Example 4

[0055] A reaction system for preparing butyraldehyde by propylene carbonylation, the structure of which is the same as that in Example 3, except that a plurality of first baffles 412 are equally spaced along the inner wall of the shell, and the first baffles are arc-shaped.

[0056] Example 5

[0057] A reaction system for preparing butyraldehyde by carbonylation of propylene, the structure of which is the same as that in Example 4, except that a second baffle plate 413 is provided on the top of the inner wall of the shell. The second baffle plate is arc-shaped and is located above the propylene inlet.

[0058] The working principle and process of this invention:

[0059] The carbon monoxide content in the system is monitored in real time by a carbon monoxide infrared detector. When the carbon monoxide content exceeds the limit, the external flow control system introduces propylene into the carbonyl synthesis reactor through the propylene addition pipeline, so that the propylene reacts with the carbon monoxide, rapidly consumes the carbon monoxide, and reduces the carbon monoxide partial pressure to a normal level.

[0060] With only circulating liquid introduced as the initial state, the circulating gas squeezes the second pusher plate and the elastic element so that the second pusher plate is on the left side of the gas outlet. The circulating liquid directly enters the carbonyl synthesis reactor. When the partial pressure of carbon monoxide increases, the starting cylinder pushes the first pusher plate to the right, which in turn moves the elastic element and the second pusher plate to the right. At this time, propylene and circulating liquid jointly push the second pusher plate, which requires greater pressure and longer time, which is beneficial for liquid mixing.

[0061] The monitoring of carbon monoxide infrared detectors has a certain time delay, which may lead to excessive addition of propylene. In this case, the circulating liquid containing propylene can be transferred to a buffer tank for storage.

[0062] like Figure 3 As shown, when the motor drives the spiral impeller to rotate, the liquid is driven to flow by the spiral impeller. After being blocked by the first baffle, part of the liquid flows back and convects with the remaining gas, so that the liquid is fully mixed.

[0063] like Figure 4 As shown, propylene liquid enters the housing from the right side, and circulating liquid enters the housing from the bottom. The two liquids are mixed by impact. This invention uses a second baffle to deepen the airflow collision between propylene and circulating gas, further enhancing the gas mixing effect.

[0064] Application Example 1

[0065] Using the reaction system for preparing butyraldehyde by propylene carbonylation as described in Example 2, the carbon monoxide partial pressure was reduced from 0.07 MPa to 0.0085 MPa in 30 minutes.

[0066] Application Example 2

[0067] Using the reaction system for preparing butyraldehyde by propylene carbonylation as described in Example 5, the carbon monoxide partial pressure was reduced from 0.07 MPa to 0.0085 MPa in 26 minutes.

[0068] Comparative Example 1

[0069] Using the existing reaction system for the carbonylation of propylene to prepare butyraldehyde, the carbon monoxide partial pressure was reduced from 0.07 MPa to 0.0085 MPa in 2 hours.

[0070] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0071] The reaction system for preparing butyraldehyde by propylene carbonylation provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. A reaction system for the preparation of butyraldehyde by propylene carbonylation, characterized in that: The reaction system includes a carbonyl synthesis reactor (1), a condenser (2), and a circulating pump (3). The top of the carbonyl synthesis reactor is connected to the air inlet pipe of the condenser, the top outlet of the condenser is provided with a tail gas pipeline (5), and the bottom liquid outlet of the condenser is connected to the upper pipe of the carbonyl synthesis reactor. The bottom of the carbonyl synthesis reactor is connected to the inlet pipe of the circulating pump, the outlet of the circulating pump is connected to the upper pipe of the carbonyl synthesis reactor, and a propylene addition pipeline (9) is also provided on the pipe connecting the outlet of the circulating pump to the upper part of the carbonyl synthesis reactor. The carbonyl synthesis reactor is also provided with a carbonyl reaction tail gas inlet pipeline (6) and a reaction flow pipeline (8), and a synthesis gas inlet pipeline (7) is provided on the carbonyl reaction tail gas inlet pipeline. The reaction system further includes a mixing and inlet device (4), which connects the propylene addition pipeline and the outlet of the circulation pump to the upper part of the carbonyl synthesis reactor. The mixing and inlet device includes: The housing (401) has a circulating air inlet (402) on one side and a propylene air inlet (403) at the bottom. The housing is a hollow cylinder. Several first baffles (412) are evenly spaced along the inner wall of the housing. The first baffles are arc-shaped. A second baffle (413) is also provided at the top of the inner wall of the housing. The second baffle is arc-shaped. A mixing unit, comprising a motor (404) and a spiral impeller (405), wherein the motor is fixed to the top of the housing and the output end of the motor extends into the housing and is fixedly connected to the spiral impeller; The pressure control unit includes a cylinder (406), an extension tube (407), a first push plate (408), a second push plate (409), and an elastic element (410). The extension tube is connected to the housing. The cylinder is fixed to one side of the extension tube. The piston of the cylinder extends into the extension tube and is fixedly connected to the first push plate. The elastic element connects the first push plate and the second push plate. The extension tube wall is provided with two air outlets (411). The two air outlets are located on opposite sides of the extension tube wall. One air outlet can be connected to the carbonyl synthesis reactor through a pipeline, and the other air outlet is connected to the buffer tank.

2. The reaction system according to claim 1, characterized in that: A carbon monoxide infrared detector (10) and a pressure controller (11) are installed on the pipe connecting the top of the carbonyl synthesis reactor to the air inlet of the condenser. A first control valve (12) is installed on the exhaust gas pipeline. The pressure controller is electrically connected to the first control valve.

3. The reaction system according to claim 1, characterized in that: The reaction system also includes a temperature controller (13), which is connected to the carbonyl synthesis reactor. A circulation loop (14) is provided on the pipes on both sides of the outlet and inlet of the circulation pump. A second control valve (15) is provided on the circulation loop. A third control valve (16) is provided at the outlet of the circulation pump. The temperature controller is electrically connected to the second control valve and the third control valve.

4. The reaction system according to claim 1, characterized in that: The carbonyl synthesis reactor is a micro-interface reactor, and the micro-interface reactor is filled with a carbonyl synthesis catalyst.

5. The reaction system according to claim 1, characterized in that: The amount of liquid circulated by the circulating pump is 1 / 4 to 1 / 5 of the total amount of liquid in the carbonyl synthesis reactor.

6. The reaction system according to claim 1, characterized in that: The temperature inside the carbonyl synthesis reactor is 85-115℃.

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