Reaction system for preparing butyraldehyde through propylene carbonylation

Abstract

The invention relates to the technical field of chemical equipment, in particular to a reaction system for preparing butyraldehyde through propylene carbonylation, the reaction system comprises a carbonyl synthesis reactor, a condenser and a circulating pump, the top of the carbonyl synthesis reactor is connected with a gas inlet pipeline of the condenser, a gas outlet in the top of the condenser is provided with a tail gas exhaust pipeline, and the circulating pump is connected with the tail gas exhaust pipeline. A bottom liquid outlet of the condenser is connected with an upper pipeline of the carbonyl synthesis reactor; the bottom of the carbonyl synthesis reactor is in pipeline connection with a liquid inlet of the circulating pump, a liquid outlet of the circulating pump is in pipeline connection with the upper part of the carbonyl synthesis reactor, and a propylene adding pipeline is also arranged on the pipeline for connecting the liquid outlet of the circulating pump and 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 partial pressure of carbon monoxide.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, and in particular to a reaction system for preparing butyraldehyde by carbonylation of propylene. Background Art

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

[0003] During the propylene hydroformylation reaction, propylene and carbon monoxide react with hydrogen to form butyraldehyde. In the existing synthesis process, the amount of carbon monoxide added is prone to disorder, resulting in a significant increase in the partial pressure of carbon monoxide in the reaction system. The current reaction system for carbonylation of propylene to prepare butanol reduces the carbon monoxide partial pressure too slowly, which seriously reduces production efficiency. Summary of the invention

[0004] The purpose of the present invention is to solve the problems described in the above background technology. A reaction system for preparing butyraldehyde by carbonylation of propylene is proposed. The reaction system can quickly reduce carbon monoxide to a normal level and quickly resume production.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a reaction system for preparing butyraldehyde by carbonylation of propylene, the reaction system comprising a carbonylation reactor, a condenser and a circulation pump,

[0006] The top of the carbonyl synthesis reactor is connected to the liquid inlet pipeline of the condenser, the top gas outlet of the condenser is provided with an exhaust gas pipeline, and the bottom liquid outlet of the condenser is connected to the upper pipeline of the carbonyl synthesis reactor;

[0007] The bottom of the carbonyl synthesis reactor is connected to the liquid inlet pipeline of the circulation pump, the liquid outlet of the circulation pump is connected to the upper pipeline of the carbonyl synthesis reactor, and a propylene addition pipeline is also provided on the pipeline connecting the liquid outlet of the circulation pump and the upper part of the carbonyl synthesis reactor;

[0008] 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.

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

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

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

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

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

[0014] Preferably, the reaction system further comprises a mixed air intake device, wherein the mixed air intake device connects the propylene addition pipeline and the air outlet of the circulation pump to the pipeline connected to the upper part of the carbonyl synthesis reactor,

[0015] The mixed air intake device comprises:

[0016] A shell, wherein one side of the shell is provided with a circulating air inlet, and the bottom of the shell is provided with a propylene air inlet;

[0017] A mixing unit, the mixing unit comprising a motor and a spiral impeller, the motor being fixed to the top of the housing, and the output end of the motor extending into the housing and fixedly connected to the spiral impeller;

[0018] A pressure control unit, the pressure control unit includes a cylinder, an extension tube, a first push plate, a second push plate and an elastic member, the extension tube is connected to the shell, 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 member connects the first push plate and the second push plate, and 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 spoilers are arranged at equal intervals along the circumference of the inner wall of the shell, and the first spoilers are arc-shaped.

[0020] Preferably, a second spoiler is further provided on the top of the inner wall of the shell, and the second spoiler is arc-shaped.

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

[0022] Preferably, two air outlet holes are provided on the wall of the extension pipe, and one of the air outlet holes is connected to the buffer tank.

[0023] The beneficial effects of the present invention are:

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

[0025] 2. The present invention uses a mixed air intake device to mix the circulating gas and propylene in advance before adding them 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 the carbon monoxide partial pressure.

[0026] 3. The present invention uses the first spoiler to disperse and mix the gas driven by the spiral blade in a "horizontal" manner, and passes through the second spoiler to control the impact of propylene and circulating gas intake to disperse and mix in a "vertical" manner, so that the gas mixing is more uniform.

[0027] 4. The present invention pushes the first push plate and the second push plate through the cylinder to provide a buffer space to prevent excessive addition of propylene. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

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

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

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

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

[0033] Illustrations: 1. carbonyl synthesis reactor, 2. condenser, 3. circulation pump, 4. mixing air intake device, 5. exhaust gas pipeline, 6. carbonyl reaction tail gas intake pipeline, 7. synthesis gas intake 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. circulation 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 member, 411. air outlet, 412. first spoiler, 413. second spoiler. DETAILED DESCRIPTION

[0034] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0035] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0036] The present invention is now further described in conjunction with specific examples. The following examples are only for explaining the present invention, but do not constitute a limitation of the present invention. The test samples and test processes used in the following examples include the following (if the specific experimental conditions are not indicated in the examples, they are usually in accordance with conventional conditions or the conditions recommended by the reagent company; the reagents, consumables, etc. used in the following examples, if not otherwise specified, can all be obtained from commercial channels).

[0037] Example 1

[0038] A reaction system for preparing butyraldehyde by carbonylation of propylene, the reaction system comprises a carbonylation reactor 1, a condenser 2 and a circulation pump 3, the top of the carbonylation reactor is connected with an air inlet pipeline of the condenser, the top air outlet of the condenser is provided with an exhaust gas pipeline 5, the bottom liquid outlet of the condenser is connected with an upper pipeline of the carbonylation reactor, the condenser condenses unreacted gas phase and inert gas in the carbonylation reactor and re-transports them back to the carbonylation reactor, and the remaining gas is sent to a flare or a recovery system for treatment through the exhaust gas pipeline.

[0039] The bottom of the carbonyl synthesis reactor is connected to the liquid inlet pipeline of the circulation pump, and the liquid outlet of the circulation pump is connected to the upper pipeline of the carbonyl synthesis reactor. A propylene addition pipeline 9 is also provided on the pipeline connecting the liquid outlet of the circulation pump and the upper part of the carbonyl synthesis reactor. The propylene addition pipeline is used to control the addition of propylene into the carbonyl synthesis reactor to consume excess carbon monoxide, thereby achieving the purpose of reducing the partial pressure.

[0040] The carbonyl synthesis reactor is also provided with a carbonyl reaction tail gas inlet pipeline 6 and a reaction flow pipeline 8. The carbonyl reaction tail gas inlet pipeline is provided with a synthesis gas inlet pipeline 7. It should be noted that the reaction system of the present invention includes a multi-stage carbonyl synthesis reactor for carbonyl synthesis reaction, and 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 upper-stage carbonyl synthesis reactor into the carbonyl synthesis reactor of the present invention. Part of the synthesis gas is transported through the synthesis gas inlet pipeline and mixed with the reaction tail gas of the upper-stage carbonyl synthesis reactor to enter the carbonyl synthesis reactor of the present invention for carbonyl synthesis reaction. In this embodiment, the amount of synthesis gas is controlled to be 18%-25% of the total amount of synthesis gas.

[0041] In this embodiment, the carbonyl synthesis reactor is a microinterface reactor, which is filled with a carbonyl synthesis catalyst, which can catalyze the reaction of propylene and synthesis gas to produce butyraldehyde. The microinterface reactor can "crush" the carbon monoxide gas so that the gas can be fully mixed with the catalyst and propylene; the carbonyl synthesis catalyst is a prior art and will not be described in detail here.

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

[0043] In this embodiment, the reaction system is also provided with a temperature controller, and a circulation loop is provided on the pipelines on both sides of the liquid outlet and liquid inlet of the circulation pump. A second control valve is provided on the circulation loop, and a third control valve is provided at the liquid 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 in the microinterface reactor is 85-115°C.

[0045] Example 2

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

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

[0048] The pressure controller is used to detect the gas pressure. When the pressure is high, the first control valve is opened and the tail 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 preparing butyraldehyde by carbonylation of propylene, the structure of the reaction system is the same as that of Example 2, except that the reaction system is further provided with a mixed air intake device 4, the mixed air intake device connects the propylene addition pipeline and the liquid outlet of the circulation pump with the pipeline connected to the upper part of the carbonyl synthesis reactor,

[0051] The mixed air intake device is composed of a shell 401, a mixing unit, and a pressure control unit, wherein a circulating air inlet 402 is provided on the right side of the shell, and a propylene air inlet 403 is provided at the bottom of the shell.

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

[0053] The pressure control unit is composed of a cylinder 406, an extension tube 407, a first push plate 408, a second push plate 409 and an elastic member 410. The extension tube is connected to the left side of the shell, 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 member connects the first push plate and the second push plate, and two air outlet holes 411 are provided on the wall of the extension tube. The two air outlet holes are arranged on opposite sides of the wall of the extension tube, one of the air outlet holes can be connected to the carbonyl synthesis reactor through a pipeline, and the other air outlet hole is connected to the buffer tank.

[0054] Example 4

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

[0056] Example 5

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

[0058] Working principle and process of the present 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, allowing propylene to react with carbon monoxide, quickly consuming carbon monoxide and reducing the carbon monoxide partial pressure to normal levels.

[0060] In the initial state, only the circulating liquid is introduced. The circulating gas squeezes the second push plate and the elastic member so that the second push plate is on the left side of the gas outlet. The circulating liquid directly enters the carbonyl synthesis reactor. When the carbon monoxide partial pressure increases, the start cylinder pushes the first push plate to the right, driving the elastic member and the second push plate to move to the right. At this time, propylene and the circulating liquid jointly push the second push plate, which requires greater pressure and longer time, which is conducive to the mixing of the liquids.

[0061] The monitoring of carbon monoxide infrared detector has a certain delay, which may lead to excessive addition of propylene. At this time, the circulating liquid containing propylene can be input into the buffer tank for retention.

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

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

[0064] Application Example 1

[0065] Using the reaction system for preparing butyraldehyde by carbonylation of propylene 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 carbonylation of propylene 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] By using the existing reaction system for preparing butyraldehyde by carbonylation of propylene, the carbon monoxide partial pressure is reduced from 0.07 MPa to 0.0085 MPa, and the time consumed is greater than or equal to 2 hours.

[0070] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0071] The above is a detailed introduction to a reaction system for preparing butyraldehyde by carbonylation of propylene provided by the present invention. Specific examples are used herein to illustrate the principle and implementation of the present invention, and the description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A reaction system for preparing butyraldehyde by carbonylation of propylene, characterized in that: The reaction system comprises a carbonyl synthesis reactor (1), a condenser (2) and a circulation pump (3). The top of the carbonyl synthesis reactor is connected to the air inlet pipeline of the condenser, the top air outlet of the condenser is provided with an exhaust gas pipeline (5), and the bottom liquid outlet of the condenser is connected to the upper pipeline of the carbonyl synthesis reactor; The bottom of the carbonyl synthesis reactor is connected to the liquid inlet pipeline of the circulation pump, the liquid outlet of the circulation pump is connected to the upper pipeline of the carbonyl synthesis reactor, and a propylene addition pipeline (9) is also provided on the pipeline connecting the liquid outlet of the circulation pump and 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 reactant flow pipeline (8), and a synthesis gas inlet pipeline (7) is provided on the carbonyl reaction tail gas inlet pipeline.

2. The reaction system according to claim 1, characterized in that: A carbon monoxide infrared detector (10) and a pressure controller (11) are provided on the pipeline connecting the top of the carbonyl synthesis reactor and the air inlet of the condenser, a first control valve (12) is provided on the exhaust gas pipeline, and 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 further comprises a temperature controller (13), which is connected to the carbonyl synthesis reactor; a circulation loop (14) is provided on pipelines on both sides of the liquid outlet and the liquid 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 liquid outlet of the circulation pump; and 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 microinterface reactor, and the carbonyl synthesis catalyst is filled in the microinterface reactor.

5. The reaction system according to claim 1, characterized in that: The amount of liquid circulated by the circulation pump is 1 / 4-1 / 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 in the carbonyl synthesis reactor is 85-115°C.

7. The reaction system according to claim 1, characterized in that: The reaction system further comprises a mixed air intake device (4), wherein the mixed air intake device connects the propylene addition pipeline and the liquid outlet of the circulation pump to the pipeline connected to the upper part of the carbonyl synthesis reactor, The mixed air intake device comprises: A shell (401), wherein a circulating air inlet (402) is provided on one side of the shell, and a propylene air inlet (403) is provided at the bottom of the shell; A mixing unit, the mixing unit comprising a motor (404) and a spiral impeller (405), the motor being fixed to the top of the housing, and the output end of the motor extending into the housing and being fixedly connected to the spiral impeller; A pressure control unit, 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 member (410), the extension tube is connected to the shell, 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 member connects the first push plate and the second push plate, and an air outlet (411) is provided on the wall of the extension tube.

8. The reaction system according to claim 7, characterized in that: The shell is a hollow cylinder, and a plurality of first spoilers (412) are arranged at equal intervals along the circumference of the inner wall of the shell, and the first spoilers are arc-shaped.

9. The reaction system according to claim 7, characterized in that: A second spoiler (413) is also provided on the top of the inner wall of the shell, and the second spoiler is arc-shaped.

10. The reaction system according to claim 7, characterized in that: The extension pipe wall is provided with two air outlet holes, one of which is communicated with the buffer tank.

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