Gas-liquid mixing reactor, production system and application of gas-liquid mixing reactor in acetic acid synthesis

Abstract

The invention belongs to the field of chemical synthesis, and discloses a gas-liquid mixing reactor, a production system and application of the gas-liquid mixing reactor in acetic acid synthesis. The gas-liquid mixing reactor comprises a shell, a gas feeding pipe, a liquid feeding pipe, a gas distributor, a liquid distributor, a guide plate, a gas-liquid separator, a gas outlet and a liquid outlet. The production system provided by the invention comprises the gas-liquid mixing reactor provided by the invention. The gas-liquid mixing reactor and the production system can be used for acetic acid synthesis. The gas-liquid mixing reactor is free of mechanical stirring, good in gas-liquid mixing effect, beneficial to improvement of reaction efficiency and conversion rate and suitable for acetic acid synthesis.

Description

Technical Field

[0001] The invention belongs to the field of chemical synthesis, and in particular relates to a gas-liquid mixing reactor, a production system and application thereof in acetic acid synthesis. Background Art

[0002] The commonly used acetic acid production technology is to make methanol and carbon monoxide react in a reactor for gas-liquid mixing. Existing reactors often use mechanical stirring to achieve gas-liquid mixing, but mechanical stirring has poor sealing, is prone to material leakage, and has poor reliability, which affects industrial continuous production.

[0003] In order to overcome the problems of mechanical stirring gas-liquid reactor, some studies have designed jet gas-liquid reactor. For example, CN104028178A discloses a method for strengthening the mixing effect of hydraulic reactor, wherein the hydraulic reactor includes a gas outlet, a baffle, a liquid injection device, a gas inlet, a gas distributor, a liquid outlet and a liquid inlet, wherein the gas inlet is located at the lower part of the reactor side, the gas outlet is located at the top of the reactor, the liquid inlet is located at the bottom of the reactor, the liquid outlet is symmetrically arranged on both sides of the lower end cap of the reactor, and the gas distributor is located between the baffle and the liquid injection device. The method realizes the mixing of raw materials by combining the gas phase distribution feeding and the liquid phase injection feeding and the coordination of the baffle, but the baffle in the method will merge the reduced bubbles into large bubbles, making the gas-liquid contact worse.

[0004] Therefore, in view of the problem that the gas-liquid mixing effect is not ideal in the prior art, the art urgently needs a gas-liquid mixing reactor and production system that does not require mechanical stirring, has good gas-liquid mixing effect, is conducive to improving reaction efficiency and conversion rate, and is suitable for acetic acid synthesis. Summary of the invention

[0005] The present invention aims to provide a gas-liquid mixing reactor without mechanical stirring, a production system and application thereof, which is suitable for synthesizing acetic acid from methanol and carbon monoxide.

[0006] A first aspect of the present invention provides a gas-liquid mixing reactor, comprising:

[0007] case,

[0008] A gas feed pipe and a liquid feed pipe passing through the lower part of the shell,

[0009] a gas distributor located at the lower part of the gas-liquid mixing reactor and connected to the gas feed pipe,

[0010] a liquid injection pipe or a liquid distributor located at the lower part of the gas-liquid mixing reactor and connected to the liquid feed pipe,

[0011] A guide plate is arranged on the inner wall of the shell,

[0012] An air outlet is arranged at the top of the housing,

[0013] a gas-liquid separator located at the upper part of the gas-liquid mixing reactor and close to the gas outlet, a liquid outlet arranged in the middle part of the shell, and

[0014] A circulating liquid feed port disposed at the top of the shell;

[0015] Wherein, the gas-liquid mixing reactor does not include a mechanical stirring device.

[0016] The gas-liquid mixing reactor of the present invention eliminates mechanical stirring. Raw materials CO and methanol enter the reactor at a certain angle under the action of a gas distributor, a liquid injection pipe or a liquid distributor and a guide plate, and the liquid in the reactor is driven to rotate. During the rotation process, a gas-liquid reaction is continuously carried out, which is beneficial to the full mixing of gas and liquid, thereby improving the reaction efficiency and conversion rate.

[0017] In the present invention, the liquid injection pipe or the liquid distributor may be located above or below the gas distributor.

[0018] In one or more embodiments, the gas-liquid mixing reactor further comprises a liquid stabilizing plate located at an upper portion of the gas-liquid mixing reactor and disposed below the gas-liquid separator.

[0019] In one or more embodiments, the length and width of the steady liquid plate are 200 mm×150 mm.

[0020] In one or more embodiments, the gas-liquid mixing reactor comprises 3-10 groups of stabilizing plates, and one group of stabilizing plates consists of three stabilizing plates.

[0021] The present invention arranges a liquid stabilizing plate on the upper part of the gas-liquid mixing reactor, which can stabilize the liquid level, increase the effective liquid level height, increase the reaction volume, and improve the reaction yield, so as to improve the output of large-scale industrial application scenarios. Using three liquid stabilizing plates to form a liquid stabilizing plate assembly and arranging 3-10 groups of liquid stabilizing plate assemblies is conducive to better stabilizing the liquid level.

[0022] In one or more embodiments, the gas distributor is an annular tubular gas distributor.

[0023] In one or more embodiments, the gas distributor is provided with gas injection holes.

[0024] In one or more embodiments, the gas jet orifice is a conical gas jet orifice.

[0025] In one or more embodiments, the top hole diameter and the bottom hole diameter of the conical gas spray hole are 0.2 mm to 20 mm.

[0026] In one or more embodiments, the top hole diameter of the conical gas injection hole is smaller than the bottom hole diameter.

[0027] In one or more embodiments, the top hole diameter of the conical gas spray hole is 1 mm to 3.5 mm, and the bottom hole diameter of the conical gas spray hole is 3 mm to 5.5 mm.

[0028] In one or more embodiments, the angle between the liquid spraying pipe and the horizontal plane is 40° to 45°.

[0030] In one or more embodiments, the liquid distributor comprises an annular pipe and a liquid nozzle connected to the annular pipe, and the angle between the liquid nozzle and the horizontal plane is 40° to 45°.

[0031] In one or more embodiments, the liquid spraying tube is a tapered liquid spraying tube, and the diameter of the end of the tapered liquid spraying tube is 5% to 50% of the tube diameter.

[0032] In one or more embodiments, the liquid nozzle is a conical liquid nozzle, and the end diameter of the conical liquid nozzle is 5% to 50% of the pipe diameter.

[0033] In one or more embodiments, the number of the liquid nozzles is 4 to 10 per square meter of the cross section of the gas-liquid mixing reactor.

[0034] The present invention is designed with respect to the gas distributor and the liquid injection pipe or the liquid distributor to ensure that the raw materials CO and methanol enter the reactor at a certain angle under the action of the gas distributor, the liquid injection pipe or the liquid distributor and the guide plate, so as to promote the rotation of the liquid in the reactor, which is beneficial to the full mixing of gas and liquid.

[0035] In one or more embodiments, the guide plate is a fin-type arc-shaped guide plate.

[0036] In one or more embodiments, the guide plate has a width of 100 mm to 500 mm and a length of 200 mm to 1000 mm.

[0037] In one or more embodiments, there are mesh holes on the guide plate.

[0038] In one or more embodiments, the number of the guide plates is 5-50.

[0039] The present invention uses a fin-type guide plate with sieve holes. The sieve holes can balance the pressure on both sides of the guide plate and simultaneously break up large bubbles in the rotating reaction liquid. The liquid is guided, which is beneficial to increase the gas-liquid contact area, and improve the reaction efficiency and conversion rate.

[0040] Another aspect of the present invention provides a method for synthesizing acetic acid using the gas-liquid mixing reactor described in any embodiment of the present invention, the method comprising the steps of:

[0041] (1) passing the mixed liquid into the liquid feed pipe and then into the gas-liquid mixing reactor via the liquid injection pipe or the liquid distributor, passing CO gas into the gas feed pipe and then into the gas-liquid mixing reactor via the gas distributor, so that the mixed liquid and CO react in the gas-liquid mixing reactor to obtain a reaction liquid containing acetic acid;

[0042] (2) refining the reaction solution into acetic acid;

[0043] The mixed liquid comprises mother liquor, methanol, dilute acid and methyl iodide, and the mother liquor is a catalyst-containing liquid obtained by flash evaporation of the reaction liquid.

[0044] In one or more embodiments, the method includes: refining a portion of the reaction liquid, and returning another portion of the reaction liquid to the gas-liquid mixing reactor through the circulating liquid feed port after cooling; preferably, the mass ratio of the refined reaction liquid to the reaction liquid returned to the gas-liquid mixing reactor is 1:(1~5), preferably 1:(1~3).

[0045] In one or more embodiments, the reaction temperature is 180°C to 250°C, preferably 190°C to 230°C.

[0046] In one or more embodiments, the reaction pressure is 2.6 MPaG to 3.5 MPaG, preferably 2.7 MPaG to 3.3 MPaG.

[0047] In one or more embodiments, the flow rate of the CO gas entering the gas-liquid mixing reactor is 30 m / s to 50 m / s.

[0048] In one or more embodiments, the flow rate of the mixed liquid entering the gas-liquid mixing reactor is 2 m / s to 6 m / s.

[0049] In one or more embodiments, the maximum temperature difference within the gas-liquid mixing reactor is ≤ 5°C.

[0050] By using the gas-liquid mixing reactor of the present invention to prepare acetic acid and adopting the reaction conditions, the maximum temperature difference in the reactor can be controlled below 5° C., making the reaction process more stable and improving the purity of the product and the reaction rate.

[0051] Another aspect of the present invention provides a production system that can be used for acetic acid synthesis, comprising:

[0052] The gas-liquid mixing reactor described in any embodiment of the present invention,

[0053] a flash evaporator connected to the liquid outlet of the gas-liquid mixing reactor,

[0054] a light component removal tower connected to the gas outlet of the flash evaporator,

[0055] A drying tower connected to the liquid outlet of the light component removal tower,

[0056] a heavy component removal tower connected to the liquid outlet of the drying tower,

[0057] a first pipeline connecting the liquid outlet of the gas-liquid mixing reactor and the circulating liquid feed port of the gas-liquid mixing reactor, and

[0058] A second pipeline is connected between the liquid outlet of the flash evaporator and the liquid feed pipe of the gas-liquid mixing reactor.

[0059] In one or more embodiments, the light component removal tower and the drying tower are combined into a light component removal-drying combined tower; in this case, the production system that can be used for acetic acid synthesis includes:

[0060] The gas-liquid mixing reactor described in any embodiment of the present invention,

[0061] a flash evaporator connected to the liquid outlet of the gas-liquid mixing reactor,

[0062] A light component removal-drying combined tower connected to the gas outlet of the flash evaporator,

[0063] a heavy component removal tower connected to the liquid outlet of the light component removal-drying combined tower,

[0064] a first pipeline connecting the liquid outlet of the gas-liquid mixing reactor and the circulating liquid feed port of the gas-liquid mixing reactor, and

[0065] A second pipeline is connected between the liquid outlet of the flash evaporator and the liquid feed pipe of the gas-liquid mixing reactor.

[0066] The acetic acid synthesis system adopted by the present invention has a simple structure. Due to the adoption of the gas-liquid mixing reactor, the conversion rate of the product is improved, the subsequent treatment process is simplified, the production cost is reduced, and the system is suitable for industrial application.

[0067] In one or more embodiments, the production system further comprises: a catalyst trap disposed between the flash evaporator and the light component removal tower.

[0068] In one or more embodiments, the production system further comprises: a catalyst trap disposed between the flash evaporator and the light component removal-drying combined tower.

[0069] In one or more embodiments, the production system further comprises: a heat exchanger disposed on the first pipeline.

[0070] In the present invention, the role of the heat exchanger is as follows: the reaction generates heat, the reaction system will heat up, and a stream of reaction liquid is drawn from the reactor and circulated to the heat exchanger to remove the reaction heat; the reaction liquid after cooling returns to the reactor from the circulating liquid feed port at the top of the reactor, and can also drive the liquid in the reactor to rotate, thereby improving the reaction efficiency and conversion rate. The catalyst trap recovers the catalyst. On the one hand, the recovered catalyst is processed and reused, reducing the catalyst cost; on the other hand, the catalyst is recovered first, which simplifies the process of subsequent product processing and brings less burden to the equipment.

[0071] Another aspect of the present invention provides a method for synthesizing acetic acid using the production system described in any embodiment of the present invention, the method comprising using the gas-liquid mixing reactor to prepare a reaction liquid containing acetic acid, and then using the flash evaporator, the catalyst trap, the light component removal tower and the heavy component removal tower to refine the reaction liquid into acetic acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0072] Figure 1 is a schematic diagram of a gas-liquid mixing reactor in some embodiments of the present invention.

[0073] Figure 2 is a schematic diagram of a gas-liquid mixing reactor in some embodiments of the present invention.

[0074] Figure 3 Schematic diagram of a liquid stabilizing plate assembly in some embodiments of the present invention.

[0075] Figure 4 Schematic diagram of gas nozzles on a gas distributor in some embodiments of the present invention.

[0076] Figure 5 is a schematic diagram of a liquid distributor in some embodiments of the present invention.

[0077] Figure 6 is a schematic diagram of an acetic acid production system according to some embodiments of the present invention.

[0078] Figure 7 is a schematic diagram of an acetic acid production system according to some embodiments of the present invention.

[0079] The following are the descriptions of the reference numerals:

[0080] 1 is a gas feed pipe, 2 is a liquid feed pipe, 3 is a guide plate, 4 is a circulating liquid feed port, 5 is a gas-liquid separator, 6 is a liquid outlet, 7 is a gas outlet, 8 is a gas distributor, 9 is a liquid distributor, 10 is a steady liquid plate, a, b, c, d, e, f are the size and spacing parameters of the steady liquid plate assembly, a1 and b1 are the top aperture and bottom aperture of the spray hole on the gas distributor, a2 and b2 are the end diameter and tube diameter of the conical liquid nozzle on the liquid distributor, α is the angle between the conical liquid nozzle and the horizontal plane, 11 is a gas-liquid mixing reactor, 12 is a flash evaporator, 13 is a light component removal-drying combined tower, 14 is a heavy component removal tower, 15 is a heat exchanger, 16 is a catalyst collector, 17 is a light component removal tower, and 18 is a drying tower. DETAILED DESCRIPTION

[0081] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in this document. Unless otherwise specified, all technical and scientific terms used in this document have the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definitions in this specification shall prevail.

[0082] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0083] Herein, “comprising”, “including”, “containing” and similar terms encompass the meanings of “consisting essentially of” and “consisting of”. For example, when “A comprises B and C” is disclosed herein, “A consists essentially of B and C” and “A consists of B and C” should be deemed to be disclosed herein.

[0084] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible sub-ranges and individual values ​​within the range (including integers and fractions).

[0085] In this document, unless otherwise specified, percentage refers to mass percentage and ratio refers to mass ratio.

[0086] Herein, the sum of the percentages of the various components of the composition is 100%.

[0087] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, modifications and equivalents of the methods and materials described in the present invention are all within the scope of the present invention.

[0088] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0089] In some embodiments, such as Figure 1 As shown, the gas-liquid mixing reactor that can be used for methanol carbonylation synthesis of acetic acid of the present invention comprises: a shell, a gas feed pipe 1, a gas distributor 8, a liquid feed pipe 2, a liquid distributor 9, a gas outlet 7, a liquid outlet 6, a gas-liquid separator 5, a guide plate 3 and a circulating liquid feed port 4.

[0090] In the present invention, what is passed into the liquid feed pipe is a mixed solution of mother liquor, methanol, diluted acid and methyl iodide. In the mixed solution, the mass fractions of mother liquor, methanol, diluted acid and methyl iodide can be 30% to 80%, 5% to 30%, 5% to 30%, and 5% to 30%, respectively. The mother liquor contains acetic acid, water, lithium salt, rhodium complex and iodine compound. In the mother liquor, the mass fractions of acetic acid, water, lithium salt (in terms of lithium), rhodium complex (in terms of rhodium) and iodine compound (in terms of iodine) can be 70% to 90%, 3% to 10%, 2000ppm to 20000ppm, 300ppm to 3000ppm, and 5% to 35%, respectively. Diluted acid can contain acetic acid and water, and optionally can also contain methyl iodide and methyl acetate. In the diluted acid, the mass fractions of acetic acid, water, methyl iodide and methyl acetate can be 30% to 60%, 30% to 70%, 0% to 15% and 0% to 5%, respectively. In the present invention, the lithium salt can be one or both selected from lithium iodide and lithium acetate. In the present invention, the rhodium complex can be one or more selected from diiododicarbonyl rhodium, triiododicarbonyl rhodium, tetraiododicarbonyl rhodium, pentaiodocarbonyl rhodium and rhodium acetate. In the present invention, the iodine compound can be one or more selected from methyl iodide, hydrogen iodide and ethyl iodide.

[0091] The gas-liquid separator suitable for the present invention may be a defoaming device.

[0092] Guide plates are arranged at intervals inside the shell.

[0093] The gas-liquid mixing reactor of the present invention preferably includes a liquid stabilizing plate. Since the rotating liquid in the reactor forms a vortex at the top liquid level, the liquid level is low in the middle and high around, which reduces the actual volume of the reaction liquid or causes a false liquid level, thereby reducing the processing capacity. With the addition of the liquid stabilizing plate, the liquid level at the top of the reactor is more stable, increasing the effective reaction volume and the processing capacity.

[0094] In some preferred embodiments, Figure 2As shown, a liquid stabilizing plate 10 can be arranged at the lower end of the gas-liquid separator 5 at the upper part of the gas-liquid mixing reactor. The length and width of the liquid stabilizing plate can be 200 mm×150 mm. According to the diameter of the gas-liquid mixing reactor, 3-10 groups of liquid stabilizing plates can be designed, and each group of liquid stabilizing plates consists of 3 liquid stabilizing plates.

[0095] In some preferred embodiments, Figure 3 As shown, three stabilizing plates are combined into a stabilizing plate assembly, one end of the stabilizing plate is welded to the inner wall of the shell, and the other end extends to the center of the gas-liquid mixing reactor. The three stabilizing plates can be as shown in FIG. Figure 3 The arrangement is shown in a triangle, or it can be arranged in a straight line with an upward tilt. Figure 3 Taking the triangular arrangement in as an example, the size and spacing parameters of the stabilizing plate assembly are preferably set to: a is 300mm~900mm, b is 150mm~450mm, c is 300mm~900mm, d is 150mm~450mm, e is 50mm~300mm, and f is 50mm~500mm.

[0096] The gas distributor is provided with a plurality of gas injection holes. In some embodiments, the gas distributor comprises an annular tube, and a conical gas injection hole is provided on the annular tube. Figure 4 As shown, the top aperture of the conical gas nozzle is a1, and the bottom aperture is b1. The top aperture a1 and the bottom aperture b1 of the conical gas nozzle can be 0.2mm to 20mm, and usually b1 is larger than a1. In some embodiments, a1 is Ф1mm, b1 is Ф3mm; or a1 is Ф1.5mm, b1 is Ф3.5mm; or a1 is Ф2mm, b1 is Ф4mm; or a1 is Ф2.5mm, b1 is Ф4.5mm; or a1 is Ф3mm, b1 is Ф5mm; or a1 is Ф3.5mm, b1 is Ф5.5mm. When the gas passes through the conical hole, the flow rate increases, and the flow rate through the hole is usually 30m / s to 50m / s. After the gas is ejected from the hole, it enters the liquid as a small-diameter bubble, which is conducive to the diffusion of the gas into the liquid and accelerates the carbonylation reaction. In the present invention, the gas distributor and the liquid distributor are used in combination.

[0097] In some embodiments, the liquid distributor comprises an annular tube and a liquid nozzle in communication with the annular tube. Figure 5 As shown, the liquid nozzle is a conical nozzle, and the angle between the liquid nozzle and the horizontal plane is α, and α is preferably 40° to 45°. The diameter b2 of the end of the conical nozzle is preferably 5% to 50% of the tube diameter a2. The flow rate of the liquid increases to 2m / s to 6m / s after passing through the liquid nozzle. The liquid is sprayed into the gas-liquid mixing reactor after passing through the liquid distributor. Under the action of the spray angle, the sprayed mixed liquid drives the liquid in the gas-liquid mixing reactor to rotate.

[0098] The guide plate can be a fin-type curved plate with a width of 100-500 mm and a length of 200-1000 mm. The guide plate has a sieve hole, which can balance the pressure on both sides of the guide plate and break up large bubbles in the rotating reaction liquid to achieve a better mixed gas-liquid phase. The present invention eliminates the traditional mechanical stirring device, so there is no leakage problem.

[0099] The gas-liquid separator can be a defoaming device, such as a wire mesh defoamer, a high-efficiency blade defoamer, a filter screen, etc. The material of the gas-liquid separator can be zirconium wire, glass fiber, ceramic fiber, PTFE mesh. The function of the gas-liquid separator is to reduce the entrainment of the reaction liquid by the reaction tail gas to the subsequent process.

[0100] The system for producing acetic acid by carbonylation of methanol comprises the gas-liquid mixing reactor, flash evaporator, light component removal tower and heavy component removal tower.

[0101] The raw material CO enters the lower part of the gas-liquid mixing reactor through the gas feed pipe and the gas distributor, and the mixed liquid of the mother liquor, dilute acid, methyl iodide, methanol, and rich liquid methanol (rich in methyl iodide) after tail gas absorption enters the lower part of the gas-liquid mixing reactor through the liquid feed pipe and the liquid distributor. The gas distributor and the liquid distributor are evenly arranged. Under the driving action of the liquid, CO rotates and rises in the reactor, and the carbonylation reaction begins.

[0102] The reaction liquid after the reaction is collected from the liquid outlet. In a preferred embodiment, a part of the reaction liquid is circulated outside the reactor to remove the reaction heat, and the other part of the reaction liquid enters the flash evaporator for flash evaporation. The mass ratio of the refined reaction liquid to the reaction liquid returned to the gas-liquid mixing reactor is preferably 1: (1 to 5), more preferably 1: (1 to 3).

[0103] In the flash evaporator, acetic acid and light components are vaporized and enter the light component removal tower. A catalyst trap is preferably arranged between the flash evaporator and the light component removal tower. The catalyst trap can capture the catalyst and return it to the bottom of the flash evaporator. The liquid phase in the flash evaporator, i.e., the mother liquor, returns to the gas-liquid mixing reactor to continue to participate in the reaction. The gas phase of the flash evaporator or the catalyst trap enters the light component removal tower to remove light component impurities such as water, methyl acetate, methyl iodide, and methyl acetate. The crude acetic acid is extracted from the kettle of the light component removal tower and enters the heavy component removal tower to further remove propionic acid and salts. Qualified acetic acid is extracted from the top of the heavy component removal tower or the side line of the top of the tower.

[0104] In a preferred embodiment, a heat exchanger can also be provided between the gas-liquid mixing reactor and the flash evaporator. The working process of the heat exchanger: the reaction generates heat, and the reaction temperature rises. A stream of reaction liquid is drawn from the upper part of the reactor and circulated to the heat exchanger to remove the reaction heat; the reaction liquid after cooling returns to the reactor from the circulating liquid feed port at the top of the reactor, which has the function of removing heat and stirring the liquid; the returned reaction liquid also has a certain direction of speed, which can drive the liquid in the reactor to rotate.

[0105] In a preferred embodiment, a drying tower is provided between the light component removal tower and the heavy component removal tower. The main function of the light component removal tower is to remove methyl iodide, methyl acetate and moisture, but water and methyl iodide are difficult to be completely removed, so a drying tower is preferably provided to further remove moisture and methyl iodide. The light component removal tower can be combined with the drying tower to form a light component removal-drying combined tower, so this goal can be achieved using only the light component removal-drying combined tower.

[0106] In some embodiments, such as Figure 6 As shown, the production system for acetic acid synthesis of the present invention includes: a gas-liquid mixing reactor 11, a flash evaporator 12 connected to the liquid outlet of the gas-liquid mixing reactor 11, a catalyst trap 16 connected to the gas outlet of the flash evaporator 12, a light component removal-drying combined tower 13 connected to the catalyst trap 16, a heavy component removal tower 14 connected to the liquid outlet of the light component removal-drying combined tower 13, a first pipeline connecting the liquid outlet of the gas-liquid mixing reactor 11 and the circulating liquid feed port of the gas-liquid mixing reactor 11, a second pipeline connecting the liquid outlet of the flash evaporator 12 and the liquid feed pipe of the gas-liquid mixing reactor 11, and a heat exchanger 15 arranged on the first pipeline.

[0107] In some embodiments, such as Figure 7 As shown, the production system for acetic acid synthesis of the present invention includes: a gas-liquid mixing reactor 11, a flash evaporator 12 connected to the liquid outlet of the gas-liquid mixing reactor 11, a light component removal tower 17 connected to the gas outlet of the flash evaporator 12, a drying tower 18 connected to the liquid outlet of the light component removal tower 17, a heavy component removal tower 14 connected to the liquid outlet of the drying tower, a first pipeline connecting the liquid outlet of the gas-liquid mixing reactor 11 and the circulating liquid feed port of the gas-liquid mixing reactor 11, a second pipeline connecting the liquid outlet of the flash evaporator 12 and the liquid feed pipe of the gas-liquid mixing reactor 11, and a heat exchanger 15 arranged on the first pipeline.

[0108] The present invention has the following beneficial effects:

[0109] 1. The gas-liquid mixing reactor of the present invention eliminates the mechanical stirring device. The raw materials CO and methanol enter the reactor at a certain angle under the action of the gas distributor, liquid distributor and guide plate, which drives the liquid in the reactor to rotate. During the rotation, the gas-liquid reaction is continuously carried out, which is conducive to the full mixing of the gas and liquid. During the rising process of the gas and liquid, the bubbles are broken on the guide plate with sieve holes, and the liquid is diverted to form finer bubbles, which is conducive to increasing the gas-liquid contact area, improving the reaction efficiency and conversion rate. The present invention effectively reduces the upper and lower temperature difference of the reactor. The upper and lower temperature difference of the ordinary non-stirring reactor is 5-15°C, and the upper and lower temperature difference of the reactor with a mechanical stirring device is generally 3-10°C. The upper and lower temperature difference of the gas-liquid mixing reactor of the present invention can reach within 5°C, making the reaction process more stable and improving the purity of the product and the reaction rate.

[0110] 2. A gas-liquid separator is provided at the gas outlet of the gas-liquid mixing reactor of the present invention to prevent the gas phase from carrying reaction droplets. The liquid contains catalyst rhodium or iridium, and the gas phase carries the droplets, which will cause the catalyst to enter the condenser. After separation in the condenser, the catalyst will continue to return to the reactor, and part of the catalyst will be precipitated in the pipeline. However, if the gas phase carries a large amount of reaction droplets, the separator will not have time to return the catalyst to the reactor, and the catalyst will enter the distillation system, which will cause serious catalyst loss.

[0111] 3. The upper part of the gas-liquid mixing reactor of the present invention is preferably provided with a liquid stabilizing plate to stabilize the liquid level, increase the effective liquid level height, and increase the reaction volume to improve the output in large-scale industrial application scenarios.

[0112] 4. The present invention eliminates the traditional mechanical agitator, reducing the problem of easy leakage of the seal during mechanical stirring that affects the operating cycle. The present invention adopts gas-liquid stirring without mechanical stirring, and the reactor only has static sealing. Under the working pressure of the reaction, the equipment is more stable.

[0113] The present invention will be described below in the form of specific examples. It should be understood that these examples are merely illustrative and are not intended to limit the scope of the present invention. The methods, reagents and materials used in the examples and comparative examples are, unless otherwise stated, conventional methods, reagents and materials in the art. The raw material compounds in the examples and comparative examples can all be purchased through commercial routes.

[0114] Example 1

[0115] This embodiment adopts Figure 2 The gas-liquid mixing reactor and Figure 6The production system shown in the figure synthesizes acetic acid. Among them, the apertures of the conical gas nozzles of the gas distributor are: a1 is Ф1mm, b1 is Ф3mm; the nozzle of the liquid distributor is conical, the nozzle diameter a2 is DN50 (nominal diameter 50mm), the diameter b2 of the end of the conical mouth is 20mm, and the angle α between the conical nozzle and the horizontal plane is 45°; the length and width of the liquid stabilizing plate are 200mm×150mm, and 3 groups of liquid stabilizing plates are used, each group of liquid stabilizing plates consists of three liquid stabilizing plates, as shown in FIG. Figure 3 As shown, three stabilizing plates are combined into a stabilizing plate assembly, one end of the stabilizing plate is welded to the inner wall of the shell, and the other end extends to the center of the gas-liquid mixing reactor, and the three stabilizing plates are arranged in a triangle; 12 guide plates are evenly arranged inside the shell, and the length and width of the guide plates are 600mm×300mm; the flow rate of the mixed liquid sprayed into the reactor is 3m / s; the mixed liquid contains mother liquor, methanol, dilute acid and methyl iodide, and the mass fractions of mother liquor, methanol, dilute acid (40wt% water + 60wt% acetic acid) and methyl iodide are 65%, 10%, 10%, and 15%, respectively; the mother liquor contains acetic acid, water, Lithium salt, rhodium complex and iodine compound, specifically, the lithium salt is lithium iodide, the rhodium complex is diiododicarbonyl rhodium, the iodine compound is hydrogen iodide, the contents of acetic acid, water, lithium iodide (in terms of lithium), diiododicarbonyl rhodium (in terms of rhodium), and hydrogen iodide (in terms of iodine) are 85%, 3%, 8000ppm, 1500ppm, and 10%, respectively; the flow rate of CO gas sprayed into the reactor is 35m / s; the pressure in the reactor is 3.0MPaG; the temperature distribution in the reactor is shown in Table 1; the mass ratio of the part of the reaction liquid entering the flash evaporator and the part entering the reactor as the circulating liquid is 1:2. Three experiments were conducted. The yield of acetic acid is shown in Table 1. The unit consumption of catalyst rhodium is 0.02g / t acetic acid.

[0116] Table 1: Reactor temperature and acetic acid yield of Example 1

[0117]

[0118] Example 2

[0119] This embodiment adopts Figure 2 The gas-liquid mixing reactor shown and Figure 7 The production system shown in the figure synthesizes acetic acid. Among them, the apertures of the conical gas nozzles of the gas distributor are: a1 is Ф2.5mm, b1 is Ф4.5mm; the nozzle of the liquid distributor is conical, the nozzle diameter a2 is DN80 (nominal diameter 80mm), the ratio of the diameter b2 of the end of the cone mouth to the nozzle diameter a2 is 1:3, and the angle α between the conical nozzle and the horizontal plane is 40°; the length and width of the liquid stabilizing plate are 200mm×150mm, and 5 groups of liquid stabilizing plates are used, each group of liquid stabilizing plates consists of three liquid stabilizing plates, such as Figure 3As shown, three stabilizing plates are combined into one stabilizing plate assembly, one end of the stabilizing plate is welded to the inner wall of the shell, and the other end extends to the center of the gas-liquid mixing reactor, and the three stabilizing plates are arranged in a triangle; 20 guide plates are evenly arranged inside the shell, and the length and width of the guide plates are 800mm×400mm; the flow rate of the mixed liquid sprayed into the reactor is 5m / s; the mixed liquid contains mother liquor, methanol, dilute acid and methyl iodide, and the mass fractions of the mother liquor, methanol, dilute acid (35wt% water + 65wt% acetic acid) and methyl iodide are 55%, 15%, 10% and 20% respectively in the mixed liquid; the mother liquor contains acetic acid Acid, water, lithium salt, rhodium complex and iodine compound, specifically, the lithium salt is lithium acetate, the rhodium complex is rhodium acetate, the iodine compound is ethyl iodide, the contents of acetic acid, water, lithium acetate (in terms of lithium), rhodium acetate (in terms of rhodium), and ethyl iodide (in terms of iodine) are 88%, 2%, 10000ppm, 1700ppm, and 8%, respectively; the flow rate of CO gas sprayed into the reactor is 40m / s; the pressure in the reactor is 2.8MPaG; the temperature distribution in the reactor is shown in Table 2; the mass ratio of the part of the reaction liquid entering the flash evaporator and the part entering the reactor as the circulating liquid is 1:2.5. Three experiments were conducted. The yield of acetic acid is shown in Table 2. The unit consumption of catalyst rhodium is 0.03g / t acetic acid.

[0120] Table 2: Reactor temperature and acetic acid yield of Example 2

[0121]

[0122] Example 3

[0123] The difference between Example 3 and Example 1 is that no liquid stabilizing plate is provided in the gas-liquid mixing reactor, and other conditions remain unchanged. The temperature distribution in the reactor and the yield of acetic acid are shown in Table 3. From the experimental results of Tables 1 and 3, it can be seen that in Example 1, the liquid stabilizing plate is provided in the reactor, which can stabilize the liquid level, increase the effective liquid level height, increase the reaction volume, and improve the reaction yield.

[0124] Table 3: Reactor temperature and acetic acid yield of Example 3

[0125]

[0126] Comparative Example 1

[0127] The difference between Comparative Example 1 and Example 1 is that the angle α between the nozzle on the liquid distributor and the horizontal plane is 90°, and other conditions remain unchanged. The temperature distribution in the reactor and the yield of acetic acid are shown in Table 4. In the reactor of Comparative Example 1, the liquid phase is sprayed vertically upward and contacts with the gas phase passing from the top, and the gas-liquid mixing is uneven at the bottom, while in Example 1, the liquid distributor is provided with a nozzle, and the nozzle has an inclination angle of 45°, which has a stirring effect on the bottom liquid, and there is no dead zone at the bottom temperature, the temperature is more uniform, and the efficiency and uniformity of gas-liquid mixing are better, so the reaction yield of Comparative Example 1 is not as good as that of Example 1.

[0128] Table 4: Reactor temperature and acetic acid yield of Comparative Example 1

[0129]

[0130] Comparative Example 2

[0131] The difference between Comparative Example 2 and Example 2 is that the nozzle holes on the gas distributor are holes with the same inner and outer diameters, that is, a1 and b1 are both Φ4mm, and other conditions remain unchanged. The temperature distribution in the reactor and the yield of acetic acid are shown in Table 5. In the reactor of Comparative Example 2, the kinetic energy of the gas phase entering the liquid phase is insufficient, and even the liquid will leak into the gas distributor when the gas velocity is low, while in Example 2, the kinetic energy of the gas entering the liquid under the action of the tapered hole is sufficient, and it is not easy to leak liquid, which is more conducive to the distribution and mixing of the gas, and the temperature is more uniform, so the reaction yield of Comparative Example 2 is not as good as that of Example 2.

[0132] Table 5: Reactor temperature and acetic acid yield of Comparative Example 1

[0133]

Claims

1. A gas-liquid mixing reactor, comprising: case, A gas feed pipe and a liquid feed pipe passing through the lower part of the shell, a gas distributor located at the lower part of the gas-liquid mixing reactor and connected to the gas feed pipe, a liquid injection pipe or a liquid distributor located at the lower part of the gas-liquid mixing reactor and connected to the liquid feed pipe, A guide plate is arranged on the inner wall of the shell, An air outlet is arranged at the top of the housing, A gas-liquid separator located at the upper part of the gas-liquid mixing reactor and close to the gas outlet, a liquid outlet disposed in the middle of the housing, and A circulating liquid feed port disposed at the top of the shell; Wherein, the gas-liquid mixing reactor does not include a mechanical stirring device.

2. The gas-liquid mixing reactor according to claim 1, characterized in that: The gas-liquid mixing reactor further comprises a liquid stabilizing plate located at the upper part of the gas-liquid mixing reactor and arranged below the gas-liquid separator; Preferably, the length and width of the liquid stabilizing plate are 200 mm×150 mm; Preferably, the gas-liquid mixing reactor comprises 3-10 groups of stabilizing plates, and one group of stabilizing plates consists of three stabilizing plates.

3. The gas-liquid mixing reactor according to claim 1, characterized in that: The gas distributor is an annular tubular gas distributor; and / or The gas distributor is provided with gas spray holes; Preferably, the gas spray hole is a conical gas spray hole; Preferably, the top aperture and bottom aperture of the conical gas spray hole are 0.2 mm to 20 mm, and the top aperture of the conical gas spray hole is smaller than the bottom aperture; Preferably, the top aperture of the conical gas spray hole is 1 mm to 3.5 mm, and the bottom aperture of the conical gas spray hole is 3 mm to 5.5 mm.

4. The gas-liquid mixing reactor according to claim 1, characterized in that: The angle between the liquid injection pipe and the horizontal plane is 40° to 45°, or the liquid distributor includes an annular tube and a liquid nozzle connected to the annular tube, and the angle between the liquid nozzle and the horizontal plane is 40° to 45°; Preferably, the liquid injection tube is a conical liquid injection tube, and the diameter of the end of the conical liquid injection tube is 5% to 50% of the tube diameter; Preferably, the liquid nozzle is a conical liquid nozzle, and the diameter of the end of the conical liquid nozzle is 5% to 50% of the pipe diameter; Preferably, the number of the liquid nozzles is 4 to 10 per square meter of the cross section of the gas-liquid mixing reactor.

5. The gas-liquid mixing reactor according to claim 1, characterized in that: The guide plate has one or more of the following features: The guide plate is a fin-type arc-shaped guide plate; The guide plate has a width of 100 mm to 500 mm and a length of 200 mm to 1000 mm; There are sieve holes on the guide plate; The number of the guide plates is 5-50.

6. A method for synthesizing acetic acid using the gas-liquid mixing reactor according to any one of claims 1 to 5, characterized in that: The method comprises the steps of: (1) passing the mixed liquid into the liquid feed pipe and then into the gas-liquid mixing reactor via the liquid injection pipe or the liquid distributor, passing CO gas into the gas feed pipe and then into the gas-liquid mixing reactor via the gas distributor, so that the mixed liquid and CO react in the gas-liquid mixing reactor to obtain a reaction liquid containing acetic acid; (2) refining the reaction solution into acetic acid; The mixed liquid comprises mother liquor, methanol, dilute acid and methyl iodide, and the mother liquor is a catalyst-containing liquid obtained by flash evaporation of the reaction liquid.

7. The method according to claim 6, characterized in that The method has one or more of the following features: The method comprises: refining a part of the reaction liquid, and returning another part of the reaction liquid to the gas-liquid mixing reactor through the circulating liquid feed port after cooling; Preferably, the mass ratio of the reaction liquid to be refined to the reaction liquid returned to the gas-liquid mixing reactor is 1:(1-5), preferably 1:(1-3); The reaction temperature is 180°C to 250°C, preferably 190°C to 230°C; The reaction pressure is 2.6 MPaG to 3.5 MPaG, preferably 2.7 MPaG to 3.3 MPaG; The flow rate of the CO gas entering the gas-liquid mixing reactor is 30m / s to 50m / s; The flow rate of the mixed liquid entering the gas-liquid mixing reactor is 2m / s to 6m / s; The maximum temperature difference in the gas-liquid mixing reactor is ≤5°C.

8. A production system for acetic acid synthesis, comprising: The gas-liquid mixing reactor according to any one of claims 1 to 5, a flash evaporator connected to the liquid outlet of the gas-liquid mixing reactor, a light component removal tower connected to the gas outlet of the flash evaporator, A drying tower connected to the liquid outlet of the light component removal tower, a heavy component removal tower connected to the liquid outlet of the drying tower, a first pipeline connecting the liquid outlet of the gas-liquid mixing reactor and the circulating liquid feed port of the gas-liquid mixing reactor, and A second pipeline connecting the liquid outlet of the flash evaporator and the liquid feed pipe of the gas-liquid mixing reactor; Wherein, the light component removal tower and the drying tower can be combined into a light component removal-drying combined tower.

9. The generation system according to claim 8, characterized in that The production system also includes: A catalyst trap disposed between the flash evaporator and the light component removal tower, and / or A heat exchanger is arranged on the first pipe.

10. A method for synthesizing acetic acid using the production system according to claim 8 or 9, characterized in that: The method comprises using the gas-liquid mixing reactor to prepare a reaction liquid containing acetic acid, and then using the flash evaporator, the catalyst trap, the light component removal tower and the heavy component removal tower to refine the reaction liquid into acetic acid.

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