A methanol carbonylation reactor and evaporator energy coupling system
By using a multi-stage reactor structure and energy coupling system, the problem of uneven mass and heat transfer was solved, achieving efficient methanol carbonylation reaction and energy recovery, improving reaction conversion rate and product purity, and reducing energy consumption.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING YANCHANG REACTION TECH RES INST CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-07-10
AI Technical Summary
The existing methanol carbonylation reactor has uneven mass and heat transfer, resulting in incomplete reaction, increased byproducts, and the high-temperature steam after the reaction cannot be effectively recovered and utilized, causing energy waste and catalyst entrainment that affects product purity.
The multi-stage reactor structure design, combined with nano-rhodium catalyst coating, jacketed gradient heating device, spiral rising guide plate and ultrasonic enhanced flash evaporation device, achieves efficient mass and heat transfer between gas and liquid phases, and improves energy utilization efficiency through heat cascade utilization.
It significantly improved the conversion rate of methanol carbonylation reaction and the yield of acetic acid, reduced energy consumption and production costs, and improved catalyst recovery efficiency and product purity.
Smart Images
Figure CN224475003U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of chemical production technology, specifically to an energy coupling system of methanol carbonylation reactor and evaporator. Background Technology
[0002] Acetic acid is an important chemical raw material, widely used in pharmaceuticals, pesticides, food and other industries. Methanol carbonylation is the mainstream process for producing acetic acid, which has the advantages of high atom economy and mild reaction conditions. However, there are still many problems in the existing technology. For example, the mass and heat transfer in the traditional reactor is uneven, which leads to incomplete reaction and increased by-products. In addition, the high-temperature steam after the reaction directly enters the flash tank, which leads to ineffective recovery and utilization, resulting in energy waste. Furthermore, the catalyst is easily entrained during the flash evaporation process, which affects the subsequent distillation and product purity.
[0003] In view of the above, this utility model is hereby proposed. Utility Model Content
[0004] The primary objective of this invention is to provide an energy coupling system for a methanol carbonylation reactor and an evaporator, which effectively solves the problems of low reaction efficiency and severe energy waste in the prior art.
[0005] In order to achieve the above-mentioned objectives of this utility model, the following technical solution is adopted:
[0006] An energy coupling system for a methanol carbonylation reactor and an evaporator includes a primary carbonylation reactor and a secondary carbonylation reactor connected in sequence. The primary carbonylation reactor has a stirring impeller at its bottom, the impeller surface of which is coated with a nano-rhodium catalyst coating. A jacketed gradient heating device is installed on the side wall of the primary carbonylation reactor. A methanol inlet and a carbon monoxide inlet are respectively located on both sides of the primary carbonylation reactor. A circulating feed inlet is located above the methanol inlet. A first discharge outlet is located at the top of the primary carbonylation reactor. The secondary carbonylation reactor has a spiral-rising guide plate inside, the surface of which has a micron-level groove structure. A feed inlet and a second heat exchanger feed inlet are respectively located on both sides of the secondary carbonylation reactor. A steam outlet is located at the top of the secondary carbonylation reactor and is connected to the evaporator.
[0007] In this invention, a multi-stage reactor structure design and energy cascade utilization are used to achieve synergistic optimization, realizing a highly efficient conversion process from raw material input to product output. When the raw material is introduced into the carbonylation primary reactor through the carbon monoxide inlet and methanol inlet, a three-dimensional turbulent flow is formed under the stirring blades within the carbonylation primary reactor. Combined with the catalytic effect of the nano-rhodium catalyst coated on the blades and the jacketed gradient heating device on the sidewall of the carbonylation primary reactor, the reaction rate is further accelerated. At this point, methanol and carbon monoxide undergo a preliminary reaction within the carbonylation primary reactor. After the preliminary reaction is completed, the reactants flow out from the first outlet at the top of the carbonylation primary reactor. The acetic acid then flows into the carbonylation secondary reactor through the inlet for deep reaction. Guided by the spiral-ascending baffles inside the reactor, the reactants form a swirling flow, and the micron-level grooves on the baffles increase the gas-liquid contact area, further improving the CO conversion rate. The carbonylation product then flows out from the middle section of the secondary reactor and into the middle section of the evaporator. An ultrasonic-enhanced flash evaporation device inside the evaporator further shortens the flash evaporation time and improves the purity of acetic acid. Simultaneously, a bottom catalyst recovery device recovers the rhodium catalyst. After flash evaporation, liquid and gaseous components are obtained. The liquid component flows out from the bottom outlet of the evaporator and returns to the carbonylation secondary reactor. The reaction continues in the carbonylation secondary reactor, while the gaseous component enters the subsequent distillation and separation section through the evaporator gaseous component outlet located at the top of the evaporator. Simultaneously, the steam generated in the carbonylation secondary reactor passes through the first and second heat exchangers successively through the steam outlet located at the top for heat exchange. After heat exchange, it is passed into a high-pressure separator connected to the second heat exchanger to obtain liquid and gaseous components again. Subsequently, the liquid component returns from the bottom of the high-pressure separator to the carbonylation primary reactor for recycling, while the gaseous component flows out through the gaseous component outlet of the high-pressure separator into the subsequent absorption section. The steam produced from the top of the carbonylation secondary reactor... The steam and gas phase components generated in the evaporator exchange heat through the first heat exchanger. The graphene thermal conductive layer embedded in the first heat exchanger and the nanoporous coating on its outer surface transfer most of the steam heat to the liquid phase components, thus better separating the liquid and gas phase components inside the evaporator and achieving initial utilization of heat. Subsequently, the remaining heat from the steam is absorbed by the second heat exchanger connected to the evaporator. The remaining heat is better absorbed by the phase change energy storage material set in the second heat exchanger and used to preheat the feed. Compared with traditional heat exchange processes, this invention improves the overall thermal efficiency of the entire system through the coupling design between the first and second heat exchangers.
[0008] In this invention, by setting a stirring blade at the bottom of the carbonylation primary reactor, the raw material is formed into a vortex under the shearing action of the blade, which breaks the methanol into microbubbles and disperses them evenly in the carbon monoxide gas phase, thereby improving the gas-liquid mass transfer effect. In addition, the vortex formed by the blade can also effectively strip the surface carbon deposits of the catalyst and maintain the exposure of active sites.
[0009] Preferably, as a further feasible option, the thickness of the nano-rhodium catalyst coating is 50-100 nm, and the specific surface area is 200-300 m² / g.
[0010] This invention also incorporates a 50-100nm thick nano-rhodium catalyst coating on the impeller surface, which creates a three-dimensional porous structure in the impeller, thereby further increasing the methanol diffusion rate. Simultaneously, the large pore channels ensure reduced CO mass transfer resistance, and the nano-rhodium catalyst coating can form specific coordination with the co-catalyst iodomethane, thereby increasing the reaction rate. The service life of this nano-rhodium catalyst coating is more than one year.
[0011] Preferably, as a further feasible option, the spiral angle of the spiral rising guide plate is 25-35°, and the spacing of the spiral rising guide plate is 1 / 5-1 / 3 of the diameter of the carbonylation secondary reactor.
[0012] In this invention, a spiral guide plate is installed in the carbonylation secondary reactor to achieve deep conversion of the raw materials. The spiral angle of the spirally rising guide plate is crucial for this invention, as a spiral angle of 25-35° shortens the residence time of the gas and liquid phases, thus suppressing backmixing. Furthermore, the invention utilizes micron-level grooves on the surface of the guide plate to form a stable liquid film through surface tension, further increasing the gas-liquid contact area compared to a conventional smooth surface. The edges of these micron-level grooves generate periodic eddies that continuously renew the catalyst interface, further improving the local mass transfer system. Additionally, the invention optimizes the spacing of the spirally rising guide plates to reduce the pressure of the coupling system.
[0013] Preferably, as a further feasible option, a first heat exchanger is provided at the bottom of the evaporator, the first heat exchanger is coupled to a second heat exchanger, the first heat exchanger is embedded with a graphene thermal conductive layer, and the outer surface of the first heat exchanger is provided with a nanoporous coating; the second heat exchanger is provided with a phase change energy storage material, and the second heat exchanger is connected to a high-pressure separator.
[0014] In this invention, a three-stage heat utilization network is constructed to achieve high heat utilization. First, the invention improves the latent heat recovery efficiency of steam by setting a first heat exchanger in the evaporator, embedding a graphene thermal conductive layer in the first heat exchanger, and coating the outer surface with a nanoporous coating. At the same time, a second heat exchanger is combined and a phase change energy storage material is loaded in the second heat exchanger to store the fluctuating load of the system. The stored heat is then released in the feed preheating stage, so that the raw material methanol maintains a stable temperature when entering the pre-reaction section, thus achieving high energy utilization.
[0015] Preferably, as a further feasible option, an ultrasonic enhanced flash evaporation device is provided above the first heat exchanger, wherein the ultrasonic enhanced flash evaporation device includes an ultrasonic generator and an atomizing nozzle connected in sequence, and a catalyst recovery device is provided at the bottom of the ultrasonic enhanced flash evaporation device.
[0016] In this invention, the ultrasonic atomizing device is coupled with the flash evaporation process. The standing wave field generated by the ultrasonic generator causes the raw materials to resonate and break down. The atomized particle size is precisely controlled by controlling the sound pressure amplitude, thereby saving energy. Furthermore, the micron-sized droplets can further increase the gas-liquid interface area, thereby improving the flash evaporation efficiency. Combined with the catalyst recovery device set at the bottom, the catalyst can be recovered and reused.
[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0018] (1) The present invention provides an energy coupling system for methanol carbonylation reactor and evaporator. This coupling system enhances the mass and heat transfer process by optimizing the reactor structure and achieves efficient energy recovery, which significantly improves the conversion rate of methanol carbonylation reaction and the yield of acetic acid, while reducing energy consumption and production costs. Attached Figure Description
[0019] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:
[0020] Figure 1 This is a schematic diagram of the energy coupling system between a methanol carbonylation reactor and an evaporator according to the present invention.
[0021] Figure 2 This is a structural diagram of the stirring blade of this utility model.
[0022] The attached diagram lists the components represented by each number as follows:
[0023] In the diagram: 1. Carbon monoxide inlet; 2. Primary carbonylation reactor; 3. Secondary carbonylation reactor; 4. High-pressure separator; 5. Second heat exchanger; 6. First heat exchanger; 7. Evaporator; 8. Gas phase component outlet of high-pressure separator; 9. Gas phase component outlet of evaporator; 10. Methanol inlet; 11. Stirring blade; 12. Jacketed gradient heating device; 13. Spiral ascending guide plate; 14. Catalyst recovery device; 15. Graphene thermal conductive layer; 16. Ultrasonic enhanced flash evaporation device. Detailed Implementation
[0024] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the embodiments described below are only some embodiments of this utility model, not all embodiments, and are only used to illustrate this utility model, and should not be regarded as limiting the scope of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.
[0025] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0027] To more clearly illustrate the technical solution of this utility model, the following description is provided in the form of specific embodiments.
[0028] Example 1
[0029] Please refer to the structure of the energy coupling system between the methanol carbonylation reactor and evaporator of this utility model. Figure 1 As shown, its specific workflow is as follows:
[0030] Please see Figure 1 Methanol and CO are continuously fed into the carbonylation primary reactor 2 through carbon monoxide inlet 1 and methanol inlet 10 at a molar ratio of 1:1.05. The feed rate is controlled at 5.8 L / min for methanol and 4.2 m³ / min for CO. Subsequently, three-dimensional turbulence is formed by stirring blades 11 installed in the carbonylation primary reactor 2. Combined with the catalytic effect of the nano-rhodium catalyst coated on the blades 11 and the jacketed gradient heating device 12 installed on the side wall of the carbonylation primary reactor 2, the reaction rate is further accelerated. The nano-rhodium catalyst coating has a thickness of 50 nm and a specific surface area of 200 m² / g. Under the gradient heating of the jacketed gradient heating device, the upper section temperature is 180℃, the middle section temperature is 170℃, and the lower section temperature is 160℃. At this time, methanol and carbon monoxide undergo a preliminary reaction in the carbonylation primary reactor 2.
[0031] After the initial reaction is completed, the reactants will flow out from the first outlet at the top of the carbonylation primary reactor 2, and then flow into the carbonylation secondary reactor 3 through the inlet for further reaction. Under the guidance of the spiral rising guide plate 13 set inside the carbonylation secondary reactor 3, the reactants form a swirling flow. At this time, the spiral angle of the spiral rising guide plate is 25°, and the spacing between the spiral rising guide plates is 1 / 5 of the diameter of the carbonylation secondary reactor. At the same time, the micron-level groove structure on the surface of the guide plate 13 increases the gas-liquid contact area, further improving the CO conversion rate. The carbonylation product will then flow out from the middle section of the carbonylation secondary reactor 3 and enter the middle section of the evaporator 7. Subsequently, the ultrasonic enhanced flash evaporation device 16 set inside the evaporator 7 further shortens the flash evaporation time and improves the purity of acetic acid. At this time, the droplet particle size generated under ultrasonic enhanced flash evaporation is 10μm. Meanwhile, the bottom catalyst recovery device 14 can also realize the recovery of rhodium catalyst.
[0032] After flash evaporation, liquid and gaseous components are obtained. The liquid component flows out from the outlet at the bottom of the evaporator 7 and returns to the carbonylation secondary reactor 3 for further reaction, while the gaseous component enters the subsequent distillation and separation section through the evaporator gaseous component outlet 9 at the top of the evaporator 7. Meanwhile, the steam generated in the carbonylation secondary reactor 3 passes through the first heat exchanger 6 and the second heat exchanger 5 from the steam outlet at the top for heat exchange. After heat exchange, it is passed into the high-pressure separator 4 connected to the second heat exchanger 5 to obtain liquid and gaseous components again. Subsequently, the liquid component returns from the bottom of the high-pressure separator 4 to the carbonylation primary reactor 2 for recycling reaction, while the gaseous component flows out through the gaseous component outlet of the high-pressure separator 4 and enters the subsequent absorption section.
[0033] The steam produced from the top of the carbonylation secondary reactor 3 will exchange heat with the liquid phase component produced in the evaporator 7 through the first heat exchanger 6. At this time, most of the steam heat is transferred to the liquid phase component through the graphene thermal conductive layer 15 embedded in the first heat exchanger 6 and the nanoporous coating on the outer surface, which better realizes the separation of the liquid phase component and the gas phase component inside the evaporator 7 and achieves the initial utilization of heat.
[0034] The remaining heat from the steam is then absorbed by a second heat exchanger 5 connected to the evaporator 7. The remaining heat is further absorbed by a phase change energy storage material installed in the second heat exchanger 5, which is then used to preheat the feed.
[0035] Example 2
[0036] Please refer to the structure of the energy coupling system between the methanol carbonylation reactor and evaporator of this utility model. Figure 1 As shown, its specific workflow is as follows:
[0037] Please see Figure 1 Methanol and CO are continuously fed into the carbonylation primary reactor 2 through carbon monoxide inlet 1 and methanol inlet 10 at a molar ratio of 1:1.05. The feed rate is controlled at 5.8 L / min for methanol and 4.2 m³ / min for CO. Subsequently, three-dimensional turbulence is formed by stirring blades 11 installed in the carbonylation primary reactor 2. Combined with the catalysis of the nano-rhodium catalyst coated on the blades 11 and the jacketed gradient heating device 12 installed on the side wall of the carbonylation primary reactor 2, the reaction rate is further accelerated. The nano-rhodium catalyst coating has a thickness of 100 nm and a specific surface area of 300 m² / g. Under the gradient heating of the jacketed gradient heating device, the upper temperature is 190℃, the middle temperature is 180℃, and the lower temperature is 170℃. At this time, methanol and carbon monoxide undergo a preliminary reaction in the carbonylation primary reactor 2.
[0038] After the initial reaction is completed, the reactants will flow out from the first outlet at the top of the carbonylation primary reactor 2, and then flow into the carbonylation secondary reactor 3 through the inlet for further reaction. Under the guidance of the spiral rising guide plate 13 set inside the carbonylation secondary reactor 3, the reactants form a swirling flow. At this time, the spiral angle of the spiral rising guide plate is 35°, and the spacing between the spiral rising guide plates is 1 / 3 of the diameter of the carbonylation secondary reactor. At the same time, the micron-level groove structure on the surface of the guide plate 13 increases the gas-liquid contact area, further improving the CO conversion rate. The carbonylation product will then flow out from the middle section of the carbonylation secondary reactor 3 and enter the middle section of the evaporator 7. Subsequently, the ultrasonic enhanced flash evaporation device 16 set inside the evaporator 7 further shortens the flash evaporation time and improves the purity of acetic acid. At this time, the droplet particle size generated under ultrasonic enhanced flash evaporation is 50μm. Meanwhile, the bottom catalyst recovery device 14 can also realize the recovery of rhodium catalyst.
[0039] After flash evaporation, liquid and gaseous components are obtained. The liquid component flows out from the outlet at the bottom of the evaporator 7 and returns to the carbonylation secondary reactor 3 for further reaction, while the gaseous component enters the subsequent distillation and separation section through the evaporator gaseous component outlet 9 at the top of the evaporator 7. Meanwhile, the steam generated in the carbonylation secondary reactor 3 passes through the first heat exchanger 6 and the second heat exchanger 5 from the steam outlet at the top for heat exchange. After heat exchange, it is passed into the high-pressure separator 4 connected to the second heat exchanger 5 to obtain liquid and gaseous components again. Subsequently, the liquid component returns from the bottom of the high-pressure separator 4 to the carbonylation primary reactor 2 for recycling reaction, while the gaseous component flows out through the gaseous component outlet of the high-pressure separator 4 and enters the subsequent absorption section.
[0040] The steam produced from the top of the carbonylation secondary reactor 3 will exchange heat with the liquid phase component produced in the evaporator 7 through the first heat exchanger 6. At this time, most of the steam heat is transferred to the liquid phase component through the graphene thermal conductive layer 15 embedded in the first heat exchanger 6 and the nanoporous coating on the outer surface, which better realizes the separation of the liquid phase component and the gas phase component inside the evaporator 7 and achieves the initial utilization of heat.
[0041] The remaining heat from the steam is then absorbed by a second heat exchanger 5 connected to the evaporator 7. The remaining heat is further absorbed by a phase change energy storage material installed in the second heat exchanger 5, which is then used to preheat the feed.
[0042] Example 3
[0043] Please refer to the structure of the energy coupling system between the methanol carbonylation reactor and evaporator of this utility model. Figure 1 As shown, its specific workflow is as follows:
[0044] Please see Figure 1 Methanol and CO are continuously fed into the carbonylation primary reactor 2 through carbon monoxide inlet 1 and methanol inlet 10 at a molar ratio of 1:1.05. The feed rate is controlled at 5.8 L / min for methanol and 4.2 m³ / min for CO. Subsequently, a three-dimensional turbulent flow is formed by the stirring blades 11 set in the carbonylation primary reactor 2. Combined with the catalysis of the nano-rhodium catalyst coated on the blades 11 and the jacketed gradient heating device 12 set on the side wall of the carbonylation primary reactor 2, the reaction rate is further accelerated. The nano-rhodium catalyst coating has a thickness of 80 nm and a specific surface area of 300 m² / g. Under the gradient heating of the jacketed gradient heating device, the upper section temperature is 190℃, the middle section temperature is 180℃, and the lower section temperature is 170℃. At this time, methanol and carbon monoxide undergo a preliminary reaction in the carbonylation primary reactor 2.
[0045] After the initial reaction is completed, the reactants will flow out from the first outlet at the top of the carbonylation primary reactor 2, and then flow into the carbonylation secondary reactor 3 through the inlet for further reaction. Under the guidance of the spiral rising guide plate 13 set inside the carbonylation secondary reactor 3, the reactants form a swirling flow. At this time, the spiral angle of the spiral rising guide plate is 35°, and the spacing between the spiral rising guide plates is 1 / 3 of the diameter of the carbonylation secondary reactor. At the same time, the micron-level groove structure on the surface of the guide plate 13 increases the gas-liquid contact area, further improving the CO conversion rate. The carbonylation product will then flow out from the middle section of the carbonylation secondary reactor 3 and enter the middle section of the evaporator 7. Subsequently, the ultrasonic enhanced flash evaporation device 16 set inside the evaporator 7 further shortens the flash evaporation time and improves the purity of acetic acid. At this time, the droplet particle size generated under ultrasonic enhanced flash evaporation is 50μm. Meanwhile, the bottom catalyst recovery device 14 can also realize the recovery of rhodium catalyst.
[0046] After flash evaporation, liquid and gaseous components are obtained. The liquid component flows out from the outlet at the bottom of the evaporator 7 and returns to the carbonylation secondary reactor 3 for further reaction, while the gaseous component enters the subsequent distillation and separation section through the evaporator gaseous component outlet 9 at the top of the evaporator 7. Meanwhile, the steam generated in the carbonylation secondary reactor 3 passes through the first heat exchanger 6 and the second heat exchanger 5 from the steam outlet at the top for heat exchange. After heat exchange, it is passed into the high-pressure separator 4 connected to the second heat exchanger 5 to obtain liquid and gaseous components again. Subsequently, the liquid component returns from the bottom of the high-pressure separator 4 to the carbonylation primary reactor 2 for recycling reaction, while the gaseous component flows out through the gaseous component outlet of the high-pressure separator 4 and enters the subsequent absorption section.
[0047] The steam produced from the top of the carbonylation secondary reactor 3 will exchange heat with the liquid phase component produced in the evaporator 7 through the first heat exchanger 6. At this time, most of the steam heat is transferred to the liquid phase component through the graphene thermal conductive layer 15 embedded in the first heat exchanger 6 and the nanoporous coating on the outer surface, which better realizes the separation of the liquid phase component and the gas phase component inside the evaporator 7 and achieves the initial utilization of heat.
[0048] The remaining heat from the steam is then absorbed by a second heat exchanger 5 connected to the evaporator 7. The remaining heat is further absorbed by a phase change energy storage material installed in the second heat exchanger 5, which is then used to preheat the feed.
[0049] Example 4
[0050] The specific operating steps are the same as in Example 3, except that the thickness of the nano-rhodium catalyst coating is adjusted to 10 nm.
[0051] Example 5
[0052] The specific operating steps are the same as in Example 3, except that the thickness of the nano-rhodium catalyst coating is adjusted to 200nm.
[0053] Example 6
[0054] The specific operating steps are the same as in Example 3, except that the spiral angle of the spiral rising guide plate is adjusted to 10°.
[0055] Example 7
[0056] The specific operating steps are the same as in Example 3, except that the spiral angle of the spiral rising guide plate is adjusted to 60°.
[0057] Comparative Example 1
[0058] The specific operating steps are the same as in Example 3, except that no stirring blades are used.
[0059] Comparative Example 2
[0060] The specific operating steps are the same as in Example 3, except that a jacketed gradient heating device is not used.
[0061] Comparative Example 3
[0062] The specific operating steps are the same as in Example 3, except that a spiral rising guide plate is not used.
[0063] Comparative Example 4
[0064] The specific operating steps are the same as in Example 3, except that the ultrasonic-enhanced flash evaporation device is not used.
[0065] Experimental Example 1: Comprehensive Performance Test of the Energy Coupling System of Methanol Carbonylation Reactor and Evaporator
[0066] 1.1 Acetic acid yield test
[0067] Samples of the effluent from the carbonylation secondary reactor after the reaction in Examples 1-11 and Comparative Examples 1-4 were taken, and the acetic acid concentration was analyzed by gas chromatography.
[0068] Each experiment was repeated 3 times, and the average value was taken.
[0069] 1.2 CO conversion rate test
[0070] The CO concentration in the reaction tail gas is detected online using an infrared gas analyzer.
[0071] 1.3 Energy Consumption Test
[0072] Record the total energy consumption of the reaction system, in kWh;
[0073] Calculate the energy consumption for producing 1 kg of acetic acid: Energy consumption (kWh / kg) = Acetic acid production / Total electricity consumption;
[0074] The specific test results are shown in Table 1 below:
[0075]
[0076] As can be seen from the data in the table above, Example 3 exhibits the best performance. However, as can be seen from the comparative examples 4-5, the coating thickness of the catalyst is also very important for this invention. In Example 4, the catalyst coating was too thin, resulting in insufficient active sites, which led to a decrease in yield and a low CO conversion rate. In Example 5, when the catalyst coating was too thick, the excessive thickness of the catalyst coating increased the mass transfer resistance, resulting in a decrease in yield and an increase in energy consumption.
[0077] By comparing Examples 6 and 7, it can be seen that the helix angle between the spiral guide plates has an impact on the reaction performance. When the helix angle in Example 6 is too small, the contact time between gas and liquid is insufficient, resulting in a decrease in the yield of acetic acid. In Example 7, the helix angle is too large, which will cause back mixing, resulting in a decrease in the yield.
[0078] By comparing Example 3 and Comparative Examples 1-4, it can be seen that when no stirring blades are used in Comparative Example 1, the mass transfer is extremely poor, and the raw materials cannot make sufficient contact, resulting in a low acetic acid yield. In Comparative Example 2, since no gradient heating device is used, the internal temperature of the reactor is uneven, which leads to reduced selectivity, increased side reactions, and a lower acetic acid yield. In Comparative Example 3, no baffle is used, resulting in severe backmixing between raw materials, which leads to a low acetic acid yield. In Comparative Example 4, no ultrasonic flash evaporation device is used, resulting in low catalyst recovery efficiency and decreased flash evaporation efficiency.
[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.
Claims
1. An energy coupling system for a methanol carbonylation reactor and an evaporator, characterized in that, The reactor comprises a primary carbonylation reactor and a secondary carbonylation reactor connected in sequence. The primary carbonylation reactor has a stirring impeller at its bottom, the impeller surface of which is coated with a nano-rhodium catalyst coating. A jacketed gradient heating device is installed on the side wall of the primary carbonylation reactor. A methanol inlet and a carbon monoxide inlet are respectively located on both sides of the primary carbonylation reactor. A circulating inlet is located above the methanol inlet. A first outlet is located at the top of the primary carbonylation reactor. The secondary carbonylation reactor has a spiral-rising guide plate inside, the guide plate surface of which has a micron-level groove structure. A feed inlet and a second heat exchanger feed inlet are respectively located on both sides of the secondary carbonylation reactor. A steam outlet is located at the top of the secondary carbonylation reactor and is connected to an evaporator.
2. The methanol carbonylation reactor and evaporator energy coupling system according to claim 1, characterized in that, The thickness of the nano-rhodium catalyst coating is 50-100 nm, and the specific surface area is 200-300 m² / g.
3. The methanol carbonylation reactor and evaporator energy coupling system according to claim 1, characterized in that, The spiral angle of the spiral rising guide plate is 25-35°, and the spacing of the spiral rising guide plate is 1 / 5-1 / 3 of the diameter of the carbonylation secondary reactor.
4. The methanol carbonylation reactor and evaporator energy coupling system according to claim 1, characterized in that, The evaporator has a first heat exchanger at the bottom, which is coupled to a second heat exchanger. The first heat exchanger has a graphene thermal conductive layer embedded in it and a nanoporous coating on its outer surface. The second heat exchanger has a phase change energy storage material inside it and is connected to a high-pressure separator.
5. The methanol carbonylation reactor and evaporator energy coupling system according to claim 4, characterized in that, An ultrasonic-enhanced flash evaporation device is provided above the first heat exchanger, wherein the ultrasonic-enhanced flash evaporation device includes an ultrasonic generator and an atomizing nozzle connected in sequence, and a catalyst recovery device is provided at the bottom of the ultrasonic-enhanced flash evaporation device.