A high-purity sec-butyl acetate production process based on butene addition method

Abstract

This invention discloses a high-purity sec-butyl acetate production process based on the butene addition method, relating to the field of sec-butyl acetate production. The process includes: Step 1, an addition esterification reaction; Step 2, a two-stage combined deacidification process, where crude ester is fed into a deacidification and dehydration device, which includes a tank containing, from top to bottom, an alkali mixing device, an aqueous continuous phase device, and a settling chamber. The crude ester and alkali solution undergo premixing and neutralization in the alkali mixing device to obtain a mixture; Mixture 1 enters the aqueous continuous phase device, where aqueous droplets are captured, aggregated, and grown on the fiber bed, forming large droplets; These large droplets enter the settling chamber for sedimentation and separation, yielding deacidified material 1; Step 3, a three-tower integrated thermal distillation process. This sec-butyl acetate production process aims to solve the technical defects of traditional processes, such as low deacidification efficiency, uneven alkali mixing, easy clogging of the fiber bed, and high energy consumption.

Description

Technical Field

[0001] This invention mainly relates to the technical field of sec-butyl acetate production, specifically a high-purity sec-butyl acetate production process based on butene addition. Background Technology

[0002] sec-butyl acetate is an important fine chemical product widely used in coatings, inks, adhesives, cleaning agents, and other fields. It can be used as an environmentally friendly solvent to replace traditional volatile organic solvents such as ethyl acetate and butyl acetate. Compared with n-butyl acetate, sec-butyl acetate has advantages such as excellent solubility, moderate evaporation rate, and lower toxicity, and its market demand has continued to grow in recent years. Currently, the main industrial production methods of sec-butyl acetate include the addition esterification method of acetic acid with butene and the esterification method of acetic acid with butanol. Among them, the butene addition method has gradually become the mainstream production process due to its advantages such as high atom economy, fewer by-products, and low production cost.

[0003] In existing butene addition processes for producing sec-butyl acetate, the crude ester product typically contains unreacted acetic acid, water, and butene oligomers as byproducts. To obtain a high-purity product, the crude ester must undergo deacidification and dehydration. Current technologies often employ alkaline washing and neutralization combined with gravity sedimentation or centrifugal separation for deacidification. However, traditional alkaline washing equipment commonly suffers from uneven mixing of the alkali solution and crude ester, easily leading to localized over-alkaliness or incomplete neutralization, affecting deacidification efficiency and increasing alkali consumption. Furthermore, the subsequent aqueous phase separation stage often uses fiber bed coalescers, which, while achieving a certain degree of droplet coalescence, are prone to clogging by impurities after long-term operation, resulting in decreased separation efficiency and requiring frequent shutdowns for cleaning or replacement, severely impacting production continuity and operational economy.

[0004] Therefore, there is a need to provide a method that can achieve efficient mixing of alkali and crude ester, online regeneration of the fiber bed, and low overall energy consumption, in order to solve the problem of low deacidification efficiency in the production of sec-butyl acetate in the existing technology. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a high-purity sec-butyl acetate production process based on butene addition method to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a process for producing high-purity sec-butyl acetate based on butene addition reaction, comprising the following steps: Step 1, addition esterification reaction, using a modified sulfonic acid type cation exchange resin as a catalyst, wherein mixed butene and glacial acetic acid undergo addition esterification reaction in a fixed-bed reactor to obtain crude ester one; Step 2, two-stage combined deacidification, wherein crude ester one is fed into a deacidification device for deacidification and dehydration treatment, wherein the deacidification device includes a tank, and alkali mixing equipment is sequentially arranged in the tank from top to bottom. The process involves a continuous aqueous phase device and a settling chamber. Crude ester 1 and alkali solution undergo premixing and neutralization reactions in an alkali mixing device to obtain mixed material 1. Mixed material 1 enters the continuous aqueous phase device, where aqueous droplets are captured, aggregated, and grown on the fiber bed to form large droplets. The large droplets enter the settling chamber for sedimentation and separation to obtain deacidified material 1. In step three, a three-tower thermal integrated distillation process is performed, in which the deacidified material 1 is sequentially fed into a light-light removal tower, a product tower, and a recovery tower for distillation and separation. Sec-butyl acetate product is collected from the side stream of the product tower.

[0007] Preferably, the deacidification equipment includes a housing, and, from top to bottom, an alkali mixing device, an aqueous phase continuous device, and a settling chamber arranged sequentially within the housing. The alkali mixing device includes, from top to bottom, multiple crude ester alkali premixing components, a secondary mixer, and an umbrella-shaped separator arranged in a connected manner within the housing. The aqueous phase continuous device includes a base plate on the inner wall of the housing, multiple vibrating components on the base plate, a support frame on the vibrating end of the vibrating components, a first guide plate on the support frame, two second guide plates hinged to both ends of the first guide plate, an adjusting component on the support frame for adjusting the rotation angle of the second guide plates, and fiber beds on the first and second guide plates. The second guide plate near the umbrella-shaped separator is used to receive the liquid discharged from the umbrella-shaped separator. In this preferred embodiment, this vertically integrated design fully utilizes gravity flow, eliminating the need for interstage pumping. It achieves continuous, efficient, and integrated operation of neutralization reaction, droplet coalescence and growth, and gravity sedimentation. The equipment has a small footprint and low investment and operating costs.

[0008] Preferably, the crude ester alkali premixing component includes an ester source pipe with one end penetrating through the housing and extending into the housing, a mixing pipe with its top connected to the ester source pipe, and a premixed liquid discharge pipe with one end connected to the bottom of the mixing pipe; it also includes an alkali dispersion pipe located inside the ester source pipe, with one end connected to the bottom of the alkali dispersion pipe and the other end sequentially penetrating through the premixed liquid discharge pipe and the housing and extending to the outside of the housing. In this preferred embodiment, the alkali solution is directly dispersed inside the ester phase, achieving rapid premixing at the microscale, avoiding local over-alkaliness or uneven mixing, and significantly improving neutralization efficiency.

[0009] Preferably, the secondary mixer has two symmetrically arranged inlet chambers, and a drain chamber is located between the two inlet chambers. The inlet chambers are connected to the drain chamber through multiple microchannels; the inlet chambers are connected to the premixed liquid discharge pipe through a pipeline. In this preferred embodiment, the microchannel structure creates highly turbulent flow within the channels, greatly enhancing liquid-liquid dispersion and mass transfer, ensuring the instantaneous and complete reaction between the alkali and trace amounts of acid, and laying the foundation for subsequent efficient separation.

[0010] Preferably, the umbrella-shaped liquid distribution component includes a frame plate disposed on the inner wall of the box, a liquid collection pipe disposed on the frame plate and connected to the liquid drainage chamber via a pipe, multiple telescopic cylinders disposed on the outer wall of the frame plate and with their actuating ends penetrating the frame plate, and a liquid distribution fan disposed at the actuating end of the telescopic cylinders; the liquid distribution fan has multiple guide grooves embedded in a circular array, and the top of the side wall of the liquid distribution fan is connected to the liquid collection pipe via a pipe. In this preferred embodiment, the umbrella-shaped liquid distribution fan can evenly and extensively distribute the mixed liquid on the fiber bed, avoiding localized liquid flow impact.

[0011] Preferably, the vibrating component includes a pad mounted on the base plate, multiple springs mounted on the pad, and a vibrating motor mounted on the pad; the top of the springs is connected to the bottom of the support frame, and the vibrating end of the vibrating motor is connected to the bottom of the support frame. In this preferred embodiment, this design allows the support frame, the guide plate above it, and the fiber bed to vibrate at a low frequency as a whole. When regeneration is required, the vibration effectively removes residual water phase and impurities adhering to the fiber bed, achieving online self-cleaning of the fiber bed, significantly extending the continuous operation cycle, and reducing downtime for maintenance.

[0012] Preferably, the adjusting component includes an annular frame disposed at the bottom of the second guide plate, an electric cylinder disposed on the support frame, and a drive rod disposed at the actuating end of the electric cylinder and slidably connected to the annular frame. In this preferred embodiment, the angle between the second guide plate and the first guide plate can be steplessly adjusted by precisely controlling the movement of the drive rod through the electric cylinder. An optimal flow angle can be set in the operating state, and it can be adjusted to be coplanar in the regeneration state to cooperate with vibration cleaning, realizing flexible switching between operating and regeneration modes.

[0013] Preferably, the fiber bed includes a trapping section, a coalescing section, and a removal section arranged sequentially along the liquid flow direction. In this preferred embodiment, the three sections have clearly differentiated functions: the trapping section captures tiny droplets, the coalescing section causes small droplets to merge and grow into larger droplets, and the removal section promotes the detachment of large droplets from the fiber surface. This gradient structure design significantly improves the removal efficiency of 1-50 μm micro-aqueous droplets, achieves high separation accuracy, and results in extremely low water content and acid value in the outlet ester phase.

[0014] Preferably, the system further includes a buffer component disposed on the inner wall of the tank. The buffer component includes an arc-shaped collecting box disposed on the inner wall of the tank, and multiple buffer tubes with one end connected to the bottom of the side wall of the arc-shaped collecting box and the other end extending to the bottom of the settling chamber. The buffer component is used to receive liquid discharged from the second guide plate away from the umbrella-shaped liquid separator. In this preferred embodiment, the radius of curvature of the arc-shaped collecting box matches the length of the second guide plate, ensuring a constant gap between the guide plate and the collecting box when the guide plate rotates, effectively collecting the liquid. The buffer tubes guide the liquid directly to the bottom of the settling chamber, avoiding splashing and disturbance during free fall, ensuring the stability of the oil-water interface in the settling chamber, and improving the gravity settling separation effect.

[0015] Preferably, the device further includes an extraction device disposed on the base plate, with its actuating end penetrating the base plate and extending into the settling chamber. The extraction device includes an ester extraction pipe with one end sequentially penetrating the housing and the base plate and extending into the settling chamber; a power cylinder disposed on the top of the base plate with its actuating end penetrating the base plate; and a connecting frame disposed on the actuating end of the power cylinder and connected to the extraction port of the ester extraction pipe. In this preferred embodiment, the position of the ester phase extraction port in the settling chamber is precisely controlled by the power cylinder. The extraction point can be adjusted in real time according to the actual oil-water interface height to ensure that pure ester phase is always extracted, avoiding accidental extraction of aqueous phase or entrainment of moisture, thereby ensuring stable output quality.

[0016] In summary, the present invention has the following main beneficial effects:

[0017] This invention provides a process for producing sec-butyl acetate, aiming to solve the problem of low deacidification efficiency in traditional processes. The process comprises three steps: First, a modified sulfonic acid cation exchange resin is used to catalyze the addition esterification reaction of mixed butene and glacial acetic acid to obtain crude ester. Second, the crude ester is fed into an integrated deacidification device, which integrates an alkali mixing unit, an aqueous phase continuous unit, and a settling chamber from top to bottom. The crude ester and alkali solution are premixed and then further intensified in the alkali mixing unit, and then evenly distributed to the fiber bed through an umbrella-shaped separator. In the aqueous phase continuous unit, tiny droplets are captured, aggregated, and grown, and finally, gravity separation occurs in the settling chamber, achieving efficient deacidification and dehydration. Finally, the deacidified material is subjected to integrated thermal distillation in a three-tower system (light weight removal tower, product tower, and recovery tower), and high-purity sec-butyl acetate is collected from the side stream of the product tower.

[0018] The alkali mixing unit achieves microscopic premixing of the ester phase through a built-in alkali dispersion tube, and combines this with a microchannel secondary mixer to create highly turbulent flow, ensuring instantaneous and complete reaction between the alkali and trace amounts of acid, thus solving the problem of localized over-alkali. The aqueous phase continuous unit uses a segmented fiber bed to perform gradient separation of 1-50μm aqueous phase droplets with extremely high precision; it is also equipped with a vibrating component that can periodically regenerate online at a frequency of 40Hz, ensuring complete removal of adhering aqueous phase droplets and effectively solving the problems of easy clogging and frequent shutdowns required by traditional fiber beds. Furthermore, the extraction device can adjust the suction port height in real time according to the oil-water interface position to ensure that pure ester phase is always extracted. Attached Figure Description

[0019] Figure 1 This is a flowchart of the production process of the present invention;

[0020] Figure 2 This is an isometric view of the device structure of the present invention;

[0021] Figure 3 This is an exploded view of the device structure of the present invention;

[0022] Figure 4 This is an exploded view of the alkali mixing device and the aqueous phase continuous device of the present invention.

[0023] Figure 5 This is an exploded view of the alkali mixing device of the present invention;

[0024] Figure 6 For the present invention Figure 5 Enlarged view of the structure at point A in the middle;

[0025] Figure 7 For the present invention Figure 5 Enlarged view of the structure at point B in the middle;

[0026] Figure 8 This is an isometric view of the extraction device structure of the present invention;

[0027] Figure 9 This is an exploded view of the aqueous phase continuous device structure of the present invention;

[0028] Figure 10 This is a cross-sectional view of the overall structure of the device of the present invention.

[0029] Figure Descriptions: 10. Box body; 20. Alkali mixing device; 21. Crude ester alkali solution premixing component; 211. Ester source pipe; 212. Mixing pipe; 213. Premixed liquid discharge pipe; 214. Alkali solution dispersion pipe; 215. Alkali source pipe; 22. Secondary mixer; 221. Liquid inlet chamber; 222. Liquid outlet chamber; 223. Microchannel; 23. Umbrella-shaped liquid separation component; 231. Frame plate; 232. Liquid collection pipe; 233. Telescopic cylinder; 234. Liquid separation fan; 2341. Guide channel; 30. Aqueous phase continuous device; 31. Base plate; 32. 321. Vibrating component; 322. Pad; 323. Spring; 324. Vibrating motor; 33. Support frame; 34. First guide plate; 35. Second guide plate; 36. Adjusting component; 361. Ring frame; 362. Electric cylinder; 363. Drive rod; 37. Fiber bed; 371. Collection section; 372. Agglomeration section; 373. Removal section; 38. Buffer component; 381. Arc-shaped collection box; 382. Buffer tube; 40. Settling chamber; 50. Extraction device; 51. Ester extraction tube; 52. Power cylinder; 53. Connecting frame. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0031] The embodiments of the present invention will now be described.

[0032] Please refer to the appendix for details. Figure 1 , 2As shown in Figures 3 and 10, in a preferred embodiment of the present invention, a process for producing high-purity sec-butyl acetate based on butene addition reaction includes the following steps: Step 1, addition esterification reaction, using a modified sulfonic acid type cation exchange resin as a catalyst, the mixed butene and glacial acetic acid undergo addition esterification reaction in a fixed-bed reactor to obtain crude ester 1; Step 2, two-stage combined deacidification, the crude ester 1 is sent to a deacidification device for deacidification and dehydration treatment, the deacidification device including a housing 10, and an alkali mixing device 20, an aqueous phase continuous device 30 and a settling chamber 40 arranged sequentially from top to bottom in the housing 10; the crude ester 1 and the alkali solution are reacted in the alkali mixing device 20... In step 0, the premixing and neutralization reaction is completed to obtain mixture 1; mixture 1 enters the aqueous phase continuous device 30, where aqueous droplets are captured, aggregated, and grown on the fiber bed 37 of the aqueous phase continuous device 30 to form large droplets; the large droplets enter the settling chamber 40 for sedimentation and separation to obtain deacidified material 1; in step 3, three-tower thermal integrated distillation, the deacidified material 1 is sequentially sent to the light removal tower, the product tower, and the recovery tower for distillation and separation, and sec-butyl acetate product is collected from the side stream of the product tower. The deacidification equipment includes a box 10, and from top to bottom, the alkali mixing device 20, the aqueous phase continuous device 30, and the settling chamber 40 are arranged in sequence in the box 10.

[0033] It should be noted that, in this preferred embodiment, a modified sulfonic acid cation exchange resin is used as a catalyst during the production of sec-butyl acetate. The modified sulfonic acid cation exchange resin is a macroporous sulfonic acid resin that has been surface-modified with organosilane to achieve a specific surface area ≥50 m² / g.

[0034] Mixed butene (n-butene content ≥60wt%) and glacial acetic acid (purity ≥99.5wt%) were mixed at a molar ratio of 1:1.1. After being heated to 75℃ in a preheater, the mixture was introduced from the top of a fixed-bed reactor with a reactor diameter of 1000 mm, a catalyst bed height of 4000 mm, a reaction temperature of 75±2℃, a reaction pressure of 1.2 MPa, and a volume hourly space velocity of 1.5 h⁻¹. -1 The mixed feedstock undergoes an addition esterification reaction in the catalyst bed to produce sec-butyl acetate. The reaction product flows out from the bottom of the reactor, is stabilized in a crude ester buffer tank, and then crude ester is obtained.

[0035] The crude ester contained 92.5 wt% sec-butyl acetate, 1.2 wt% unreacted acetic acid, 0.3 wt% water, 6.0 wt% byproducts such as butene oligomers, and an acid value (calculated as acetic acid) of 1.5 mg KOH / g.

[0036] The crude ester is fed into the alkali mixing device 20, which mixes the crude ester with alkali. The mixture is then fed into the aqueous phase continuous device 30, where it aggregates small aqueous droplets. The aggregated liquid then flows into the settling chamber 40 along with the mixture. Inside the settling chamber 40, large aqueous droplets settle downwards under gravity, forming a continuous aqueous phase layer at the bottom. The purified ester phase flows upwards. The settling chamber 40 operates at 45°C with a residence time of 3 minutes. The aqueous phase layer is intermittently discharged under the control of an interface meter, while the ester phase is discharged from the extraction device 50 at the top of the settling chamber 40.

[0037] The deacidified material is sequentially fed into the light-light residue removal tower, the product tower, and the recovery tower for distillation separation.

[0038] Lightweight component removal tower: theoretical plate number 30, top temperature 45℃, bottom temperature 95℃, operating pressure 0.4 MPa, reflux ratio 3. Unreacted butene and low-boiling-point substances (dimethyl ether, water, etc.) are collected from the top of the tower, pressurized by a compressor, and returned to the reaction unit. The bottom material is sent to the product tower.

[0039] Product column: A high-efficiency packed column with 70 theoretical plates, a top temperature of 105℃, a bottom temperature of 125℃, atmospheric pressure operation, and a reflux ratio of 10. The side stream is collected at the 50th theoretical plate from the top. The sec-butyl acetate collected from the side stream is cooled and used as the product. The vapor phase at the top of the product column (105℃) provides a heat source for the reboiler of the light component removal column through a heat exchanger, achieving heat integration and reducing steam consumption by approximately 35%.

[0040] Recovery tower: theoretically 25 plates, top temperature 105℃, bottom temperature 140℃, operating pressure slightly negative (absolute pressure 0.08 MPa), reflux ratio 2. The sec-butyl acetate and acetic acid collected from the top of the tower are returned to the deacidification buffer tank, while the heavy components (butene oligomers, polymers) from the bottom of the tower are sent out as fuel oil.

[0041] Finished product quality: The purity of the sec-butyl acetate product obtained from the side stream was 99.85% (gas chromatography), the acid value (calculated as acetic acid) was 0.003 mgKOH / g (GB / T 7304), the water content was 0.03% (Karl Fischer method), the color was 5 Hazen (GB / T 3143), and the evaporation residue was 0.0008% (GB / T 6324.2), which fully meets the quality requirements for high-purity sec-butyl acetate.

[0042] Please refer to the appendix for details. Figure 3 , 4As shown in Figures 5, 6, and 7, in another preferred embodiment of the present invention, the alkali mixing device 20 includes a plurality of crude ester alkali premixing components 21, a secondary mixer 22, and an umbrella-shaped liquid separator 23 arranged sequentially from top to bottom within the housing 10 and interconnected with each other; the crude ester alkali premixing component 21 includes an ester source pipe 211 with one end penetrating through the housing 10 and extending into the housing 10, a mixing pipe 212 with its top connected to the ester source pipe 211, and a premixed liquid discharge pipe 213 with one end connected to the bottom of the mixing pipe 212; it also includes an alkali dispersion pipe 214 located within the ester source pipe 211, an alkali source pipe 215 with one end connected to the bottom of the alkali dispersion pipe 214 and the other end sequentially penetrating through the premixed liquid discharge pipe 213 and the housing 10 and extending to the outside of the housing 10, and the secondary mixer 22 is symmetrically provided with two liquid inlet chambers. 221, a drain chamber 222 is provided inside the secondary mixer 22 and located between the two inlet chambers 221. The inlet chamber 221 is connected to the drain chamber 222 through multiple microchannels 223. The inlet chamber 221 is connected to the premixed liquid discharge pipe 213 through a pipe. The umbrella-shaped liquid distribution component 23 includes a frame plate 231 disposed on the inner wall of the housing 10, a collection pipe 232 disposed on the frame plate 231 and connected to the drain chamber 222 through a pipe, multiple telescopic cylinders 233 disposed on the outer wall of the frame plate 231 and whose actuating end penetrates the frame plate 231, and a liquid distribution fan 234 disposed on the actuating end of the telescopic cylinder 233. Multiple guide grooves 2341 are embedded in a ring array on the liquid distribution fan 234, and the top of the side wall of the liquid distribution fan 234 is connected to the collection pipe 232 through a pipe.

[0043] It should be noted that, in this preferred embodiment, when the alkali mixing device 20 is operating, the crude ester is at a concentration of 5 m... 3 A flow rate of / h enters the crude ester alkali premixing unit 21. In the crude ester alkali premixing unit 21, the crude ester enters from the ester source pipe 211, and the alkali solution (1.5wt% NaOH aqueous solution) flows at a rate of 0.25 m. 3 A flow rate of / h (the volume ratio of alkali solution to crude ester is 1:20, and the amount of alkali solution added is 1.08 times the theoretical neutralization amount) enters from the alkali source pipe 215, is dispersed in the ester source pipe 211 through the alkali solution dispersion pipe 214, and then initially mixed with the crude ester in the mixing pipe 212. The material after initial mixing enters the secondary mixer 22 through the premixed liquid discharge pipe 213;

[0044] In the secondary mixer 22, the material enters two inlet chambers 221 respectively, and then enters the outlet chamber 222 through the microchannel 223, where it is mixed by impact. The equivalent diameter of the microchannel 223 is 1.0 mm, and the material flows in a turbulent state with a Reynolds number of 5000-8000 within the microchannel 223.

[0045] The neutralized mixture enters the collection pipe 232 of the umbrella-shaped liquid separator 23 through the pipeline, and is then transported to the liquid separator fan 234 through the pipeline with the valve opened. After being guided by the guide groove 2341 on the liquid separator fan 234, it enters the fiber bed 37.

[0046] The extension length of the liquid separator 234 can be adjusted under the drive of the telescopic cylinder 233 to avoid interference with the second guide plate 35.

[0047] Please refer to the appendix for details. Figure 3 , 4 As shown in Figures 8 and 9, in another preferred embodiment of the present invention, the aqueous phase continuous device 30 includes a base plate 31 disposed on the inner wall of the housing 10, a plurality of vibrating components 32 disposed on the base plate 31, a support frame 33 disposed on the vibrating end of the vibrating component 32, a first guide plate 34 disposed on the support frame 33, two second guide plates 35 respectively hinged to both ends of the first guide plate 34, an adjusting component 36 disposed on the support frame 33 for adjusting the rotation angle of the second guide plates 35, and a fiber bed disposed on the first guide plate 34 and the second guide plates 35. 37; The second guide plate 35 near the umbrella-shaped liquid distribution component 23 is used to receive the liquid discharged from the umbrella-shaped liquid distribution component 23. The vibration component 32 includes a pad 321 disposed on the base plate 31, a plurality of springs 322 disposed on the pad 321, and a vibration motor 323 disposed on the pad 321; the top of the springs 322 is connected to the bottom of the support frame 33, and the vibration end of the vibration motor 323 is connected to the bottom of the support frame 33. The adjustment component 36 includes an annular frame 361 disposed at the bottom of the second guide plate 35, and a ring frame 361 disposed on the support frame 31. The fiber bed 37 includes an electric cylinder 362 on the housing 3, and a drive rod 363 located at the actuating end of the electric cylinder 362 and slidably connected to the ring frame 361. The fiber bed 37 includes a collection section 371, an aggregation section 372, and a removal section 373 arranged sequentially along the liquid flow direction. It also includes a buffer component 38 located on the inner wall of the housing 10. The buffer component 38 includes an arc-shaped collecting box 381 located on the inner wall of the housing 10, and multiple buffer tubes 382 with one end connected to the bottom of the side wall of the arc-shaped collecting box 381 and the other end extending to the bottom of the settling chamber 40. 8 is used to receive the liquid discharged from the second guide plate 35 away from the umbrella-shaped liquid distribution component 23, and also includes an extraction device 50 disposed on the base plate 31 with its actuating end passing through the base plate 31 and extending into the settling chamber 40. The extraction device 50 includes an ester extraction tube 51 with one end sequentially passing through the box body 10 and the base plate 31 and extending into the settling chamber 40, a power cylinder 52 disposed on the top of the base plate 31 with its actuating end passing through the base plate 31, and a connecting frame 53 disposed on the actuating end of the power cylinder 52 and connected to the extraction port of the ester extraction tube 51.

[0048] It should be noted that, in this preferred embodiment, when the aqueous phase continuous device 30 is working, the second guide plate 35 near the umbrella-shaped liquid separator 23 receives the mixed liquid discharged from the umbrella-shaped liquid separator 23, and the mixed liquid flows through the fiber bed 37.

[0049] The structure of fiber bed 37: the collecting section 371 is filled with a mixture of glass fibers and modified polypropylene fibers with a diameter of 10-20 μm, and the angle between the fibers and the flow direction is 20°; the coalescence section 372 is filled with modified polypropylene fibers with a diameter of 20-30 μm, and the angle between the fibers and the flow direction is 50°; the removal section 373 is filled with smooth modified polypropylene fibers with a diameter of 30-50 μm, and the angle between the fibers and the flow direction is 5°.

[0050] Operating mode: During normal deacidification operation, the two second guide plates 35 are adjusted to a preset angle by adjusting component 36. When the mixture flows through the fiber bed 37, tiny aqueous droplets (1-50 μm) are initially captured in the capture section 371, then aggregated into larger droplets (0.5-2 mm) in the coalescence section 372, and finally removed in the removal section 373. The larger droplets detach from the fiber bed 37 and enter the settling chamber 40.

[0051] Regeneration Mode: Online regeneration is performed every 6 hours of operation. During regeneration, the umbrella-shaped liquid distribution component 23 corresponding to the regenerated fiber bed 37 stops discharging liquid, and the two second guide plates 35 are adjusted to be coplanar with the first guide plate 34 by the adjusting component 36. The vibration component 32 is turned on and vibrates at a frequency of 40 Hz and an amplitude of 1.5 mm for 60 seconds to completely remove the aqueous phase film and residual large droplets attached to the fiber bed 37. Vibration is then stopped, and the bed is left to stand for 60 seconds to allow the removed aqueous phase to completely enter the settling chamber 40. Then, the guide plates are returned to their operating angle by the adjusting component 36, and feeding is resumed.

[0052] Furthermore, when the vibrating component 32 is working, after the vibrating motor 323 is powered on, the vibrating end of the vibrating motor 323 drives the support frame 33, the first guide plate 34, the second guide plate 35 and the fiber bed 37 to vibrate.

[0053] Furthermore, when the adjusting component 36 is working, the telescopic end of the electric cylinder 362 drives the drive rod 363 to move, and the drive rod 363 drives the second guide plate 35 to rotate through the ring frame 361;

[0054] Furthermore, when the buffer component 38 is working, since the radius of curvature of the arc-shaped collecting box 381 is consistent with the length of the second guide plate 35, and the distance between the second guide plate 35 and the arc-shaped collecting box 381 is consistent when the second guide plate 35 rotates, the liquid discharged from the fiber bed 37 falls into the arc-shaped collecting box 381, and then enters the settling chamber 40 through the buffer pipe 382 to prevent liquid splashing.

[0055] Furthermore, when the extraction device 50 is working, the ester extraction tube 51 can be connected to the negative pressure system. After the negative pressure system is turned on, the ester liquid is extracted through the ester extraction tube 51, and the actuator of the power cylinder 52 adjusts the suction end height of the ester extraction tube 51 through the connecting frame 53.

[0056] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the invention and are not intended to limit it. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the invention, but such modifications, substitutions, and variations are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A process for producing high-purity sec-butyl acetate based on butene addition, characterized in that, Includes the following steps: Step 1: Addition esterification reaction. A modified sulfonic acid-type cation exchange resin was used as a catalyst to carry out an addition esterification reaction of mixed butene and glacial acetic acid in a fixed-bed reactor to obtain crude ester one. Step 2: Two-stage combined deacidification. The crude ester is fed into a deacidification device for deacidification and dehydration treatment. The deacidification device includes a box (10), an alkali mixing device (20), an aqueous phase continuous device (30), and a settling chamber (40) arranged sequentially from top to bottom in the box (10). Crude ester 1 and alkaline solution undergo premixing and neutralization reactions in alkaline mixing device (20) to obtain mixture 1; Once the mixture enters the aqueous phase continuous device (30), the aqueous phase droplets are captured, aggregated and grown on the fiber bed (37) of the aqueous phase continuous device (30), forming large droplets; Large droplets enter the settling chamber (40) for sedimentation and separation, yielding deacidified material 1; Step 3: Three-tower integrated thermal distillation. After deacidification, the material is sequentially fed into the light-removal tower, the product tower, and the recovery tower for distillation and separation. The sec-butyl acetate product is collected from the side stream of the product tower.

2. The process for producing high-purity sec-butyl acetate based on butene addition as described in claim 1, characterized in that, The deacidification equipment includes a housing (10), an alkali mixing device (20), an aqueous phase continuous device (30), and a settling chamber (40) arranged sequentially from top to bottom within the housing (10). The alkali mixing device (20) includes a plurality of crude ester alkali premixing components (21), a secondary mixer (22), and an umbrella-shaped liquid separator (23) arranged sequentially from top to bottom in the box (10) and interconnected with each other. The aqueous phase continuous device (30) includes a base plate (31) disposed on the inner wall of the housing (10), a plurality of vibrating components (32) disposed on the base plate (31), a support frame (33) disposed on the vibrating end of the vibrating component (32), a first guide plate (34) disposed on the support frame (33), two second guide plates (35) respectively hinged to the two ends of the first guide plate (34), an adjustment component (36) disposed on the support frame (33) for adjusting the rotation angle of the second guide plates (35), and a fiber bed (37) disposed on the first guide plate (34) and the second guide plate (35). The second guide plate (35) near the umbrella-shaped liquid distribution component (23) is used to receive the liquid discharged from the umbrella-shaped liquid distribution component (23).

3. The process for producing high-purity sec-butyl acetate based on butene addition as described in claim 2, characterized in that, The crude ester alkaline solution premixing component (21) includes an ester source pipe (211) that extends through the box (10) and into the box (10), a mixing pipe (212) that is connected to the ester source pipe (211) at the top, and a premixed liquid discharge pipe (213) that is connected to the bottom of the mixing pipe (212) at one end. It also includes an alkaline dispersion tube (214) located inside the ester source tube (211), with one end connected to the bottom of the alkaline dispersion tube (214) and the other end sequentially passing through the premixed liquid discharge tube (213), the box (10) and extending to the outside of the box (10).

4. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 3, characterized in that, The secondary mixer (22) is symmetrically provided with two liquid inlet chambers (221), and a liquid outlet chamber (222) is provided in the secondary mixer (22) and located between the two liquid inlet chambers (221). The liquid inlet chamber (221) is connected to the liquid outlet chamber (222) through multiple microchannels (223). The liquid inlet chamber (221) is connected to the premixed liquid discharge pipe (213) through a pipe.

5. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 4, characterized in that, The umbrella-shaped liquid distribution component (23) includes a frame plate (231) disposed on the inner wall of the box (10), a liquid collection pipe (232) disposed on the frame plate (231) and connected to the drain chamber (222) through a pipe, a plurality of telescopic cylinders (233) disposed on the outer wall of the frame plate (231) and whose actuating end penetrates the frame plate (231), and a liquid distribution fan (234) disposed on the actuating end of the telescopic cylinder (233). The liquid distribution fan (234) is provided with a ring array of multiple guide grooves (2341), and the top of the side wall of the liquid distribution fan (234) is connected to the liquid collection pipe (232) through a pipe.

6. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 2, characterized in that, The vibration component (32) includes a pad (321) disposed on the base plate (31), a plurality of springs (322) disposed on the pad (321), and a vibration motor (323) disposed on the pad (321). The top of the spring (322) is connected to the bottom of the support frame (33), and the vibration end of the vibration motor (323) is connected to the bottom of the support frame (33).

7. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 2, characterized in that, The adjusting component (36) includes an annular frame (361) disposed at the bottom of the second guide plate (35), an electric cylinder (362) disposed on the support frame (33), and a drive rod (363) disposed at the actuating end of the electric cylinder (362) and slidably connected to the annular frame (361).

8. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 2, characterized in that, The fiber bed (37) includes a collection section (371), a coalescing section (372), and a removal section (373) arranged sequentially along the liquid flow direction.

9. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 2, characterized in that, It also includes a buffer component (38) disposed on the inner wall of the box (10). The buffer component (38) includes an arc-shaped collection box (381) disposed on the inner wall of the box (10), and a plurality of buffer tubes (382) with one end connected to the bottom of the side wall of the arc-shaped collection box (381) and the other end extending to the bottom of the settling chamber (40). The buffer component (38) is used to receive the liquid discharged from the second guide plate (35) away from the umbrella-shaped liquid distribution component (23).

10. The process for producing high-purity sec-butyl acetate based on butene addition according to claim 2, characterized in that, It also includes an extraction device (50) disposed on the base plate (31) with its execution end penetrating the base plate (31) and extending into the settling chamber (40). The extraction device (50) includes an ester extraction tube (51) with one end sequentially penetrating the box body (10) and the base plate (31) and extending into the settling chamber (40), a power cylinder (52) disposed on the top of the base plate (31) with its execution end penetrating the base plate (31), and a connecting frame (53) disposed on the execution end of the power cylinder (52) and connected to the extraction port of the ester extraction tube (51).

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