Double-section shear mixing horizontal alkylation reactor
The design of a horizontal alkylation reactor with two-stage shear mixing solves the problem of low mixing efficiency in sulfuric acid alkylation reactors, achieving efficient mixing of raw materials and acid phase, improving reaction rate and catalyst life, while reducing energy consumption.
Patent Information
- Application Number
- CN202511314005.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-15
- Publication Date
- 2025-12-16
AI Technical Summary
Existing sulfuric acid alkylation reactors have low mixing efficiency, which leads to limited reaction rates, increased side reactions, and the potential generation of acid-soluble oils, affecting catalyst life and equipment corrosion.
The horizontal alkylation reactor employs a two-stage shear mixing design. Through the design of the internal circulation sleeve, circulation chamber, and stirring components, it achieves zoned circulation and efficient mixing of raw materials and acid. The synergistic effect of the raw material stirring paddle and the circulating acid shearing paddle enhances the dispersion and mixing efficiency.
It increases the reaction rate, reduces side reactions and the formation of acid-soluble oils, extends catalyst life, and reduces energy consumption.
Smart Images
Figure CN121130801A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of petrochemicals, and in particular to a horizontal alkylation reactor with two-stage shear mixing. Background Technology
[0002] With increasingly stringent environmental protection requirements, the production of clean gasoline is receiving growing attention. Alkylated oil, as an important gasoline blending component, occupies a crucial position in modern refining processes due to its superior properties such as high octane number, low sulfur, low olefins, and low aromatics. Alkylated oil is primarily prepared through alkylation reactions, and the performance of the reactor directly affects product quality and production efficiency. Currently, the sulfuric acid alkylation process is widely used industrially, with the alkylation reactor as its core equipment. Compared to the hydrofluoric acid process, sulfuric acid alkylation offers advantages such as higher safety, lower corrosiveness, and easier regeneration of waste acid. The principle of this process is that isobutane and olefins undergo an addition reaction under the action of a concentrated sulfuric acid catalyst to produce branched alkanes with high octane numbers.
[0003] However, existing sulfuric acid alkylation reactors still suffer from low mixing efficiency. Due to the significant density difference and high viscosity between sulfuric acid and hydrocarbons, traditional stirring methods struggle to achieve thorough micro-mixing, leading to limited reaction rates, increased side reactions, and the potential generation of acid-soluble oils, which can affect catalyst life. Furthermore, uneven mixing can cause localized overheating, exacerbating equipment corrosion and coking risks. Summary of the Invention
[0004] To address the problem of low mixing efficiency in existing sulfuric acid alkylation reactors, this application provides a horizontal alkylation reactor with two-stage shear mixing.
[0005] This application provides a horizontal alkylation reactor with two-stage shear mixing, employing the following technical solution:
[0006] A horizontal alkylation reactor with two-stage shear mixing, comprising:
[0007] The shell and the inner circulation sleeve are arranged inside the shell. The inner circulation sleeve has a circulation chamber inside the inner circulation sleeve. A feeding chamber is formed between the inner circulation sleeve and the shell.
[0008] Both the acid feed pipe and the raw material feed pipe are connected to the circulation chamber;
[0009] The stirring assembly includes a drive source and a stirring shaft. The drive source is located outside the housing, and the stirring shaft is located inside the circulation chamber. The drive source is connected to the stirring shaft. The circulation chamber contains a raw material stirring paddle, a raw material distributor, a circulating acid shearing paddle, and a circulating acid distributor. The raw material distributor is connected to the raw material feed pipe, and the circulating acid distributor is connected to the acid feed pipe. The raw material stirring paddle and the circulating acid shearing paddle are coaxially fixed to the stirring shaft. The circulating acid shearing paddle is located between the raw material distributor and the circulating acid distributor. The raw material stirring paddle is located on the side away from the circulating acid shearing paddle relative to the raw material distributor.
[0010] By adopting the above technical solution, and by setting up an internal circulation sleeve, circulation chamber, and feed chamber, the reaction materials are zonally circulated and efficiently mixed. The raw material stirring paddle and the circulating acid shearing paddle in the stirring assembly work together to enhance the dispersion and mixing efficiency of acid and raw materials, increase the reaction rate, reduce side reactions and the formation of acid-soluble oils, and extend the catalyst life.
[0011] In some embodiments, the raw material stirring paddle includes a fixed ring and first blades. The fixed ring is fixedly installed on the stirring shaft, and the first blades are arranged at intervals along the circumference of the fixed ring. The number of first blades is 3-6, and the diameter of the first blade is 0.5-0.8 times the inner diameter of the inner circulation sleeve.
[0012] In some embodiments, the circulating acid shearing impeller includes a fixed disk and a second impeller blade. The fixed disk is fixedly installed on the stirring shaft, and the number of the second impeller blades is 4-8, with the diameter of the second impeller blades being 0.4-0.8 times the inner diameter of the inner circulation sleeve.
[0013] In some embodiments, the raw material distributor includes a raw material inlet pipe and a plurality of first annular branch pipes. The raw material inlet pipe is arranged radially along the first annular branch pipes and is connected to the first annular branch pipes. Each first annular branch pipe is coaxially arranged and spaced apart along the axial direction of the raw material inlet pipe. A plurality of first injection holes are provided on the first annular branch pipes, and the first injection holes are arranged facing the side of the raw material stirring paddle.
[0014] In some embodiments, a second injection hole is provided on the first annular branch pipe, and the second injection hole is arranged in the axial direction of the first annular branch pipe.
[0015] In some embodiments, the circulating acid distributor includes a circulating acid inlet pipe and a plurality of second annular branch pipes. The circulating acid inlet pipe is arranged radially along the second annular branch pipes and is connected to the second annular branch pipes. Each second annular branch pipe is coaxially arranged and spaced apart along the axial direction of the raw material inlet pipe. A plurality of second injection holes are provided on the second annular branch pipes, and the second injection holes are arranged on the side facing the raw material stirring paddle.
[0016] In some embodiments, a fourth injection hole is provided on the second annular branch pipe, and the fourth injection hole is arranged in the axial direction of the second annular branch pipe.
[0017] In some implementations, the number of second annular branches of the circulating acid distributor is 2-3 times the number of first annular branches of the raw material distributor.
[0018] In some embodiments, the diameter of the first and third injection holes is 10-30 mm, and the diameter of the second and fourth injection holes is 5-20 mm.
[0019] In some embodiments, the axial distance between the raw material distributor and the raw material agitator is 0.3-0.8 times the diameter of the raw material agitator, and the axial distance between the circulating acid distributor and the circulating acid shearing impeller is 0.2-0.6 times the diameter of the circulating acid shearing impeller.
[0020] Compared with the prior art, this application includes at least one of the following beneficial technical effects:
[0021] 1. In this invention, the raw materials are uniformly dispersed through a raw material distributor, and the circulating acid is uniformly dispersed through a circulating acid distributor with high-density spray holes. This significantly improves the contact effect between the acid and hydrocarbon phases. Combined with the synergistic effect of the two-stage shearing and stirring structure, it not only achieves precise distribution and efficient mixing of the reactants, but also effectively suppresses the occurrence of alkylation side reactions.
[0022] 2. A combined design scheme of axial flow hydrofoil propeller and radial flow disk turbine propeller is adopted. The hydrofoil propeller achieves low-energy axial fluid transport, while the disk turbine propeller completes local enhanced shear mixing. The overall energy consumption is significantly reduced compared with traditional high-speed agitation.
[0023] 3. By independently setting up the raw material feed pipe, raw material stirring paddle, raw material distributor, acid feed pipe, circulating acid shearing paddle, and circulating acid distributor, it is possible to achieve the integration of strong shear mixing and high-lift reaction. The modular ring pipe distributor and the partitioned stirring structure make the horizontal alkylation reactor have the advantages of both internal compactness and high reaction efficiency. Attached Figure Description
[0024] Figure 1 This is a schematic diagram of the overall structure of a horizontal alkylation reactor in one embodiment of this application;
[0025] Figure 2 This is a schematic diagram of the structure of the stirring assembly in one embodiment of this application;
[0026] Figure 3 This is a schematic diagram of the structure of the raw material stirring paddle in one embodiment of this application;
[0027] Figure 4This is a schematic diagram of the structure of a circulating acid shearing paddle in one embodiment of this application;
[0028] Figure 5 This is a schematic diagram of the structure of a raw material distributor in one embodiment of this application;
[0029] Figure 6 This is a schematic diagram of the structure of a circulating acid distributor in one embodiment of this application.
[0030] In the picture:
[0031] 1. Shell; 2. Inner circulation sleeve; 21. Circulation chamber; 22. Feed chamber; 3. Acid feed pipe; 4. Raw material feed pipe; 5. Stirring assembly; 51. Drive source; 52. Stirring shaft; 53. Raw material stirring paddle; 531. Fixing ring; 532. First blade; 54. Raw material distributor; 541. Raw material inlet pipe; 542. First annular branch pipe; 543. First injection hole; 544. Second injection hole; 55. Circulating acid shearing paddle; 551. Fixing disc; 552. Second blade; 56. Circulating acid distributor; 561. Circulating acid inlet pipe; 562. Second annular branch pipe; 563. Third injection hole; 564. Fourth injection hole. Detailed Implementation
[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0033] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.
[0034] Reference Figure 1 and Figure 2This application provides a horizontal alkylation reactor with two-stage shear mixing, including a shell 1 and an inner circulation sleeve 2. The inner circulation sleeve 2 is disposed inside the shell 1 and has a circulation chamber 21. A feed chamber 22 is formed between the inner circulation sleeve 2 and the shell 1. The horizontal alkylation reactor also includes an acid feed pipe 3 and a raw material feed pipe 4, both of which are connected to the circulation chamber 21. It also includes a stirring assembly 5, which includes a drive source 51 and a stirring shaft 52. In this embodiment, the drive source 51 is specifically a drive motor. The drive source 51 is fixed outside the shell 1, and the stirring shaft 52 is disposed inside the circulation chamber 21. The output shaft of the drive source 51 is coaxially fixed with the stirring shaft 52. The circulation chamber 21 is equipped with a raw material stirring paddle 53, a raw material distributor 54, a circulating acid shearing paddle 55, and a circulating acid distributor 56. The raw material distributor 54 is connected to the raw material feed pipe 4, and the circulating acid distributor 56 is connected to the acid feed pipe 3. The raw material stirring paddle 53 and the circulating acid shearing paddle 55 are coaxially fixed to the stirring shaft 52. The circulating acid shearing paddle 55 is located between the raw material distributor 54 and the circulating acid distributor 56, with the raw material stirring paddle 53 on the side of the raw material distributor 54 away from the circulating acid shearing paddle 55. Both the raw material distributor 54 and the circulating acid distributor 56 are positioned towards the raw material stirring paddle 53. Acid enters the circulating acid distributor 56 from the acid feed pipe 3. The circulating acid distributor 56 achieves uniform dispersion of the acid phase through spraying. Raw materials enter the raw material distributor 54 from the raw material feed pipe 4. The raw material distributor 54 achieves distribution of raw materials through spraying. At the same time, the drive source 51 drives the stirring shaft 52 to rotate. The stirring shaft 52 drives the raw material stirring paddle 53 and the circulating acid shearing paddle 55 to rotate. This not only achieves precise distribution and efficient mixing of the reactants, but also effectively suppresses the occurrence of alkylation side reactions.
[0035] Reference Figure 3 Specifically, in this embodiment, the raw material stirring paddle 53 is a hydrofoil-type paddle. The raw material stirring paddle 53 includes a fixing ring 531 and first blades 532. The fixing ring 531 is fixedly installed on the stirring shaft 52. The first blades 532 are arranged at intervals along the circumference of the fixing ring 531, with 3-6 blades in total. The diameter of the first blade 532 is 0.5-0.8 times the inner diameter of the inner circulation sleeve 2 (since the inner diameter of the inner circulation sleeve is variable, the inner diameter referred to here is the maximum inner diameter of the inner circulation sleeve). The angle of the first blade 532 is 15°-30° (here, the angle refers to the angle between the propeller chord and the propeller rotation plane). The raw material stirring paddle 53, with its specific number, diameter, and angle of blades, optimizes stirring efficiency, enhances the axial and radial flow of the raw material, improves mixing uniformity, and reduces energy consumption.
[0036] Reference Figure 5The raw material distributor 54 includes a raw material inlet pipe 541 and multiple first annular branch pipes 542. The raw material inlet pipe 541 is arranged radially along the first annular branch pipes 542 and is connected to the first annular branch pipes 542. Each first annular branch pipe 542 is coaxially and equidistantly spaced, and multiple first injection holes 543 are opened on the first annular branch pipes 542, with the first injection holes 543 facing the side of the raw material stirring paddle 53. The raw material distributor 54 adopts the design of annular branch pipes and axial injection holes to achieve uniform distribution of raw materials, avoid local excessively high or low concentrations, and improve the uniformity and selectivity of the reaction. Second injection holes 544 are opened on the first annular branch pipes 542, with the second injection holes 544 facing the axial direction of the first annular branch pipes 542. In this embodiment, the diameter of the first injection hole 543 is 10-30 mm and the diameter of the second injection hole 544 is 5-20 mm. By adding a second injection hole 544 to the annular branch pipe, the three-dimensional distribution effect of the raw materials is further enhanced, the three-dimensional uniformity of mixing is improved, and the dead zone is reduced.
[0037] Reference Figure 4 Furthermore, in this embodiment, the circulating acid shearing impeller 55 is specifically a disc turbine impeller. The circulating acid shearing impeller 55 includes a fixed disk 551 and second blades 552. The fixed disk 551 is fixedly installed on the stirring shaft 52. The number of second blades 552 is 4-8, and the diameter of the second blades 552 is 0.4-0.8 times the inner diameter of the inner circulation sleeve 2 (since the inner diameter of the inner circulation sleeve is variable, the inner diameter referred to here is the maximum inner diameter of the inner circulation sleeve). Through the design of the fixed disk 551 and multiple second blades 552, the circulating acid shearing impeller 55 enhances the shearing and dispersion ability of the acid phase, promotes the micro-mixing of acid and hydrocarbons (raw materials), increases the reaction interface area, and improves the alkylation reaction efficiency.
[0038] Reference Figure 6The circulating acid distributor 56 includes a circulating acid inlet pipe 561 and multiple second annular branch pipes 562. The circulating acid inlet pipe 561 is arranged radially along the second annular branch pipes 562 and is connected to the second annular branch pipes 562. Each second annular branch pipe 562 is coaxially and equidistantly spaced. Multiple third injection holes 563 are provided on each second annular branch pipe 562, with the third injection holes 563 located on the side facing the raw material stirring paddle 53. A fourth injection hole 564 is provided on each second annular branch pipe 562, oriented towards the axial direction of the second annular branch pipe 562. In this embodiment, the diameter of the third injection hole 563 is 10-30 mm, and the diameter of the fourth injection hole 564 is 5-20 mm. The multiple second annular branch pipes 562 and the third injection holes 563 achieve uniform acid distribution, improving the utilization efficiency of the acid catalyst. Adding a fourth radial injection hole 564 to the acid distributor enhances the three-dimensional dispersion ability of the acid phase, further improves the contact efficiency between the acid and the raw materials, and promotes the reaction.
[0039] In this embodiment, the number of annular branch pipes in the circulating acid distributor 56 is 2-3 times the number of annular branch pipes in the raw material distributor 54. By setting more annular branch pipes for acid distribution, the characteristics of high viscosity and difficult dispersion of the acid phase are adapted, ensuring sufficient dispersion of the acid phase and improving the overall mixing and reaction effect.
[0040] In this embodiment, the axial distance between the raw material distributor 54 and the raw material stirring impeller 53 is 0.3-0.6 times the diameter of the raw material stirring impeller 53, and the axial distance between the circulating acid distributor 56 and the circulating acid shear impeller 55 is 0.2-0.5 times the diameter of the circulating acid shear impeller 55. By limiting the axial distance between the raw material distributor 54 and the raw material stirring impeller 53, and the axial distance between the circulating acid distributor 56 and the circulating acid shear impeller 55, the mixing efficiency and energy consumption are further balanced, so that the horizontal alkylation reactor has the advantages of both compact internal structure and high reaction efficiency.
[0041] Reference Figure 5 and Figure 6 In this embodiment, both the raw material distributor 54 and the circulating acid distributor 56 are fixed by radially extending ribs, which are evenly distributed along the circumference of the annular branch pipe. The ribs are connected to the annular branch pipe by U-bolts. The raw material stirring paddle 53 and the circulating acid shearing paddle 55 are detachably mounted on the stirring shaft 52 by keyway connection or flange bolt connection.
[0042] In some embodiments, the horizontal reactor provided in this application is used to produce high-octane alkylated oil, using post-etherified C4 as feedstock. The reaction temperature is 6.9°C, the reaction pressure is 0.44 MPa, the alkyl-to-olefin ratio of the feed is 8.5, the acid concentration is 93%-97%, and the acid-to-hydrocarbon volume ratio is 1.01. The feed stirring impeller 53 has 3 blades, the blade diameter is 0.55 times the diameter of the inner circulation sleeve 2, the blade angle is 20°, and the operating speed is 526 r / min. The circulating acid shear impeller 55 has 4 blades, the blade diameter is 0.45 times the diameter of the inner circulation sleeve 2. The diameters of the first injection hole 543 and the second injection hole 544 are 15 mm. The diameters of the third injection hole 563 and the fourth injection hole 564 are 8 mm. The axial distance between the raw material distributor 54 and the raw material stirring paddle 53 is 0.3 times the diameter of the raw material stirring paddle 53, and the axial distance between the circulating acid distributor 56 and the circulating acid shearing paddle 55 is 0.4 times the diameter of the circulating acid shearing paddle 55.
[0043] The C4 feedstock after etherification enters the feedstock distributor 54 through the feedstock inlet pipe 541 and is evenly dispersed into the reactor through the first spray hole 543 and the second spray hole 544. At the same time, the circulating acid enters the circulating acid distributor 56 through the circulating acid inlet pipe 561 and is distributed in the reactor area with high density through the third spray hole 563 and the fourth spray hole 564. The drive source 51 drives the stirring shaft 52 to rotate, the feedstock stirring paddle 53 shears the feedstock at high speed and pushes the material to the right axial direction, and the circulating acid shearing paddle 55 performs radial enhanced shearing on the acid phase. The two phases fully contact and react in the two-stage mixing zone. The reaction mixture forms a forced internal circulation under the stirring action. The high-temperature material is cooled by the reactor heat exchange tube group and returned to the reaction zone to maintain a constant temperature reaction condition of 6.9°C. The mixture after reaction is separated by sedimentation, and the acid hydrocarbon emulsion is discharged from the upper outlet 8.
[0044] The change in sulfuric acid concentration in waste acid was determined using the acid-base titration method specified in GB / T 534-2014 "Industrial Sulfuric Acid". The conversion rate of the feedstock olefins was calculated using GB / T 30519-2014 "Determination of Hydrocarbon Composition in Light Petroleum Fractions and Products". After treatment by the horizontal reactor provided in this application, the acid consumption of the alkylation reactor was reduced to 75 kg / t, and the conversion rate of the feedstock olefins reached 99.5%.
[0045] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. A horizontal alkylation reactor with two-stage shear mixing, characterized in that, include: The shell (1) and the inner circulation sleeve (2) are disposed inside the shell (1). The inner circulation sleeve (2) is provided with a circulation cavity (21) and a feeding cavity (22) is formed between the inner circulation sleeve (2) and the shell (1). Both the acid feed pipe (3) and the raw material feed pipe (4) are connected to the circulation chamber (21); The stirring assembly (5) includes a drive source (51) and a stirring shaft (52). The drive source (51) is located outside the housing (1), and the stirring shaft (52) is located inside the circulation chamber (21). The drive source (51) is connected to the stirring shaft (52) in a driving connection. The circulation chamber (21) is provided with a raw material stirring paddle (53), a raw material distributor (54), a circulating acid shearing paddle (55), and a circulating acid distributor (56). The raw material distributor (54) is connected to the raw material feed pipe (4), and the circulating acid distributor (56) is connected to the acid feed pipe (3). The raw material stirring paddle (53) and the circulating acid shearing paddle (55) are coaxially fixed to the stirring shaft (52). The circulating acid shearing paddle (55) is located between the raw material distributor (54) and the circulating acid distributor (56). The raw material stirring paddle (53) is located on the side away from the circulating acid shearing paddle (55) relative to the raw material distributor (54).
2. The horizontal alkylation reactor with two-stage shear mixing according to claim 1, characterized in that: The raw material stirring paddle (53) includes a fixing ring (531) and a first blade (532). The fixing ring (531) is fixedly installed on the stirring shaft (52). The first blades (532) are arranged at intervals along the circumference of the fixing ring (531). The number of the first blades (532) is 3-6. The diameter of the first blade (532) is 0.5-0.8 times the inner diameter of the inner circulation sleeve (2) in which it is located.
3. The horizontal alkylation reactor with two-stage shear mixing according to claim 1, characterized in that: The circulating acid shearing impeller (55) includes a fixed disk (551) and a second impeller (552). The fixed disk (551) is fixedly installed on the stirring shaft (52). The number of the second impeller (552) is 4-8, and the diameter of the second impeller (552) is 0.4-0.8 times the inner diameter of the inner circulation sleeve (2).
4. The horizontal alkylation reactor with two-stage shear mixing according to claim 1, characterized in that: The raw material distributor (54) includes a raw material inlet pipe (541) and a plurality of first annular branch pipes (542). The raw material inlet pipe (541) is arranged radially along the first annular branch pipes (542) and is connected to the first annular branch pipes (542). Each first annular branch pipe (542) is coaxially arranged and spaced apart along the axial direction of the raw material inlet pipe (541). A plurality of first injection holes (543) are opened on the first annular branch pipes (542), and the first injection holes (543) are arranged facing the side of the raw material stirring paddle (53).
5. A horizontal alkylation reactor with two-stage shear mixing according to claim 4, characterized in that: The first annular branch pipe (542) is provided with a second injection hole (544), which is oriented toward the axis of the first annular branch pipe (542).
6. A horizontal alkylation reactor with two-stage shear mixing according to claim 5, characterized in that: The circulating acid distributor (56) includes a circulating acid inlet pipe (561) and a plurality of second annular branch pipes (562). The circulating acid inlet pipe (561) is arranged radially along the second annular branch pipes (562) and is connected to the second annular branch pipes (562). Each second annular branch pipe (562) is coaxially arranged and spaced apart along the axial direction of the raw material inlet pipe (541). A plurality of third injection holes (563) are opened on the second annular branch pipes (562), and the third injection holes (563) are arranged on the side facing the raw material stirring paddle (53).
7. A horizontal alkylation reactor with two-stage shear mixing according to claim 6, characterized in that: The second annular branch pipe (562) is provided with a fourth injection hole (564), which is arranged in the direction of the axis of the second annular branch pipe (562).
8. A horizontal alkylation reactor with two-stage shear mixing according to claim 6, characterized in that: The number of second annular branch pipes (562) of the circulating acid distributor (56) is 2-3 times the number of first annular branch pipes (542) of the raw material distributor (54).
9. A horizontal alkylation reactor with two-stage shear mixing according to claim 7, characterized in that: The diameter of the first injection hole (543) and the third injection hole (563) is 10-30 mm, and the diameter of the second injection hole (544) and the fourth injection hole (544) is 5-20 mm.
10. A horizontal alkylation reactor with two-stage shear mixing according to claim 1, characterized in that: The axial distance between the raw material distributor (54) and the raw material stirring paddle (53) is 0.3-0.8 times the diameter of the raw material stirring paddle (53), and the axial distance between the circulating acid distributor (56) and the circulating acid shearing paddle (55) is 0.2-0.6 times the diameter of the circulating acid shearing paddle (55).