An extraction column for hydrogen peroxide production

Abstract

The application discloses a kind of extraction column for hydrogen peroxide production, including tower body, composite tray is arranged in tower body, composite tray includes sieve plate, flow guide support, composite packing layer, downcomer, flow guide packing layer, flow guide support is located below sieve plate, above composite packing layer;The upper end of downcomer is flush with sieve plate, passes through flow guide support and composite packing layer, and the lower end is located in the gap area between composite packing layer and flow guide packing layer.The extraction column structure is simple, convenient existing sieve plate extraction column structure is reformed, easy to popularize and apply, can effectively solve the problem, such as extraction tower working condition deterioration in hydrogen peroxide production, extraction concentration does not reach standard, extraction residue is too high and working fluid flux decreases, has important significance for improving extraction efficiency, reducing extraction tower liquid holdup and ensuring the safe and stable operation of device.

Description

Technical Field

[0001] This invention relates to equipment for hydrogen peroxide production processes, and more particularly to an extraction tower for hydrogen peroxide production. Background Technology

[0002] The main process for producing hydrogen peroxide using the anthraquinone method can be divided into four stages: hydrogenation, oxidation, extraction, and post-treatment. Among these, the extraction process involves the migration of hydrogen peroxide from the organic phase to the aqueous phase. In this process, the design of the extraction tower is crucial, as its structure plays a vital role in the yield and quality of hydrogen peroxide, and even the safe operation of the entire plant.

[0003] Currently, sieve plate extraction towers are used in the extraction stage of hydrogen peroxide production. Sieve plate extraction towers have advantages such as low cost, large throughput, and high transfer efficiency, and are widely used in chemical production processes. In recent years, with the development of hydrogen peroxide production technology, in order to improve hydrogen efficiency and the production efficiency of the unit, and effectively reduce material consumption, energy consumption, and production costs, high-performance working fluid systems containing TBU components have been widely promoted. However, the properties of working fluids containing TBU components are prone to a series of changes during system operation. In industrial units, this manifests as the working fluid easily emulsifying inside the extraction tower, and difficulty in coalescence after dispersion. This situation easily causes a series of problems in the current sieve plate extraction tower operation: for example, reduced extraction tower throughput, inability of small droplets of working fluid to form an effective liquid layer below the sieve plate, and even flooding of the extraction tower, affecting the safe operation of the unit. Traditional sieve plate extraction towers have a relatively simple structure and cannot effectively suppress interlayer backmixing, resulting in low extraction efficiency. Therefore, a large number of trays are generally required to meet the extraction and raffinate concentration requirements, resulting in a large extraction tower volume and liquid holdup, and increased initial investment. Summary of the Invention

[0004] This invention addresses the shortcomings of existing extraction tower structures in hydrogen peroxide production processes by proposing a novel composite tray extraction tower. This tower optimizes the extraction process in hydrogen peroxide production, particularly in cases where the working fluid system is prone to water contamination and emulsification. It effectively reduces the hydrogen peroxide content in the raffinate while simultaneously increasing the hydrogen peroxide concentration in the effluent at the bottom of the tower. The novel composite tray extraction tower features a simple structure, facilitating modification of existing sieve-plate extraction towers and enabling widespread application. It effectively solves problems such as deteriorating extraction tower conditions, substandard extraction concentrations, excessive raffinate, and decreased working fluid throughput in hydrogen peroxide production. This invention is significant for improving extraction efficiency, reducing tower height and liquid holdup, and ensuring the safe and stable operation of the equipment.

[0005] To solve the above-mentioned technical problems, the present invention provides an extraction tower for hydrogen peroxide production, comprising a tower body 101, characterized in that a composite tower plate 201 is provided inside the tower body 101, the composite tower plate 201 comprising a sieve plate 1, a flow guide support 2, a composite packing layer 3, a downcomer 9, and a flow guide packing layer 8, the flow guide support 2 being located below the sieve plate 1 and above the composite packing layer 3; the upper end of the downcomer 9 is flush with the sieve plate 1, passes through the flow guide support 2 and the composite packing layer 3, and the lower end is in the gap area between the composite packing layer 3 and the flow guide packing layer 8.

[0006] Furthermore, the sieve plate 1 is fixed on the sieve plate support beam, and the distance between two adjacent sieve plates is 300~850 mm, preferably 400~800 mm.

[0007] Furthermore, the number of composite trays is 35-60, preferably 45-55.

[0008] Furthermore, the flow guide 2 is a skeleton structure composed of a circular ring and multiple rigid filaments, with one end of each filament connected to the circular ring and the other end converging above the ring. The number of flow guides 2 in each composite tray 201 is preferably 10-100, more preferably 40-80. The number of rigid filaments in a single flow guide 2 is 2-6, preferably 3-4. Preferably, the rigid filaments are equidistantly distributed on the circular ring. Preferably, the angle between the rigid filaments and the horizontal direction is 20-60°, more preferably 30-55°. Preferably, each rigid filament has the same length. Preferably, the diameter of the rigid filaments is 0.2-0.5 mm.

[0009] Furthermore, the material of the flow guide 2 is one or more of stainless steel, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber. The height of the flow guide 2 is 5~100 mm, preferably 10~80 mm. The distance between the top of the flow guide 2 and the upper sieve plate 1 is 0~10 mm, preferably 0~5 mm.

[0010] Furthermore, the filler of the composite filler layer 3 is one or more of the following: wire mesh corrugated filler, gas-liquid filter wire mesh, wire mesh demister, and perforated plate corrugated filler, preferably a combination of two or more of the following: wire mesh corrugated filler, gas-liquid filter wire mesh, and wire mesh demister; the filler material is stainless steel, or each filler material is one or more of the following: polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber, combined with stainless steel, preferably a combination of two or more of the following: polypropylene, polytetrafluoroethylene, and glass fiber, combined with stainless steel; the porosity of the filler selected in the composite filler layer 3 is ≥90%, preferably ≥93%; the thickness of the composite filler layer 3 is 1~200 mm, preferably 5~100 mm.

[0011] Furthermore, the lower part of the extraction tower is provided with an oxidation liquid inlet 102. Above the oxidation liquid inlet 102, in the nth composite tray 201 (the composite trays 201 are numbered sequentially from the bottom of the extraction tower upwards), the volume of stainless steel material in the composite packing layer 3... V 1. Combined volume with other materials V The ratio of 2 is r ,in n When the value is 1~10, r =0.1~1; preferably 0.2~0.7; n =11~20, r =0.3~1.5; preferably 0.5~2; n =21~30, r =0.8~6; preferably 1~4.5; n =31~40, r =0.9~10; preferably 1.1~8; n =41~50, r =1~15, preferably 1.2~13; n >50, r =1~20; preferably 1~15.

[0012] Furthermore, the distance between the top of the composite packing layer 3 and the bottom of the flow guide bracket 2 is 0~200 mm, preferably 0~100 mm; more preferably, fixing plates are provided above and below the composite packing layer 3, and the lower end of the flow guide bracket 2 contacts the fixing plate 4 above the composite packing layer 3. Preferably, a composite packing layer fixing bracket 6 is provided on the fixing plate 5 below the composite packing layer 3.

[0013] Furthermore, the height of the downcomer 9 is 100~350 mm, preferably 150~300 mm; the downcomer 9 is distributed alternately between the middle and the edge of adjacent sieve plates 1.

[0014] Furthermore, the flow guiding packing layer 8 is a wire mesh corrugated packing and / orifice plate corrugated packing, wherein each packing material is one or more of stainless steel, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber, preferably a combination of two or more of stainless steel, polypropylene, polytetrafluoroethylene, and glass fiber; the porosity of the packing selected for the flow guiding packing layer 8 should be ≥93%, preferably ≥95%; the thickness of the flow guiding packing layer 8 is 0~120 mm, preferably 5~60 mm; the distance between the bottom of the flow guiding packing layer 8 and the lower sieve plate 1 is 0~100 mm, preferably 0~50 mm. Preferably, the flow guiding packing layer 8 is fixed using a flow guiding packing layer fixing bracket 7.

[0015] The composite extraction tower sieve plate for anthraquinone hydrogen peroxide production provided by this invention has the following advantages over existing sieve plates:

[0016] 1. This invention provides a composite packing layer below each sieve plate in the extraction tower. This composite packing layer effectively promotes the coalescence of small droplets in the working fluid and facilitates the separation of emulsified working fluid droplets into organic and aqueous phases. It forms an organic layer of a certain thickness below the sieve plate, preventing the entrainment of the aqueous phase in the working fluid passing through the sieve holes, providing stable momentum for the working fluid to float, and preventing a decrease in the working fluid throughput of the extraction tower. Simultaneously, the formation of the organic layer below the sieve plate helps renew the surface of the dispersed phase droplets, improving extraction efficiency.

[0017] 2. The present invention provides a flow guide support between each sieve plate and the composite packing layer in the extraction tower. This can promote the working liquid flowing through the composite packing layer to accumulate below the sieve plate after passing through the flow guide support, avoiding short circuits between the working liquid and the sieve plate. This results in a uniform distribution of the liquid accumulation layer below the sieve plate, making full use of each opening of the sieve plate, increasing the mass transfer area between the dispersed phase and the continuous phase, which is beneficial to maintaining the stability of the internal operating conditions of the extraction tower and improving the extraction efficiency.

[0018] 3. The composite packing layer is composed of a variety of materials selected according to the operating conditions of the extraction tower in the industrial unit. The proportion of each material used in each layer is changed according to the state of the working liquid during the actual operation of the extraction tower, so as to cope with the complex operating conditions in each tower section, enhance the throughput of specific tower sections, avoid material accumulation or even flooding in the extraction tower, and ensure the safe and stable operation of the production unit.

[0019] 4. Conventional sieve plate extraction towers can limit backmixing between two adjacent sieve plates. However, the corrugated regular packing selected for the flow guiding packing layer of this invention consists of several vertically arranged corrugated sheets, which have high porosity, large specific surface area, and good wettability and self-distribution ability. The regular channels formed between the corrugated sheets of this type of packing allow liquid to flow, which can effectively cooperate with the sieve plates to suppress the deviation of the working liquid and limit backmixing between adjacent sieve plates, thereby improving the extraction efficiency. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the extraction tower structure;

[0021] Figure 2 This is a schematic diagram of a composite tray structure;

[0022] Figure 3 This is a schematic diagram showing the distribution of downcomers between adjacent trays;

[0023] Figure 4 This is a schematic diagram of a single flow guide support structure;

[0024] Figure 5 A schematic diagram showing the distribution of flow guide supports in each layer of the composite tower tray;

[0025] Among them, 101 is the tower body, 102 is the oxidant inlet, 103 is the hydrogen peroxide outlet, 104 is the pure water inlet, and 105 is the working liquid outlet; 201 is the composite tower plate, 1 is the sieve plate, 2 is the flow guide support, 3 is the composite packing layer, 4 / 5 are the packing layer fixing clamps, 6 is the composite packing layer fixing support, 7 is the flow guide packing layer fixing support, 8 is the flow guide packing layer, and 9 is the downcomer. Detailed Implementation

[0026] The preferred embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific implementation schemes. It should be noted that the embodiments described below are only some embodiments of the present invention, not all embodiments, and are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without making inventive improvements are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, they are performed according to conventional conditions or manufacturer's recommended conditions.

[0027] The following combination Figure 1-5 The operation process of the extraction tower of the present invention is described below:

[0028] like Figure 1 The extraction tower includes a tower body 101, a composite tower plate 201 is provided inside the tower body 101, and an oxidation liquid inlet 102 is provided at the bottom of the extraction tower, a pure water inlet 104 is provided at the top, a hydrogen peroxide outlet 103 is provided at the bottom, and a working liquid outlet 105 is provided at the top.

[0029] Pure water (continuous phase) and oxidizing liquid (dispersed phase) flow counter-currently. The working liquid (oxidizing liquid) containing hydrogen peroxide enters the extraction tower through oxidizing liquid inlet 102, passes vertically upward through each tower section, and redisperses into droplet clusters on each plate. Pure water enters the tower through pure water inlet 104 at the top and flows into the lower tower section through the downcomer. During the upward movement of the working liquid, it passes through each level of sieve plates, and the surface of the dispersed phase droplets is repeatedly renewed, with hydrogen peroxide continuously entering the aqueous phase from inside the working liquid.

[0030] To more clearly illustrate the present invention, specific embodiments are described below.

[0031] Example 1

[0032] Reference Figure 1 , 2The diagram shows an embodiment of an anthraquinone hydrogen peroxide extraction tower. In this industrial extraction tower, the spacing between adjacent sieve plates is 400 mm, and the downcomer height is 200 mm. The downcomers are distributed alternately between the middle and edge of adjacent sieve plates. The flow guide support structure is made of stainless steel and polypropylene, and its height is 60 mm. The composite packing layer is made of wire mesh corrugated packing, with each type of packing material being stainless steel. The porosity of the composite packing layer is 95%, and its thickness is 100 mm. The flow guide packing layer is made of perforated plate corrugated packing, also made of stainless steel, with a porosity of 95% and a thickness of 100 mm. The extraction tower has a total of 40 composite trays.

[0033] In the aforementioned equipment, the aqueous phase flow rate is controlled at 10 m³ / s. 3 / h, control the oxidizing liquid flow rate at 500 m³ / h. 3 The hydrogen peroxide content in the extract and the raffinate of the extraction tower in this embodiment were measured under the extraction conditions of / h. The hydrogen peroxide content in the extract and the raffinate of this embodiment were 401.0 g / L and 0.15 g / L, respectively.

[0034] Example 2

[0035] Reference Figure 1 , 2 The diagram shows an embodiment of an anthraquinone hydrogen peroxide extraction tower. In this industrial unit, the distance between adjacent sieve plates is 500 mm, and the downcomer height is 150 mm. The downcomers are distributed alternately between the middle and edge of adjacent sieve plates. The flow guide support is made of stainless steel and polytetrafluoroethylene (PTFE), and its height is 10 mm. The composite packing layer is a gas-liquid filter mesh, made of stainless steel and PTFE. The porosity of the composite packing layer is 92%, and its thickness is 50 mm. Above the working liquid distributor... n In the tower section, the stainless steel material has a volume V 1. Volume of polytetrafluoroethylene material V The ratio of 2 is r ,in n When the value is 1~10, r =0.7; n =11~20, r =1; n =21~30, r =5; n =31~40, r =12; n =41~50, r =9, n >50, r=15; the flow guiding packing layer is made of wire mesh corrugated packing, and the material of the packing is stainless steel. The porosity of the flow guiding packing layer is 97%, and the thickness of the flow guiding packing layer is 50 mm. A total of 51 composite sieve plates are installed in this extraction tower.

[0036] In the aforementioned equipment, the water phase flow rate is controlled at 13 m³. 3 / h, control the oxidizing liquid flow rate at 650 m³ / h. 3 The hydrogen peroxide content in the extract and the raffinate of the extraction tower in this embodiment were measured under the extraction conditions of / h. The hydrogen peroxide content in the extract and the raffinate of this embodiment were 440.0 g / L and 0.13 g / L, respectively.

[0037] Example 3

[0038] Reference Figure 1 , 2 The diagram shows an embodiment of an anthraquinone hydrogen peroxide extraction tower. In this industrial unit, the distance between adjacent sieve plates is 700 mm, and the downcomer height is 350 mm. The downcomers are distributed alternately between the middle and edge of adjacent sieve plates. The flow guide support is made of stainless steel and polypropylene, and its height is 20 mm. The composite packing layer consists of wire mesh corrugated packing and perforated plate corrugated packing, each made of stainless steel and polypropylene. The porosity of the composite packing layer is 95%, and the total thickness of the composite packing layer is 100 mm. Above the working liquid distributor... n In the tower section, the stainless steel material has a volume V 1. Volume of polypropylene material V The ratio of 2 is r ,in n When the value is 1~10, r =0.9; n =11~20, r =1.5; n =21~30, r =5.5; n =31~40, r =8; n =41~50, r =10; No flow-guiding packing layer. The extraction tower contains 43 composite sieve plates.

[0039] In the aforementioned equipment, the water phase flow rate is controlled at 19 m³. 3 / h, control the oxidant flow rate at 950 m³ / h. 3 The hydrogen peroxide content in the extract and the raffinate of the extraction tower in this embodiment were measured under the extraction conditions of / h. The hydrogen peroxide content in the extract and the raffinate of this embodiment were 420.0 g / L and 0.20 g / L, respectively.

[0040] Comparative Example 1

[0041] Compared with Example 2, the only difference is that Comparative Example 1 did not have a flow guide. The extraction results were: the hydrogen peroxide content in the extract and the hydrogen peroxide content in the raffinate were 385.2 g / L and 0.22 g / L, respectively.

[0042] Comparative Example 2

[0043] Compared with Example 2, the only difference is that the composite filler layer material of Comparative Example 2 is polytetrafluoroethylene. The extraction results are as follows: the hydrogen peroxide content in the extract and the hydrogen peroxide content in the raffinate are 401.5 g / L and 0.20 g / L, respectively.

[0044] Comparative Example 3

[0045] Compared with Example 2, the only difference is that Comparative Example 3 lacks the flow guide support, composite packing layer, and flow guide packing layer. The extraction results were: the hydrogen peroxide content in the extract and the hydrogen peroxide content in the raffinate were 353.2 g / L and 0.29 g / L, respectively.

Claims

1. An extraction tower for hydrogen peroxide production, comprising a tower body (101), characterized in that, The tower body (101) is equipped with a composite tower plate (201), which includes a sieve plate (1), a flow guide support (2), a composite packing layer (3), a downcomer (9), and a flow guide packing layer (8). The flow guide support (2) is located below the sieve plate (1) and above the composite packing layer (3). The upper end of the downcomer (9) is flush with the sieve plate (1), passes through the flow guide support (2) and the composite packing layer (3), and the lower end is located in the gap area between the composite packing layer (3) and the flow guide packing layer (8). The flow guide bracket (2) is a skeleton structure composed of a circular ring and multiple hard filaments. One end of the multiple hard filaments is connected to the circular ring, and the other end is intersected above the circular ring. The material of the flow guide bracket (2) is one or more of stainless steel, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber. The composite filler layer (3) is made of one or more of polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber, combined with stainless steel.

2. The extraction tower according to claim 1, characterized in that, The height of the flow guide bracket (2) is 5~100 mm; the distance between the top of the flow guide bracket (2) and the upper screen plate (1) is 0~10 mm.

3. The extraction tower according to claim 2, characterized in that, The height of the flow guide bracket (2) is 10~80 mm; the distance between the top of the flow guide bracket (2) and the upper screen plate (1) is 0~5 mm.

4. The extraction tower according to claim 1, characterized in that, The filler of the composite filler layer (3) is one or more of the following: wire mesh corrugated filler, gas-liquid filter wire mesh, wire mesh demister, and perforated plate corrugated filler; the material of each filler is a combination of two or more of polypropylene, polytetrafluoroethylene, and glass fiber with stainless steel.

5. The extraction tower according to claim 4, characterized in that, The filler of the composite filler layer (3) is a combination of two or more of the following: wire mesh corrugated filler, gas-liquid filter wire mesh, and wire mesh demister.

6. The extraction tower according to claim 4, characterized in that, The composite trays (201) are numbered sequentially from the bottom of the tower upwards. In the nth composite tray, the volume of stainless steel material in the composite packing layer (3) is... V 1. Combined volume with other materials V The ratio of 2 is r ,in n When the value is 1~10, r =0.1~1; n =11~20, r =0.3~1.5; n =21~30, r =0.8~6; n =31~40, r =0.9~10; n =41~50, r =1~15; n >50, r =1~20.

7. The extraction tower according to claim 6, characterized in that, n When the value is 1~10, r =0.2~0.7; n =11~20, r =0.5~1.5; n =21~30, r =1~4.5; n =31~40, r =1.1~8; n =41~50, r =1.2~13; n >50, r =1~15.

8. The extraction tower according to claim 1, characterized in that, The composite filler layer (3) uses filler with a porosity of ≥90% and a thickness of 1 ~200 mm.

9. The extraction tower according to claim 8, characterized in that, The composite filler layer (3) uses filler with a porosity of ≥93%; the thickness of the composite filler layer (3) is 5~100 mm.

10. The extraction tower according to claim 1, characterized in that, The distance between the top of the composite filler layer (3) and the bottom of the flow guide (2) is 0~200 mm.

11. The extraction tower according to claim 10, characterized in that, The distance between the top of the composite filler layer (3) and the bottom of the flow guide (2) is 0~100 mm.

12. The extraction tower according to claim 1, characterized in that, The height of the downcomer (9) is 100~350 mm; the downcomer (9) is distributed alternately between the middle and the edge between adjacent sieve plates.

13. The extraction tower according to claim 12, characterized in that, The height of the downcomer (9) is 150~300 mm.

14. The extraction tower according to claim 1, characterized in that, The flow guiding packing layer is a wire mesh corrugated packing and / or a perforated plate corrugated packing, wherein each packing material is one or more of stainless steel, polypropylene, polyvinyl chloride, polytetrafluoroethylene, polyvinylidene fluoride, and glass fiber.

15. The extraction tower according to claim 14, characterized in that, Each filler in the flow-guiding filler layer is made of a combination of two or more of the following materials: stainless steel, polypropylene, polytetrafluoroethylene, and glass fiber.

16. The extraction tower according to claim 1, characterized in that, The porosity of the filler material selected for the flow guiding packing layer is ≥93%; the thickness of the flow guiding packing layer is 0 ~120 mm.

17. The extraction tower according to claim 16, characterized in that, The porosity of the filler material selected for the flow guiding filler layer is ≥95%; the thickness of the flow guiding filler layer is 0~60 mm.

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