An adsorption column and purification system

Abstract

The utility model provides a kind of adsorption tower and purification system, belong to chemical separation equipment technical field.The adsorption tower includes tower body, the inside of the tower body includes filler layer, the filler layer includes sieve plate, stainless steel wire net, support layer and molecular sieve adsorption layer from bottom to top superimposed;The tower body is also equipped with material inlet, product outlet, regeneration gas inlet, inert gas inlet and inert gas outlet.The utility model is reasonable in structure, and is applicable to the efficient, continuous separation of high viscosity azeotrope, such as long-chain alkyl mercaptan.

Description

Technical Field

[0001] This utility model relates to the field of chemical separation equipment technology, and in particular to an adsorption tower and purification system. Background Technology

[0002] In fine chemical production, the efficient purification of azeotropic mixtures with similar boiling points that are difficult to separate by conventional distillation has always been a technical challenge. Long-chain alkyl thiols, such as n-dodecyl thiols and n-octadecyl thiols, are important raw materials for fine chemicals. During their preparation, the target product readily forms azeotropes with structurally similar branched isomers, hindering subsequent high-end applications.

[0003] Currently, industrial equipment used for separating such materials is mostly distillation columns, especially high-vacuum distillation columns designed to lower boiling points. However, the structure and working principle of existing distillation separation equipment lead to a series of engineering application problems when applied to such specific systems. First, to maintain high vacuum operation, the equipment system must integrate complex vacuum units (such as steam jet pumps and mechanical vacuum pumps). These peripheral auxiliary devices not only increase the complexity and footprint of the system, but also directly drive up operating costs due to their high-frequency maintenance requirements. Second, for mass transfer separation of high-viscosity systems, the internal components of traditional tower equipment (such as plate towers and conventional packed towers) are prone to a sharp reduction in effective mass transfer area due to uneven liquid distribution and channeling, resulting in unsatisfactory separation efficiency. To achieve certain separation requirements, it is often necessary to increase the tower height or diameter, which significantly increases equipment investment. Furthermore, high vacuum places extremely high demands on the overall sealing performance of the equipment. With numerous dynamic sealing points (such as pumps and valves), even minor leaks during long-term operation can easily lead to vacuum instability, affecting the stability of continuous production.

[0004] Given the aforementioned drawbacks of distillation, adsorption separation technology, particularly fixed-bed adsorption based on molecular sieves, has attracted attention as a promising alternative. However, existing adsorption tower structures have inherent limitations when pushing adsorption technology towards large-scale continuous industrial applications. For high-viscosity materials such as long-chain alkyl thiols, improper tower internals design can easily lead to uneven material distribution across the tower cross-section, resulting in severe wall flow and channeling. This prevents the adsorbent bed from being fully utilized, significantly reducing the effective mass transfer area and resulting in low single-tower separation efficiency. Furthermore, the lack of optimized internal structure makes it difficult to achieve multi-stage precision adsorption and timely removal of impurity enrichment within a single tower, hindering the simultaneous guarantee of high-purity main product yield and effective separation of by-products in continuous operation. Existing adsorption tower structures are often designed for gas-phase mass transfer or low-viscosity liquids, failing to fully consider the specific flow and distribution requirements of high-viscosity liquids under adsorption separation conditions.

[0005] Therefore, from the perspective of equipment structure, there is an urgent need to design a new type of adsorption tower with internal components specifically designed for high-viscosity materials, along with a corresponding purification system. It should be able to circumvent the complexities of high-vacuum systems and fundamentally improve the flow and distribution of high-viscosity materials through innovative internal structural design, thereby enhancing mass transfer efficiency and providing a reliable equipment foundation for the efficient, stable, and energy-saving continuous separation of long-chain alkyl thiols azeotropic compounds. Utility Model Content

[0006] The purpose of this invention is to overcome the shortcomings of existing high-vacuum distillation columns, such as complex equipment, high energy consumption, and unreasonable internal component design of existing adsorption columns leading to uneven distribution of high-viscosity materials and low separation efficiency. This invention provides an adsorption column and purification system with a reasonable structural design that can ensure uniform material distribution and efficient collection, and is particularly suitable for the continuous adsorption and separation of long-chain alkyl thiols azeotropic compounds.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides an adsorption tower, including a tower body, the interior of which includes a packing layer, the packing layer including a sieve plate, a stainless steel wire mesh, a support layer and a molecular sieve adsorption layer stacked from bottom to top;

[0009] The tower body is also equipped with:

[0010] The material inlet, located at the top of the tower, is used to introduce the azeotropic mixture;

[0011] The product outlet is located at the bottom of the tower and is used to separately discharge the material rich in branched alkyl thiols and the material rich in straight alkyl thiols from the azeotropic mixture separated by the molecular sieve adsorption layer.

[0012] The regenerated gas inlet, located at the top of the tower, is used to introduce a heat medium to elute straight-chain alkyl thiols adsorbed on the molecular sieve adsorption layer.

[0013] The inert gas inlet, located at the bottom of the tower, is used to introduce inert gas to cool the entire tower.

[0014] The inert gas outlet, located at the top of the tower, is used to discharge the inert gas flowing from the bottom to the top of the tower.

[0015] This invention utilizes a bottom-up packing layer structure comprising a sieve plate, stainless steel wire mesh, a support layer, and a molecular sieve adsorption layer. This ensures the stability of the adsorbent bed and the uniform flow of gas / liquid, preventing adsorbent particle loss and bed blockage. The stepped structure of the stainless steel wire mesh, support layer, and molecular sieve adsorption layer effectively combines the three core functions of interception, support, and distribution. The support layer possesses high mechanical strength, providing solid support for the relatively fragile molecular sieve adsorbent particles above, preventing them from being compacted or broken under their own weight and operating pressure. The ceramic ball support layer forms a "distribution plate" with numerous pores, avoiding "channeling" (where fluid preferentially chooses the path of least resistance, resulting in most adsorbent not being utilized). The molecular sieve is primarily supported on the support layer through "bridging" rather than being trapped within its pores. Any molecular sieve that falls into the pores of the top layer of ceramic balls is firmly blocked by the dense stainless steel wire mesh below.

[0016] Optionally, the support layer is composed of tightly arranged porous ceramic balls and is disposed on the stainless steel wire mesh to compact and fix the stainless steel wire mesh.

[0017] Optionally, the stainless steel wire mesh has a mesh size of 18-22; the porous ceramic ball has a diameter of 7-9 mm.

[0018] Optionally, a feed distributor is provided inside the tower body below the material inlet to uniformly distribute the azeotropic mixture entering the tower to the entire cross-section of the packing layer.

[0019] Optionally, the feed distributor is one or more of a disc distributor, a tubular distributor, and a narrow-slot liquid distributor.

[0020] Optionally, a bottom liquid collector is provided inside the tower body above the product outlet to collect the liquid flowing out from the packing layer and transport it to the product outlet.

[0021] Optionally, the bottom liquid collector is a louvered liquid collector or a disc liquid collector.

[0022] Optionally, the tower body is filled with two packing layers, namely a first fixed bed packing layer and a second fixed bed packing layer; between the first fixed bed packing layer and the second fixed bed packing layer, from top to bottom, are arranged an intermediate liquid collector for collecting liquid from the first fixed bed packing layer and an intermediate distributor for redistributing the liquid collected by the intermediate liquid collector to the second fixed bed packing layer.

[0023] Optionally, the intermediate liquid collector is a louvered liquid collector, and the intermediate distributor is a narrow-slot liquid distributor.

[0024] Secondly, this utility model provides a purification system, including multiple adsorption towers as described in the first aspect and a valve switching system arranged in parallel.

[0025] The valve switching system is configured to control multiple adsorption towers to be in adsorption, regeneration, and cooling states respectively, so as to achieve continuous separation and purification of materials.

[0026] Optionally, the purification system further includes a raw material tank, a product testing system, a product tank, a by-product testing system, a by-product tank, a steam generator, and a nitrogen source;

[0027] The valve switching system includes a control unit and multiple valves connected between the pipelines;

[0028] The control unit is configured to control the opening and closing states of the plurality of valves according to a preset program, so as to periodically switch each adsorption tower to adsorption, regeneration and cooling states respectively.

[0029] The raw material tank is connected to the material inlet of each adsorption tower via pipelines and valves; the product outlet of each adsorption tower is selectively connected to the inlet of the product detection system or the by-product detection system via pipelines and valves; the outlet of the product detection system is connected to both the product tank and the raw material tank; the outlet of the by-product detection system is connected to both the by-product tank and the raw material tank; the steam generator is connected to the regeneration gas inlet of each adsorption tower via pipelines and valves; and the nitrogen source is connected to the inert gas inlet of each adsorption tower via pipelines and valves.

[0030] Optionally, the product testing system includes a first online analyzer; the control unit is signal-connected to the first online analyzer and configured to: judge the purity of linear alkyl mercaptans in the material rich in linear alkyl mercaptans discharged from the product outlet of the adsorption tower in the regeneration state based on the real-time detection signal of the first online analyzer; when the purity is qualified, control the valve on the pipeline connecting the product testing system and the product tank to send the material into the product tank; otherwise, control the valve on the pipeline connecting the product testing system and the raw material tank to return the material to the raw material tank.

[0031] Optionally, the by-product detection system includes a second online analyzer; the control unit is signal-connected to the second online analyzer and configured to: judge the content of straight-chain alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet of the adsorption tower in the adsorption state based on the real-time detection signal of the second online analyzer; when the content is lower than a first preset threshold, control the valve on the pipeline connecting the by-product detection system and the by-product tank to send the material into the by-product tank; otherwise, control the valve on the pipeline connecting the by-product detection system and the raw material tank to return the material to the raw material tank.

[0032] Optionally, the control unit is connected to the second online analyzer of the by-product detection system and is configured to: judge the content of straight-chain alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet of the adsorption tower in the adsorption state based on the real-time detection signal of the second online analyzer; when the content continuously reaches a second preset threshold within a preset time, determine that the adsorbent in the adsorption tower is close to saturation, and control the valve switching system to switch the tower from the adsorption state to the regeneration state.

[0033] Compared with the prior art, the beneficial effects of this utility model include at least one of the following:

[0034] 1) The adsorption tower has a reasonable structural design, which effectively improves separation efficiency and operational stability;

[0035] By employing a bottom-up packing layer structure comprising a sieve plate, stainless steel wire mesh, a support layer, and a molecular sieve adsorption layer, the stability of the adsorbent bed and the uniform flow of gas / liquid are ensured, preventing adsorbent particle loss and bed clogging. The stepped structure composed of the stainless steel wire mesh, support layer, and molecular sieve adsorption layer balances the three core functions of interception, support, and distribution. The support layer possesses high mechanical strength, providing solid support for the relatively fragile molecular sieve adsorbent particles above, preventing them from being compacted or broken under their own weight and operating pressure. The ceramic ball support layer forms a "distribution plate" with numerous pores, avoiding "channeling" (i.e., fluid preferentially choosing the path of least resistance, resulting in most adsorbent not being utilized). The molecular sieve is primarily supported on the support layer through "bridging" rather than being trapped within its pores. Any molecular sieve that falls into the pores of the top layer of ceramic balls is firmly blocked by the dense stainless steel wire mesh below.

[0036] By setting a feed distributor (such as a disc, tube, or narrow trough type) below the material inlet and a bottom liquid collector (such as a louver or disc type) above the product outlet, and optionally setting an intermediate liquid collector and intermediate distributor, the distribution and collection of liquid in the tower are significantly improved, effectively avoiding channeling and wall flow phenomena and improving mass transfer efficiency.

[0037] 2) The integrated purification system enables continuous automated operation;

[0038] The purification system uses multiple adsorption towers arranged in parallel, and controls each tower to alternately perform adsorption, regeneration and cooling steps through a valve switching system, realizing true continuous production and avoiding the intermittent defects of traditional batch operation. The system has a compact structure and flexible operation, and the adsorption-regeneration cycle can be flexibly adjusted according to actual production needs to ensure long-term stable operation of the system, making it suitable for large-scale industrial production.

[0039] 3) Energy-saving and environmentally friendly, reducing operating costs;

[0040] This invention provides a separation path completely different from high-vacuum distillation. Utilizing the principle of adsorption separation, it operates under near-ambient temperature and pressure conditions, fundamentally eliminating the need for complex high-vacuum systems and the enormous energy consumption associated with phase change, thus significantly reducing equipment investment and operating costs. Simultaneously, this technology avoids the sealing challenges and the risk of decomposition of heat-sensitive materials inherent in high-vacuum environments, providing a more energy-efficient, stable, and reliable industrial solution for azeotropic separation. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the adsorption tower of this utility model;

[0042] Wherein, 1-material inlet; 2-product outlet; 3-regenerated gas inlet; 4-inert gas inlet; 5-inert gas outlet; 6-packing layer; 7-feed distributor; 8-bottom liquid collector; 9-intermediate liquid collector; 10-intermediate distributor; 6a-first fixed bed packing layer; 6b-second fixed bed packing layer; 100-adsorption tower;

[0043] Figure 2 This is a schematic diagram of the fixed bed packing layer of this utility model;

[0044] Among them, 61-sieve plate; 62-stainless steel wire mesh; 63-support layer; 64-molecular sieve adsorption layer;

[0045] Figure 3 This is a schematic diagram of the purification system of this utility model;

[0046] Among them, 100-Adsorption tower (100A, 100B, 100C); 101-Raw material tank; 102-Product detection system; 103-Product tank; 104-By-product detection system; 105-By-product tank; 106-Steam generator; 107-Nitrogen source; 108-First online analyzer; 109-Second online analyzer. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0048] In the description of this utility model, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0050] Example 1

[0051] See Figure 1 This embodiment provides an adsorption tower 100, which includes a cylindrical tower body.

[0052] The tower body is equipped with:

[0053] Material inlet 1, located at the top of the tower, is used to introduce the azeotropic mixture (such as a mixed solution of n-dodecyl mercaptan and 2-dodecyl mercaptan) to be separated, which consists of straight-chain alkyl mercaptan and branched-chain alkyl mercaptan.

[0054] Product outlet 2, located at the bottom of the tower, is used to separately discharge the material rich in branched alkyl thiols and the material rich in straight alkyl thiols from the azeotropic mixture separated by molecular sieve adsorption layer 64.

[0055] Regeneration gas inlet 3, located at the top of the tower, is used to introduce a heat medium (such as steam) to wash away straight-chain alkyl thiols adsorbed on the molecular sieve adsorption layer 64.

[0056] Inert gas inlet 4, located at the bottom of the tower, is used to introduce inert gas (such as nitrogen) to cool the entire tower.

[0057] Inert gas outlet 5 is located at the top of the tower and is used to discharge inert gas flowing from the bottom to the top of the tower.

[0058] The interior of the tower includes a packing layer 6. See also Figure 2 The packing layer 6 comprises, from bottom to top, a sieve plate 61, a stainless steel wire mesh 62, a support layer 63, and a molecular sieve adsorption layer 64. The support layer 63 is composed of tightly arranged porous ceramic balls with a diameter of approximately 8 mm, positioned on top of the stainless steel wire mesh 62 to compact and fix the 20-mesh stainless steel wire mesh 62. The molecular sieve adsorption layer 64 is an MFI type molecular sieve, preferably Cu. 2+ Modified MFI molecular sieves are used for the selective adsorption of straight-chain alkyl thiols.

[0059] Cu 2+ The preparation method of modified MFI molecular sieve is as follows: Weigh a certain amount of MFI molecular sieve (ZSM-5) and soak it in Cu. 2+ The sample was soaked in a 0.10 mol / L copper sulfate solution at room temperature for 72 h. After soaking, it was filtered, washed with deionized water until neutral, and then activated in a muffle furnace at 390 °C for 6 h to obtain Cu. 2+ Modified MFI type molecular sieve adsorbent.

[0060] In a preferred embodiment, a feed distributor 7 is provided inside the tower body below the material inlet 1. In this embodiment, the distributor is a narrow-slot liquid distributor, which is used to evenly distribute the azeotropic mixture entering the tower to the entire cross-section of the packing layer 6.

[0061] In a preferred embodiment, a bottom liquid collector 8 is provided inside the tower body above the product outlet 2. In this embodiment, the liquid collector is a louvered liquid collector, which is used to collect the liquid flowing out from the packing layer and transport it to the product outlet 2.

[0062] In a preferred embodiment, the tower body is filled with two layers of packing 6, namely a first fixed-bed packing layer 6a and a second fixed-bed packing layer 6b. Between the first fixed-bed packing layer 6a and the second fixed-bed packing layer 6b, from top to bottom, are arranged the following:

[0063] Intermediate liquid collector 9 is used to collect liquid from the first fixed bed packing layer 6a;

[0064] Intermediate distributor 10 is used to redistribute the liquid collected by intermediate collector 9 to the second fixed bed packing layer 6b.

[0065] In this embodiment, the intermediate liquid collector 9 is a louvered liquid collector, and the intermediate distributor 10 is a narrow-slot liquid distributor.

[0066] Brief description of working principle (corresponding to the structure of this embodiment):

[0067] The adsorption tower 100 achieves the separation of azeotropic mixtures through its specific internal structure.

[0068] During the separation operation, the azeotropic mixture enters through the material inlet 1 at the top of the tower, is evenly distributed by the feed distributor 7, and then flows downward through the packing layer 6. In this process, the molecular sieve adsorption layer 64 selectively adsorbs straight-chain alkyl mercaptans, while the unadsorbed material rich in branched-chain alkyl mercaptans continues to flow downward, is collected by the bottom collector 8, and is discharged from the product outlet 2, i.e., the adsorption state.

[0069] When it is necessary to recover the adsorbed linear alkyl mercaptans, a heat medium (such as steam) can be introduced from the regeneration gas inlet 3 at the top of the tower, passing down through the packing layer 6, to wash off and carry away the linear alkyl mercaptans adsorbed on the molecular sieve adsorption layer 64. At this time, the material rich in linear alkyl mercaptans is discharged from the product outlet 2, which is the regeneration state.

[0070] After regeneration is complete, inert gas (such as nitrogen) can be introduced from the inert gas inlet 4 at the bottom of the tower, passing upward through the packing layer 6 to cool and purge the inside of the tower. Then the gas is discharged from the inert gas outlet 5 at the top of the tower, i.e., in a cooled state.

[0071] Example 2

[0072] See Figure 3 This embodiment provides a purification system for the continuous separation and purification of long-chain alkyl thiols azeotropes (such as a mixed solution of n-dodecyl thiols and 2-dodecyl thiols).

[0073] The purification system includes three adsorption towers 100 (100A, 100B, 100C) arranged in parallel and a valve switching system. Each adsorption tower 100 has the structure described in Example 1.

[0074] The purification system also includes a raw material tank 101, a product testing system 102, a product tank 103, a by-product testing system 104, a by-product tank 105, a steam generator 106, and a nitrogen source 107.

[0075] The purification system is controlled by a valve switching system. The valve switching system includes a control unit (not shown in the figure, but may be implemented by a programmable logic controller (PLC) for example) and multiple valves (not shown in detail in the figure) connected between the pipelines.

[0076] The raw material tank 101 is connected to the material inlet 1 of each adsorption tower 100 through pipelines and valves.

[0077] The product outlet 2 of each adsorption tower 100 is selectively connected to the inlet of the product detection system 102 or the by-product detection system 104 via pipelines and valves.

[0078] The outlet of the product testing system 102 is connected to the product tank 103, and its outlet is also connected to the raw material tank 101. In this embodiment, the product testing system 102 includes a first online analyzer 108; the control unit is signal-connected to the first online analyzer 108 and is configured to: judge the purity of linear alkyl mercaptans in the material rich in linear alkyl mercaptans discharged from the product outlet 2 of the adsorption tower 100 in the regeneration state based on the real-time detection signal of the first online analyzer 108; when the purity is qualified (e.g., 99% or 99.5% or higher), control the valve on the pipeline connecting the product testing system 102 and the product tank 103 to send the material into the product tank 103; otherwise, control the valve on the pipeline connecting the product testing system 102 and the raw material tank 101 to return the material to the raw material tank 101.

[0079] The outlet of the by-product detection system 104 is connected to the by-product tank 105, and its outlet is also connected to the raw material tank 101. In this embodiment, the by-product detection system 104 includes a second online analyzer 109; the control unit is signal-connected to the second online analyzer 109 and is configured to: judge the content of straight-chain alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet 2 of the adsorption tower 100 in the adsorption state based on the real-time detection signal of the second online analyzer 109; when the content is lower than a first preset threshold (e.g., 5 wt%), control the valve on the pipeline connecting the by-product detection system 104 and the by-product tank 105 to send the material into the by-product tank 105; otherwise, control the valve on the pipeline connecting the by-product detection system 104 and the raw material tank 101 to return the material to the raw material tank 101.

[0080] The control unit is connected to the second online analyzer 109 of the by-product detection system 104 and is configured to: judge the content of straight-chain alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet 2 of the adsorption tower 100 in the adsorption state based on the real-time detection signal of the second online analyzer 109; when the content continuously reaches the second preset threshold (e.g., 1 wt%) within a preset time (e.g., more than 3 minutes), determine that the adsorbent in the adsorption tower 100 is close to saturation, and control the valve switching system to switch the tower from the adsorption state to the regeneration state.

[0081] The steam generator 106 is connected to the regeneration gas inlet 3 of each adsorption tower 100 via pipelines and valves.

[0082] Nitrogen source 107 is connected to inert gas inlet 4 of each adsorption tower 100 via pipelines and valves.

[0083] The control unit is configured to control the opening and closing states of multiple valves according to a preset program, so as to periodically switch each adsorption tower 100 to adsorption, regeneration or cooling state, thereby realizing continuous separation and purification of materials.

[0084] A typical work cycle is as follows:

[0085] Under the programmed control of the control unit, the valve switching system periodically operates the pipeline valves, causing the three adsorption towers (100A, 100B, 100C) to enter different working states respectively, and realizes the coordinated rotation of states, thereby ensuring the continuous operation of the entire system.

[0086] During one operating cycle, the control unit controls the valve switching system so that:

[0087] One of the adsorption towers (e.g., 100A) has its material inlet 1 connected to the raw material tank 101, and its product outlet 2 connected to the by-product detection system 104. The tower is in a state of separating azeotropic mixtures and discharging materials rich in branched alkyl mercaptans.

[0088] Another adsorption tower (e.g., 100B) has its regeneration gas inlet 3 connected to the steam generator 106, and its product outlet 2 connected to the product detection system 102. The tower is in a state of introducing a heat medium and discharging materials rich in straight-chain alkyl mercaptans.

[0089] The inert gas inlet 4 of the third adsorption tower (e.g., 100C) is connected to the nitrogen source 107, and its inert gas outlet 5 is open. The tower is in a state of being cooled by introducing inert gas.

[0090] The product testing system 102 uses a first online analyzer 108 to detect the material discharged from the product outlet 2 of the adsorption tower 100B in the regeneration state in real time. Based on the detection signal, the system controls the corresponding valves through the control unit to introduce the qualified linear alkyl mercaptan material into the product tank 103, and return the unqualified material to the raw material tank 101.

[0091] The by-product detection system 104 uses a second online analyzer 109 to detect the material discharged from the product outlet 2 of the adsorption tower 100A in the adsorption state in real time. Based on the detection signal, the system controls the corresponding valves through the control unit to introduce the branched alkyl mercaptan material with a straight-chain alkyl mercaptan content lower than the first set threshold into the by-product tank 105, and to return the material with a content higher than the first set threshold to the raw material tank 101.

[0092] When the control unit determines that the adsorbent in a certain adsorption tower (e.g., 100A) is approaching saturation based on preset conditions (e.g., the second online analyzer 109 detects that the content of linear alkyl mercaptan in its outlet material is continuously higher than the second set threshold), and at the same time confirms that other towers (e.g., 100C and 100B) have completed the current stage of tasks (e.g., cooling and regeneration are completed), the control unit drives the valve switching system to change the opening and closing combination of valves on each pipeline, switching the adsorption-saturated tower (100A) from the adsorption state to the regeneration state, and at the same time, the working state of the other towers is also rotated accordingly.

[0093] Through the coordinated operation of the control unit and the valve switching system, multiple adsorption towers can be ensured to periodically and alternately undertake different separation and regeneration tasks, thereby achieving continuous feeding and continuous purification of materials at the system level.

[0094] In summary, the adsorption tower and purification system of this invention achieve the following technical effects:

[0095] 1) By setting up a packing layer structure consisting of a sieve plate, stainless steel wire mesh, support layer, and molecular sieve adsorption layer from bottom to top, the stability of the adsorbent bed and the uniform flow of gas / liquid are ensured, preventing adsorbent particle loss and bed clogging. The support layer is composed of tightly arranged porous ceramic balls of specific specifications (e.g., 7-9 mm in diameter), which work in conjunction with stainless steel wire mesh of specific mesh size (e.g., 18-22 mesh) to compact and fix the stainless steel wire mesh, forming a stepped structure that combines the three core functions of interception, support, and distribution. This structure provides solid support for the relatively fragile molecular sieve adsorbent particles above, preventing them from being compacted or broken under their own weight and operating pressure. The ceramic ball support layer forms a "distribution plate" with a large number of pores, avoiding "channeling" (i.e., fluid preferentially selects the path of least resistance, resulting in most of the adsorbent not being utilized). The molecular sieve is mainly supported on the support layer by "bridging" rather than being trapped in it in large quantities, rather than being intercepted by its pores. Even if a small amount of molecular sieve falls into the gaps between the ceramic balls, it will be effectively intercepted by the dense stainless steel wire mesh below.

[0096] 2) By installing a feed distributor (such as a disc distributor, tubular distributor, or narrow trough distributor) below the material inlet and a bottom liquid collector (such as a louvered liquid collector or disc liquid collector) above the product outlet, and optionally installing intermediate liquid collectors and intermediate distributors (such as louvered liquid collectors and narrow trough distributors), the distribution and collection of liquid in the tower are significantly improved, effectively avoiding channeling and wall flow phenomena and improving mass transfer efficiency.

[0097] 3) The purification system uses multiple adsorption towers arranged in parallel, and controls each tower to alternately perform adsorption, regeneration and cooling steps through a valve switching system, realizing true continuous production and avoiding the intermittent defects of traditional batch operation. The system has a compact structure and flexible operation, and the adsorption-regeneration cycle can be flexibly adjusted according to actual production needs to ensure long-term stable operation of the system, making it suitable for large-scale industrial production.

[0098] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An adsorption tower (100), comprising a tower body, characterized in that, The interior of the tower body includes a packing layer (6), which includes a sieve plate (61), a stainless steel wire mesh (62), a support layer (63), and a molecular sieve adsorption layer (64) stacked from bottom to top. The tower body is also equipped with: Material inlet (1), located at the top of the tower, is used to introduce azeotropic mixture; Product outlet (2), located at the bottom of the tower, is used to discharge the material rich in branched alkyl thiols and the material rich in straight alkyl thiols from the azeotropic mixture separated by the molecular sieve adsorption layer (64); The regenerated gas inlet (3) is located at the top of the tower and is used to introduce a heat medium to wash away straight-chain alkyl thiols adsorbed on the molecular sieve adsorption layer (64). Inert gas inlet (4), located at the bottom of the tower, is used to introduce inert gas to cool the entire tower. The inert gas outlet (5) is located at the top of the tower and is used to discharge the inert gas flowing from the bottom of the tower to the top of the tower.

2. The adsorption tower according to claim 1, characterized in that, The support layer (63) is composed of porous ceramic balls arranged in a tight manner and is placed on the stainless steel wire mesh (62) to compact and fix the stainless steel wire mesh (62).

3. The adsorption tower according to claim 2, characterized in that, The stainless steel wire mesh (62) has a mesh size of 18-22; the porous ceramic ball has a diameter of 7-9 mm.

4. The adsorption tower according to claim 1, characterized in that, The interior of the tower body is equipped with a feed distributor (7) below the material inlet (1) to uniformly distribute the azeotropic mixture entering the tower to the entire cross-section of the packing layer (6); and / or, The tower body is equipped with a bottom liquid collector (8) above the product outlet (2) for collecting liquid flowing out of the packing layer and conveying it to the product outlet (2); and / or, The tower body is filled with two layers of packing (6), namely a first fixed-bed packing layer (6a) and a second fixed-bed packing layer (6b); between the first fixed-bed packing layer (6a) and the second fixed-bed packing layer (6b), from top to bottom, are arranged the following: An intermediate liquid collector (9) is used to collect liquid from the first fixed bed packing layer (6a); An intermediate distributor (10) is used to redistribute the liquid collected by the intermediate collector (9) to the second fixed bed packing layer (6b).

5. The adsorption tower according to claim 4, characterized in that, The feed distributor (7) is one of a disc distributor, a tubular distributor, or a narrow-slot liquid distributor; and / or, The bottom liquid collector (8) is a louvered liquid collector or a disc liquid collector; and / or, The intermediate liquid collector (9) is a louvered liquid collector, and the intermediate distributor (10) is a narrow-slot liquid distributor.

6. A purification system, characterized in that, Includes multiple adsorption towers (100) arranged in parallel as described in any one of claims 1-5 and a valve switching system; The valve switching system is configured to control multiple adsorption towers (100) to be in adsorption, regeneration, and cooling states respectively, so as to achieve continuous separation and purification of materials.

7. The purification system according to claim 6, characterized in that, The purification system also includes a raw material tank (101), a product testing system (102), a product tank (103), a by-product testing system (104), a by-product tank (105), a steam generator (106), and a nitrogen source (107); The valve switching system includes a control unit and multiple valves connected between the pipelines; The control unit is configured to control the opening and closing states of the plurality of valves according to a preset program, so as to periodically switch each adsorption tower (100) to be in the adsorption, regeneration, and cooling states respectively. The raw material tank (101) is connected to the material inlet (1) of each adsorption tower through pipelines and valves; The product outlet (2) of each adsorption tower is selectively connected to the inlet of the product detection system (102) or the by-product detection system (104) via pipelines and valves; The outlet of the product testing system (102) is connected to the product tank (103) and the raw material tank (101) respectively; The outlet of the by-product detection system (104) is connected to the by-product tank (105) and the raw material tank (101) respectively; The steam generator (106) is connected to the regeneration gas inlet (3) of each adsorption tower through pipelines and valves; The nitrogen source (107) is connected to the inert gas inlet (4) of each adsorption tower through pipelines and valves.

8. The purification system according to claim 7, characterized in that, The product testing system (102) includes a first online analyzer (108); the control unit is signal-connected to the first online analyzer (108) and is configured to: judge the purity of linear alkyl mercaptan in the material rich in linear alkyl mercaptan discharged from the product outlet (2) of the adsorption tower (100) in the regeneration state according to the real-time detection signal of the first online analyzer (108); when the purity is qualified, control the valve set on the pipeline connecting the product testing system (102) and the product tank (103) to send the material into the product tank (103); otherwise, control the valve set on the pipeline connecting the product testing system (102) and the raw material tank (101) to return the material to the raw material tank (101).

9. The purification system according to claim 7, characterized in that, The by-product detection system (104) includes a second online analyzer (109); the control unit is signal-connected to the second online analyzer (109) and is configured to: judge the content of linear alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet (2) of the adsorption tower (100) in the adsorption state according to the real-time detection signal of the second online analyzer (109) on the material. When the content is lower than a first preset threshold, control the valve set on the pipeline connecting the by-product detection system (104) and the by-product tank (105) to send the material into the by-product tank (105); otherwise, control the valve set on the pipeline connecting the by-product detection system (104) and the raw material tank (101) to return the material to the raw material tank (101).

10. The purification system according to claim 7, characterized in that, The control unit is connected to the second online analyzer (109) of the by-product detection system (104) and is configured to: judge the content of linear alkyl mercaptan in the material rich in branched alkyl mercaptan discharged from the product outlet (2) of the adsorption tower (100) in the adsorption state according to the real-time detection signal of the second online analyzer (109); when the content continuously reaches the second preset threshold within a preset time, it is determined that the adsorbent in the adsorption tower (100) is close to saturation, and the valve switching system is controlled to switch the tower from the adsorption state to the regeneration state.

Images