Dehydration regeneration method and system for isopropanol molecular sieve
By regenerating molecular sieves through low-temperature purging and stepwise heating, the problem of structural damage to molecular sieves during high-temperature regeneration is solved, thus achieving stability of molecular sieves and continuous and efficient purification of isopropanol.
Patent Information
- Application Number
- CN202511856828.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-02-24
AI Technical Summary
During the high-temperature regeneration process, the crystal structure of molecular sieves is destroyed, and the adsorption performance is permanently reduced, leading to frequent replacement of packing materials, which increases costs and losses.
The molecular sieve is regenerated by low-temperature purging and stepwise heating. Low-temperature purging removes residual liquid isopropanol and moisture, while stepwise heating is carried out to a suitable temperature to avoid high-temperature shock and ensure the structural stability of the molecular sieve.
It extends the service life of molecular sieves, improves the purification accuracy and production efficiency of isopropanol, and reduces the frequency and cost of replacing packing materials.
Smart Images
Figure CN121550984A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of chemical product separation and purification technology, specifically to a method and system for dehydrating and regenerating isopropanol molecular sieves. Background Technology
[0002] Isopropanol is an important industrial solvent and chemical raw material, and its purity is crucial for many applications. Molecular sieve adsorption is currently the mainstream technology for the deep dehydration of isopropanol in industry. However, this technology has a drawback: during the molecular sieve regeneration stage, high-temperature (typically 200-300℃) purge gases (such as nitrogen) are required to remove the adsorbed moisture from the molecular sieve. Prolonged exposure to high temperatures damages the crystal structure of the molecular sieve, permanently reducing its adsorption capacity and necessitating frequent replacement of the packing material, thus increasing costs and losses. Summary of the Invention
[0003] This invention provides a method and system for dehydrating and regenerating isopropanol molecular sieves to solve the problem that the crystal structure of molecular sieves is destroyed and the adsorption performance is permanently reduced when the molecular sieves are continuously exposed to high temperatures.
[0004] In a first aspect, the present invention provides a method for dehydrating and regenerating isopropanol molecular sieves, which is applied to an isopropanol molecular sieve dehydration and regeneration system. The system includes an adsorption tower equipped with a molecular sieve and a regeneration gas circulation pipeline. The adsorption tower is used for dehydrating isopropanol and regenerating the molecular sieve. The regeneration gas circulation pipeline consists of a cooler, a circulation device and a heater connected in sequence through the pipeline. The outlet of the adsorption tower is connected to one end of the cooler through the pipeline, and the inlet is connected to one end of the heater through the pipeline. The methods include: When the adsorption tower is in molecular sieve regeneration mode, the outlet and inlet of the adsorption tower are opened so that the waste gas in the adsorption tower is cooled through the regeneration gas circulation pipeline and then used for low-temperature purging of the adsorption tower. After the first preset time of low-temperature purging, the heater is started to heat the regeneration gas in the regeneration gas circulation pipeline in stages. In response to the detection that the regeneration gas has reached the first temperature threshold, the heating parameters of the heater are adjusted to heat the regeneration gas in the regeneration gas circulation pipeline to the second temperature threshold, thereby completing the molecular sieve regeneration. The second temperature threshold is greater than the first temperature threshold.
[0005] The regeneration gas is heated to a lower initial temperature by low-temperature purging inside the adsorption tower. During this stage, residual liquid isopropanol and a large amount of unbound water are removed from the adsorption tower, preventing coking or impact on the molecular sieve at high temperatures. Secondly, the temperature inside the adsorption tower is gradually increased through staged heating, ensuring that the moisture in the adsorption tower bed is completely and gradually removed. This avoids high-temperature impact on the molecular sieve structure caused by regeneration at a fixed high temperature. After removing the moisture from the molecular sieve through staged heating, a thorough regeneration is performed. Low-temperature purging and staged heating avoid structural damage to the molecular sieve due to sudden temperature changes, extend the service life of the molecular sieve, and effectively protect the crystal structure of the molecular sieve.
[0006] In one alternative implementation, the method further includes: Timing begins upon detecting that the regeneration gas has reached the second temperature threshold. The heater is turned off after the timing reaches the second preset duration; The outlet and inlet of the adsorption tower are closed.
[0007] By heating in stages and then raising the temperature to the second temperature threshold, the moisture in the molecular sieve is completely removed. Since it takes time for the heat to be evenly distributed in the adsorption tower, the heating time is timed to ensure that the heat is transferred evenly and stably to the adsorption tower bed within the second preset time. The heater is turned off after the second preset time is reached to avoid unnecessary heating, thus ensuring the structural stability of the molecular sieve and realizing its regeneration.
[0008] In one alternative implementation, the method further includes: After the outlet and inlet of the control adsorption tower are closed, the control adsorption tower is switched to isopropanol dehydration mode.
[0009] By switching to isopropanol dehydration mode after molecular sieve regeneration in the adsorption tower, the cycle from adsorption regeneration to re-adsorption is completed, ensuring the continuous and stable operation of the isopropanol dehydration process, greatly improving the overall production efficiency, and ensuring the purification accuracy of isopropanol.
[0010] In one optional implementation, the heater is activated to heat the regeneration gas in the regeneration gas circulation pipeline in stages, including: The heating power of the heater is increased at preset time intervals until the temperature reaches the first preset threshold.
[0011] By controlling the heating power of the heater, the molecular sieve is heated step by step. The gradual temperature rise reduces the physical damage to the molecular sieve caused by thermal stress and sudden increase in vapor pressure, thus ensuring its adsorption capacity and extending its lifespan.
[0012] In one optional embodiment, the adsorption tower includes: a first adsorption tower and a second adsorption tower, and the method further includes: When the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is controlled to be in isopropanol dehydration mode. In response to the completion of molecular sieve regeneration in the first adsorption tower, the first adsorption tower is switched to isopropanol dehydration mode, and the outlet and inlet of the first adsorption tower are closed.
[0013] When the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is in molecular sieve dehydration mode. This dual-tower switching improves the efficiency of isopropanol dehydration. For example, when the first adsorption tower is in molecular sieve regeneration mode, the molecular sieve flowing into the tower is regenerated through staged heating. This ensures that the molecular sieve can dehydrate isopropanol in the next stage of the adsorption tower's dehydration mode, achieving continuous isopropanol purification. Thus, the dual-tower switching mode achieves both isopropanol purification and molecular sieve regeneration, ensuring that isopropanol purification can also be achieved through the other adsorption tower during the molecular sieve regeneration stage.
[0014] In one alternative implementation, the method further includes: In response to the completion of isopropanol dehydration in the second adsorption tower, the second adsorption tower is switched to molecular sieve regeneration mode, and the outlet and inlet of the second adsorption tower are opened to connect the second adsorption tower to the regeneration gas circulation pipeline.
[0015] The first adsorption tower is controlled to operate stably in dehydration mode, thereby allowing the second adsorption tower to be switched from the production line to the regeneration gas circulation pipeline for regeneration of the molecular sieve. This achieves alternating adsorption and regeneration between the two towers, thus enabling continuous production.
[0016] In a second aspect, the present invention provides an isopropanol molecular sieve dehydration and regeneration system, the system comprising an adsorption tower equipped with a molecular sieve and a regeneration gas circulation pipeline, the adsorption tower being used for dehydrating isopropanol and regenerating the molecular sieve. The regenerated gas circulation pipeline consists of a cooler, a circulation device, and a heater connected sequentially via pipelines. The outlet of the adsorption tower is connected to one end of the cooler via a pipeline, and the inlet is connected to one end of the heater via a pipeline. The system also includes a controller, which includes: The memory and processor are interconnected and communicate with each other. The memory stores computer instructions, and the processor executes the computer instructions to perform the isopropanol molecular sieve dehydration and regeneration method described in the first aspect or any of its corresponding embodiments.
[0017] In one alternative implementation, the circulation device is a circulating fan.
[0018] The adsorption tower is purged and heated by a circulating fan. This purging and heating process removes residual liquid isopropanol and a large amount of unbound water from the adsorption tower, preventing coking at high temperatures or impact on the molecular sieve.
[0019] In one alternative implementation, the system further includes a gas-liquid separator.
[0020] The gas-liquid separator is connected to the cooler and is used to separate the liquid from the regeneration gas.
[0021] During the molecular sieve regeneration stage, the high-temperature regeneration gas desorbs the water and a small amount of isopropanol adsorbed in the molecular sieve, forming a high-temperature mixed steam. The high-temperature steam is cooled in the cooler. When the temperature drops below the dew point of each component in the mixture, the steam condenses into liquid. Therefore, the medium flowing out of the cooler is a low-temperature gas carrying liquid. In order to prevent these liquids from entering the circulation device and affecting the working performance of the circulation device, it is necessary to separate these liquids through a gas-liquid separator to ensure the continuous and stable operation of the regeneration gas circulation pipeline.
[0022] In one alternative implementation, the system further includes: a regenerated gas buffer tank and a regenerated gas drying tower; The regeneration gas buffer tank is connected to the heater and is used to buffer the regeneration gas in the regeneration gas circulation pipeline; The regenerated gas drying tower is installed between the adsorption tower and the heater via pipelines to remove moisture and / or impurities from the regenerated gas.
[0023] The regeneration gas before entering the heater is dried by passing it through a regeneration gas drying tower, thereby adsorbing the residual moisture in the regeneration gas and reducing the impact of changes in ambient air humidity during the regeneration process. By setting up a regeneration gas buffer, the regeneration gas is buffered, ensuring the stable operation of the heater and circulation device and improving the temperature control accuracy. Attached Figure Description
[0024] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0025] Figure 1 This is a schematic diagram of the isopropanol molecular sieve dehydration and regeneration system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first process of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention; Figure 3This is a schematic diagram of the second process of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the third process of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the process flow of the isopropanol molecular sieve dehydration and regeneration system according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the controller of the isopropanol molecular sieve dehydration and regeneration system according to an embodiment of the present invention; The following are the labels in the diagram: 1021, First adsorption tower; 1022, Second adsorption tower; 3, Heater; 4, Cooler; 5, Circulating fan; 6, Gas-liquid separator; 7, Regenerated gas buffer tank; 8, Regenerated gas drying tower; 9, Dust filter; 10, Drain pump. Detailed Implementation
[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.
[0028] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0029] As an optional application scenario of this invention, such as Figure 1The diagram shows a structural schematic of an isopropanol molecular sieve dehydration and regeneration system. The system includes an adsorption tower 102 equipped with a molecular sieve and a regeneration gas circulation pipeline 103. The adsorption tower 102 is used for dehydrating isopropanol and regenerating the molecular sieve. The regeneration gas circulation pipeline 103 consists of a cooler, a circulation device, and a heater connected sequentially through a pipeline. The outlet of the adsorption tower is connected to one end of the cooler through a pipeline, and the inlet is connected to one end of the heater through a pipeline. The system also includes a controller 101, which is used to execute the isopropanol molecular sieve dehydration and regeneration method. The overall process of the controller 101 executing the isopropanol molecular sieve dehydration and regeneration method is detailed in the relevant description of the method embodiment below, and will not be repeated hereafter.
[0030] Isopropanol is an important industrial solvent and chemical raw material, and its purity is crucial for many applications. Molecular sieve adsorption is currently the mainstream technology for deep dehydration of isopropanol in industry. However, this technology suffers from problems such as thermal degradation of molecular sieves, high system energy consumption, and low regeneration efficiency. Specifically, the molecular sieve regeneration stage requires high-temperature purge gas to remove adsorbed water from the molecular sieve; for example, nitrogen gas at 200°C to 300°C can be used to remove adsorbed water. Prolonged exposure to high temperatures can damage the crystal structure of the molecular sieve, permanently reducing its adsorption capacity and necessitating frequent packing replacements, increasing costs and downtime losses. Furthermore, traditional regeneration processes typically employ a constant high-temperature "extensive" regeneration method, using the same high temperature for both initial bed heating and subsequent residual water purging, resulting in inefficient and inefficient use of thermal energy.
[0031] Based on the above problems, this embodiment focuses on analyzing the influence of the temperature inside the adsorption tower during molecular sieve dehydration and regeneration on the molecular sieve, and how to control the temperature during the regeneration stage to protect the molecular sieve crystal structure, and provides a method for dehydrating and regenerating isopropanol molecular sieves that can significantly extend the life of molecular sieves.
[0032] According to an embodiment of the present invention, an embodiment of a method for dehydrating and regenerating isopropanol molecular sieves is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.
[0033] This embodiment provides a method for dehydrating and regenerating isopropanol molecular sieves, which can be used in the aforementioned isopropanol molecular sieve dehydration and regeneration system. Figure 2 This is a flowchart of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: When the adsorption tower is in molecular sieve regeneration mode, control the opening of the gas outlet and gas inlet of the adsorption tower so that the waste gas in the adsorption tower is cooled through the regeneration gas circulation pipeline and then used to purge the adsorption tower at low temperature.
[0034] It should be noted that isopropanol is highly hygroscopic and will absorb moisture from the air. Dehydrating isopropanol can improve its purity. However, molecular sieve adsorption is one of the most effective and common methods for isopropanol dehydration. Molecular sieves, as special materials, have a precise pore structure that allows them to selectively adsorb water molecules from isopropanol, thus achieving separation and purification. During molecular sieve adsorption, only water molecules with a diameter smaller than the pore size of the molecular sieve are adsorbed. The molecular sieve adsorption process is reversible; this is the molecular sieve regeneration stage. In the regeneration stage, the water molecules adsorbed by the molecular sieve are released by heating, thus regenerating the molecular sieve, restoring its activity, and preparing it for the next dehydration of isopropanol.
[0035] In the molecular sieve regeneration mode, since the adsorption tower has just completed the dehydration of isopropanol, the molecular sieve in the adsorption tower has adsorbed a large number of water molecules and the waste gas in the adsorption tower is saturated with water vapor and isopropanol vapor. Therefore, the outlet and inlet of the adsorption tower are controlled to open so that the waste gas in the adsorption tower is cooled through the regeneration gas circulation pipeline and then used to purge the adsorption tower at low temperature.
[0036] Step S202: After the first preset time of low-temperature purging, start the heater to heat the regeneration gas in the regeneration gas circulation pipeline in stages.
[0037] In the low-temperature purging stage, the residual heat of the heater or a small amount of external heat source is used to purge and heat the adsorption tower, initially heating the regeneration gas to a relatively low temperature, such as 100°C to 150°C. This is used to purge residual liquid isopropanol and a large amount of unbound water from the adsorption tower, preventing coking or impact on the molecular sieve at high temperatures. The regeneration gas in the regeneration gas circulation pipeline is heated in stages by the heater, for example, raising the temperature to 180°C and maintaining it at 180°C for a preset time, then raising the temperature to 220°C and maintaining it at 220°C for a preset time, ensuring that the moisture in the adsorption tower bed is completely and gradually removed.
[0038] In step S203, in response to detecting that the regeneration gas has reached the first temperature threshold, the heating parameters of the heater are adjusted to heat the regeneration gas in the regeneration gas circulation pipeline to the second temperature threshold, thereby completing the molecular sieve regeneration. The second temperature threshold is greater than the first temperature threshold.
[0039] It should be noted that the first temperature threshold is the temperature reached during the step-by-step heating stage, for example, the first temperature threshold is 220℃. After reaching 220℃, high-temperature purification is achieved by continuing to raise the temperature to a second temperature threshold, for example, the second temperature threshold is 240℃. The second temperature threshold is maintained for a set time, which is shorter than a preset time, to ensure that moisture is completely removed.
[0040] The isopropanol molecular sieve dehydration and regeneration method provided in this embodiment heats the regeneration gas to a low initial temperature by performing low-temperature purging inside the adsorption tower. During this stage, residual liquid isopropanol and a large amount of unbound water in the adsorption tower are removed, preventing coking or impact on the molecular sieve at high temperatures. Secondly, the temperature inside the adsorption tower is gradually increased through staged heating, ensuring that the moisture in the adsorption tower bed is completely and gradually removed, avoiding high-temperature impact on the molecular sieve on the adsorption tower bed caused by regeneration at a fixed high temperature, which would damage the molecular sieve structure. After removing the moisture in the molecular sieve through staged heating, a thorough regeneration is performed again. Low-temperature purging and staged heating avoid structural damage to the molecular sieve due to sudden temperature changes, extend the service life of the molecular sieve, and effectively protect the crystal structure of the molecular sieve.
[0041] This embodiment provides a method for dehydrating and regenerating isopropanol molecular sieves, which can be used in isopropanol molecular sieve dehydration and regeneration systems. Figure 3 This is a flowchart of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention, such as... Figure 3 As shown, the process includes the following steps: Step S301: When the adsorption tower is in molecular sieve regeneration mode, control the opening of the adsorption tower's outlet and inlet to allow the waste gas inside the adsorption tower to be cooled through the regeneration gas circulation pipeline and then used for low-temperature purging of the adsorption tower. For details, please refer to... Figure 2 Step S201 of the illustrated embodiment will not be described again here.
[0042] Step S302: After the first preset time of low-temperature purging, start the heater to heat the regeneration gas in the regeneration gas circulation pipeline in stages.
[0043] Specifically, step S302 above includes: Step S3020: Increase the heating power of the heater according to a preset time interval until the temperature reaches the first preset temperature threshold.
[0044] Specifically, the heater is controlled to heat at a first power for a preset time according to a preset time interval; once the preset time is reached, the heater is controlled to heat at a second power for a preset time, where the second heating power is greater than the first heating power, and then the heating power of the heater continues to increase until the temperature reaches a first preset temperature threshold. The preset time interval can be flexibly set according to the physical characteristics of the molecular sieve; for example, the preset time interval is 30 seconds.
[0045] By controlling the heating power of the heater, the molecular sieve is heated step by step. The gradual temperature rise reduces the physical damage to the molecular sieve caused by thermal stress and sudden increase in vapor pressure, thus ensuring its adsorption capacity and extending its lifespan.
[0046] Step S303: In response to detecting that the regeneration gas has reached a first temperature threshold, the heating parameters of the heater are adjusted to heat the regeneration gas in the regeneration gas circulation pipeline to a second temperature threshold, completing the molecular sieve regeneration. The second temperature threshold is greater than the first temperature threshold. For details, please refer to [link to details]. Figure 2 Step S203 of the illustrated embodiment will not be described again here.
[0047] Step S304: In response to detecting that the regeneration gas has reached the second temperature threshold, start timing.
[0048] The second temperature threshold is greater than the first temperature threshold, and the second temperature threshold is 240℃, so that the moisture in the molecular sieve is completely removed by finally using high temperature.
[0049] Step S305: After the timing duration reaches the second preset duration, turn off the heater.
[0050] It should be noted that the second preset duration was calculated based on the conclusions drawn from a large number of experiments, taking into account requirements such as bed thickness, gas flow rate, and regeneration depth.
[0051] Step S306: Close the outlet and inlet of the adsorption tower.
[0052] It should be noted that multiple control valves are installed on the regeneration gas circulation pipeline, which are used to close the gas outlet and gas inlet of the adsorption tower.
[0053] By heating in stages and then raising the temperature to the second temperature threshold, the moisture in the molecular sieve is completely removed. Since it takes time for the heat to be evenly distributed in the adsorption tower, the heating time is timed to ensure that the heat is transferred evenly and stably to the adsorption tower bed within the second preset time. The heater is turned off after the second preset time is reached to avoid unnecessary heating, thus ensuring the structural stability of the molecular sieve and realizing its regeneration.
[0054] Step S307: Control the adsorption tower to switch to isopropanol dehydration mode.
[0055] It should be noted that when the adsorption tower is in isopropanol dehydration mode, the isopropanol feedstock enters from the bottom of the adsorption tower, and the qualified isopropanol after purification flows out from the top of the adsorption tower.
[0056] By switching to isopropanol dehydration mode after molecular sieve regeneration in the adsorption tower, the cycle from adsorption regeneration to re-adsorption is completed, ensuring the continuous and stable operation of the isopropanol dehydration process, greatly improving the overall production efficiency, and ensuring the purification accuracy of isopropanol.
[0057] The isopropanol molecular sieve dehydration and regeneration method provided in this embodiment can be used in the aforementioned isopropanol molecular sieve dehydration and regeneration system. Specifically, it is applied to an isopropanol molecular sieve dehydration and regeneration system comprising at least two adsorption towers. When the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is in molecular sieve dehydration mode. The efficiency of isopropanol dehydration is improved by switching between the two towers. For example, when the first adsorption tower is in molecular sieve dehydration mode, the isopropanol flowing into the adsorption tower is dehydrated. After one round of dehydration, the molecular sieve inside the adsorption tower is in a water-saturated state, i.e., an adsorption-saturated state. At this time, the operating mode of the first adsorption tower is switched to molecular sieve regeneration mode, thereby achieving the purification of isopropanol and the regeneration of the molecular sieve through the dual-tower switching mode, ensuring that the purification of isopropanol can also be achieved through the other adsorption tower during the molecular sieve regeneration stage.
[0058] Figure 4 This is a flowchart of the isopropanol molecular sieve dehydration and regeneration method according to an embodiment of the present invention, such as... Figure 4 As shown, the process includes the following steps: Step S401: When the adsorption tower is in molecular sieve regeneration mode, control the opening of the gas outlet and gas inlet of the adsorption tower so that the waste gas in the adsorption tower is cooled through the regeneration gas circulation pipeline and then used to purge the adsorption tower at low temperature.
[0059] Specifically, step S401 above includes: In step S4010, while the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is controlled to be in isopropanol dehydration mode.
[0060] In the isopropanol dehydration mode, isopropanol enters from the bottom of the adsorption tower and is dehydrated by the molecular sieve inside the tower, which adsorbs water molecules from the isopropanol. Qualified isopropanol flows out from the top.
[0061] Step S402: After the first preset time of low-temperature purging, the heater is started to heat the regeneration gas in the regeneration gas circulation pipeline in stages; for details, please refer to [link to relevant documentation]. Figure 2 Step S202 of the illustrated embodiment will not be described again here.
[0062] In step S403, in response to detecting that the regeneration gas has reached the first temperature threshold, the heating parameters of the heater are adjusted to heat the regeneration gas in the regeneration gas circulation pipeline to the second temperature threshold, thereby completing the molecular sieve regeneration. The second temperature threshold is greater than the first temperature threshold.
[0063] Specifically, step S403 includes: In step S4030, in response to the completion of molecular sieve regeneration in the first adsorption tower, the first adsorption tower is switched to isopropanol dehydration mode, and the outlet and inlet of the first adsorption tower are closed.
[0064] It should be noted that the molecular sieve regeneration of the first adsorption tower includes: firstly, low-temperature purging of the first adsorption tower to heat the regeneration gas to a relatively low initial temperature; during this stage, residual liquid isopropanol and a large amount of unbound water in the first adsorption tower are removed to prevent coking or impact on the molecular sieve at high temperatures; secondly, a gradual temperature increase is achieved in the first adsorption tower through staged heating to ensure that the moisture in the first adsorption tower bed is completely and gradually removed, avoiding high-temperature impact on the molecular sieve structure caused by regeneration at a fixed high temperature. The outlet and inlet of the first adsorption tower are closed by a control valve installed on the regeneration gas circulation pipeline.
[0065] In step S404, in response to the completion of isopropanol dehydration in the second adsorption tower, the second adsorption tower is switched to molecular sieve regeneration mode, and the outlet and inlet of the second adsorption tower are opened so that the second adsorption tower is connected to the regeneration gas circulation pipeline.
[0066] The first adsorption tower is already in dehydration mode and operating stably, allowing the second adsorption tower to be switched from the production line to the regeneration gas circulation pipeline for regeneration of the molecular sieve. This achieves alternating adsorption and regeneration between the two towers, thus enabling continuous production.
[0067] When the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is in molecular sieve dehydration mode. This dual-tower switching improves the efficiency of isopropanol dehydration. For example, when the first adsorption tower is in molecular sieve regeneration mode, the molecular sieve flowing into the tower is regenerated through staged heating. This ensures that the molecular sieve can dehydrate isopropanol in the next stage of the adsorption tower's dehydration mode, achieving continuous isopropanol purification. Thus, the dual-tower switching mode achieves both isopropanol purification and molecular sieve regeneration, ensuring that isopropanol purification can also be achieved through the other adsorption tower during the molecular sieve regeneration stage.
[0068] As one or more specific application embodiments of the present invention, this embodiment provides a workflow for an isopropanol molecular sieve dehydration and regeneration system, employing the isopropanol molecular sieve dehydration and regeneration method described in the above method embodiments, such as... Figure 5 As shown, the isopropanol molecular sieve dehydration and regeneration system 501 includes an adsorption tower equipped with a molecular sieve and a regeneration gas circulation pipeline. The adsorption tower is used for dehydrating isopropanol and regenerating the molecular sieve. The adsorption tower includes a first adsorption tower 1021 and a second adsorption tower 1022.
[0069] The regenerated gas circulation pipeline consists of a cooler 4, a circulating fan 5, and a heater 3 connected sequentially through the pipeline. The outlet of the adsorption tower is connected to one end of the cooler 4 through the pipeline, and the inlet is connected to one end of the heater 3 through the pipeline.
[0070] It should be noted that heater 3 can be an electric heater or a thermal oil heater. The system is also equipped with a temperature controller and temperature sensors. The temperature sensors are located at different positions on the adsorption tower bed, and the temperature controller receives the temperature signals from the temperature sensors located at different positions on the adsorption tower bed.
[0071] Taking the regeneration of molecular sieve by the first adsorption tower 1021 and the dehydration of isopropanol by the second adsorption tower 1022 as an example, the first adsorption tower 1021 is purged and heated by the circulating fan 5. The purging and heating removes the residual liquid isopropanol and a large amount of unbound water in the first adsorption tower 1021, avoiding coking at high temperature or impact on the molecular sieve.
[0072] The isopropanol molecular sieve dehydration and regeneration system also includes a gas-liquid separator 6, which is connected to a cooler 4 and is used to separate the liquid in the regeneration gas.
[0073] During the molecular sieve regeneration stage, the high-temperature regeneration gas desorbs the water and a small amount of isopropanol adsorbed in the molecular sieve, forming a high-temperature mixed steam. The high-temperature steam is cooled in the cooler. When the temperature drops below the dew point of each component in the mixture, the steam condenses into liquid. Therefore, the medium flowing out of the cooler is a low-temperature gas carrying liquid. In order to prevent these liquids from entering the circulation device and affecting the working performance of the circulation device, it is necessary to separate these liquids through a gas-liquid separator to ensure the continuous and stable operation of the regeneration gas circulation pipeline.
[0074] The isopropanol molecular sieve dehydration and regeneration system also includes: a regeneration gas buffer tank 7 and a regeneration gas drying tower 8; The regeneration gas buffer tank 7 is connected to the heater 3 and is used to buffer the regeneration gas in the regeneration gas circulation pipeline; The regeneration gas drying tower 8 is installed between the first adsorption tower 1021, the second adsorption tower 1022 and the heater 3 via pipelines, and is used to remove moisture and / or impurities from the regeneration gas.
[0075] It should be noted that the regeneration gas before entering the heater 3 is dried by the regeneration gas drying tower 8, thereby adsorbing the residual moisture in the regeneration gas and reducing the impact of changes in ambient air humidity during the regeneration process; by setting up the regeneration gas buffer 7 to buffer the regeneration gas, the stable operation of the heater 3 and the circulating fan 5 is ensured, and the temperature control accuracy is improved.
[0076] The graded regeneration process includes adsorption, unloading, hot blowing, cold blowing, and liquid filling.
[0077] During the adsorption stage, the inlet and outlet valves of the first adsorption tower 1021 are opened, the raw material enters from the bottom of the adsorption tower, and the qualified product is output from the top of the adsorption tower.
[0078] During the unloading stage, after the adsorption process is completed, each unloading valve and the pressure balance valve of the regenerated gas buffer tank 7 are opened in sequence, and the isopropanol from the adsorption tower is discharged to the raw material buffer tank through the discharge pump 10.
[0079] During the hot blowing stage, after the first adsorption tower 1021 is unloaded, the regeneration gas process is opened in sequence, and the circulating fan 5 and heater 3 are started to hot blow the regeneration adsorption tower. The water removed from the first adsorption tower 1021 during the regeneration process is condensed by the cooler 4 and then enters the gas-liquid separator 6 for gas-liquid separation of the regeneration gas.
[0080] During the cold blowing stage, the heater 3 is stopped to perform cold blowing on the first adsorption tower 1021, so that the temperature is kept constant.
[0081] During the liquid filling stage, the first adsorption tower 1021 is pre-adsorption liquid filled to ensure a smooth transition. After the liquid filling process, the first adsorption tower 1021 completes a full "adsorption-regeneration" cycle, preparing for the next adsorption.
[0082] The isopropanol molecular sieve dehydration and regeneration system in this embodiment also includes a dust filter 9, which is connected to the outlet of the adsorption tower via a pipeline and is used to remove dust from the dehydrated isopropanol.
[0083] The schematic diagram of the controller of the isopropanol molecular sieve dehydration and regeneration system provided in this embodiment of the invention can execute the isopropanol molecular sieve dehydration and regeneration method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.
[0084] Figure 6 This is a schematic diagram of the controller of an isopropanol molecular sieve dehydration and regeneration system provided in an embodiment of the present invention.
[0085] The following is a detailed reference. Figure 6This diagram illustrates a controller suitable for implementing the isopropanol molecular sieve dehydration and regeneration system in an embodiment of the present invention. The controller may include a processor (e.g., a central processing unit, graphics processor, etc.) 601, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 602 or a program loaded from memory 608 into random access memory (RAM) 603. RAM 603 also stores various programs and data required for the operation of the electronic device. The processor 601, ROM 602, and RAM 603 are interconnected via bus 604. Input / output (I / O) interface 605 is also connected to bus 604.
[0086] Typically, the following devices can be connected to I / O interface 605: input devices 606 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 607 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 608 including, for example, magnetic tapes, hard disks, etc.; and communication devices 609. Communication device 609 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 6 A controller with various devices is shown, but it should be understood that it is not required to implement or have all of the devices shown, and may alternatively implement or have more or fewer devices.
[0087] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 609, or installed from a memory 608, or installed from a ROM 602. When the computer program is executed by the processor 601, it performs the functions defined in the isopropanol molecular sieve dehydration and regeneration method of the embodiments of the present invention.
[0088] Figure 6 The controller shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.
[0089] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as recordable on a storage medium, or implemented as computer code originally stored on a remote storage medium or a non-transitory machine-readable storage medium and subsequently stored on a local storage medium after being downloaded via a network. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the isopropanol molecular sieve dehydration and regeneration method shown in the above embodiments is implemented.
[0090] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.
[0091] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A method for dehydrating and regenerating isopropanol molecular sieves, characterized in that, An isopropanol molecular sieve dehydration and regeneration system is provided. The system includes an adsorption tower equipped with a molecular sieve and a regeneration gas circulation pipeline. The adsorption tower is used for dehydrating isopropanol and regenerating the molecular sieve. The regeneration gas circulation pipeline consists of a cooler, a circulation device, and a heater connected in sequence through the pipeline. The outlet of the adsorption tower is connected to one end of the cooler through the pipeline, and the inlet is connected to one end of the heater through the pipeline. The method includes: When the adsorption tower is in molecular sieve regeneration mode, the outlet and inlet of the adsorption tower are opened so that the waste gas in the adsorption tower is cooled by the regeneration gas circulation pipeline and then used to purge the adsorption tower at low temperature. After a first preset time of low-temperature purging, the heater is started to heat the regeneration gas in the regeneration gas circulation pipeline in stages. In response to the detection that the regeneration gas has reached a first temperature threshold, the heating parameters of the heater are adjusted to heat the regeneration gas in the regeneration gas circulation pipeline to a second temperature threshold, thereby completing the molecular sieve regeneration. The second temperature threshold is greater than the first temperature threshold.
2. The method according to claim 1, characterized in that, The method further includes: Timing begins upon detecting that the regeneration gas has reached the second preset temperature threshold. The heater is turned off after the timing period reaches the second preset duration; The outlet and inlet of the adsorption tower are closed.
3. The method according to claim 2, characterized in that, The method further includes: After closing the outlet and inlet of the adsorption tower, the adsorption tower is switched to isopropanol dehydration mode.
4. The method according to claim 1, characterized in that, The step of activating the heater to heat the regeneration gas in the regeneration gas circulation pipeline in stages includes: The heating power of the heater is increased at preset time intervals until the temperature reaches a first preset threshold.
5. The method according to claim 1, characterized in that, The adsorption tower includes: a first adsorption tower and a second adsorption tower, and the method further includes: When the first adsorption tower is in molecular sieve regeneration mode, the second adsorption tower is controlled to be in isopropanol dehydration mode; In response to the completion of molecular sieve regeneration in the first adsorption tower, the first adsorption tower is switched to isopropanol dehydration mode, and the outlet and inlet of the first adsorption tower are closed.
6. The method according to claim 5, characterized in that, The method further includes: In response to the completion of isopropanol dehydration in the second adsorption tower, the second adsorption tower is switched to molecular sieve regeneration mode, and the outlet and inlet of the second adsorption tower are opened so that the second adsorption tower is connected to the regeneration gas circulation pipeline.
7. An isopropanol molecular sieve dehydration and regeneration system, characterized in that, The system includes an adsorption tower equipped with a molecular sieve and a regeneration gas circulation pipeline. The adsorption tower is used for dehydrating isopropanol and regenerating the molecular sieve. The regenerated gas circulation pipeline is composed of a cooler, a circulation device, and a heater connected sequentially through the pipeline. The outlet of the adsorption tower is connected to one end of the cooler through a pipeline, and the inlet is connected to one end of the heater through a pipeline. The system also includes a controller, which includes: A memory and a processor are interconnected, the memory storing computer instructions, and the processor executing the computer instructions to perform the isopropanol molecular sieve dehydration and regeneration method according to any one of claims 1 to 6.
8. The system according to claim 7, characterized in that, The circulation device is a circulating fan.
9. The system according to claim 8, characterized in that, The system also includes: a gas-liquid separator. The gas-liquid separator is connected to the cooler and is used to separate the liquid from the regeneration gas.
10. The system according to claim 9, characterized in that, The system also includes: a regenerated gas buffer tank and a regenerated gas drying tower; The regenerated gas buffer tank is connected to the heater and is used to buffer the regenerated gas in the regenerated gas circulation pipeline; The regenerated gas drying tower is installed between the adsorption tower and the heater via a pipeline, and is used to remove moisture and / or impurities from the regenerated gas.