Tobacco reusing alcohol decontamination system based on adsorption-pervaporation coupling

Abstract

The utility model discloses a tobacco reuse alcohol impurity removal system based on adsorption-permeation vaporization coupling, the system includes adsorption jar and permeation vaporization membrane component, the adsorption jar includes raw material entrance and water entrance, be equipped with a plurality of adsorption medium in the adsorption jar, the adsorption jar is connected the permeation vaporization membrane component through the filter, the permeation vaporization membrane component includes preferential alcohol permeation vaporization membrane, the permeation side export of permeation vaporization membrane component is connected high -purity alcohol export, and the osmosis side export of permeation vaporization membrane component is connected the adsorption jar through first circulating pipeline. The utility model through coupling adsorption and membrane separation technology, and initiatively create low alcohol adsorption environment, effectively solved high concentration alcohol tobacco smell material and remove not thoroughly, solvent loss is big and the technical problem of production discontinuous, realized the efficient, continuous depth purification and recycling of alcohol.

Description

Technical Field

[0001] This utility model belongs to the field of solvent purification and tobacco processing technology, specifically relating to a purification and impurity removal system for alcohol solvents reused in tobacco processing. Background Technology

[0002] In tobacco processing, alcohol is typically used to extract aroma compounds from tobacco. After extraction, the alcohol is recovered through processes such as distillation for recycling. However, after multiple cycles, off-flavor compounds from tobacco gradually accumulate in the recovered high-concentration alcohol. These mainly include some volatile phenols, aldehydes and ketones, oily substances, and other impurities present in low amounts but with extremely low threshold values ​​and significant sensory impact. Even trace amounts of these impurities can affect the quality of the reused alcohol, leading to a decrease in the flavor consistency of subsequent tobacco products.

[0003] Currently, the main methods for removing such off-flavors from alcohol include activated carbon adsorption or multiple distillations. However, these methods have obvious limitations: (1) The off-flavor substances are highly miscible with alcohol, which leads to a significant decrease in the adsorption selectivity of the adsorbent for impurities, resulting in incomplete removal. (2) Traditional adsorption is often accompanied by a large amount of solvent entrainment loss, and the adsorption medium is easily saturated, requiring frequent shutdowns for regeneration or replacement, which is difficult to adapt to the needs of continuous production.

[0004] Pervaporation membrane separation technology, as a novel membrane separation technology, performs excellently in organic solvent dehydration or organic matter recovery. However, while a single pervaporation membrane can concentrate alcohol, it cannot selectively retain all complex tobacco flavor impurities. Therefore, there is an urgent need to develop a new solution that can synergistically combine the advantages of adsorption and membrane separation to achieve continuous, stable, and deep depurification of high-concentration alcohol. Utility Model Content

[0005] To address the problems of poor adsorption selectivity, discontinuous operation, and incomplete impurity removal by single membrane separation technology in the process of removing impurities from tobacco recycled alcohol, the applicant discovered in its research that when the concentration of tobacco recycled alcohol is reduced, impurities can be effectively removed during adsorption, improving the impurity removal efficiency. Based on this discovery, this invention provides a tobacco recycled alcohol impurity removal system based on adsorption-pervaporization coupling. This system aims to achieve deep removal of tobacco flavor impurities and efficient alcohol recovery through process coupling, ensuring continuous production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A tobacco-recycled alcohol removal system based on adsorption-pervaporization coupling includes an adsorption tank 11 and a pervaporation membrane module 8. The adsorption tank 11 includes a raw material inlet 1 and a water inlet 2. The adsorption tank 11 contains a plurality of adsorption media 5. The adsorption tank 11 is connected to the pervaporation membrane assembly 8 via a filter 4. The pervaporation membrane assembly 8 includes a preferred alcohol pervaporation membrane. The permeate-side outlet of the pervaporation membrane assembly 8 is connected to a high-purity alcohol outlet 9, and the residual outlet of the permeate membrane assembly 8 is connected to the adsorption tank 11 through a first circulation pipeline 10.

[0007] Preferably, the pervaporation membrane module 8 is selected from any one of organic stacked membrane modules, spiral wound membrane modules, or inorganic tubular membrane modules.

[0008] Preferably, the preferred alcohol pervaporation membrane is a polydimethylsiloxane (PDMS), polyoctylmethylsiloxane (POMS), or a mixture thereof.

[0009] Preferably, the adsorption medium 5 is a macroporous adsorption resin, and the particle size range of the macroporous adsorption resin is 0.5~2mm.

[0010] Preferably, the tobacco reuse alcohol purification system includes at least two adsorption tanks 11, all of which are connected in parallel. By switching valves, one or more adsorption tanks are in normal adsorption-pervaporization coupling operation, while the other adsorption tank is in regeneration or standby mode, thereby achieving continuous and uninterrupted operation of the entire system.

[0011] Preferably, the filter 4 is a precision filter used to intercept and adsorb particles.

[0012] Preferably, the pore size of the precision filter is 50-100 micrometers, which is sufficient to intercept and adsorb particles.

[0013] Preferably, the adsorption tank 11 is further provided with a second circulation outlet, which is connected to the adsorption tank 11 via a circulation pump 6 and a second circulation pipeline 12. The second circulation pipeline 12 and the circulation pump 6 are used to enhance the contact between the fluid inside the tank and the adsorption medium.

[0014] Preferably, the tobacco reuse alcohol purification system also includes a control system.

[0015] Preferably, the adsorption tank is equipped with an online concentration detection sensor, and the control system is connected to the online concentration detection sensor. The control system can dynamically adjust the flow rates of the high-concentration alcohol and water feed pipelines based on the feedback data from the online concentration detection sensor to maintain the alcohol concentration in the adsorption tank within a preset range.

[0016] Preferably, the tobacco reuse alcohol purification system further includes a regenerated liquid circulation pipeline and a heating device for in-situ regeneration of raw material tanks that are not in operation.

[0017] The above system can be operated using general methods in the art. To further improve the impurity removal effect, the following methods can also be used: (1) The high-concentration tobacco recycled alcohol to be treated is used as raw material and is fed into the adsorption tank 11 through the raw material inlet 1, and water is fed into the adsorption tank 11 through the water inlet 2, so that the alcohol concentration in the liquid in the adsorption tank 11 is 25wt% to 35wt%; in the adsorption tank 11, the adsorption medium adsorbs the liquid. (2) The adsorption-treated liquid enters the pervaporation membrane module 8 after being filtered by the filter 4. The pervaporation membrane module 8 is operated at an operating temperature of 30~45℃ and a permeation side pressure of 1000~3000Pa. High-purity alcohol is obtained on the permeation side of the pervaporation membrane module 8, and the permeate obtained on the permeate side of the pervaporation membrane module 8 is returned to the adsorption tank 11 to form a cycle.

[0018] Preferably, the method for removing impurities from tobacco using alcohol further includes a step of regenerating the adsorption medium.

[0019] Preferably, the regeneration step of the adsorption medium includes one or more combinations of elution with high-temperature alcohol, steam purging, or hot nitrogen purging. This can remove odor substances adsorbed on the medium.

[0020] When operating two or more adsorption tanks in parallel, when the adsorption performance of the adsorption medium in the adsorption tank in use drops to a preset value or reaches adsorption saturation, the feeding into that adsorption tank can be stopped, and the system can be switched to other adsorption tanks in parallel. The adsorption medium in the adsorption tank where feeding has stopped can be desorbed and regenerated to restore its adsorption capacity and achieve continuous production.

[0021] Preferably, the concentration of the high-concentration tobacco recycled alcohol to be treated is 50wt% to 95wt%.

[0022] After being processed by the pervaporation membrane assembly 8, the concentration of high-purity alcohol obtained on the permeate side can reach 65wt% to 75wt%, and the alcohol concentration of the obtained permeate is 20wt% to 25wt%.

[0023] Preferably, the operating temperature of the adsorption tank 11 is 30℃~50℃, in order to balance adsorption efficiency and system energy consumption.

[0024] Preferably, the method employs at least two raw material tanks connected in parallel.

[0025] The beneficial effects of this utility model are as follows: (1) By injecting pure water into the adsorption tank, the high concentration of alcohol is actively diluted to a low concentration range. The solubility of tobacco odor molecules in the liquid phase is reduced, making them easier to be captured by the adsorption medium. This greatly improves the adsorption selectivity and capacity of the adsorption medium for tobacco impurities in a low alcohol environment, and solves the technical bottleneck of the difficulty in adsorbing impurities in high concentration alcohol.

[0026] (2) Coupled pervaporation membrane separation technology concentrates the low-concentration alcohol after adsorption to obtain a high-concentration purified alcohol product. At the same time, the low-alcohol permeate after membrane separation is returned to the adsorption tank, realizing a closed-loop circulation of alcohol and significantly reducing solvent loss.

[0027] (3) By adopting a design of at least two adsorption tanks in parallel and with valve switching, the offline regeneration of the adsorption medium and the online continuous operation of the system can be realized, which solves the problem of discontinuous production in traditional adsorption processes and improves the overall production efficiency.

[0028] (4) This utility model is particularly suitable for processing tobacco extract recycled alcohol, which can effectively remove the accumulated off-flavor substances, improve the quality of recycled alcohol, ensure the flavor stability of tobacco products, and the process is compact with relatively low energy consumption. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling described in this utility model.

[0030] Figure 2 This is a comparison chart of the adsorption efficiency of the adsorption medium at different alcohol concentrations in Example 2.

[0031] Figure 3 This is a comparison chart of the impurity removal efficiency of different processes in Comparative Example 1.

[0032] In the diagram, 1 is the raw material inlet, 2 is the water inlet, 3 is the valve, 4 is the filter, 5 is the adsorption medium, 6 is the circulation pump, 7 is the pump, 8 is the pervaporation membrane module, 9 is the high-purity alcohol outlet, 10 is the first circulation pipeline, 11 is the adsorption tank, and 12 is the second circulation pipeline. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the following embodiments.

[0034] Example 1 Adopting such Figure 1The illustrated tobacco-recycled alcohol purification system based on adsorption-pervaporization coupling includes an adsorption tank 11 and a pervaporation membrane assembly 8. The adsorption tank 11 includes a raw material inlet 1 and a water inlet 2. The adsorption tank 11 contains a plurality of adsorption media 5. The adsorption tank 11 is connected to the pervaporation membrane assembly 8 through a filter 4. The pervaporation membrane assembly 8 includes a pervaporation membrane that prioritizes alcohol permeation. The permeate-side outlet of the pervaporation membrane assembly 8 is connected to a high-purity alcohol outlet 9. The residual outlet of the pervaporation membrane assembly 8 is connected to the adsorption tank 11 through a first circulation pipeline 10.

[0035] The preferred alcohol pervaporation membrane is polydimethylsiloxane (PDMS), polyoctylmethylsiloxane (POMS), or a mixture thereof.

[0036] The adsorption medium 5 is a macroporous adsorption resin with a particle size range of 0.5~2mm.

[0037] The tobacco reuse alcohol purification system includes at least two adsorption tanks 11, all of which are connected in parallel. By switching valves, one or more adsorption tanks are in normal adsorption-pervaporization coupling operation, while the other adsorption tank is in regeneration or standby mode, thereby achieving continuous and uninterrupted operation of the entire system.

[0038] The filter 4 is a precision filter used to intercept and adsorb particles in the adsorption medium.

[0039] The precision filter has a pore size of 50-100 micrometers, which is sufficient to intercept and adsorb particles.

[0040] The adsorption tank 11 is also provided with a second circulation outlet, which is connected to the adsorption tank 11 via a circulation pump 6 and a second circulation pipeline 12. The second circulation pipeline 12 and the circulation pump 6 are used to enhance the contact between the fluid inside the tank and the adsorption medium.

[0041] The tobacco reuse alcohol purification system also includes a control system.

[0042] The adsorption tank is equipped with an online concentration detection sensor, and the control system is connected to the online concentration detection sensor. Based on the feedback data from the online concentration detection sensor, the control system can dynamically adjust the flow rates of the high-concentration alcohol and water feed pipelines to maintain the alcohol concentration in the adsorption tank within a preset range.

[0043] The tobacco recycling alcohol purification system also includes a regenerated liquid circulation pipeline and a heating device. It is used for in-situ regeneration of raw material tanks that are not in operation.

[0044] The above-described apparatus was used to process tobacco recycled alcohol. The raw material to be processed contained the following impurities: neophytadiene 7580 ppm, phenethyl alcohol 820 ppm, benzyl alcohol 530 ppm, megastigmatrienone 410 ppm, pyranone 350 ppm, furanone 280 ppm, farnesylacetone 150 ppm, and dihydrodamasconone 40 ppm.

[0045] Recycled tobacco alcohol is fed into adsorption tank 11 through raw material inlet 1, while water is simultaneously injected into the adsorption tank through water inlet 2. The flow rates of the two feed streams are adjusted by an online concentration detection sensor and control system to maintain a stable alcohol concentration of approximately 30 wt% in the mixed solution within adsorption tank 11. The solution inside the tank is continuously circulated by circulation pump 6, flowing through the adsorption medium, where off-flavor substances are selectively adsorbed. The 30 wt% alcohol solution after adsorption treatment passes through a precision filter with a pore size of 80 micrometers to remove any potentially entrained resin particles.

[0046] The filtrate is pumped by pump 7 to the pervaporation membrane module 8. This membrane module uses a PDMS membrane that preferentially permeates alcohol. The operating temperature is 30~45℃, and the permeate-side pressure is 1000~3000Pa. In the membrane module, alcohol preferentially permeates through the membrane, resulting in purified alcohol with a concentration of 70wt% on the permeate side, which is collected through the high-purity alcohol outlet 9. On the osmate side, the osmate with an alcohol concentration reduced to approximately 22wt% is returned to the adsorption tank 11 via the first circulation pipeline 10 to participate in the circulation.

[0047] The system operates continuously. When the impurity content in the alcohol at the outlet of adsorption tank 11 begins to rise, indicating that adsorption is approaching saturation, the feed valve of that tank is closed, and the system switches to another pre-regenerated parallel adsorption tank to continue operation. The adsorption tank with the feed closed is regenerated by circulating elution with 85°C hot alcohol, and the regenerated resin can be reused.

[0048] Example 2 In the coupled process of this invention, the key lies in maintaining a low alcohol concentration of 25wt%-35wt% in the raw material tank, which significantly optimizes the adsorption process. Under this low concentration environment, the selected macroporous adsorption resin exhibits a much higher adsorption selectivity for off-flavor substances such as tobacco phenols, aldehydes, and ketones than for alcohol. Although the adsorption medium simultaneously adsorbs a small amount of alcohol molecules during physical adsorption, this is negligible because: the concentration of off-flavor substances is extremely low, and their total amount is much smaller than that of alcohol; the adsorption medium has a stronger affinity for off-flavor substances, and off-flavor substances preferentially occupy adsorption sites in dynamic equilibrium; and in absolute terms, the amount of co-adsorbed alcohol is insignificant compared to the total amount of alcohol in the entire circulating system (for example, each kilogram of adsorbent may adsorb approximately 2 mg of off-flavor substances while only adsorbing approximately 2 mg of alcohol, while the total alcohol in the system is measured in tons). Therefore, the co-adsorption effect of alcohol does not affect the material balance and process economy of the system, and the resulting alcohol loss is negligible. This low-concentration operation strategy is one of the core principles enabling this process to achieve efficient and continuous impurity removal.

[0049] To more clearly illustrate the effect of alcohol concentration on adsorption performance, the apparatus described in Example 1 was used, and the concentration of the feed liquid in adsorption tank 11 was controlled at 30%, 42%, 57%, and 85%, respectively, using the same recycled alcohol as raw material, and the remaining operation methods were the same as in Example 1.

[0050] The adsorption efficiency of the adsorption medium at different alcohol concentrations is statistically analyzed as follows: Figure 2 As shown.

[0051] like Figure 2 As shown, ethanol concentration has different effects on the adsorption efficiency of substances with different polarities. However, in general, under the condition of conventional high concentration ethanol (e.g., >80%), the adsorption efficiency is low, resulting in incomplete purification. This indicates that the high alcohol environment has a general inhibitory effect on the adsorption capacity of the entire system.

[0052] When the alcohol concentration of the diluted raw material is in a low range, the resin can exert its best adsorption performance.

[0053] Comparative Example 1 For the raw materials in Example 1, they were treated using membrane separation technology only (operating conditions and membranes were the same as those in the pervaporation membrane module of Example 1) and adsorption technology only (operating conditions were the same as those in the adsorption tank of Example 1).

[0054] The effects of membrane separation alone, adsorption alone, and adsorption-membrane coupling process in Example 1 were compared.

[0055] like Figure 3As shown, this coupled process is far superior to the process of treating alone in terms of odor removal efficiency. More importantly, its pervaporation membrane module exhibits excellent retention and permeation characteristics for key flavor substances such as benzyl alcohol and phenylethanol, which enables it to retain the target aroma components to the maximum extent while efficiently removing impurities.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A tobacco-recycled alcohol purification system based on adsorption-pervaporization coupling, characterized in that, It includes an adsorption tank (11) and a pervaporation membrane assembly (8). The adsorption tank (11) includes a raw material inlet (1) and a water inlet (2). The adsorption tank (11) is provided with a plurality of adsorption media (5). The adsorption tank (11) is connected to the pervaporation membrane assembly (8) through a filter (4). The pervaporation membrane assembly (8) includes a preferred alcohol pervaporation membrane. The permeation side outlet of the pervaporation membrane assembly (8) is connected to a high-purity alcohol outlet (9), and the residual side outlet of the pervaporation membrane assembly (8) is connected to the adsorption tank (11) through a first circulation pipeline (10).

2. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The pervaporation membrane module (8) is selected from any one of organic stacked membrane modules, spiral wound membrane modules or inorganic tubular membrane modules.

3. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The preferred alcohol pervaporation membrane is polydimethylsiloxane, polyoctylmethylsiloxane, or a mixture thereof.

4. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The adsorption medium (5) is a macroporous adsorption resin with a particle size range of 0.5~2mm.

5. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The tobacco reuse alcohol purification system includes at least two adsorption tanks (11), and all the adsorption tanks (11) are arranged in parallel.

6. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The adsorption tank (11) is also provided with a second circulation outlet, which is connected to the adsorption tank (11) through a circulation pump (6) and a second circulation pipeline (12).

7. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The filter (4) is a precision filter.

8. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 7, characterized in that, The pore size of the precision filter is 50~100 micrometers.

9. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The tobacco recycling alcohol purification system also includes a control system, and the adsorption tank is equipped with an online concentration detection sensor, which is connected to the control system.

10. The tobacco-recycled alcohol depurification system based on adsorption-pervaporization coupling according to claim 1, characterized in that, The tobacco reuse alcohol purification system also includes a regenerated liquid circulation pipeline and a heating device.

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