Extraction method and extraction system of nicotine

Abstract

The invention relates to a nicotine extraction method and system. The nicotine extraction method comprises the following steps: performing countercurrent extraction on a tobacco raw material and water under ultrasonic and pressurized conditions to obtain an extracting solution; concentrating the extracting solution to obtain a concentrated solution; adjusting the pH of the concentrated solution to be alkaline; extracting the alkalized concentrated solution by using an organic solvent to obtain an extracting solution; and removing the organic solvent in the extract liquor. The nicotine extraction method is beneficial to reducing the dosage of the inorganic strong base and the organic solvent, sulfuric acid is not needed, and the purity of nicotine is improved.

Description

Technical Field

[0001] The present application relates to the field of nicotine extraction, and in particular to a nicotine extraction method and extraction system. Background Art

[0002] Nicotine, also known as nicotine, is an alkaloid found in Solanaceae plants (Solanum), and is also an important component of tobacco. It is easily soluble in water, alcohol, ether, alkane and other solvents. At present, a nicotine extraction process is as follows: first, the tobacco raw material is alkalized and piled for 3h to 4h, and then sent to a flat plate leaching device, and extracted by an organic solvent. The obtained extract is sent to a sulfuric acid stripping device for extraction to prepare a nicotine sulfate salt solution, and an inorganic alkali solution is added to the concentrated nicotine sulfate salt solution to adjust it to alkalinity (for example, pH ≥ 10), and then an organic solvent is added for extraction to obtain a nicotine-organic solvent mixture. Finally, the nicotine-organic solvent mixture is solvent recovered to obtain nicotine. However, the above method still has the following problems: a large amount of inorganic strong alkali, a large amount of sulfuric acid, and a high impurity content. Summary of the invention

[0003] Based on this, some embodiments of the present application provide a method for extracting nicotine, which is beneficial to reducing the amount of inorganic strong base and organic solvent used, and does not require the use of sulfuric acid, thereby improving the purity of nicotine.

[0004] In addition, some other embodiments of the present application also provide a nicotine extraction system.

[0005] A method for extracting nicotine comprises the following steps:

[0006] The tobacco raw material and water are subjected to countercurrent extraction under ultrasonic and pressurized conditions to obtain an extract;

[0007] Concentrating the extract to obtain a concentrated solution;

[0008] Adjusting the pH of the concentrated solution to be alkaline;

[0009] Extracting the alkalized concentrated solution with an organic solvent to obtain an extract;

[0010] The organic solvent in the extract is removed.

[0011] In some of the embodiments, during the countercurrent extraction process, the ultrasonic frequency is 25 Hz to 50 Hz; and / or the extraction pressure is 0.1 MPa to 0.15 MPa.

[0012] In some embodiments, during the countercurrent extraction process, the mass ratio of the tobacco raw material to water is 1:(5-6);

[0013] And / or, the temperature of the countercurrent extraction is 50°C to 55°C.

[0014] In some embodiments, the step of concentrating the extract is performed by using a membrane concentration method;

[0015] Optionally, in the step of concentrating the extract, the extract is first filtered through a porous ceramic membrane and then concentrated through a nanofiltration membrane;

[0016] Optionally, in the step of concentrating the extract, the temperature is 20° C. to 40° C. and the pressure is 2 MPa to 4 MPa;

[0017] Optionally, the density of the concentrate is 1.2 g / cm 3 ~1.25g / cm 3 , nicotine content is 12mg / mL~15mg / mL.

[0018] In some embodiments, in the step of adjusting the pH of the concentrated solution to be alkaline, the pH of the concentrated solution is adjusted to be greater than or equal to 10; optionally, the pH of the concentrated solution is adjusted to be 10-11.

[0019] In some embodiments, in the step of extracting the alkalized concentrated solution with an organic solvent, a viscosity reducing agent is also added;

[0020] Optionally, the viscosity reducing agent includes one or more of guar gum, carboxymethyl cellulose salt and hydroxyethyl cellulose salt;

[0021] Optionally, the mass of the viscosity reducing agent is 1% to 5% of the mass of the alkalized concentrated solution.

[0022] In some embodiments, the organic solvent includes one or more of n-hexane, petroleum ether, No. 6 solvent oil and dichloromethane;

[0023] and / or, the volume ratio of the alkalized concentrated solution to the organic solvent is 1:(0.8-1.5);

[0024] And / or, in the step of extracting the alkalized concentrated solution with an organic solvent, centrifugal extraction is adopted.

[0025] In some embodiments, in the step of removing the organic solvent in the extract, the temperature is 50° C. to 55° C. and the vacuum degree is 0.06 MPa to 0.08 MPa.

[0026] In some embodiments, the process further comprises: distilling and purifying the crude nicotine product after removing the organic solvent;

[0027] Optionally, the distillation and purification step comprises:

[0028] Under the conditions of vacuum degree of 0.08MPa-0.1MPa and temperature of 90℃-100℃, water is introduced into the distillation system, the reflux ratio is set to full recovery, and the front fraction is collected;

[0029] When no liquid flows out of the collection port, the temperature is raised to 110°C to 120°C, the reflux ratio is set to (2 to 5):1, and nicotine is collected.

[0030] A nicotine extraction system, comprising:

[0031] A countercurrent extraction device comprises an extraction body, an ultrasonic unit and a pressurizing unit arranged in the extraction body;

[0032] a concentrating device, connected to the countercurrent extraction device, and used for concentrating the extract;

[0033] an alkaline adjusting device, connected to the concentrating device, for adjusting the pH of the concentrated liquid to be alkaline;

[0034] An extraction device, connected to the alkaline adjustment device, for extracting the concentrated solution after pH adjustment;

[0035] The solvent removal device is connected to the extraction device and is used to remove the organic solvent in the extraction liquid.

[0036] In some of these embodiments, the concentrating device is a membrane concentrating device;

[0037] Optionally, the concentrating device comprises a porous ceramic membrane and a nanofiltration membrane, the porous ceramic membrane is used to filter the extract, and the nanofiltration membrane is used to concentrate the filtered extract.

[0038] In some embodiments, the extraction device comprises a centrifugal extractor.

[0039] In some of the embodiments, a distillation device is further included, which is connected to the solvent removal device and is used to distill and purify the crude nicotine after the organic solvent is removed.

[0040] The present application study found that nicotine in tobacco raw materials will form a bound state with organic acids in tobacco raw materials. The bound nicotine is easily soluble in water and insoluble in organic solvents. Therefore, it can be directly extracted by water, and oil-soluble impurities cannot be extracted at this time. By countercurrent extraction of tobacco raw materials and water under ultrasonic and pressurized conditions, it is possible to extract with as little water as possible, that is, a high one-time extraction rate of nicotine can be achieved, and the nicotine concentration is high, and it can be directly concentrated without the use of the sulfuric acid stripping process commonly used in the industry, reducing the production process, and at the same time reducing the risk of impurities produced by the reaction of the extract with sulfuric acid and affecting the purity of nicotine. Since nicotine sulfate is not obtained by sulfuric acid stripping, high-salt and high-COD (chemical oxygen demand) sewage is not produced in the subsequent separation of nicotine, reducing the environmental burden of sewage treatment. By concentrating the extract, it is beneficial to reduce the amount of alkaline reagent used in the subsequent alkalization treatment. By adjusting the pH of the concentrated solution to alkaline, the bound nicotine is converted into free nicotine. Through extraction with an organic solvent, the free nicotine is dissolved in the organic solvent, and other water-soluble impurities remain in the aqueous phase. Nicotine can then be obtained by removing the organic solvent.

[0041] Therefore, the nicotine extraction method of some embodiments of the present application includes steps such as water countercurrent extraction, concentration, adjusting the pH to alkaline, extraction, and removal of organic solvents, without the need for back extraction with acidic reagents such as sulfuric acid, thereby reducing the amount of alkaline reagents used and improving the purity of nicotine. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A schematic diagram of a process flow of a method for extracting nicotine in some embodiments of the present application;

[0044] Figure 2 A schematic diagram of the structure of a nicotine extraction system according to some embodiments of the present application;

[0045] Figure 3 This is a GCMS data chart of the crude nicotine obtained in step (4) of Example 1;

[0046] Figure 4 This is the GCMS spectrum of the crude nicotine obtained in step (4) of Example 1;

[0047] Figure 5This is a GCMS data chart of the nicotine-containing n-hexane extract obtained in step (1) of Comparative Example 1;

[0048] Figure 6 This is the GCMS spectrum of the nicotine-containing n-hexane extract obtained in step (1) of Comparative Example 1;

[0049] Figure 7 This is a GCMS data chart of the concentrated nicotine sulfate obtained in step (3) of Comparative Example 1;

[0050] Figure 8 This is the GCMS spectrum of the concentrated nicotine sulfate obtained in step (3) of Comparative Example 1;

[0051] Fig. 9 is a gas chromatogram of pure nicotine in Example 1;

[0052] Fig.10 This is the gas chromatogram of pure nicotine in Comparative Example 1. DETAILED DESCRIPTION

[0053] In order to facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the specific embodiments. The preferred embodiments of the present application are provided in the specific embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0055] Unless otherwise specified or there is a contradiction, the terms and phrases used in this application have the following meanings:

[0056] In this application, "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0057] In the description of the present application, “plurality” means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0058] In this application, "one or several" refers to any one, any two or more of the listed items. Among them, "several" refers to any two or more of the listed items.

[0059] In this application, the percentage concentration involved, unless otherwise specified, refers to the final concentration. The final concentration refers to the proportion of the added component in the system after the addition of the component.

[0060] In this application, "further", "further", "particularly", "for example", "such as", "example", "for example", etc. are used for descriptive purposes, indicating that the previous and subsequent different technical solutions are related in terms of the content covered, but should not be understood as a limitation on the previous technical solution, nor can it be understood as a limitation on the protection scope of this document. In this document, unless otherwise specified, A (such as B) means that B is a non-limiting example of A, and it can be understood that A is not limited to B.

[0061] In this application, "optionally", "optional", and "optional" mean optional, that is, any one of the two parallel schemes of "yes" or "no". If multiple "optional" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent of each other. In this application, descriptions such as "optionally contain", "optionally include", etc. mean "contain or not contain". "Optional component X" means that component X exists or does not exist, or means that component X is contained or not contained.

[0062] When a numerical range is disclosed in this application, the above range is considered to be continuous and includes the minimum and maximum values ​​of the range, as well as every value between such minimum and maximum values. Further, when a range refers to an integer, every integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise indicated, all ranges disclosed in this application should be understood to include any and all subranges included therein.

[0063] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0064] The terms "including" and "having" and any variations thereof in the embodiments of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or components that are inherent to these processes, methods, products, or devices.

[0065] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0066] In the flowchart of the present application, although the various steps are displayed in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise clearly stated in the text, the execution of these steps is not strictly restricted in order and they can be performed in other orders. Moreover, at least part of the steps in the figure may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily performed at the same time, but can be performed at different times. Their execution order is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of other sub-steps or stages.

[0067] As described in the background technology, the traditional nicotine extraction process first piles the tobacco raw materials for 3 to 4 hours, during which a large amount of inorganic strong alkali is used. Then the alkalized tobacco raw materials are extracted with organic solvents for 4 hours. Since the bulk density of the tobacco raw materials is very small, 0.25g / cm 3 ~0.4g / cm 3 In order to achieve a high extraction rate, the amount of organic solvent used is huge, the risk of solvent evaporation loss is serious, the risk of static electricity accumulation is increased, the production cost is high, and the production process is prone to flammability and explosion. For example: a single batch of 20 tons of tobacco volume, according to the bulk density of 0.3g / cm 3 , volume 60m 3 After adding alkaline water to alkalize, the volume is 70m 3 , the tobacco raw material needs to be completely extracted, and the amount of organic solvent must be at least 100m 3 Therefore, the production equipment of this method is expensive, the production safety risk is high, the solvent loss is large, and the tobacco residue after extraction contains inorganic strong alkali and large amount of solvent residue, which conflicts with the trend of green environmental protection, and the cost of tobacco residue waste treatment is high.

[0068] In addition, since the extraction solvent is an organic solvent during the extraction process, nicotine and other oil-soluble impurities (esters, waxes, ketones, terpenes, phenols, etc.) are separated at the same time, so it is necessary to acid-reverse-extract the nicotine-organic solvent extract with an acid such as an aqueous sulfuric acid solution to obtain a nicotine sulfate solution. At this time, nicotine can be dissolved in the aqueous phase through the acid-base salt-forming property, and the oil-soluble impurities are retained in the organic solvent. Nicotine sulfate is in a bound state, and it is necessary to add an inorganic strong base again to free the nicotine, and then add an organic solvent for extraction. At this time, the residual water phase is high-salt and high-COD wastewater, which is extremely difficult to treat and has a heavy environmental burden.

[0069] Based on this, the present application provides a green and environmentally friendly nicotine extraction method and extraction system that is beneficial to reducing the amount of inorganic strong bases and acids used and improving the purity.

[0070] Specifically, the first aspect of the present application provides a method for extracting nicotine, see Figure 1 , including the following steps S110 to S150:

[0071] Step S110: subjecting the tobacco raw material to countercurrent extraction with water under ultrasonic and pressurized conditions to obtain an extract.

[0072] Step S120: Concentrating the extract to obtain a concentrated solution.

[0073] Step S130: adjusting the pH of the concentrated solution to be alkaline.

[0074] Step S140: extracting the alkalized concentrated solution with an organic solvent to obtain an extract.

[0075] Step S150: removing the organic solvent in the extract.

[0076] The present application study found that nicotine in tobacco raw materials will form a bound state with organic acids in tobacco raw materials. The bound nicotine is easily soluble in water and insoluble in organic solvents. Therefore, it can be directly extracted by water, and oil-soluble impurities cannot be extracted at this time. By countercurrent extraction of tobacco raw materials and water under ultrasonic and pressurized conditions, it is possible to extract with as little water as possible, that is, a high one-time extraction rate of nicotine can be achieved, and the nicotine concentration is high, and it can be directly concentrated without the use of the sulfuric acid stripping process commonly used in the industry, reducing the production process, and at the same time reducing the risk of impurities produced by the reaction of the extract with sulfuric acid and affecting the purity of nicotine. Because nicotine sulfate is not obtained by sulfuric acid stripping, in the subsequent separation of nicotine, high-salt and high-COD (chemical oxygen demand) sewage is not produced, reducing the environmental burden of sewage treatment. By concentrating the extract, it is beneficial to reduce the amount of alkaline reagent used in the subsequent alkalization treatment. By adjusting the pH of the concentrated solution to alkaline, the bound nicotine is converted into free nicotine. Through extraction with an organic solvent, the free nicotine is dissolved in the organic solvent, and other water-soluble impurities remain in the aqueous phase. Nicotine can then be obtained by removing the organic solvent.

[0077] Therefore, the nicotine extraction method of some embodiments of the present application includes steps such as water countercurrent extraction, concentration, adjusting the pH to alkaline, extraction, and removal of organic solvents, without the need for back extraction with acidic reagents such as sulfuric acid, thereby reducing the amount of alkaline reagents used and improving the purity of nicotine.

[0078] In addition, the nicotine extraction method of some embodiments of the present application does not adopt the traditional alkalization and stacking method, but uses water for countercurrent extraction, which greatly reduces the amount of alkaline reagents and organic solvents used, and at the same time provides a new extraction method that is different from the traditional process.

[0079] Countercurrent extraction refers to the process in which the material and the solvent move continuously at the same time during the extraction process, but in opposite directions. In the present application, countercurrent extraction is used to utilize two immiscible substances to flow in reverse in a device, thereby realizing the separation and extraction of substances. And by extracting the solvent with water, the tobacco raw material does not need to be pretreated, only needs to be crushed, and then the continuous feeding, extraction, and slag process are realized through the countercurrent extraction equipment to obtain the extract. In addition to containing water, the tobacco raw material is not polluted in the extraction process, does not involve the use of inorganic strong alkali and organic solvents, reduces the risk of solvent volatilization loss and static electricity accumulation, greatly reduces the environmental burden of tobacco slag material treatment, has low environmental burden and cost, and has high safety in the extraction process. In addition, by countercurrent extraction, the extraction process is transformed into continuous production to improve production efficiency. In the actual production process, the daily processing capacity of tobacco raw materials can reach hundreds of tons.

[0080] In some embodiments, during the countercurrent extraction process, the ultrasonic frequency is 25 Hz to 50 Hz. For example, the ultrasonic frequency can be, but is not limited to, 25 Hz, 30 Hz, 35 Hz, 40 Hz, 45 Hz, 50 Hz, or a range consisting of any two of these values.

[0081] In some embodiments, during the countercurrent extraction process, the extraction pressure is 0.1 MPa to 0.15 MPa. For example, the extraction pressure may be, but is not limited to, 0.1 MPa, 0.11 MPa, 0.12 MPa, 0.13 MPa, 0.14 MPa, 0.15 MPa, or a range consisting of any two of these values.

[0082] During the countercurrent extraction process, ultrasound and pressure are used to allow extraction with as little water as possible, achieving a higher one-time extraction rate of nicotine, a higher nicotine content, and direct membrane concentration. If tobacco raw materials are directly subjected to conventional extraction with water, multiple extractions are required to achieve a high nicotine extraction rate. The amount of water used is large, and the nicotine content in the extract after filtration is extremely low. The pH of the final extract is neutral to weakly alkaline. During the concentration process, there is almost no concentration difference between the permeate phase and the retentate phase. Once nicotine passes through the membrane, it will also pass through with water. Therefore, in order to increase the content of effective substances in the extract and thus form an effective concentration difference, the extract is acidified in the traditional process to convert the nicotine therein into a bound state. However, on the one hand, due to the large volume of the extract, the amount of sulfuric acid required to be added will be very large. On the other hand, during the sulfuric acid acidification process, chlorophyll, carotenoids, etc. in the water extract will be dehydrated, oxidized, sulfonated, etc. by sulfuric acid, and phenolic substances in the water extract will undergo sulfonation, oxidation, esterification, etc.; proteins in the water extract will undergo amino acid hydrolysis and other reactions. In the subsequent extraction process, the crude impurities of nicotine will increase significantly, and the purity of the final product will also be low. Furthermore, the extraction of nicotine through the nicotine sulfate intermediate will still generate wastewater with high sulfate content, which has a heavy environmental burden. In some embodiments of the present application, by optimizing the water extraction process, the nicotine content in the extract is higher, and membrane concentration can be directly performed, avoiding the use of inorganic strong acids such as sulfuric acid, the crude product has fewer impurities, the product purity is higher, and no sulfate wastewater is generated.

[0083] In some embodiments, the mass ratio of tobacco raw material to water is 1:(5-6). For example, the mass ratio of tobacco raw material to water can be, but is not limited to, 1:5, 1:5.2, 1:5.4, 1:5.6, 1:5.8, 1:6, or a range consisting of any two of these values. By optimizing the extraction process of tobacco raw material to water, a higher nicotine extraction rate can be achieved when the mass ratio of tobacco raw material to water is 1:(5-6), and the nicotine concentration in the extract is high, so that the next step of membrane concentration treatment can be directly carried out without acidification treatment.

[0084] In some embodiments, the tobacco raw material is in powder form. For example, the mesh size of the tobacco raw material is 80-100 meshes. Using powdered tobacco raw material is more conducive to extraction.

[0085] In some embodiments, the temperature of the countercurrent extraction is 50° C. to 55° C. By performing the countercurrent extraction at a certain heating temperature, the bound nicotine can be quickly separated from the tobacco raw material, and after a simple solid-liquid separation, an extract containing bound nicotine is obtained. It can be understood that the temperature of the countercurrent extraction can be provided by heating the water to a certain temperature.

[0086] In some embodiments, the countercurrent extraction step further includes solid-liquid separation to obtain an extract.

[0087] In some embodiments, step S110 includes: under the conditions of an ultrasonic frequency of 25 Hz to 50 Hz and an extraction pressure of 0.1 MPa to 0.15 MPa, countercurrent extraction is performed on the tobacco raw material and water in a mass ratio of 1:(5 to 6), the water temperature is 50°C to 55°C, and solid-liquid separation is performed to obtain an extract.

[0088] In some embodiments, the step of concentrating the extract adopts membrane concentration.

[0089] Nicotine is unstable in nature, and is easily deteriorated when exposed to light and high temperature. It has many types of impurities, and its physical and chemical properties are extremely similar to those of other alkaloid impurities, which limits the improvement of nicotine purity. In the traditional process, the high temperature during the solvent removal and water removal process will cause nicotine to degrade and oxidize and deteriorate, and produce new impurities, so that the purity of the final nicotine is not high, and the appearance is prone to yellowing and reddish. In some embodiments of the present application, by using membrane concentration treatment on the extract, the entire concentration and purification process is carried out at room temperature, without involving high-temperature treatment, no phase change, no chemical reaction, the nicotine component is not easy to oxidize and deteriorate, and it is not easy to bring in other impurities and cause the product to decompose and denature, which is particularly suitable for heat-sensitive substances such as nicotine. After membrane concentration, a tobacco concentrate containing bound nicotine is obtained.

[0090] In addition, the tobacco extract is concentrated through membrane concentration, which also solves the problem of high energy consumption in water concentration. For example, evaporation and concentration of 1 ton of water requires 1 ton of steam, and the cost of steam is 250 yuan / ton, while the membrane concentration equipment consumes 10kwh of electricity to concentrate 1 ton of water, and the industrial electricity cost is 1 yuan / kwh, and the electricity consumption is 10 yuan.

[0091] In addition, water is used as a solvent in the tobacco extraction process, and no organic solvent extraction process is involved. The content of oil-soluble components (esters, waxes, ketones, terpenes, phenols, etc.) in the concentrate after membrane concentration is extremely low, and it does not need to be processed through the nicotine sulfate intermediate process, which simplifies the process and improves purity.

[0092] Therefore, the extract can be concentrated by membrane treatment at room temperature without the need for high-temperature heating and concentration, making the nicotine component less likely to oxidize and deteriorate, less likely to bring in other impurities and cause decomposition and denaturation of the product, which is beneficial to improving the purity of nicotine while reducing energy consumption.

[0093] In some embodiments, in the step of concentrating the extract, the extract is first filtered through a porous ceramic membrane and then concentrated through a nanofiltration membrane. The porous ceramic membrane is mainly composed of a porous structure, which enables the ceramic membrane to have a high specific surface area and a small pore size, thereby having good screening and separation functions. The nanofiltration membrane forms a low-pressure reverse osmosis under the driving force of the pressure difference to complete the concentration of the extract.

[0094] In some embodiments, in the step of concentrating the extract, the temperature is 20° C. to 40° C. and the pressure is 2 MPa to 4 MPa.

[0095] In some embodiments, the density of the concentrate is 1.2 g / cm 3 ~1.25g / cm 3 , nicotine content is 12mg / mL~15mg / mL.

[0096] In some embodiments, the water collected after the concentration process can also be used for countercurrent extraction, thereby achieving recycling.

[0097] In some embodiments, the mass ratio of tobacco raw material to concentrated liquid is 6: 1. For example, 1 ton of tobacco concentrated liquid can be obtained for every 6 tons of tobacco raw material.

[0098] In some embodiments, the pH of the concentrate is 4-5.

[0099] In some embodiments, in the step of adjusting the pH of the concentrate to be alkaline, the pH of the concentrate is adjusted to be greater than or equal to 10. For example, the pH of the concentrate is adjusted to be 10 to 11. By adjusting the pH of the concentrate to be alkaline, nicotine is freed and transferred from the aqueous phase to the organic phase, and then the nicotine is separated by extraction. In addition, since water extraction is used in the process of extracting tobacco raw materials, the content of oil-soluble components in the tobacco raw materials in the extract is very small, which improves the purity of nicotine in the organic phase after extraction.

[0100] In some embodiments, in the step of adjusting the pH of the concentrated solution to be alkaline, an inorganic alkaline agent, such as a sodium hydroxide solution, is added. In one example, the mass percentage concentration of the sodium hydroxide solution is 30%. It is understood that in other embodiments, in the step of adjusting the pH of the concentrated solution to be alkaline, other alkaline agents can also be used.

[0101] In some embodiments, a viscosity reducer is added to the step of extracting the concentrate with the organic solvent. Nicotine belongs to alkaloids (organic amines) and has the property of being soluble in water and oil. Under alkaline conditions, nicotine is in a free state, and nicotine transfers mass from an aqueous solution to an organic solvent; under acidic conditions, nicotine and acid are in a combined state to form a salt structure. Nicotine is soluble in water but difficult to dissolve in organic solvents. The concentrated solution containing bound nicotine has a pH of 4 to 5 and is acidic. After adjusting the pH to alkaline, the viscosity is high. By adding a viscosity reducer, the viscosity of the alkalized tobacco concentrate is greatly reduced. At the same time, the risk of emulsification and low extraction rate in the subsequent extraction process is reduced, and the nicotine yield is further improved.

[0102] In some embodiments, the viscosity reducing agent includes one or more of guar gum, carboxymethyl cellulose salt, and hydroxyethyl cellulose salt.

[0103] In some embodiments, the mass of the viscosity reducing agent is 1% to 5% of the mass of the alkalized concentrated solution. For example, the mass of the viscosity reducing agent is 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5% of the mass of the alkalized concentrated solution, or a range consisting of any two of these values.

[0104] In some embodiments, the organic solvent includes one or more of n-hexane, petroleum ether, No. 6 solvent oil and dichloromethane.

[0105] In some embodiments, the volume ratio of the concentrate to the organic solvent is 1:(0.8-1.5). For example, the volume ratio of the concentrate to the organic solvent can be, but is not limited to, 1:0.8, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, or a range consisting of any two of these values.

[0106] In some embodiments, the step of extracting the concentrated solution with an organic solvent uses a centrifugal extraction method. By using the centrifugal extraction method, the organic extractant quickly separates the free nicotine through mixing, mass transfer, and centrifugal separation, thereby improving the separation efficiency and obtaining an extract of nicotine and an organic solvent. In addition, through the combined action of the viscosity reducing agent and the centrifugal force, the entrainment in the water phase is reduced during the separation of nicotine by the organic solvent, and the nicotine separation rate is also increased, and the nicotine content in the residual water phase is less than 0.1 mg / mL.

[0107] In addition, the use of centrifugal separation combined with countercurrent extraction achieves continuous automated production, providing a greener, simpler, more efficient and more automated process.

[0108] Specifically, during the centrifugal extraction process, the volume ratio of the alkalized concentrated solution and the organic solvent is controlled by controlling the flow rates of the two.

[0109] In some embodiments, in the step of removing the organic solvent from the extract, the temperature is 50°C to 55°C, and the vacuum degree is 0.06MPa to 0.08MPa. Through the above treatment, the organic solvent is recovered for recycling, and crude nicotine is obtained at the same time. Since some embodiments of the present application are extracted by water, then concentrated and purified, extracted after alkalization, and the solvent is recovered, the oily impurities in the obtained nicotine are extremely low, and the purity of the crude nicotine can reach more than 96%. And because there are few oil-soluble impurities, the sulfuric acid stripping process commonly used in the industry can be avoided, which reduces the production process. At the same time, because nicotine sulfate is not obtained through sulfuric acid stripping, high-salt and high-COD wastewater is not produced in the subsequent separation of nicotine, reducing the environmental burden of sewage treatment.

[0110] In some embodiments, the method further includes: performing distillation purification on the crude product after removing the organic solvent.

[0111] Specifically, the steps of rectification and purification include:

[0112] Under the conditions of vacuum degree of 0.08MPa-0.1MPa and temperature of 90℃-100℃, water is introduced into the system, the reflux ratio is set to full recovery, and the front fraction is collected;

[0113] When no liquid flows out of the collection port, the temperature is raised to 110°C to 120°C, the reflux ratio is set to (2 to 5):1, and nicotine is collected.

[0114] In some embodiments, in the distillation purification step, the mass of water is 5% to 10% of the mass of crude nicotine. For example, the mass of water is 5%, 6%, 7%, 8%, 9%, 10% of the mass of crude nicotine, or a range consisting of any two of these values.

[0115] In order to ensure that the purity and aroma of nicotine meet the usage standards of e-cigarettes and medicines during the nicotine distillation process, the principle of azeotropy of nicotine, water, and low-boiling point trace impurities at 90°C to 100°C is used in the distillation process. In the distillation process, water is added to the system. At this time, the system azeotropes. After the transition fraction is taken out, the temperature is raised again to collect qualified high-purity products with a purity of more than 99.8% and a positive aroma.

[0116] The second aspect of the present application provides a nicotine extraction system, see Figure 2, including: a countercurrent extraction device 210, a concentration device 220, an alkaline adjustment device 230, an extraction device 240 and a solvent removal device 250;

[0117] Among them, the countercurrent extraction device 210 includes an extraction body, an ultrasonic unit and a pressurizing unit arranged in the extraction body, which are used to perform countercurrent extraction of tobacco raw materials and water under ultrasonic and pressurized conditions; the concentration device 220 is connected to the countercurrent extraction device 210, and is used to concentrate the extract; the alkaline adjustment device 230 is connected to the concentration device 220, and is used to adjust the pH of the concentrated solution to alkaline; the extraction device 240 is connected to the alkaline adjustment device 230, and is used to extract the concentrated solution after the pH is adjusted; the solvent removal device 250 is connected to the extraction device 240, and is used to remove the organic solvent in the extract.

[0118] In the present application, communication refers to communication in the direction of nicotine extraction.

[0119] The nicotine extraction system of some embodiments of the present application includes a countercurrent extraction device 210, a concentration device 220, an alkaline adjustment device 230, an extraction device 240 and a solvent removal device 250. When used for nicotine extraction, the separation and extraction of nicotine in tobacco raw materials can be quickly completed by using a water extraction method, the concentration device 220 is used for concentration treatment, the alkaline adjustment device 230 is used to adjust the pH of the concentrate to alkaline, the extraction device 240 is used for extraction, and the organic solvent is removed by the solvent removal device 250 to obtain nicotine. In addition, the above-mentioned nicotine extraction system can achieve a daily processing capacity of hundreds of tons of tobacco raw materials, and the production process is safe, green and environmentally friendly, with a high degree of automation, low labor demand, and high industrial benefits.

[0120] In some embodiments, in the countercurrent extraction device 210, the extraction body is a tubular extraction device.

[0121] In some embodiments, the ultrasound unit is an ultrasound generator.

[0122] In some embodiments, the pressurizing unit is a booster pump, which is used to pressurize the extraction medium (i.e., water). Specifically, the working principle of the booster pump is as follows: a very low pressure is applied to a large-diameter air-driven piston, and when this pressure acts on a small-area piston, a high pressure is generated. Through a two-position five-way air-controlled reversing valve, the booster pump can achieve continuous operation. The high-pressure plunger controlled by the one-way valve continuously discharges the liquid.

[0123] When the pressure between the drive part and the output liquid part reaches equilibrium, the booster pump stops running and no longer consumes air. When the output pressure drops or the air drive pressure increases, the booster pump automatically starts running until the pressure reaches equilibrium again and stops automatically.

[0124] A single air-controlled non-balanced gas distribution valve is used to realize the automatic reciprocating motion of the pump. The air drive part of the pump body is made of aluminum alloy. The liquid contact part is made of carbon steel or stainless steel according to the medium. Generally, the pump has two ports: air inlet and exhaust. The air pressure that can be generated at the air inlet is called negative pressure; the air pressure that can be generated at the exhaust port is called positive pressure.

[0125] Therefore, in some embodiments of the present application, water is pressurized by a booster pump, and ultrasonic action is generated by an ultrasonic generator, so that the tobacco raw material and water are countercurrently extracted under ultrasonic and pressurized conditions.

[0126] In some embodiments, the countercurrent extraction device 210 further includes a heat exchanger for heating the extraction solvent.

[0127] In some embodiments, the countercurrent extraction device 210 further includes an extruder for extruding the extracted solid residue.

[0128] In some embodiments, the countercurrent extraction device 210 further includes an extraction liquid collection unit, which is used to collect the extraction liquid. For example, the extraction liquid collection unit can be, but is not limited to, an extraction liquid collection tank.

[0129] In some embodiments, the countercurrent extraction device 210 further includes an extraction solvent carrying unit for carrying the extraction solvent. For example, the extraction solvent carrying unit may be, but is not limited to, an extraction solvent collection tank.

[0130] Specifically, the countercurrent extraction device 210 includes an extraction body, an ultrasonic unit and a pressurizing unit arranged in the extraction body, an extraction solvent carrying unit, a heat exchanger, an extruder, and an extraction liquid collecting unit. The heat exchanger is used to heat the extraction solvent in the extraction solvent carrying unit, and the extraction solvent and the tobacco raw material are subjected to countercurrent extraction through the extraction body. During the countercurrent extraction process, the ultrasonic unit and the pressurizing unit perform ultrasonic and pressurization on the extraction solvent and the tobacco raw material, and the extracted material is subjected to solid-liquid separation through the extruder, and the obtained extraction liquid is collected by the extraction liquid collecting unit.

[0131] In some embodiments, the concentration device 220 is a membrane concentration device. In some embodiments, the concentration device 220 includes a porous ceramic membrane and a nanofiltration membrane, wherein the porous ceramic membrane is used to filter the extract, and the nanofiltration membrane is used to concentrate the filtered extract.

[0132] In some embodiments, the alkaline adjustment device 230 may be an alkaline adjustment kettle.

[0133] In some embodiments, the extraction device 240 includes a centrifugal extractor. The centrifugal extractor is beneficial to improving the extraction efficiency on the one hand, and on the other hand, it cooperates with the countercurrent extraction device 210 to achieve continuous and large-scale production.

[0134] In some embodiments, the organic solvent removal device 250 includes an organic solvent evaporator.

[0135] In some embodiments, the nicotine extraction system further comprises a distillation device, and the distillation device is used to perform distillation and purification on the crude nicotine after the solvent is removed.

[0136] Specifically, the distillation device includes a distillation tower. Specifically, the filler in the distillation tower can be a theta ring filler.

[0137] In some embodiments, the distillation device further comprises a reflux ratio controller, which is used to control the reflux condition in the distillation tower. For example, the reflux ratio controller may be, but is not limited to, an electromagnetic reflux ratio controller.

[0138] In some embodiments, the nicotine extraction system is used to perform the nicotine extraction method of the first aspect.

[0139] In order to make the purpose and advantages of the present application clearer, the nicotine extraction method and extraction system of the present application and their effects are further described in detail in combination with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and shall not be used to limit the present application. The following embodiments do not include other components except for unavoidable impurities unless otherwise specified. The drugs and instruments used in the embodiments are conventionally selected in the art unless otherwise specified. The experimental methods for which specific conditions are not specified in the embodiments are implemented according to conventional conditions, such as the conditions described in the literature and books or the methods recommended by the manufacturer.

[0140] Example 1

[0141] This embodiment provides a method for extracting nicotine, comprising the following steps:

[0142] (1) The tobacco raw material with a nicotine content of 0.7% by mass is crushed to 100 meshes, and is uniformly fed into a countercurrent extraction device (taking 2 units as an example) from the feeding port at a rate of 1.5 tons / hour, with a material-liquid ratio of 1:5 (i.e., tobacco raw material: water = 1:5). The temperature of the extraction solvent water is heated to 50° C. by a heat exchanger. During the extraction process, the ultrasonic frequency is 45 Hz, and the extraction pressure is 0.15 MPa. After the extraction, the residue is evenly discharged from the residue outlet to the residue collection point after passing through the extruder. The extract is collected from the liquid outlet on the same side of the feeding port to the extract transfer tank, and then transported to the extract collection tank.

[0143] (2) The extract collected in the extract collection tank is passed through a ceramic membrane / nanofiltration membrane concentration unit. The membrane concentration temperature is set to 35°C and the membrane concentration pressure is set to 2MPa. The density of the concentrated extract is 1.22g / cm 3The nicotine content is 15 mg / mL. The water collected after concentration is returned to the countercurrent extraction process for repeated use.

[0144] (3) The tobacco concentrate was transported to a pH adjustment kettle at a rate of 4 tons / hour, 180 kg of a 30% sodium hydroxide aqueous solution was added to adjust the pH to 10.8, and then 80 kg of a viscosity reducer sodium hydroxymethyl cellulose was added to reduce the viscosity to 198 mPa.s. 3 / h, n-hexane 4.5m 3 The alkalized tobacco concentrate and n-hexane are transported to a centrifugal extractor at a rate of / h to extract and separate nicotine to obtain a nicotine-organic solvent mixed solution.

[0145] (4) The nicotine-organic solvent mixture was transferred to an organic solvent evaporator, the vacuum degree was set to 0.08 MPa, the temperature was set to 50° C., the organic solvent was recovered, and 460 kg of crude nicotine was obtained.

[0146] (5) The crude nicotine was transferred to a distillation kettle, and the vacuum degree was set to 0.1 MPa. The temperature was first raised to 95° C., and then the valve was opened to suck in 23 kg of distilled water through negative pressure. The reflux ratio controller was set to full extraction, and a mixture of water, fore fraction, and a small amount of nicotine was extracted to a fore fraction collection tank. When no liquid flowed out from the extraction outlet, the temperature was continued to be raised to 110° C., and the reflux ratio controller was set to a reflux ratio of 3:1, and qualified products were extracted to a pure product collection tank, thereby obtaining 420 kg of high-purity nicotine, and a comprehensive nicotine preparation yield of 83.3%.

[0147] Comparative Example 1

[0148] Comparative Example 1 provides a method for extracting nicotine, comprising the following steps:

[0149] (1) 40 tons of tobacco stems containing 0.7% nicotine by mass were crushed to a fineness of 4 mesh, and 19.2 tons of tap water were sprayed on them. After being evenly wetted, 1 ton of calcium oxide was added and stirred evenly. The temperature was set at 20°C, and the tobacco stems were piled for alkalization for 3 hours. After the alkalization, the tobacco stems were sent to a 60-ton continuous extraction machine through a scraper and an auger, and extracted continuously for 2 hours with 17 tons of n-hexane to obtain a n-hexane extract of nicotine.

[0150] (2) The n-hexane extract of nicotine obtained in step (1) is pumped into a continuous extraction tank storing 2.5 tons of 10% (m / m) sulfuric acid solution, so that nicotine is dissolved in the sulfuric acid solution and n-hexane flows into the storage tank. When the pH value of the sulfuric acid solution is 4.5, the extraction is stopped to obtain nicotine sulfate.

[0151] (3) The nicotine sulfate obtained in step (2) is placed in a concentration tank, the temperature is set to 70° C., the vacuum degree is 0.08 MPa, and the nicotine sulfate is concentrated to 0.8 tons to obtain 665 kg of concentrated nicotine sulfate with a nicotine mass percentage concentration of 40%, wherein the mass of nicotine is 266 kg.

[0152] (4) Add 150 kg of 30% by mass sodium hydroxide aqueous solution to the concentrated nicotine sulfate obtained in step (3) to adjust the pH value to 10.8, then add 10 tons of n-hexane, cool the mixture with low-temperature water, seal the continuous extraction tank, stir at 18 rpm for 6 min, let stand for 25 min, separate the layers, repeat the extraction 4 times, remove impurities in the lower layer, and obtain the n-hexane solution containing nicotine in the upper layer.

[0153] (5) The upper layer of n-hexane solution containing nicotine is pumped into a concentration tank, heated to 67° C. with steam or heat transfer oil in the interlayer of the concentration tank, cooled to 4° C., and the n-hexane solution is recovered. After acid washing, 262 kg of crude nicotine is obtained.

[0154] (6) The crude nicotine obtained in step (5) is conveyed to a distillation kettle, and the temperature is first raised to 95° C. at a vacuum degree of 0.1 MPa. At this time, a valve is opened to suck in 13 kg of distilled water by negative pressure, and the reflux ratio controller is set to full extraction, and a mixture of water, fore fraction, and a small amount of nicotine is extracted to a fore fraction collection tank. When no liquid flows out from the extraction outlet, the temperature is further raised to 110° C., and the reflux ratio controller is set to a reflux ratio of 3:1, and qualified products are extracted to a pure product collection tank, thereby obtaining 218.4 kg of high-purity nicotine, and the comprehensive preparation yield of nicotine is 78%.

[0155] The following is the test part:

[0156] (1) Nicotine impurity detection - GCMS (gas chromatography-mass spectrometry) detection conditions are as follows:

[0157] 1. Sample pretreatment

[0158] Reagents: methanol (AR), nicotine samples;

[0159] Take 20 μL of nicotine sample, dilute it to 1 mL with methanol, filter it through a 0.22 μm filter membrane, and then analyze it by GC-MS.

[0160] 2. Instrument conditions

[0161] 2.1. Gas chromatograph conditions are set as follows:

[0162] Chromatographic column: DB-WAX capillary column; stationary phase is polyethylene glycol; specification [30m (length) × 0.25mm (inner diameter) × 0.25μm (film thickness)];

[0163] Inlet temperature: 250°C;

[0164] Carrier gas: helium (purity ≥ 99.999%), constant flow rate: 2 mL / min;

[0165] Injection volume: 1 μL, split injection, split ratio: 100:1;

[0166] Program temperature rise: initial temperature 60°C, hold for 2 min, increase to 230°C at a rate of 10°C / min, hold for 8 min.

[0167] 2.2. Mass spectrometry conditions are set as follows:

[0168] Chromatography and mass spectrometry interface temperature: 250°C;

[0169] Ionization method: electron impact source (EI);

[0170] Ionization energy: 70 eV;

[0171] Ion source temperature: 230°C;

[0172] Solvent delay: 3min;

[0173] Mass scanning range: 50m / z~350m / z;

[0174] Scan mode: full scan mode.

[0175] (2) Nicotine purity test - GC gas chromatography test conditions are as follows:

[0176] 1. Sample pretreatment

[0177] Reagents: methanol (AR), nicotine samples;

[0178] Take 20 μL of nicotine sample, dilute it to 1 mL with methanol, filter it through a 0.22 μm filter membrane, and then analyze it by GC.

[0179] 2. The gas chromatograph conditions are set as follows:

[0180] Chromatographic column: DB-5 capillary column; stationary phase is polyethylene glycol; specification [30m (length) × 0.25mm (inner diameter) × 0.25μm (film thickness)];

[0181] Inlet temperature: 250°C;

[0182] Carrier gas: helium (purity ≥ 99.999%), constant flow rate: 1 mL / min; hydrogen flow rate 30 mL / min, air flow rate 300 mL / min;

[0183] Injection volume: 1 μL, split injection, split ratio: 40:1;

[0184] Programmed temperature: The initial temperature of the column oven was 100°C, and it was increased to 280°C at 20°C / min and maintained for 3 min.

[0185] The GCMS chart of the crude nicotine obtained in step (4) of Example 1 is as follows: Figure 3 and Figure 4 As shown. Among them, Figure 3 This is the GCMS data of the crude nicotine obtained in step (4) of Example 1. Figure 4 This is the GCMS spectrum of the crude nicotine obtained in step (4) of Example 1. The substances and peak areas corresponding to each retention time of the crude nicotine obtained in step (4) of Example 1 are shown in Table 1 below.

[0186] Table 1

[0187]

[0188]

[0189] The GCMS graph of the nicotine-containing n-hexane extract obtained in step (1) of Comparative Example 1 is as follows: Figure 5 and Figure 6 As shown, Figure 5 This is a GCMS data chart of the nicotine-containing n-hexane extract obtained in step (1) of Comparative Example 1. Figure 6 This is the GCMS spectrum of the n-hexane extract containing nicotine obtained in step (1) of comparative example 1. The substances and peak areas corresponding to each retention time of the n-hexane extract containing nicotine obtained in step (1) of comparative example 1 are shown in Table 2 below.

[0190] Table 2

[0191]

[0192]

[0193]

[0194]

[0195] It can be seen from the above gas chromatography-mass spectrometry (GCMS) test results that the purity of the crude nicotine obtained in Example 1 of the present application is 98.466%, and the total number of impurities is 29, while the purity of the crude nicotine obtained in Comparative Example 1 is 76.126%, and the total number of impurities is 65. In terms of impurity types, the crude nicotine in Comparative Example 1 has many types of oil-soluble impurities such as esters, ketones, and polyols, and the content is high.

[0196] In addition, according to the purity and impurity distribution of the crude nicotine products of Example 1 and Comparative Example 1, the crude nicotine product of Example 1 can be directly subjected to distillation purification, while the crude nicotine product of Comparative Example 1 contains many types of oil-soluble impurities with high content, and needs to be stripped by aqueous sulfuric acid solution to remove the oil-soluble impurities, thereby obtaining a crude nicotine product with relatively high purity, and then subjected to distillation purification to obtain the product.

[0197] The GCMS graph of the concentrated nicotine sulfate obtained in step (3) of Comparative Example 1 is as follows: Figure 7 and Figure 8 As shown, Figure 7 This is the GCMS data diagram of the concentrated nicotine sulfate obtained in step (3) of Comparative Example 1, Figure 8 This is the GCMS spectrum of the concentrated nicotine sulfate obtained in step (3) of comparative example 1. The substances and peak areas corresponding to each retention time of the concentrated nicotine sulfate obtained in step (3) of comparative example 1 are shown in Table 3 below.

[0198] Table 3

[0199]

[0200]

[0201] from Figures 7-8 As can be seen from Table 3, the purity of the crude nicotine in Comparative Example 1 is increased to 96.729% after being prepared with nicotine sulfate, the number of impurities is reduced to 28, and the oil-soluble impurities such as esters, ketones, and polyols are significantly reduced, but still lower than the purity of the crude nicotine in Example 1.

[0202] The gas chromatography purity test results of the pure nicotine obtained in Example 1 and Comparative Example 1 are as follows: Fig. 9 and Fig.10 As shown. Among them, Fig. 9 is the gas chromatogram of the pure nicotine of Example 1, Fig.10 is the gas chromatogram of the pure nicotine of Comparative Example 1. Fig. 9 and Fig.10 It can be clearly seen that the purity of nicotine in Example 1 is 99.957%, the purity of nicotine in Comparative Example 1 is 99.878%, and the number of nicotine impurities in Example 1 is only 4, while the number of nicotine impurities in Comparative Example 1 is 8.

[0203] It can be seen from the above experimental results that the nicotine extraction method and extraction system of the embodiment of the present application are conducive to reducing the amount of strong alkali used, and at the same time, inorganic acids such as sulfuric acid are not used, so that the purity of nicotine is high, the process is simple, and it is more environmentally friendly, reducing the environmental burden of sewage treatment. At the same time, continuous and efficient production can be achieved, providing a new method and system for the extraction of nicotine.

[0204] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0205] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A method for extracting nicotine, characterized in that: The steps include: The tobacco raw material and water are subjected to countercurrent extraction under ultrasonic and pressurized conditions to obtain an extract; Concentrating the extract to obtain a concentrated solution; Adjusting the pH of the concentrated solution to be alkaline; Extracting the alkalized concentrated solution with an organic solvent to obtain an extract; The organic solvent in the extract is removed.

2. The method for extracting nicotine according to claim 1, characterized in that: During the countercurrent extraction, the ultrasonic frequency is 25 Hz to 50 Hz; And / or, during the countercurrent extraction process, the extraction pressure is 0.1 MPa to 0.15 MPa; And / or, during the countercurrent extraction process, the mass ratio of the tobacco raw material to water is 1:(5-6); And / or, the temperature of the countercurrent extraction is 50°C to 55°C.

3. The method for extracting nicotine according to claim 1, characterized in that: In the step of concentrating the extract, membrane concentration is used; Optionally, in the step of concentrating the extract, the extract is first filtered through a porous ceramic membrane and then concentrated through a nanofiltration membrane; Optionally, in the step of concentrating the extract, the temperature is 20° C. to 40° C. and the pressure is 2 MPa to 4 MPa; Optionally, the density of the concentrate is 1.2 g / cm 3 ~1.25g / cm 3 , nicotine content is 12mg / mL~15mg / mL.

4. The method for extracting nicotine according to claim 1, characterized in that: In the step of adjusting the pH of the concentrated solution to be alkaline, the pH of the concentrated solution is adjusted to be greater than or equal to 10; optionally, the pH of the concentrated solution is adjusted to be 10-11.

5. The method for extracting nicotine according to claim 1, characterized in that: In the step of extracting the alkalized concentrated solution with an organic solvent, a viscosity reducing agent is also added; Optionally, the viscosity reducing agent includes one or more of guar gum, carboxymethyl cellulose salt and hydroxyethyl cellulose salt; Optionally, the mass of the viscosity reducing agent is 1% to 5% of the mass of the alkalized concentrated solution.

6. The method for extracting nicotine according to claim 1, characterized in that: The organic solvent includes one or more of n-hexane, petroleum ether, No. 6 solvent oil and dichloromethane; and / or, the volume ratio of the alkalized concentrated solution to the organic solvent is 1:(0.8-1.5); and / or, in the step of extracting the alkalized concentrated solution with an organic solvent, centrifugal extraction is used; And / or, in the step of removing the organic solvent in the extract, the temperature is 50° C. to 55° C. and the vacuum degree is 0.06 MPa to 0.08 MPa.

7. The method for extracting nicotine according to any one of claims 1 to 6, characterized in that: Also includes: performing distillation purification on the crude nicotine product after removing the organic solvent; Optionally, the distillation and purification step comprises: Under the conditions of vacuum degree of 0.08MPa-0.1MPa and temperature of 90℃-100℃, water is introduced into the distillation system, the reflux ratio is set to full recovery, and the front fraction is collected; When no liquid flows out of the collection port, the temperature is raised to 110°C to 120°C, the reflux ratio is set to (2 to 5):1, and the purified nicotine is collected.

8. A nicotine extraction system, characterized in that: include: A countercurrent extraction device, comprising an extraction body, an ultrasonic unit and a pressurizing unit arranged in the extraction body, for performing countercurrent extraction of tobacco raw material and water under ultrasonic and pressurized conditions; a concentrating device, connected to the countercurrent extraction device, and used for concentrating the extract; an alkaline adjusting device, connected to the concentrating device, for adjusting the pH of the concentrated liquid to be alkaline; An extraction device, connected to the alkaline adjustment device, for extracting the concentrated solution after pH adjustment; The solvent removal device is connected to the extraction device and is used to remove the organic solvent in the extraction liquid.

9. The nicotine extraction system according to claim 8, characterized in that: The concentrating device is a membrane concentrating device; Optionally, the concentrating device comprises a porous ceramic membrane and a nanofiltration membrane, the porous ceramic membrane is used to filter the extract, and the nanofiltration membrane is used to concentrate the filtered extract.

10. The nicotine extraction system according to claim 8 or 9, characterized in that: The extraction device comprises a centrifugal extractor; And / or, the nicotine extraction system further comprises a distillation device, which is connected to the solvent removal device and is used for distilling and purifying the crude nicotine after the organic solvent is removed.

Images