Method for extracting high-purity nicotine from waste tobacco

Abstract

The invention relates to the technical field of nicotine extraction from tobaccos, in particular to a method for extracting high-purity nicotine from waste tobaccos, which comprises the following steps: crushing the waste tobaccos; stirring nicotine in free tobacco by using an alkaline aqueous solution; extracting by using a mixed organic solvent and collecting a lower-layer extracting solution; removing water and filtering by using anhydrous sodium sulfate, and collecting filtrate; performing rotary evaporation and concentration to obtain a nicotine crude product, and recovering the organic solvent; carrying out reduced pressure distillation on the nicotine crude product for further purification to obtain a nicotine solution; carrying out silica gel column chromatography on the nicotine solution to further purify and collect a nicotine fraction; concentrating the fractions by using rotary evaporation until the fractions are dry; and heating and dissolving the nicotine with an organic solvent, slowly cooling, and recrystallizing to finally obtain the nicotine crystal with the purity of more than or equal to 99%. According to the method, the waste tobacco can be treated on a large scale, the nicotine can be efficiently extracted, the cost is low, the purity of the obtained nicotine is extremely high, the waste tobacco can be turned into wealth, and part of environmental problems are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of extracting high-purity nicotine from waste tobacco. Background Art

[0002] With the continuous development of the national economy and the continuous improvement of people's living standards, cigarettes have frequently appeared in people's lives. Incomplete statistics show that the number of cigarettes produced in China each month far exceeds 180 billion. Such a huge number makes it urgent to deal with cigarette waste. The main components of cigarettes are tar and nicotine, and nicotine has different applications in industries such as medicine, tobacco, agriculture, and chemical industry.

[0003] Nicotine, also known as Nicotine, is an organic compound with the chemical formula C 10 H 10 N2, with a molecular weight of 162.232, is an indispensable component in cigarettes. The strength of the cigarette depends on the nicotine content, which can make people addicted and dependent. It is a colorless or light yellow oily liquid. It can be used in the pharmaceutical industry (as raw materials for health cigarettes, smoking cessation creams, and the production of high-grade edible or feed tobacco proteins), the tobacco industry (can be added to compound cigarettes to improve cigarette quality and remove miscellaneous odors, and for the production of cigarette substitutes, such as tea cigarettes), agriculture (used as a compounding component of pesticides, herbicides, and plant growth regulators, meeting the requirements of green food production; can also be compounded with fertilizers to increase fertilizer efficiency and reduce the loss of ammonium nitrogen; nicotine in the form of a smoke agent can be used for the disinfection of poultry houses), and the chemical industry (can be used to prepare nicotinic acid and its series of derivatives, such as nicotinamide, nicotinic acid creatine, nicotinic acid tocopherol, etc.).

[0004] Existing nicotine extraction technologies have low extraction purity. For example, in the invention patent with the application publication number CN109512014A, the content is as follows: (1) Heat and reflux the tobacco raw material with a mixed solution of a carbonate solution / bicarbonate solution and an alkaline solution, then filter and take the filtrate; (2) Extract the filtrate of step (1) with an organic solution 2-3 times and combine the organic phase extraction solutions; the organic solution is n-hexane and / or ethyl acetate; (3) Concentrate the organic phase extraction solution at 25-50°C to obtain a yellow oily liquid, which is the nicotine in the tobacco. And in the invention patent with the application publication number CN105768202A, the content is: Add the alkaline ionic liquid salt solution and tobacco waste into a synthesis extractor for atmospheric pressure extraction at a temperature of 50-70°C for 25-35 minutes to obtain nicotine; the alkaline ionic liquid salt solution is made of an alkaline ionic liquid and potassium acetate. And other processes, the obtained nicotine has a low purity.

[0005] The inventors of the present application found that using an alkaline aqueous solution can preferentially liberate nicotine from tobacco, and then a mixed organic solvent can be used to efficiently extract nicotine. The organic solvent in the extract can be reused through rotary evaporation. By performing vacuum distillation, a nicotine solution can be obtained. After purification by silica gel column chromatography, a high-purity nicotine solution can be obtained. Finally, recrystallization and vacuum drying can yield nicotine crystals with a purity of ≥99%. Summary of the Invention

[0006] The present invention is used to solve the problem of recycling nicotine from waste tobacco.

[0007] The technical means adopted by the present invention to solve the above problems are as follows: The waste tobacco is crushed, soaked in an alkaline aqueous solution to liberate nicotine, then extracted with a mixed organic solvent, the organic solvent in the extract is recovered, a crude nicotine product is obtained, the nicotine vapor is collected and condensed by vacuum distillation, further purified by silica gel column chromatography, the fraction containing nicotine is collected and evaporated to dryness, dissolved in ethyl acetate, heated and cooled to precipitate nicotine crystals, and the crystals are collected and vacuum dried to obtain high-purity nicotine.

[0008] Specifically, the present application provides a method for extracting high-purity nicotine from waste tobacco, which successively includes the following steps:

[0009] (1) Collect waste tobacco and crush it using a crusher or other instrument;

[0010] (2) Place the crushed tobacco in distilled water for soaking;

[0011] (3) Slowly add sodium hydroxide solution to adjust the pH of the aqueous solution and stir;

[0012] (4) Use a mixed solvent of dichloromethane and ethyl acetate to extract the alkalized solution;

[0013] (5) Collect the lower-layer extract, add anhydrous sodium sulfate to dry it until the solution is clear, filter and collect the extract;

[0014] (6) Recover the organic solvent from the extract by rotary evaporation to obtain a crude nicotine product;

[0015] (7) Perform vacuum distillation on the crude nicotine product, collect and condense the nicotine vapor to obtain a nicotine solution;

[0016] (8) Further purify the nicotine solution using silica gel column chromatography;

[0017] (9) Rotate and evaporate the collected fraction to dryness;

[0018] (10) Dissolve the nicotine concentrated to dryness in ethyl acetate;

[0019] (11) Heat to completely dissolve the nicotine, and slowly cool to precipitate nicotine crystals;

[0020] (12) Collect the crystals and dry them under vacuum to obtain high-purity nicotine.

[0021] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (1), the state of the filter tip fragmentation is fragments of 2-3 mm.

[0022] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (2), the dosage of distilled water is 1 L of distilled water corresponding to every 100 g of tobacco.

[0023] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (3), the concentration of sodium hydroxide is 0.8 mol / L. Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (3), the pH of the aqueous solution is adjusted to 10-11.

[0024] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (3), it is stirred at 40 °C for 45 minutes.

[0025] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (4), the ratio of dichloromethane to ethyl acetate in the mixed solvent is 1:1.

[0026] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (4), every 1 L of the aqueous solution needs to be extracted with 1 L of the mixed organic solvent.

[0027] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (4), it must be gently shaken for 5 minutes each time during extraction, left to stand for 15 minutes to separate layers, and the extraction is repeated three times.

[0028] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (5), 50 g of anhydrous sodium sulfate needs to be added to every 1 L of the extract.

[0029] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (6), the parameters of rotary evaporation are a water bath temperature of 40 °C, a vacuum degree of 200-300 mbar, and a rotation speed of 60 rpm.

[0030] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (6), the extract of every 100 g of waste tobacco is concentrated to 5-10 ml of crude nicotine.

[0031] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in the step (7), the parameters of vacuum distillation are a temperature of 100-120 °C and a vacuum degree of 50-100 mbar.

[0032] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, the steam at 100 - 120°C in step (7) is nicotine steam. Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, the silica gel in step (8) is 200 - 300 mesh.

[0033] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, the chromatography column in step (8) is compacted with dichloromethane. Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, for every 100 g of the extraction solution of waste tobacco in step (8), 5 ml of dichloromethane is used to dissolve the fraction collected by reduced pressure distillation and added to the top of the column.

[0034] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in step (8), a mixed solution with a dichloromethane - methanol mixing ratio of 95:5 is used as the mobile phase for elution, and the flow rate is 1 ml / min.

[0035] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, the parameters of rotary evaporation in step (9) are the same as those in (6). Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in step (10), the dosage of ethyl acetate is 10 ml for every 100 g of the dried extract of the waste tobacco extraction solution.

[0036] Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in step (11), it is heated to 50°C and slowly cooled to 4°C. Furthermore, in a method for extracting nicotine from waste tobacco according to the present application, in step (12), the nicotine purity is ≥99%.

[0037] Furthermore, a method for extracting nicotine from waste tobacco according to the present application successively includes the following steps:

[0038] (1) Collect waste tobacco and crush it to 2 - 3 mm;

[0039] (2) Put every 100 g of the crushed tobacco into 1 L of distilled water for soaking;

[0040] (3) Slowly add 0.8 mol / L sodium hydroxide solution to adjust the pH of the aqueous solution to 10 - 11, and stir at 40°C for 45 minutes;

[0041] (4) Use 1 L of a mixed solvent with a dichloromethane - ethyl acetate mixing ratio of 1:1 to extract the alkalized solution for every 1 L of the aqueous solution. Each time of extraction, gently shake for 5 minutes, let it stand for 15 minutes to separate layers, and repeat extraction three times;

[0042] (5) Add 50 g of anhydrous sodium sulfate to every 1 L of the lower-layer extract and dry until the solution becomes clear, then filter and collect the extract;

[0043] (6) Set the parameters of rotary evaporation as water bath temperature 40 °C, vacuum degree 200 - 300 mbar, and rotation speed 60 rpm to recover the organic solvent in the extract. The extract of every 100 g of waste tobacco is concentrated to 5 - 10 ml of crude nicotine;

[0044] (7) Set the parameters of vacuum distillation as temperature 100 - 120 °C, vacuum degree 50 - 100 mbar, collect and condense the steam at 100 - 120 °C to obtain nicotine solution;

[0045] (8) Fill a chromatography column with silica gel of 200 - 300 mesh, compact it with dichloromethane to remove the air in the silica gel. Dissolve the fraction collected by vacuum distillation with 5 ml of dichloromethane for every 100 g of waste tobacco extract, add it to the top of the column, and use a mixed solution of dichloromethane and methanol with a mixing ratio of 95:5 as the mobile phase for elution, with a flow rate of 1 ml / min, and collect the nicotine fraction;

[0046] (9) Set the parameters of rotary evaporation as water bath temperature 40 °C, vacuum degree 200 - 300 mbar, and rotation speed 60 rpm to concentrate the nicotine fraction to dryness;

[0047] (10) Dissolve the dried product of every 100 g of waste tobacco extract with 10 ml of ethyl acetate;

[0048] (11) Heat to 50 °C to completely dissolve the nicotine, and slowly cool to 4 °C to precipitate nicotine crystals;

[0049] (12) Collect the crystals and dry them under vacuum to obtain nicotine with a purity ≥ 99%;

[0050] Compared with the prior art, the present invention has the following advantages:

[0051] This method has low cost, can process waste tobacco in large quantities to efficiently extract nicotine, and the obtained nicotine has extremely high purity. Specific embodiments

[0052] The present application is further described through the following specific embodiments:

[0053] Method for determining nicotine content: Refer to the national tobacco industry standard of the People's Republic of China "YC / T 246 - 2008 Determination of nicotine in tobacco and tobacco products - Gas chromatography method".

[0054] Take 100 g of waste tobacco, crush it to a size of 2 - 3 mm, add 1 L of distilled water, slowly add 0.8 mol / L sodium hydroxide solution to adjust the pH of the solution to 10 - 11, heat to 40 °C and stir for 45 minutes. Filter and collect the aqueous solution. Extract the aqueous solution with a mixed organic solution of 500 ml of dichloromethane and 500 ml of ethyl acetate, collect the lower extraction liquid, gently shake for 5 minutes each time during extraction, and let it stand for 15 minutes to separate layers. Add 50 g of anhydrous sodium sulfate to the collected lower extraction liquid to dry the extraction liquid, and filter and collect the extraction liquid until the solution becomes clear. Set the parameters of rotary evaporation as a water bath temperature of 40 °C, a vacuum degree of 200 - 300 mbar, and a rotation speed of 60 rpm to rotary evaporate the extraction liquid, recover the organic solution, concentrate the extraction liquid to 5 ml to obtain crude nicotine. Set the parameters of vacuum distillation as a temperature of 100 - 120 °C and a vacuum degree of 50 - 100 mbar, collect and condense the steam at 100 - 120 °C to obtain a nicotine solution. Fill a chromatography column with silica gel of 200 - 300 mesh, compact it with dichloromethane and remove the air in the silica gel, dissolve the fraction collected by vacuum distillation with 5 ml of dichloromethane, add it to the top of the column, and use a mixed solution with a dichloromethane - methanol mixing ratio of 95:5 as the mobile phase for elution, with a flow rate of 1 ml / min, and collect the nicotine fraction. Concentrate the collected fraction to dryness with a rotary evaporator with parameters of a water bath temperature of 40 °C, a vacuum degree of 200 - 300 mbar, and a rotation speed of 60 rpm. Add 10 ml of ethyl acetate, heat to 50 °C and then slowly cool to 4 °C to precipitate nicotine crystals. Filter, wash with a small amount of cold ethyl acetate, collect the crystals, and vacuum - dry the crystals to obtain nicotine with a purity ≥ 99%.

[0055] Finally, it should be noted that the above - mentioned embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered by the claims of the present invention.

Claims

1. A method for extracting high-purity nicotine from waste tobacco, characterized in that, It successively includes the following steps: (1) Crush the waste tobacco into fragments of 2-3 mm; (2) Soak it according to the ratio of adding 1 L of distilled water to every 100 g of crushed tobacco; (3) Add a 0.8 mol / L sodium hydroxide solution to adjust the pH of the aqueous solution to 10-11, and stir at 40 °C for 45 minutes; (4) Extract with a mixed solvent with a volume ratio of dichloromethane to ethyl acetate of 1:

1. For every 1 L of aqueous solution, 1 L of the mixed solvent is used. Each extraction is shaken for 5 minutes and left to stand for 15 minutes for phase separation. Repeat the extraction 3 times, and collect the lower-layer extraction solution; (5) Add anhydrous sodium sulfate to the lower-layer extraction solution to dry it until the solution is clear. The dosage of the anhydrous sodium sulfate is 50 g added to every 1 L of extraction solution; (6) Filter and collect the extraction solution, perform rotary evaporation to recover the organic solvent, and concentrate to obtain crude nicotine. The extraction solution of every 100 g of crushed tobacco is concentrated to 5-10 ml of crude nicotine. The parameters of the rotary evaporation are: water bath temperature 40 °C, vacuum degree 200-300 mbar, rotation speed 60 rpm; (7) Perform vacuum distillation on the crude nicotine, and collect the fraction at 100-120 °C. The vacuum degree of the vacuum distillation is 50-100 mbar; (8) Dissolve the nicotine fraction in step (7) with 5 ml of dichloromethane for every 100 g of crushed tobacco extraction solution. Pack a chromatography column with silica gel of 200-300 mesh, compact the silica gel with dichloromethane, use a mixed solution of dichloromethane and methanol with a volume ratio of 95:5 as the mobile phase, elute at a flow rate of 1 ml / min, and collect the fraction containing nicotine; (9) Rotate evaporate the fraction in step (8) to dryness, with the same parameters as in step (6); (10) Dissolve the concentrated nicotine with ethyl acetate, heat to 50 °C until completely dissolved, and then slowly cool to 4 °C to precipitate nicotine crystals. Use 10 ml of ethyl acetate to dissolve the dried product of every 100 g of crushed tobacco extraction solution; (11) Collect the crystals and dry them under vacuum to obtain nicotine crystals with a purity ≥99%; 2. The method according to claim 1, characterized in that, In step (3), the concentration of the sodium hydroxide solution is 0.8 mol / L, and the pH of the aqueous solution is adjusted to 10-11.

3. The method according to claim 1, wherein In step (4), the volume ratio of the mixed solvent is 1:

1.

4. The method according to claim 1, wherein In step (6), the water bath temperature of the rotary evaporation is 40 °C, the vacuum degree is 200-300 mbar, and the rotation speed is 60 rpm.

5. The method according to claim 1, wherein In step (6), the degree of rotary evaporation is that the extraction solution of every 100 g of crushed tobacco is concentrated to 5-10 ml of crude nicotine.

6. The method according to claim 1, characterized in that, In step (7), the temperature of the vacuum distillation is 100-120 °C, and the vacuum degree is 50-100 mbar.

7. The method according to claim 1, characterized in that, In step (8), the dosage of dichloromethane is 5 ml for every 100 g of crushed tobacco extraction solution.

8. The method according to claim 1, wherein In step (8), the mobile phase of the silica gel column chromatography is a dichloromethane-methanol mixed solution with a volume ratio of 95:

5.

9. The method according to claim 1, wherein In step (10), the dosage of ethyl acetate is 10 ml for the dried product of every 100 g of crushed tobacco extraction solution.