Method for preparing high-purity nornicotine from cinnabar smoke residues

Abstract

The invention belongs to the technical field of reutilization of tobacco residues, and particularly relates to a method for preparing high-purity nornicotine from cinnabar smoke residues, which comprises the following steps: adding a proper amount of dilute acid solution into the cinnabar smoke residues to obtain a cinnabar smoke residue-dilute acid mixture, carrying out ultrasonic-assisted extraction on the cinnabar smoke residue-dilute acid mixture, and carrying out coarse filtration on the extracting solution to obtain high-purity nornicotine; then filtering by adopting an ultrafiltration membrane and a nanofiltration membrane in sequence to obtain nornicotine extract, carrying out supercritical carbon dioxide extraction, adding the nornicotine extract obtained after extraction into an alkali solution, carrying out secondary supercritical carbon dioxide extraction, and separating to obtain high-purity nornicotine. According to the technical scheme, the characteristic tobacco leaf residues of cinnabar tobacco are developed and utilized, extraction is carried out in combination with supercritical carbon dioxide and membrane separation technologies, small molecular proteins, pigments, non-polar compounds and the like can be effectively removed, and the purity of the product is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of tobacco residue recycling, and particularly relates to a method for preparing high-purity nornicotine by utilizing cinnabar tobacco residue. Background Art

[0002] Nornicotine (nornicotine), a heterocyclic compound containing nitrogen heteroatoms, has a molecular formula of C9H12N2 and a molecular weight of 148.20. Nornicotine exists naturally in tobacco and is a degradation product of nicotine in tobacco. Studies have shown that a large amount of nicotine in cinnabar tobacco is converted into nornicotine, and it has the advantages of thick and mellow smoke, less strength, and a unique "glutinous rice fragrance", which has received continuous attention from the cigarette industry. However, during the use of special tobacco leaves such as cinnabar tobacco, a large amount of residue and waste will be generated, resulting in a waste of resources and even environmental pollution. Therefore, the re-extraction and utilization of tobacco residues and waste will be conducive to the preparation of high value-added products, promote the development of the green economy, and improve the ecological environment.

[0003] In recent years, the utilization of tobacco residues mainly includes extracting high value-added deep-processing products such as nicotine and solanesol, and the remaining residue is used to make organic fertilizer or the tobacco residue is directly fermented to make organic fertilizer. There are many processes for extracting nicotine and solanesol from tobacco waste residues, such as Chinese patent CN201910636858.X discloses a combined process of large-scale continuous countercurrent extraction and supercritical carbon dioxide extraction of nicotine; Chinese patent CN202010614621.4 discloses a method for purifying nicotine using a short-range molecular distiller and high-speed countercurrent chromatography; Chinese patent CN117362272A discloses a high-speed countercurrent chromatography method for separating high-purity natural nicotine from tobacco extracts; Chinese patent CN104072336A discloses a supercritical chromatography method for extracting solanesol from tobacco waste. At present, the reports are mainly aimed at extracting nicotine or solanesol from tobacco leaves and their wastes, but there are no reports on the process for preparing nornicotine from tobacco wastes with cinnabar characteristics. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing high-purity nornicotine by utilizing cinnabar cigarette residue, so as to realize a method for extracting and purifying nornicotine from cinnabar cigarette residue.

[0005] To achieve the above objectives, this application is implemented through the following technical solutions:

[0006] A method for preparing high-purity nornicotine using cinnabar cigarette residues comprises the following steps:

[0007] S1. Add an appropriate amount of dilute acid solution to the cinnabar smoke residue and stir evenly to obtain a cinnabar smoke residue-dilute acid mixture;

[0008] S2. subjecting the cinnabar smoke residue-dilute acid mixture to ultrasonic-assisted extraction, and subjecting the collected final extract to coarse filtration to obtain a transparent and clear filtrate;

[0009] S3. Filtering the filtrate with an ultrafiltration membrane to remove polysaccharides and proteins with larger molecular weights, filtering again with a nanofiltration membrane to remove organic substances with smaller molecular weights, and then concentrating to obtain nornicotine salt extract A;

[0010] S4, putting the nornicotine salt extract A obtained in step S3 into an extraction kettle, performing supercritical carbon dioxide extraction and separation, and obtaining the nornicotine salt extract B in the extraction kettle;

[0011] S5. Add an alkaline solution to the nornicotine salt extract B, adjust the pH value to 10-13, and obtain a nornicotine extract, which is then loaded into an extraction kettle, and ethanol water is added as an entrainer to perform supercritical carbon dioxide extraction and separation to obtain high-purity nornicotine.

[0012] Furthermore, in step S1, the cinnabar smoke residue comprises two parts, the first part is the cinnabar smoke powder after extraction, and the second part is the extract obtained after freezing alcohol precipitation and filtration in the process of preparing the pure oil.

[0013] Furthermore, in step S1, the dilute acid is an inorganic acid, and the pH value of the dilute acid solution is 2-4.

[0014] Furthermore, in step S2, the temperature during ultrasound is 40-60°C, the ultrasound power is 200-400W, and the extraction time is 30min.

[0015] Furthermore, in step S3, the membrane filtration treatment uses one of microfiltration, ultrafiltration, nanofiltration or reverse osmosis membrane.

[0016] Furthermore, in step S4, supercritical carbon dioxide extraction and separation are performed, and its main parameters are: extraction pressure 12-20 MPa, extraction temperature 40-45°C, separation pressure 5-7 MPa, separation temperature 45-50°C, and extraction time 2-3 h.

[0017] Furthermore, in step S5, the alkaline solution is one or more of KOH, NaOH, Ca(OH)2, ammonia water, and Na2CO3.

[0018] Furthermore, in step S5, supercritical carbon dioxide extraction and separation are performed, and its main parameters are: extraction pressure 25-30 MPa, extraction temperature 50-55°C, separation pressure 6-8 MPa, separation temperature 55-60°C, entrainer 70-85% ethanol, and extraction time 2-4 h.

[0019] The beneficial effects of the present invention are:

[0020] This technical solution is aimed at the development and utilization of the characteristic tobacco leaf residues of cinnabar tobacco. The amount of organic solvent used in the whole process is very small. Only ethanol water is used as an entrainer in supercritical extraction, which reduces environmental pollution and conforms to the concept of green development. Combining supercritical carbon dioxide and membrane separation technology for extraction can effectively remove small molecular proteins, pigments, non-polar compounds, etc., greatly improving the purity of the product. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is described in detail below through examples. The following examples are merely exemplary and can only be used to explain and illustrate the technical solution of the present invention, but cannot be construed as limiting the technical solution of the present invention.

[0022] Example 1

[0023] The extraction of nornicotine from Yunnan Hongda C1F cinnabar tobacco residues is carried out through the following process steps:

[0024] S1. Add an appropriate amount of dilute sulfuric acid solution to the Yunnan Hongda C1F cinnabar smoke residue, and stir mechanically to obtain a Yunnan Hongda C1F cinnabar smoke residue-dilute sulfuric acid mixture. The mass ratio of Yunnan Hongda C1F cinnabar smoke residue to the dilute sulfuric acid solution is 1:2, and the volume percentage of the dilute sulfuric acid solution is 35%.

[0025] S2. The residue in step S1 is subjected to ultrasonic-assisted extraction with a mixture of dilute sulfuric acid at an extraction temperature of 45° C., an ultrasonic power of 200 W, and an extraction time of 30 min. A transparent and clear mixture of residue and dilute acid is obtained by coarse filtration.

[0026] S3, ultrafiltration treatment is performed on the filtrate of step S2 using an ultrafiltration membrane to remove macromolecular substances such as polysaccharides and proteins, and then nanofiltration treatment is performed using a nanofiltration membrane to remove small molecular organic matter, and the nicotine salt solution A is obtained after concentration.

[0027] S4. The nornicotine salt extract A is placed in an extraction kettle for supercritical carbon dioxide extraction, with the main parameters being: extraction pressure of 20 MPa, extraction temperature of 45°C, separation pressure of 7 MPa, separation temperature of 50°C, and extraction time of 2 h. Non-polar, especially volatile small molecule compounds are further removed to obtain nornicotine salt extract B in the extraction kettle.

[0028] S5. Add 55% by volume of KOH solution to the nornicotine salt extract B, adjust the pH value to 12, and obtain the nornicotine extract. Then put it into an extraction kettle, add 75% ethanol water as an entrainer, and perform supercritical carbon dioxide extraction and separation. The main parameters are: extraction pressure of 30 MPa, extraction temperature of 55°C, separation pressure of 8 MPa, separation temperature of 60°C, entrainer of 75% ethanol, and extraction time of 2 h to obtain high-purity nornicotine.

[0029] Example 2

[0030] The extraction of nornicotine from B1F cinnabar tobacco residue in Shizong, Qujing, Yunnan, is carried out through the following process steps:

[0031] S1. Add an appropriate amount of dilute sulfuric acid solution to the B1F cinnabar smoke residue in Shizong, Qujing, Yunnan, and stir mechanically to obtain a mixture of B1F cinnabar smoke residue in Shizong, Qujing, Yunnan and dilute sulfuric acid. The mass ratio of B1F cinnabar smoke residue in Shizong, Qujing, Yunnan to dilute sulfuric acid is 1:2.5, and the volume percentage of the dilute sulfuric acid solution is 30%.

[0032] S2, subjecting the residue in step S1 and the mixture of dilute sulfuric acid to ultrasonic-assisted extraction, the extraction temperature is 40° C., the ultrasonic power is 200 W, and the extraction time is 30 min. A transparent and clear residue and dilute acid mixed solution is obtained by coarse filtration.

[0033] S3, ultrafiltration treatment is performed on the filtrate of step S2 to remove macromolecular substances such as polysaccharides and proteins, and then nanofiltration treatment is performed to remove small molecular organic substances, and nicotine salt solution A is obtained after concentration.

[0034] S4. The nicotine salt extract A is placed in an extraction kettle for supercritical carbon dioxide extraction, with the main parameters being: extraction pressure of 18 MPa, extraction temperature of 42°C, separation pressure of 6 MPa, separation temperature of 45°C, and extraction time of 2 h. Non-polar, especially volatile small molecule compounds are further removed to obtain the nicotine salt extract B in the extraction kettle.

[0035] S5. Add 60% NaOH solution by volume to the nornicotine salt extract B, adjust the pH value to 12, and obtain the nornicotine extract. Then put it into an extraction kettle, add 75% ethanol water as an entrainer, and perform supercritical carbon dioxide extraction and separation. The main parameters are: extraction pressure of 30 MPa, extraction temperature of 55°C, separation pressure of 8 MPa, separation temperature of 60°C, entrainer of 75% ethanol, and extraction time of 2 h to obtain high-purity nornicotine.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any equivalent changes or modifications made according to the essence of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing high-purity nornicotine using cinnabar cigarette residue, characterized in that: The following steps are involved: S1. Add an appropriate amount of dilute acid solution to the cinnabar smoke residue and stir evenly to obtain a cinnabar smoke residue-dilute acid mixture; S2. subjecting the cinnabar smoke residue-dilute acid mixture to ultrasonic-assisted extraction, and subjecting the collected final extract to coarse filtration to obtain a transparent and clear filtrate; S3. Filtering the filtrate with an ultrafiltration membrane to remove polysaccharides and proteins with larger molecular weights, filtering again with a nanofiltration membrane to remove organic substances with smaller molecular weights, and then concentrating to obtain nornicotine salt extract A; S4, putting the nornicotine salt extract A obtained in step S3 into an extraction kettle, performing supercritical carbon dioxide extraction and separation, and obtaining the nornicotine salt extract B in the extraction kettle; S5. Add an alkaline solution to the nornicotine salt extract B, adjust the pH value to 10-13, and obtain a nornicotine extract, which is then loaded into an extraction kettle, and ethanol water is added as an entrainer to perform supercritical carbon dioxide extraction and separation to obtain high-purity nornicotine.

2. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S1, the cinnabar smoke residue comprises two parts, the first part is the cinnabar smoke powder after extraction, and the second part is the extract obtained after freezing alcohol precipitation and filtration in the process of preparing the pure oil.

3. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S1, the dilute acid is an inorganic acid, and the pH value of the dilute acid solution is 2-4.

4. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S2, the temperature during ultrasound is 40-60°C, the ultrasound power is 200-400W, and the extraction time is 30min.

5. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S3, the membrane filtration treatment uses one of microfiltration, ultrafiltration, nanofiltration or reverse osmosis membrane.

6. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S4, supercritical carbon dioxide extraction and separation are performed, and its main parameters are: extraction pressure 12-20 MPa, extraction temperature 40-45° C., separation pressure 5-7 MPa, separation temperature 45-50° C., and extraction time 2-3 h.

7. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S5, the alkaline solution is one or more of KOH, NaOH, Ca(OH)2, ammonia water, and Na2CO3.

8. The method for preparing high-purity nornicotine using cinnabar smoke residue according to claim 1, characterized in that: In step S5, supercritical carbon dioxide extraction and separation are performed, and its main parameters are: extraction pressure 25-30 MPa, extraction temperature 50-55°C, separation pressure 6-8 MPa, separation temperature 55-60°C, entrainer 70-85% ethanol, and extraction time 2-4 h.