Preparation of sweet-flavor porous carbon material and application in heated cigarette

Abstract

The application discloses a preparation method of sweet and fragrant porous carbon material and application of the sweet and fragrant porous carbon material in a heated cigarette, and relates to the technical field of the preparation of the sweet and fragrant porous carbon material. The preparation method comprises the following steps: selecting clean and dry tobacco stems, soaking the tobacco stems in water, taking out the tobacco stems and draining water, and reserving the tobacco stems; placing the tobacco stems in a microwave reactor to microwave expand the tobacco stems; crushing the expanded tobacco stems; dissolving the powder in a mixed solution of KOH and sodium benzenesulfonate, adding cross-linking materials, and heating to solidify the materials; crushing and carbonizing the materials to obtain tobacco stem porous carbon materials; and loading 2,3-dihydro-3-hydroxy-5-(2-mercaptoethoxy)-6-methyl-4(H)-pyran-4-one on the tobacco stem porous carbon materials to form sweet and fragrant porous carbon materials. The application realizes the technical effects of high loading and uniform release by using waste tobacco stems to customize the sweet and fragrant porous carbon material with special morphology and structure; and the specific sweet and fragrant molecular structure and the base spices are matched to form the sensory effect of rich sweet and fragrant and stable flavor.

Description

Technical Field

[0001] This invention relates to the field of heated cigarette material development technology, and in particular to the preparation of a sweet-smelling porous carbon material and its application in heated cigarettes. Background Technology

[0002] Heated cigarettes are a new form of tobacco consumption. They primarily utilize a heating device to heat tobacco products (such as shredded tobacco or reconstituted tobacco) at a low temperature, causing them to release volatile aroma compounds and nicotine, which are then inhaled by the consumer. Their low-temperature, non-combustible nature distinguishes them significantly from conventional cigarettes and e-cigarettes. Therefore, to achieve a similar smoke effect to conventional cigarettes, heated cigarettes require the addition of smoke-generating agents (such as glycerin or propylene glycol) to produce a sufficient amount of smoke. Simultaneously, because most of the latent aroma compounds do not undergo effective thermal decomposition and transformation under low-temperature heating, heated cigarettes have a low content of aroma compounds and a weak flavor. To compensate for this lack of aroma compounds, external flavorings are typically added, loading volatile flavorings onto the shredded or reconstituted tobacco to achieve a richer and fuller flavor experience.

[0003] Currently, the flavoring process commonly used in heated cigarettes still borrows from that of conventionally burned cigarettes, employing spraying or coating methods to combine flavorings and fragrances with the tobacco core material. However, it is well known in the art that conventionally processed tobacco core materials (such as shredded tobacco, reconstituted tobacco leaves, and tobacco sticks) lack adsorption capacity for volatile flavorings at the microscopic level because their internal physical structure remains essentially unchanged. This results in problems such as weak flavoring loading capacity, low loading amount, and significant flavor loss during processing. Therefore, there is an urgent need to develop a specific volatile flavoring loading material to overcome these problems. Common adsorption materials include diatomaceous earth, molecular sieves, and activated carbon. While these materials have strong adsorption capacity, they often have some fatal flaws in heated cigarettes, such as weak desorption capacity due to π-π stacking, excessively high desorption temperatures, weak pore diffusion capacity due to small or uneven pores, uneven surface diffusion gradients, and flavoring deterioration caused by the catalytic cracking effect of the material itself at high temperatures. Therefore, research on the applicability of such materials in heated cigarettes is crucial for studying the modification and personalized application of these materials.

[0004] Furthermore, regarding the flavoring materials in heated cigarette fillers, they must not only possess a strong flavor loading capacity but also satisfy the tiered release of flavor molecules; otherwise, it will lead to inconsistencies in the aroma and flavor profile with each puff, resulting in significant sensory differences. Sweetness is a common and very important flavor profile in cigarettes. However, for this flavor characteristic, ordinary filler materials often struggle to effectively achieve a stable release of the target flavor, making it relatively difficult to maintain the aroma. To maintain the uniformity and stability of the aroma characteristics, customized matching of filler materials, structure, and flavoring formulations is urgently needed.

[0005] Therefore, how to personalize the construction of heating cigarette core loading materials, and how to modify the molecular structure of volatile flavorings to obtain a sweet-flavored heating cigarette core design scheme with high loading, uniform release, and stable flavor, have become important issues in the current development of heating cigarette materials. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a sweet-scented porous carbon material for preparation and its application in heated cigarettes, which solves the problems of poor adsorption-desorption capacity, unstable structure and uneven release of sweet aroma in the prior art.

[0007] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0008] A method for preparing a sweet-smelling porous carbon material includes the following steps:

[0009] S1. Select clean, dry tobacco stems with a length of 1-5cm, soak them in water for 24 hours, then remove and drain for later use.

[0010] S2. Place the tobacco stems obtained in S1 into a microwave reactor and microwave them at 2500W for 5-30 minutes.

[0011] S3. Crush the expanded tobacco stems into powder with a particle size of 400-800 mesh.

[0012] S4. Dissolve the tobacco stem powder obtained in S3 in a 1:10 mixture of 1% KOH and 0.1% sodium benzenesulfonate, stir at 100°C for 48 hours, then add PEO-PI-PS crosslinking agent, and continue stirring and heating until the material is cured.

[0013] S5. After crushing the above soft template material, place it in a tubular pyrolysis furnace and carbonize it at 300°C for 15 min under N2 protection. Then, increase the temperature to 850°C at a program of 15°C / min and carbonize it for 90 min to obtain the porous carbon material of tobacco stem.

[0014] S6. 2,3-Dihydro-3-hydroxy-5-(2-mercaptoethoxy)-6-methyl-4(H)-pyran-4-one is loaded into the tobacco stem porous carbon material obtained in S5 above to form a sweet-scented porous carbon material.

[0015] Preferably, the tobacco stems in S1 are from the discarded tobacco stems after leaf threshing and re-drying, and the moisture content of the tobacco stems during the soaking and rehydration process is 27.5%-35%.

[0016] Preferably, the crushing method for S3 is to first mechanically pre-crush to 60-200 mesh, and then ball-mill to 400-800 mesh.

[0017] Preferably, the PEO-PI-PS crosslinker in S4 has a molecular weight of 2000-10000, wherein the mass ratio of PEO, PI, and PS is 10:2:1, and the dispersant is 90% PO-10 and 10% water.

[0018] Preferably, the loading in S6 is achieved using vacuum adsorption at a negative pressure of 100 Pa, with repeated adsorption until near saturation, resulting in a saturation adsorption capacity of 107.3 mg / g. The loading mechanism includes both weak physical adsorption and strong chemical bonding between the sweet aroma molecules and the porous carbon active sites.

[0019] Application of a sweet-smelling porous carbon material in heated cigarettes.

[0020] Preferably, the sweet-scented porous carbon material is used to prepare heated cigarette cores, the heated cigarette cores comprising: a filtering section, a cooling section, and a heating section, the heating section being composed of the sweet-scented porous carbon material and tobacco leaf sheets.

[0021] Preferably, the tobacco leaf sheets include: ethyl maltol, 2,5-dimethylpyrazine, menthol, 2-acetylpyrrole, vanillin, tobacco essential oil, and maple extract, with each component accounting for 0.1‰, 0.13‰, 0.5‰, 0.1‰, 0.15‰, 1.5‰, and 0.5‰ of the total mass of the tobacco leaf sheets, respectively.

[0022] Preferably, the tobacco leaf sheets contain: ethyl maltol, 2,5-dimethylpyrazine, menthol, 2-acetylpyrrole, vanillin, tobacco essential oil, and maple extract, with each component accounting for 0.1‰, 0.13‰, 0.5‰, 0.1‰, 0.15‰, 1.5‰, and 0.5‰ of the total mass of the tobacco leaf sheets, respectively.

[0023] Preferably, the heating temperature of the heating section is 135℃-300℃.

[0024] The above-described technical solution of the present invention has the following beneficial effects:

[0025] (1) By using waste tobacco stems to construct a sweet-smelling porous carbon material with a special morphology, the problem of matching the release kinetics of volatile molecules with the material is solved, and the technical effect of high load and uniform release is achieved.

[0026] (2) The specific sweet aroma molecular structure combines with the active sites of porous materials and is paired with base fragrance to form a sensory effect of rich sweet aroma and stable flavor. Attached Figure Description

[0027] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0028] Figure 1 This is a three-dimensional structural schematic diagram of the sweet-smelling porous carbon material of the present invention.

[0029] Figure 2 This is a scanning electron microscope image of a sweet-smelling porous carbon material.

[0030] Figure 3 This is a schematic diagram illustrating the application of the sweet-smelling porous carbon material of the present invention in heated cigarette cores. Detailed Implementation

[0031] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0032] This invention discloses the preparation of a sweet-smelling porous carbon material and its application in heated cigarettes. The method uses tobacco stem waste as raw material and, through processes such as microwave expansion, crushing, pulping, cross-linking, soft template pore-forming, flavor loading, flavor modification, and cigarette core composite, prepares a sweet-smelling porous carbon flavoring material for heated cigarettes. Applying this material to the cigarette core of heated cigarettes yields a heated cigarette with a full-bodied sweet aroma and stable flavor release, achieving a personalized and functional heated cigarette consumption experience. The following examples illustrate this in detail:

[0033] Example 1

[0034] (1) A method for preparing a sweet-smelling porous carbon material, comprising the following steps:

[0035] S1. Select clean, dry tobacco stems that have been threshed and re-dried after being threshed and are about 5 cm long. Soak them in 60℃ hot water for 24 hours, then remove them and drain off the surface moisture for later use.

[0036] S2. Place the tobacco stems obtained in S1 in a microwave reactor and microwave them at 2500W for 5-30 minutes until the tobacco stems expand 2-3 times in volume and become brittle and dry.

[0037] S3. The expanded tobacco stems are crushed into powder with a particle size of 400 mesh. The crushing process adopts mechanical pre-crushing, sieving to remove large particles of fiber that are difficult to crush to obtain coarse powder of 60-200 mesh, and then crushed to 400 mesh using a ball mill.

[0038] S4. Take 10g of the above tobacco stem powder and add it in batches to a mixture of 1% KOH and 0.1% sodium benzenesulfonate at a mass ratio of 10 times while stirring. Then, stir at 100℃ for 48 hours until the reaction is complete. After that, continuously add 1g of PEO-PI-PS crosslinking material (pre-crosslinked, with a mass ratio of PEO, PI, and PS of 10:2:1, and the dispersant being 90% PO-10 and 10% water, with a molecular weight controlled at around 2000) while stirring and heating until the material is cured.

[0039] S5. After crushing the above-mentioned soft template material, place it in a tubular pyrolysis furnace and carbonize it at 300℃ for 15 min under N2. Then, increase the temperature to 850℃ at a rate of 15℃ / min and carbonize for 90 min to obtain porous carbon material from tobacco stems. The scanning electron microscope image of the material is shown below. Figure 2 As shown, the specific surface area of ​​the material under this process is 859.7 m2 / g, the average pore size is 0.21 μm, and the soft template agent residue is less than 1.5%.

[0040] S6. 2,3-Dihydro-3-hydroxy-5-(2-mercaptoethoxy)-6-methyl-4(H)-pyran-4-one was loaded onto the above-mentioned tobacco stem porous carbon material. The loading was carried out by vacuum adsorption at a negative pressure of 100 Pa, and adsorption was carried out repeatedly until it was close to saturation (the saturation adsorption capacity was 107.3 mg / g), and finally the target sweet-smelling porous carbon material was formed.

[0041] (2) A method for preparing a heated cigarette core containing a sweet-smelling porous carbon material is as follows:

[0042] S1. The cigarette core consists of three parts: a filter section, a cooling section, and a heating section. The three parts are assembled in a segmented composite manner to form the heated cigarette core.

[0043] The heating section is composed of porous carbon material and conventional tobacco leaf sheets.

[0044] Specifically, the porous carbon material in the heating section and the conventional tobacco leaf sheets are stacked along a central axis, with the porous carbon material near the mouthpiece (specifically, as shown in the image). Figure 3 As shown, where: a) filtration section; b) cooling section; c) porous carbon material; d) thin sheet), the axial length ratio of the porous carbon material to the conventional tobacco leaf thin sheet is 1:3.

[0045] Specifically, the tobacco flakes, in addition to conventional additives, smoking agents, and water, also contain base flavorings such as ethyl maltol, 2,5-dimethylpyrazine, menthol, 2-acetylpyrrole, vanillin, tobacco essential oil, and maple extract; preferably, each component accounts for 0.1‰, 0.13‰, 0.5‰, 0.1‰, 0.15‰, 1.5‰, and 0.5‰ of the total mass of the flakes.

[0046] (3) Result evaluation:

[0047] Central needle heating was used, with central heating temperatures of 180℃, 210℃, and 250℃. The flavor characteristics and sensory effects are shown in Table 1 below.

[0048] Table 1

[0049]

[0050] Example 2

[0051] Similar to Example 1, in order to further modify the microstructure of the porous carbon material from tobacco stems to obtain greater loading capacity, more stable aroma characteristics, and release behavior, the specific process parameters for Example 2 are changed as follows:

[0052] (1) Crush the expanded tobacco stems into powder with a particle size of 800 mesh;

[0053] (2) Take 10g of the above tobacco stem powder and add it in batches to a mixture of 1% KOH and 0.1% sodium benzenesulfonate at a mass ratio of 10 times while stirring. Then, stir at 100°C for 48 hours until the reaction is complete. After that, continuously add 3g of PEO-PI-PS crosslinking material (pre-crosslinked, with a mass ratio of PEO, PI and PS of 10:2:1, and the dispersant being 90% PO-10 and 10% water, with a molecular weight controlled at around 5000) and continue stirring and heating until the material is cured.

[0054] (3) The above-mentioned soft template material was crushed and placed in a tubular pyrolysis furnace, carbonized at 300℃ for 15 min under N2, and then carbonized at 850℃ for 90 min at a programmed temperature increase of 15℃ / min to obtain porous carbon material from tobacco stems. The specific surface area of ​​the material under this process is 1017.5 m². 2 / g, with an average pore size of 0.3μm and a soft template agent residue of less than 1.5%;

[0055] (4) Finally, 2,3-dihydro-3-hydroxy-5-(2-mercaptoethoxy)-6-methyl-4(H)-pyran-4-one was loaded onto the above-mentioned tobacco stem porous carbon material. The loading was carried out by vacuum adsorption at a negative pressure of 100 Pa, and adsorption was carried out repeatedly until it was close to saturation (the saturation adsorption capacity was 119.4 mg / g), and the target sweet-smelling porous carbon material was finally formed.

[0056] (5) The sweet-scented porous carbon material is used in heated cigarettes, employing a central needle heating method with central heating temperatures of 210℃, 240℃, and 280℃. Its flavor characteristics and sensory effects are shown in Table 2 below:

[0057] Table 2

[0058]

[0059] As shown in Tables 1 and 2, the sweet-scented porous carbon material prepared in this application exhibits stable flavor characteristics and sensory effects when used in heated cigarette cores at temperatures ranging from 135 to 300°C, and is particularly stable at temperatures ranging from 180 to 280°C.

[0060] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various different choices and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a sweet-smelling porous carbon material, characterized in that, Includes the following steps: S1. Select clean, dry tobacco stems 1-5 cm long, soak them in water for 24 hours, then remove and drain for later use. S2. Place the tobacco stems obtained in S1 into a microwave reactor and microwave them at 2500W for 5-30 minutes. S3. Crush the expanded tobacco stems into powder with a particle size of 400-800 mesh. S4. Dissolve the powder in a 1:10 mixture of 1% KOH and 0.1% sodium benzenesulfonate, stir at 100 °C for 48 h, then add the PEO-PI-PS crosslinking agent, and continue stirring and heating until the material is cured. S5. After the material solidified in step S4 is crushed, it is placed in a tubular pyrolysis furnace and carbonized at 300 ℃ for 15 min under N2 protection. Then, the temperature is increased to 850 ℃ at a rate of 15 ℃ / min and carbonized for 90 min to obtain porous carbon material of tobacco stem. S6. 2,3-Dihydro-3-hydroxy-5-(2-mercaptoethoxy)-6-methyl-4(H)-pyran-4-one is loaded into the tobacco stem porous carbon material obtained in S5 above to form a sweet-scented porous carbon material.

2. The method for preparing the sweet-scented porous carbon material according to claim 1, characterized in that, The tobacco stems in S1 are selected from discarded tobacco stems after leaf threshing and re-drying, and the moisture content of the tobacco stems during the soaking and rehydration process is 27.5%-35%.

3. The method for preparing the sweet-scented porous carbon material according to claim 1, characterized in that, The crushing method for S3 is to first mechanically pre-crush it to 60-200 mesh, and then ball-mill it to 400-800 mesh.

4. The method for preparing the sweet-scented porous carbon material according to claim 1, characterized in that, The PEO-PI-PS crosslinker in S4 has a molecular weight of 2000-10000, with a mass ratio of PEO, PI, and PS of 10:2:

1. The dispersant includes 90% PO-10 and 10% water.

5. The method for preparing the sweet-scented porous carbon material according to claim 1, characterized in that, The load in S6 is subjected to vacuum adsorption at a negative pressure of 100 Pa, and adsorption is carried out repeatedly until saturation.

6. The application of a sweet-scented porous carbon material prepared by any one of the preparation methods according to claims 1-5 in heated cigarettes.

7. The application according to claim 6, characterized in that, The sweet-scented porous carbon material is used to prepare heated cigarette cores. The heated cigarette cores include a filter section, a cooling section, and a heating section. The heating section is composed of the sweet-scented porous carbon material and tobacco leaf sheets.

8. The application according to claim 7, characterized in that, The tobacco leaf sheets include: ethyl maltol, 2,5-dimethylpyrazine, menthol, 2-acetylpyrrole, vanillin, tobacco essential oil, and maple extract, with each component accounting for 0.1‰, 0.13‰, 0.5‰, 0.1‰, 0.15‰, 1.5‰, and 0.5‰ of the total mass of the tobacco leaf sheets, respectively.

9. The application according to claim 7, characterized in that, The heating temperature of the heating section is 135℃-300℃.

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