WO2015097327A1 - Inclusion of catalysts in reconstituted tobacco formulations for reducing the emission of toxic products - Google Patents

Abstract

The invention relates to a mixture of reconstituted tobacco with catalysts for reducing the emission of toxic products of the tobacco, and to the method for producing said mixture.

Description

 INCLUSION OF CATALYSTS IN RECONSTITUTED TOBACCO FORMULATIONS FOR THE REDUCTION OF THE ISSUANCE OF TOXIC PRODUCTS.

Field of the Invention

The present invention relates to a process for the preparation of reconstituted tobacco including catalysts and the mixture of reconstituted tobacco with catalysts for the reduction of the emission of toxic products.

State of the art

Reconstituted tobacco means that material made from tobacco stalks, leaf remains, tobacco fines and other materials derived from the tobacco plant or of plant origin that are processed by means of typical papermaking processes and fines of tobacco that are not usable in the primary processes of cigarette making. The reconstituted tobacco is manufactured from tobacco stalks and tobacco fines produced in the primary tobacco processing. It consists of sheets, of the type of paper that is cut into strips and mixed with those of tobacco leaf in appropriate machinery for packaging in the form of cigarettes or in other types of presentations for other items that can be smoked, such as rolling tobacco (RYO) or for filling tubes (MYO), pipe tobacco and others.

The typical stages in the process of making reconstituted tobacco are the following:

 1. Storage of raw materials, which includes the receipt and storage of these.

 2. Extraction of soluble components in aqueous solvents. In this stage an aqueous extract is obtained which must be concentrated and added again at a later stage of the process and an insoluble portion rich in fibers.

 3. Extract concentration stage, which usually corresponds to a removal of water by evaporation to concentrate the components extracted in the previous stage.

4. Refining of the insoluble portion and modification of the properties of the fibers to be able to proceed with its rolling. As described in patent ES2096728, which describes the use of an agent capable of breaking the cross-links of pectins by alkaline earth metals. In this way the released pectins can be distributed evenly throughout the material.

 5. Formed in sheets. The cellulosic material is made of paper sheets.

6. Reapplication of the concentrated extract on the sheets and application of an agent capable of restoring the cross-links of the pectins, or subjecting the sheets to conditions where the cross-linking of the pectins can take place, so that the shape of the material is stabilized.

 7. Drying and slicing of the sheets, where the material is given its shape and final moisture to be mixed with the tobacco leaf strips and processed in the appropriate machinery.

All the processes described and that are part of the manufacturing process of reconstituted tobacco are subject to multiple modifications. In this way there is a large number of patents, where each and every one of the operations described are modified and even replaced by other alternatives. Thus, for example, raw materials including lignocellulosic materials have been modified, the inclusion of binder or adhesive materials to improve the mechanical properties of the sheets obtained has been considered, as described in US5584306, the inclusion of additives for confer special characteristics such as aromas and flavors to the material [US8434496] by modifying the final properties and texture of the material. The final form of these materials has been varied from compact sheets to granular or even spongy materials or the direct use of the sheets to make rolling products [WO2008056099]. Additives have been included to improve the development of the smoking process, such as micronized calcium carbonate [WO2012170761] that improves combustibility and helps reduce emissions of CO and other components. In these and other patents, another series of process modifications have been proposed such as the pectin dissolution system, the extraction system and the extractant solution, destructive agents of the cross-links between the pectins, the agents and processes to restore those bonds in the post-forming stage, the forming system, etc. New applications and products continue to appear in the patent literature every year.

On the other hand, in EP2092838 patent the utility of the mixture of meso and macroporous type catalysts, such as MCM41 materials with various modifications as well as meso-macroporous carbons, especially activated to reduce the emission of most of the compounds analyzed in the main (and secondary) stream of tobacco smoke, both in the gases and in the liquids retained in the filters and in the traps.

 There is therefore a need to provide a reconstituted tobacco that includes a catalyst in order to reduce the fumes generated in the smoking process, such that the present invention solves the aforementioned problem by making reconstituted tobacco incorporating materials capable of reduce the toxicity of the fumes generated in the smoking process of said reconstituted tobacco and its mixtures with tobacco or other products likely to be smoked (such as reconstituted tobacco that did not incorporate catalysts).

Description of the invention

 Thus, in a first aspect, the present invention relates to a mixture (hereinafter mixture of the present invention) comprising reconstituted tobacco and / or expanded tobacco and at least one catalyst selected from:

 a) SAB-15 aluminosilicate type, or its acidic, sodium forms, exchanged with Fe, Na, K, Ca, Ce, Zr, its oxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof,

 b) Na-MCM-41, Na-Fe-MCM-41, Na-Ce-MCM-41, Na-Zr-MCM-41, mixtures thereof with Fe, Ce or Zr oxides; and mixtures, or

 c) mesoporous activated carbons.

 In the present invention, reconstituted tobacco refers to tobacco made from tobacco stalks, leaf residues, tobacco fines or plant-derived tobacco plant processed by typical papermaking processes and tobacco fines that They are not usable in primary cigarette making processes.

 In the present invention, expanded tobacco refers to tobacco whose volume has been expanded by rapid evaporation of a substance, such as dry ice.

In the present invention mesoporous activated carbon refers to mesoporous activated carbon with a particle size between 1-100 μηι, of high degree of activation, with a SBET surface between 1200-4200 m ² / g, a VMIC volume comprised between 0.4-1.2 cm ³ / g and a VMESO volume between 0.6-2.8 cm ³ / g as an additive to reduce the toxic and carcinogenic substances present in tobacco smoke.

 In a particular embodiment, the catalyst concentration with respect to the rest of the constituent material of the mixture of the present invention is comprised between 0.1-60% by weight, more particularly between 10-35% by weight.

In another embodiment, the catalyst concentration with respect to the final mixture of tobacco, reconstituted tobacco, expanded tobacco and other materials likely to be smoked is between 0.5-15% by weight, more particularly between 3-8%.

In another particular embodiment of the present invention, the thickness of the reconstituted tobacco is between 10-500 microns.

In another particular embodiment of the present invention the reconstituted or expanded tobacco is in a proportion comprised between 1-99% by weight with respect to the final mixture.

 In another aspect, the present invention relates to a process for the preparation of reconstituted and / or expanded tobacco of the present invention comprising an inclusion step of at least one catalyst selected from: a) SAB-15 type aluminosilicate, or their acidic, sodium forms, exchanged with Fe, Na, K, Ca, Ce, Zr, their oxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof,

 b) Na-MCM-41, Na-Fe-MCM-41, Na-Ce-MCM-41, Na-Zr-MCM-41, their mixtures with Fe, Ce or Zr oxides, and mixtures, or

 c) mesoporous activated carbons.

Description of the figures

The figure shows details of the chromatograms (a, b and c) of the liquids retained in the traps obtained for the mixture of reference tobacco and reconstituted tobacco, as well as for the mixture of reference tobacco and reconstituted tobacco including (as described) one of the catalysts by way of example of the reduction obtained in almost all the peaks detected. Dashed line: mixtures of 3R4F with reconstituted tobacco with SBA foam catalyst; continuous line: tobacco without catalyst. Detailed description of the invention

 In all the examples the same reconstituted tobacco was used, obtained from reference tobacco of the University of Kentucky, 3R4F, to which different catalysts were added. These materials were mixed with normal 3R4F tobacco in proportions that accounted for a percentage of catalyst over the total mixture of the order of 5% and smoked in a smoking machine under conditions given by the ISO standard (ISO 3308, 2 s draft of duration, volume aspirated 35 ml_, frequency of drafts 60 s and loss of pressure in the draft less than 300 Pa).

 CO was determined, the fraction condensed in filters, TPM-F, in the traps, TPM-T (which represents the fraction that could pass to the lungs of smokers), nicotine, as well as a multitude of compounds present in both the gaseous fraction as in the condensed liquid fraction of the mainstream of tobacco smoke as described in Marcilla A., et al. 201 1. Reduction of tobacco smoke components yields by zeolites and synthesized AI-MCM-41. Microporous and Mesoporous Materials 161, 14-24. The results were compared with those obtained by smoking mixtures including reconstituted tobacco without catalyst in the same proportion as those containing catalyst, as well as with only 3R4F tobacco and 3R4F tobacco to which the same amount of catalyst has been added, but directly mixing Dust with tobacco. The cigarettes, once prepared, were conditioned at room temperature and 60% relative humidity, keeping them in a desiccator provided with a saturated solution of sodium nitrite, at least for 48 hours before being smoked.

Preparation of reconstituted tobacco. Tobacco mixed with 100 3R4F cigarettes from the University of Kentucky was intensively mixed. 10 g of this tobacco was extracted at 60 ° C using 8 parts of distilled water for each part of tobacco. The resulting suspension was allowed to settle for 20 min. After separating the extract by decantation, the resulting tobacco paste was ground in a steel roller mill for 5 minutes. The resulting paste was resuspended in water to a solids concentration of approximately 1%. After 10 minutes of homogenization, it was filtered through a metal sieve with a light of 50 μ. The resulting sheet had a moisture content of the order of 70%. Subsequently, approximately 2.3 g of an aqueous solution containing 3.2% by weight of hydrogen ammonium orthophosphate and 6.8% by weight of ammonia was added as a pectin releasing agent. The liquid extract obtained in the first stage was concentrated by evaporation to a concentration of approximately 74% of Water. Said extract was heated to 54 ° C and projected onto the previously obtained sheet approximately 10 seconds after spraying with the pectin releasing agent. Subsequently, the sheet was dried at 35 ° C for 24 h and the reconstituted tobacco sheet was obtained which was cut into small pieces and stored, in an atmosphere of controlled temperature and humidity equal to those used in the conditioning of the tobacco, until later mixed with tobacco or direct smoking. The thickness of the sheets obtained was adjusted to approximately 150 μ, this being a variable that has a marked influence on the subsequent behavior of the mixture in the smoking process, as will be discussed later.

Reconstituted tobacco including catalyst.

 In the examples presented below, different samples of reconstituted tobacco including catalysts were used. For the preparation of these samples, the procedure was analogous to that described in the previous section, with the only modification that the appropriate amount of each catalyst has been incorporated in the resuspension stage of the insoluble tobacco mass in the extraction process, then of the refining process. In this regard it should be noted that the catalyst can be incorporated at any other stage of the process.

The apparent density of the catalyst markedly affects the thickness achieved in the final product sheet. Since the catalysts used tend to have very low apparent densities, of the order of 100 kg / m ³ , the weight per unit area of these sheets decreases as the concentration of incorporated catalyst increases, if the thickness is maintained. If the weight is maintained per unit area, the thickness increases significantly. In the following examples a catalyst concentration in the reconstituted tobacco of the order of 20% by weight has been used, the thicknesses of the same order as those obtained for the reconstituted tobacco without catalyst have been maintained and a catalyst concentration has been used in the final mixture of the order of 5% by weight, which means mixing the tobacco with the reconstituted tobacco in a proportion of 4 to 1 by weight. The final effect of the catalysts on the processed products will depend, as already indicated, on the choice of these and other variables. The thickness of the reconstituted tobacco sheets with catalyst, their density, the volume available for mixing with tobacco, the homogeneity of the resulting mixture, the process of mixing with tobacco, as well as other aspects, can have a positive or negative effect. in the process. In the examples described, it has been decided to maintain the thickness of the reconstituted tobacco sheets obtained, by adjusting the amount of starting tobacco for the preparation of each paste, since the filtering surface for the preparation of the sheet of material has been kept constant

 For the realization of these examples, three catalysts, C1, C2 and C3, were used. The first two correspond to macroporous amorphous silica materials of the SBA-15 type, the second one in the form of foam, and the third corresponds to an activated carbon of high degree of activation and a marked mesoporous character. Catalyst 1 synthesized following the procedure described in patent application P201201266. The following method described in Meynen V., et al. Has been used to obtain the foam. Verified syntheses of mesoporous materials. Microporous and mesoporous materials. 125. 170-223. 2009 For the preparation of C3 the procedure described in patent application P201300305 has been followed.

 Table 1 shows a brief summary of the experiments carried out with the different samples of 3R4F tobacco (we will name them as T), tobacco + catalyst (TCi), tobacco + reconstituted tobacco (TTR) and tobacco + (reconstituted tobacco + catalyst) (TTRCi).

Table 1.- Mixtures carried out in the different tests performed and characteristics of cigarettes The results obtained in each of the smoking experiments carried out, grouped by type of catalyst used, are shown below. In this way, the effect this causes on the mainstream of tobacco smoke when it is mixed directly with the tobacco can be observed or added to the manufacturing process of the reconstituted tobacco.

Example 1: Tests performed with the SBA-15 catalyst

 Some of the results obtained when testing with the SBA-15 catalyst are shown below. In all cases 5% catalyst has been incorporated, either directly or included in the reconstituted tobacco. Samples with reconstituted tobacco include 30-35% of this material. All prepared cigarettes have a mass that ranges around 0.8 g.

 Table 2. Percentage of catalyst, CO and TPM obtained by smoking tobacco under controlled conditions.

Como se puede observar en los datos de la tabla en presencia de tabaco reconstituido se produjo un leve aumento de CO y TPM. En presencia de catalizador, tanto en contacto directo, como adicionado en el proceso de elaboración de tabaco reconstituido, se observaron reducciones de bastante importancia, siendo en este caso mejor el contacto directo. Las reducciones conseguidas en el TPM-T fueron muy interesantes, en ambos casos se consiguieron reducciones superiores al 50% de la fracción generada con respecto al tabaco de referencia.

As can be seen in the data in the table in the presence of reconstituted tobacco, there was a slight increase in CO and TPM. In the presence of a catalyst, both in direct contact and in the process of making reconstituted tobacco, significant reductions were observed, direct contact being better in this case. The reductions achieved in the TPM-T were very interesting, in both cases reductions greater than 50% of the fraction generated with respect to the reference tobacco were achieved.

Below are the reductions already mentioned that were obtained for CO, TPM-F and TPM-T. Table 3. Reductions obtained in CO and TPM

Table 4 shows the values for some of the most relevant compounds found in the gas fraction of the mainstream of tobacco smoke.

 Table 4. Concentration of the compounds analyzed in the gases from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the gases from the smoking of the rest of the samples.

As for the liquid fraction condensed in traps in the case of nicotine, mixing T and TR obtained practically the same amount (0.65 and 0.68 mg / cigarette) while using catalyst C1 a reduction of the order of 66% was obtained while when using TR including this catalyst the reduction was 57%. Table 5 shows some of the compounds selected in the extract of the traps, including nicotine, and a behavior similar to that described for this can be observed.

 Table 5. Concentration of the compounds analyzed in the TPM-T fraction from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the smoking of the rest of the samples.

As can be seen in Table 5 the reductions obtained in the condensed fraction in the smoke trap (fraction that would be inhaled by the smoker), in the presence of catalyst, were very high and, therefore, very interesting since this fraction is eliminated in a large proportion.

Figure 1 shows, by way of example, the comatogram obtained from this fraction in the case where a reference tobacco mixture with reconstituted tobacco including the foam SBA catalyst was smoked. To better observe the commented effect, the chromatogram has been divided into three zones and the signal obtained for the mixture that does not include the catalyst in each of the resulting figures has been displaced by one unit (1 minute) on the x-axis and arbitrary in the axis of the y (maintaining the scale indicated in each figure). A marked decrease in the area of almost all the peaks detected can be seen. Example 2: Tests performed with the c2 foam catalyst

 Table 6. Percentage of catalyst, CO and TPM obtained by smoking tobacco under controlled conditions.

Table 7. Reductions obtained in CO and TPM

Reaction u% TPM-T TPM-F

TTR -20.00 -7.69 -6.36

TC2 -2.73 32.69 18.18

TTRC2 32.73 65.38 46.36

In the presence of catalyst, both in direct contact, and added in the process of making reconstituted tobacco, significant reductions were observed, being in this case better when the catalyst was added to the reconstituted tobacco.

 Table 8. Concentration of the compounds analyzed in the gases coming from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the gases coming from the smoking of the rest of the samples.

Compound T (mg / cigarette) TTRC2 (%)

Propionaldehyde 0.0228 65.3

Toluene 0.0324 52.6 Benzene 0.117 34.6

Chlorine-methane 0.046 23.9

 HCN 0.01 1 39.1

 Acetaldehyde 0.54 55.6

 VOC's 3.32 36.7

The amount of nicotine in the presence of the C2 catalyst was reduced 52% while when TR was used including this catalyst the reduction was 68%. Table 9 shows some of the compounds selected in the extract of the traps and a behavior similar to that described for nicotine can be observed.

 Table 9. Concentration of the compounds analyzed in the TPM-T fraction from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the smoking of the rest of the samples.

En presencia del catalizador C2 es destacable los resultados obtenidos cuando este se adiciona al tabaco reconstituido, puesto que la cantidad de algunos compuestos, ya sean gases o líquidos, son reducidos en proporciones superiores al 50%.

In the presence of the C2 catalyst, the results obtained when it is added to the reconstituted tobacco are remarkable, since the amount of some compounds, whether gases or liquids, are reduced in proportions greater than 50%.

 Example 3: Tests carried out an active carbon

The results obtained when testing with the C3 catalyst were the following: Table 10. Percentage of catalyst, CO and TPM obtained by smoking tobacco under controlled conditions.

En presencia de catalizador, tanto en contacto directo, como adicionado en el proceso de elaboración de tabaco reconstituido, se observaron reducciones de bastante importancia en ambos tipos de contacto.

In the presence of a catalyst, both in direct contact and in the process of making reconstituted tobacco, significant reductions were observed in both types of contact.

 The values for some of the most relevant compounds found in the gas fraction of the mainstream of tobacco smoke are shown below.

 Table 12. Concentration of the compounds analyzed in the gases from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the gases from the smoking of the rest of the samples.

Compound T (mg / cigarette) TC3 (%) TTRC3 (%)

Propionaldehyde 0.0228 38.9 57.2 Toluene 0.0324 28.9 53.0

 Benzene 0.117 35.5 34.0

 Chloromethane 0.046 34.8 21.7

 HCN 0.01 1 25.5 41.8

 Acetaldehyde 0.54 48.1 55.6

 VOC's 3.32 31.3 41.6

Nicotine in the presence of the C3 catalyst achieves a reduction of the order of 74% while when using TR including this catalyst the reduction is 78%. Table 10 shows some of the compounds selected in the extract of the traps and a behavior similar to that described for nicotine can be observed.

Table 13. Concentration of the compounds analyzed in the TPM-T fraction from the smoking of the reference tobacco and percentage reduction with respect to said tobacco of the different compounds analyzed in the smoking of the rest of the samples.

En este caso, para las diferentes fracciones generadas, el comportamiento del catalizador fue muy bueno en ambos tipos de muestra.

In this case, for the different fractions generated, the behavior of the catalyst was very good in both types of sample.

Figure 3 shows the chromatogram obtained, which shows the good behavior already mentioned. Tables 2 to 13, and Figure 1, show that the catalysts used when added to the reconstituted tobacco provided a significant reduction in the amount of toxic compounds that appear in tobacco smoke. This reduction also contributed to a significant decrease in most of the compounds present in tobacco smoke, which implies a less negative effect, both in active and passive smokers, without causing appreciable changes in organoleptic properties and the taste and consistency of tobacco.

Claims

 1. Mixture comprising reconstituted tobacco and / or expanded tobacco and at least one catalyst selected from:  a) SAB-15 aluminosilicate type, or its acidic, sodium forms, exchanged with Fe, Na, K, Ca, Ce, Zr, its oxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof,  b) Na-MCM-41, Na-Fe-MCM-41, Na-Ce-MCM-41, Na-Zr-MCM-41, mixtures thereof with Fe, Ce or Zr oxides; and mixtures or  c) mesoporous activated carbons.  2. Mixture according to claim 1, wherein the catalyst concentration with respect to the rest of the constituent material is comprised between 0.1-60% by weight.  3. Mixture according to claim 2, wherein the catalyst concentration with respect to the rest of the constituent material is between 10-35% by weight.  4. Mixture according to claim 1, wherein the catalyst concentration with respect to the final tobacco mixture is between 0.5-15% by weight. 5. Mixture according to claim 4, wherein the catalyst concentration with respect to the final tobacco mixture is between 3-8% by weight.  6. Mixture according to claim 1, wherein the thickness of the reconstituted tobacco is between 10-500 microns.  7. Mixture according to claim 1, wherein the reconstituted or expanded tobacco is in a proportion comprised between 1-99% by weight with respect to the final mixture.  Method for the preparation of reconstituted tobacco and / or expanded tobacco according to any of the preceding claims, characterized in that it comprises an inclusion step of at least one catalyst selected from:  a) SAB-15 aluminosilicate type, or its acidic, sodium forms, exchanged with Fe, Na, K, Ca, Ce, Zr, its oxides of Fe, Na, K, Ca, Ce, Zr and mixtures thereof,  b) Na-MCM-41, Na-Fe-MCM-41, Na-Ce-MCM-41, Na-Zr-MCM-41, mixtures thereof with Fe, Ce or Zr oxides; and mixtures,  c) mesoporous activated carbons.