María Isabel Beltrán Rico

The thermal decomposition of a heat-not-burn (HNB) tobacco at four temperatures (250–400 °C) was studied via thermogravimetric analysis (TGA) and Multi-shot pyrolizer experiments (Py-GC/MS), and the effect of four potential additives, USY Beta and beta zeolites and Silica Lovel 6000 and SBA-15 silicates at three concentrations (5, 15 and 25% w/w) under an inert and oxidative atmosphere was analyzed. Different techniques were applied showing that the presence of the additives modifies the decomposition processes (TGA). Py-GC/MS showed that these tobaccos generate large amounts of Nicotine and Glycerine. Acid compounds are the most abundant compounds under an inert atmosphere, while Oxygenated compounds predominate under an oxidative atmosphere. In both atmospheres, Furans and Aromatics present in a significant abundance at high temperatures. The additives used reduce both the number and the concentration of most of the compounds generated, especially at high temperatures and concentrations. Moreover, SBA-15 shows good aptitudes to reduce the formation of some individual compounds included in the FDA’s HPHC list, such as Acetone and Acetaldehyde. Finally, smoking experiments corroborated that all additives produce marked reductions in TPM, i.e., the majority fraction obtained, and in practically all the compounds generated. Phenol, a toxicant compound that was detected in a significant amount, is also markedly reduced. SBA-15 is the material that presents a major reduction in the TPM and the principal compounds generated. These results may be of great interest for further reducing the toxicity of smoking this type of heat-not-burn tobacco product.

In this study, the influence of the incorporation of eucalyptus (EO), tea tree (TT) and rosemary (RO) essential oils and Chiriyuyo extract (CE) on the structure and properties of thermoplastic starch (TPS) obtained from potato starch, glycerin and water was evaluated. All oils and the extract were used at a concentration of 0.5 g/100 g of TPS, while for TT, the effect of the concentration was also studied. The mixtures obtained were processed by extrusion and thermocompression molding. The sheets were characterized by XRD, FTIR, TGA, SEM and analyses of their mechanical properties, antimicrobial characteristics and biodegradability. The results show that the use of small concentrations of the oils in 70TPS does not induce changes in the TPS structure according to the results of XRD, FTIR and TGA, with each essential oil and CE affecting the mechanical properties unevenly, although in all cases, antimicrobial activity was obtained, and the biodegradability of TPS in soil was not modified. An increase in the concentration of TT in 60TPS causes marked changes in the crystallinity of TPS, providing a greater modulus with a higher concentration of TT. Regardless of the amount of TT, all sheets maintain antimicrobial characteristics, and their biodegradation in soil is delayed with a higher oil content.

Nowadays, the use of tobacco biomass as an energy source is being valued. Therefore, it is important to know the processes that take place during combustion and pyrolysis, as well as the substances that are formed. In this work, we study the compounds obtained during the decomposition of NNN as a function of temperature under inert and oxidant atmospheres. Moreover, the effect of the addition of SBA-15 and MCM-41 is analyzed. Two different techniques, i.e., TG/FTIR (low heating rates) and EGA Py/GC/MS (high heating rates), are used. At low temperatures NNN is almost unaltered, but it is volatilized and dragged by the carrier gas. When increasing the temperature, decomposition takes place, with pyridines being one of the most abundant compounds observed. The main compound obtained during the pyrolysis are 3- pyridinecarbonitrile, myosmine and nornicotine, which are precursors of NNN. When NNN is mixed with SBA-15, the decomposition of the NNN nitrosamine is favored at low temperatures where the yield in pyridine compounds increases. The catalysts modify the temperature and intensity of the processes, especially under an oxidative atmosphere where the residue is oxidized, showing a third loss of weight. These materials modify the compositions of gases, mainly under an O₂ atmosphere (3-pyridinecarbonitrile and myosmine showed the major effect). SBA-15 with fibrous morphology obtains the best reductions at pyrolysis conditions.

The synthesis of SBA-15 has been optimized using sodium silicate, an inexpensive precursor of SBA-15. In this work, the influence of synthesis times of the precipitation and the hydrothermal treatment steps, on the textural properties developed as well as for reducing the toxic compounds generated in tobacco smoking, has been studied. The hydrothermal treatment has been proved to be necessary to obtain materials with adequate performance in this particular application. Twenty-four hours of hydrothermal treatment provide materials with the best properties. Although the reaction stage usually involves the mixing of reagents during 24 h, 40 min is enough to obtain a material with stick-like morphology and typical textural properties. Moreover, between 1 and 2 h of reaction time, the material proved to have the best performance for the purpose of reducing the toxicity of the products generated during the tobacco smoking process. These results are of great significance for an eventual scaling up to industrial scale of the SBA-15 manufacturing process. Results of a pilot plant experiment in a batch of 4 kg of SBA-15 are reported.

SBA-15 has been employed as a tobacco additive with the objective of reducing the toxic and carcinogenic components in tobacco smoke. The effect of the synthesis conditions (temperature, time, and stirring rate) on this application was studied in this paper. The SBA-15 was characterized (RDX, N₂ adsorption isotherms, SEM and apparent density), mixed with the 3R4F reference tobacco, and smoked under standard conditions. The composition of the gas and condensed fractions also was analyzed. The morphology of the material plays an important role on this application and is highly influenced by the three variables studied. Long fibers show improved efficiency compared to short fibers. The tar reduction effect was improved when increasing the time of synthesis. Nevertheless, a maximum was observed with temperature (40 °C) and stirring rate (700 rpm). The optimal synthesis conditions obtained were 24 h, 40 °C and 700 rpm, yielding reductions as high as 68% for tar, 67% for nicotine, and 31% for CO. The scaling-up process has only been reported in terms of grams but never in a preindustrial scale (around 4 kg), and thus the results of this analysis show a promising material with properties and behavior similar with respect to the sample synthesized at laboratory scale.

El diseño de materiales y envases biodegradables activos es uno de los retos de la sociedad cuyo fin es tratar de resolver los problemas ambientales que se han generado por los residuos plásticos desarrollando envases biodegradables que permitan mejorar la conservación de los alimentos y alargar su vida útil. Se analizó la preparación de una mezcla ideal utilizando almidón de papa termoplástico (AP), extracto de árbol de té (AT) y goma arábiga (GA), obteniendo luego de un proceso de extrusión y prensado las planchas de biopolímero termoplástico, que fueron analizadas para determinar sus propiedades antimicrobianas. Se elaboraron19 muestras de planchas de biopolímeros con distintas proporciones AP, AT y GA. Los resultados obtenidos de los biopolímeros a base de AP/GA (60/2) y (70/5) mostraron mayores actividades antimicrobianas contra bacterias Gram positivas y negativas, respectivamente, seguidas de las formulaciones con AP/EAT (60/1) y (70/0,5). No se observó un efecto sinérgico entre el AT y la GA. Se encontró que la variación en la formulación del AP con AT y GA influyó en la actividad antimicrobiana del producto obtenido.

Different SBA-15 (SBA, Santa Barbara Amorphous) materials were synthetized at different temperature and time during of the hydrothermal treatment. The obtained SBA-15 were characterized by N₂ adsorption isotherms, scanning electron microscopy (SEM), X-ray diffraction (DRX), and density in order to establish the influence of these variables on their properties. Mixtures of the obtained catalysts with 3R4F tobacco were prepared and smoked under the ISO 3308 conditions. Temperature of the hydrothermal treatment slightly affects the tars that evolved in the smoking process of the corresponding catalyst tobacco mixtures. Contrarily, the time of the hydrothermal treatment has a marked effect on the reductions of toxic compounds in the smoke. Developed porosity has a positive correlation with the observed tar reduction, whereas the apparent density has a negative correlation with the reduction in toxicity. Moreover, the removal of the supernatant liquors during the hydrothermal treatment does not strongly modify the properties of the materials and may represent an interesting simplification of the process.