Producción de biodiésel mejorada por esterificación y transesterificación asistida por ultrasonidos de aceite de oliva no comestible

In the first phase of this study, inedible olive oil with different initial free fatty acid concentrations (2.5, 5.0, and 10.0%) was processed through acid-catalyzed esterification. Various heating methods were used for this purpose. The ultrasound-assisted esterification and traditional magnetic stirrer-assisted esterification methods were similar to each other in terms of their effects on free fatty acid reduction. However, the ultrasound reaction time was significantly shorter than that of the traditional magnetic stirrer. In the second phase of this study, biodiesel production was carried out through the ultrasound-assisted transesterification of inedible olive oil. Independent variables were, namely, ultrasound power level (30, 90, and 150 W), methanol/oil mole ratio (3, 9, and 15), catalyst concentration (0.5, 1.0, and 1.5%), ultrasound time (15, 30, and 45 min), and reaction temperature (45, 55, and 65 °C), which affected the yield indices and physicochemical constants of the produced biodiesel. The purest biodiesel (98.95%) and the highest amount of yield (92.69%) were observed when using an ultrasound power level of 90 W, a methanol/oil mole ratio of 9, a catalyst concentration of 1.0%, an ultrasound time of 30 min, and a reaction temperature of 55 °C. Optimizing the reaction conditions of the ultrasound operation can effectively increase the biodiesel yield (92.69%), while reducing the energy consumption (4.775 kWh/kg) and shortening the reaction time (30 min), compared to the traditional magnetic stirrer (77.28%, 2.17 kWh/kg, and 120 min, respectively). Therefore, ultrasound-assisted transesterification can serve as an effective alternative because of its fast and economic operation for making biodiesel out of inedible olive oil.En la primera fase de este estudio, el aceite de oliva no comestible tenía diferentes concentraciones iniciales de ácidos grasos libres (2,5, 5,0 y 10,0%) y se procesó mediante esterificación catalizada por ácido. Se utilizaron varios métodos de calentamiento para este propósito. La esterificación asistida por ultrasonido y los métodos tradicionales de esterificación asistida por agitador magnético fueron similares entre sí en términos de sus efectos sobre la reducción de ácidos grasos libres. Sin embargo, el tiempo de reacción usando ultrasonidos fue significativamente más corto que el de agitador magnético tradicional. En la segunda fase de este estudio, la producción de biodiesel, a partir de aceite de oliva no comestible, se llevó a cabo mediante transesterificación asistida por ultrasonidos. Las variables independientes fueron, nivel de potencia de ultrasonido (30, 90 y 150 W), relación molar metanol/aceite (3, 9 y 15), concentración de catalizador (0,5, 1,0 y 1,5%), tiempo de ultrasonido (15, 30 y 45 min) y temperatura de reacción (45, 55 y 65 °C) que afectaron al rendimiento y a las constantes fisicoquímicas del biodiesel producido. El biodiésel más puro (98,95%) y el mayor rendimiento (92,69%) se observaron cuando se utilizó un nivel de potencia de ultrasonido de 90 W, una relación molar de metanol / aceite de 9, una concentración de catalizador del 1,0%, un tiempo de ultrasonido de 30 min, y una temperatura de reacción de 55 °C. La optimización de las condiciones de reacción de la operación de ultrasonido puede aumentar efectivamente el rendimiento de biodiésel (92,69%), al tiempo que reduce la cantidad de consumo de energía (4,775 kWh/kg) y acorta el tiempo de reacción (30 min), en comparación con el agitador magnético tradicional (77,28 %, 2,17 kWh/kg y 120 min, respectivamente). Por lo tanto, la transesterificación asistida por ultrasonido puede servir como una alternativa eficaz debido a su operación rápida y económica en la producción de biodiesel a partir de aceite de oliva no comestible

Mejora de la estabilidad oxidativa del aceite de oliva: Incorporación de Espirulina y evaluación de su sinergismo con ácido cítrico

The effects of different Spirulina concentrations used alone and in combination with citric acid on the oxidative stability of olive oil were assessed. The amounts of primary and secondary oxidation products produced in Spirulina samples were lower than that of the control. The improved oxidative stability indices of Spirulina samples with and without citric acid were in the range of 85.20–94.47% and 258.10–260.21%, respectively. In comparison with the control, Spirulina samples manifested significantly higher carotenoid and chlorophyll contents at the beginning and end of the storage period. The presence of these bioactive compounds results from the presence of Spirulina in the medium and can thus retard the oxidation of olive oil. A higher oxidative stability was reached using BHT in comparison with Spirulina samples. Furthermore, no synergistic action was observed in possible connections between citric acid and Spirulina. In conclusion, Spirulina can enhance oxidative stability and improve the shelf life of olive oil.Se evaluaron los efectos de diferentes concentraciones de Espirulina usadas solas y en combinación con ácido cítrico sobre la estabilidad oxidativa del aceite de oliva. Las cantidades de productos de oxidación primarios y secundarios producidos en muestras de Espirulina fueron menores que las del control. Además, la estabilidad oxidativa de muestras de Espirulina con y sin ácido cítrico estaban en el intervalo de 85,20–94,47% y 258,10–260,21%, respectivamente. En comparación con el control, las muestras de Espirulina mostraron un contenido significativamente mayor de carotenoides y clorofila al inicio y al final del período de almacenamiento. La presencia de estos compuestos bioactivos y la presencia de Espirulina en el medio pueden retardar la oxidación del aceite de oliva. Se obtuvo una mayor estabilidad oxidativa usando BHT en comparación con muestras de Espirulina. Además, no se observó ninguna acción sinérgica en las posibles combinaciones entre el ácido cítrico y la Espirulina. En conclusión, la Espirulina puede mejorar la estabilidad oxidativa y la vida útil del aceite de oliva

Estabilidad oxidativa del aceite de soja conteniendo aceite de rosa e irradiado con UV y rayos X

The effects of UV radiation and X-ray on the oxidative stability of soybean oil were investigated. Also, rose oil was incorporated into soybean oil and its antioxidant activity was compared with that of α-tocopherol during accelerated storage. Treating the samples with radiation (UV and X-ray) stimulated the oxidation process in soybean oil in comparison with samples that did not receive radiation. X-rayed samples had significantly higher amounts of oxidation products than UV irradiated samples. The X-ray caused more oxidation in the samples due to its higher energy content. Also, the antioxidant activity of rose oil was comparable with that of α-tocopherol.Se investigaron los efectos de la radiación UV y los rayos X sobre la estabilidad oxidativa del aceite de soja. Además, el aceite de rosa se incorporó al aceite de soja y su actividad antioxidante se comparó con la del α-tocoferol durante el almacenamiento acelerado. El tratamiento de las muestras con radiación (UV y rayos X) fomentó el proceso de oxidación del aceite de soja en comparación con las muestras que no recibieron radiación. Las muestras con rayos X tenían cantidades significativamente más altas de productos de oxidación que las muestras irradiadas con UV. Los rayos X causaron más oxidación en las muestras debido a su mayor contenido de energía. Además, la actividad antioxidante del aceite de rosa fue comparable con la del α-tocoferol

Molecular simulation techniques as applied to silica and carbon-based adsorbents for carbon capture

There has been ongoing interest in research to mitigate climate change through carbon capture (CC) by adsorption. This guideline is meant to introduce computational chemistry techniques in CC by applying them to mesoporous structures and disordered morphologies. The molecular simulation techniques presented here use examples of literature studies on silica and carbon-based adsorbents. An initial summary of molecular simulation techniques and concepts is first presented. This is followed by a section on molecular simulation applications in mesoporous amorphous silica, both functionalized and not. Novel strategies to validate and output useful results are discussed, specifically when modelling chemisorption. The use of computational chemistry to build upon experimental results is reviewed, and a similar summation is presented for carbon-based adsorbents. The final section provides a short review of computational chemistry methods in novel applications and highlights potential complications. Computational chemistry techniques provide a streamlined method of gathering data across a range of conditions. Alongside experimental studies, these techniques can provide valuable information on underlying molecular mechanisms. This paper aims to be a starting point for navigating these numerical methods by providing an initial understanding of how these techniques can be applied to carbon capture while clarifying the current and inherent limitations present

Controlled trial of an mHealth intervention to promote healthy behaviours in adolescence (TeenPower): Effectiveness analysis

Aim To evaluate the effectiveness on lifestyle change of an mHealth intervention to promote healthy behaviours in adolescence (TeenPower) and to analyse the predictors of the mHealth intervention effectiveness. Design This study is designed as a non‐randomized controlled trial with a two‐arm structure. Methods Adolescents of 12–16‐year old were recruited from three school districts, with access to the Internet and smartphone/tablet devices. The intervention group was invited to engage in the mHealth intervention (TeenPower) for 6 months in addition to a school‐based intervention. The control group only followed the school‐based intervention. A repeated measures factorial ANOVA was used and the main effectiveness outcome was the lifestyle change measured by the adolescent lifestyle profile. Results The outcomes of the mHealth intervention (TeenPower) show a significant effect on nutrition (ƞ2p = 0.03, p = .03), positive life perspective (ƞ2p = 0.04, p = .01), and global lifestyle (ƞ2p = 0.02, p = .05), with a dropout rate of 62.1%. The analysis of the effectiveness predictors of the mHealth intervention suggested that older adolescents tended to show a significant increase in the rates of stress management (r = .40; p < .05). Conclusions Although the considerable dropout rate, the mHealth intervention presented significant impact on multiple lifestyle domains, providing support for the effectiveness of mHealth interventions for health promotion as an add‐on to standard interdisciplinary interventions. Impact Adolescents must have the necessary and appropriate knowledge for the correct and responsible decision‐making regarding their health and lifestyle. Innovative strategies (mHealth intervention) were used to promote healthy behaviours. This study evaluates the effectiveness of an mHealth intervention (TeenPower) specifically designed for adolescents. We found a significant impact in several lifestyle domains such as health responsibility, nutrition, positive life perspective, and global lifestyle.info:eu-repo/semantics/publishedVersio

Improving oxidative stability of olive oil: Incorporation of Spirulina and evaluation of its synergism with citric acid

The effects of different Spirulina concentrations used alone and in combination with citric acid on the oxidative stability of olive oil were assessed. The amounts of primary and secondary oxidation products produced in Spirulina samples were lower than that of the control. The improved oxidative stability indices of Spirulina samples with and without citric acid were in the range of 85.20–94.47% and 258.10–260.21%, respectively. In comparison with the control, Spirulina samples manifested significantly higher carotenoid and chlorophyll contents at the beginning and end of the storage period. The presence of these bioactive compounds results from the presence of Spirulina in the medium and can thus retard the oxidation of olive oil. A higher oxidative stability was reached using BHT in comparison with Spirulina samples. Furthermore, no synergistic action was observed in possible connections between citric acid and Spirulina. In conclusion, Spirulina can enhance oxidative stability and improve the shelf life of olive oil