Rosaura Peña - Academia.edu (original) (raw)
Papers by Rosaura Peña
Revista de Energía Química y Física
The continuous combustion of non-renewable fossil fuels and the depletion of the natural resource... more The continuous combustion of non-renewable fossil fuels and the depletion of the natural resources from which they come and, consequently, the continuous increase of carbon dioxide (CO2) emissions into the atmosphere are intensifying the search for the conversion of carbon dioxide to fuels and value-added chemicals, with the main objective of reducing emissions and creating renewable and sustainable energy sources. In this sense, there is a lot of interest in the photocatalytic reduction of CO2 with H2O, mainly using solar energy, which is a renewable source with a continuous and easily available light supply. Recent progress in this area has focused on the development of promising photocatalysts, primarily based on TiO2. In this context, this article analyzes: (i) the role of CO2 in the treatment of problems related to energy and global warming, (ii) the fundamental knowledge of the photocatalytic reduction of CO2, (iii) the role of the catalysts of copper-doped TiO2 in the photoca...
Industrial & Engineering Chemistry Research, 2009
Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum ba... more Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum based fuels. In its production, however, variables such as raw material, catalyst, and co-solvent are an issue worth exploring because of the impact they have on final biodiesel properties. Therefore, this work aims to establish the effect of the aforesaid variables on methyl ester content, viscosity, acidity, and water content of biodiesel produced from castor oil. In this context, the methanolysis of castor oil has been conducted at 60°C in a batch reactor, and the effect of three alkaline catalysts (CH 3 ONa, NaOH, and KOH) and a co-solvent (hexane) has been established. It is concluded that sodium methoxide leads to considerably higher methyl ester content than the other essayed catalysts. Besides, when utilizing a co-solvent the methyl ester content increases up to a very close value (95.5%) to that established by the EN14214 norm (>96.5%). This has been ascribed to a significant improvement on oil-methanol contact.
Fuel, 2013
ABSTRACT NaX zeolite loaded with potassium nitrate was prepared, characterized and applied as het... more ABSTRACT NaX zeolite loaded with potassium nitrate was prepared, characterized and applied as heterogeneous catalyst in the transesterification of sunflower oil with methanol. The influence of the loaded amount of KNO3, the methanol/oil molar ratio and catalyst amount on the final methyl esters content was studied. The catalysts were characterized by atomic absorption spectrometry (AAS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and CO2 temperature programmed desorption (CO2-TPD). The results demonstrated that methyl esters content was highly influenced by basicity and the catalyst with the highest catalytic activity was obtained using an amount of 35 wt.% KNO3. The produced biodiesel was 98.2% methyl esters when the transesterification reaction was carried out at atmospheric pressure, a reaction temperature of 60 °C, a reaction time of 6 h, with a 21:1 M ratio of methanol to sunflower oil, and a catalyst amount of 10%. The biodiesel obtained at these conditions met the European norm EN-14214 regarding viscosity and acid value.
CIERMMI Women in Science Engineering and Technology TXV, 2021
The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studi... more The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studied worldwide. The main purpose is to decrease emissions to the environment that are associated with global warming, as well as the creation of renewable and sustainable energy sources. In the aforementioned process, the absorption of CO2 is of paramount importance as well as the reactor where the CO2 conversion takes place. In this context, the objective of this chapter is to present and analyze the results of the CO2 absorption in alkaline solutions in capillary reactors. A hydrodynamic study is included in order to establish the operational window of liquid and gas velocities in order to achieve the Taylor flow regime. All experiments were conducted in a capillary reactor (dc = 3 mm). The studied variables were temperature, NaOH concentration (0-0.75 M) and capillary length (300 and 100 mm). It was found that the volumetric mass transfer coefficient of the absorption of CO2 in water in...
Revista de Energía Química y Física
The continuous combustion of non-renewable fossil fuels and the depletion of the natural resource... more The continuous combustion of non-renewable fossil fuels and the depletion of the natural resources from which they come and, consequently, the continuous increase of carbon dioxide (CO2) emissions into the atmosphere are intensifying the search for the conversion of carbon dioxide to fuels and value-added chemicals, with the main objective of reducing emissions and creating renewable and sustainable energy sources. In this sense, there is a lot of interest in the photocatalytic reduction of CO2 with H2O, mainly using solar energy, which is a renewable source with a continuous and easily available light supply. Recent progress in this area has focused on the development of promising photocatalysts, primarily based on TiO2. In this context, this article analyzes: (i) the role of CO2 in the treatment of problems related to energy and global warming, (ii) the fundamental knowledge of the photocatalytic reduction of CO2, (iii) the role of the catalysts of copper-doped TiO2 in the photoca...
Industrial & Engineering Chemistry Research, 2009
Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum ba... more Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum based fuels. In its production, however, variables such as raw material, catalyst, and co-solvent are an issue worth exploring because of the impact they have on final biodiesel properties. Therefore, this work aims to establish the effect of the aforesaid variables on methyl ester content, viscosity, acidity, and water content of biodiesel produced from castor oil. In this context, the methanolysis of castor oil has been conducted at 60°C in a batch reactor, and the effect of three alkaline catalysts (CH 3 ONa, NaOH, and KOH) and a co-solvent (hexane) has been established. It is concluded that sodium methoxide leads to considerably higher methyl ester content than the other essayed catalysts. Besides, when utilizing a co-solvent the methyl ester content increases up to a very close value (95.5%) to that established by the EN14214 norm (>96.5%). This has been ascribed to a significant improvement on oil-methanol contact.
Fuel, 2013
ABSTRACT NaX zeolite loaded with potassium nitrate was prepared, characterized and applied as het... more ABSTRACT NaX zeolite loaded with potassium nitrate was prepared, characterized and applied as heterogeneous catalyst in the transesterification of sunflower oil with methanol. The influence of the loaded amount of KNO3, the methanol/oil molar ratio and catalyst amount on the final methyl esters content was studied. The catalysts were characterized by atomic absorption spectrometry (AAS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and CO2 temperature programmed desorption (CO2-TPD). The results demonstrated that methyl esters content was highly influenced by basicity and the catalyst with the highest catalytic activity was obtained using an amount of 35 wt.% KNO3. The produced biodiesel was 98.2% methyl esters when the transesterification reaction was carried out at atmospheric pressure, a reaction temperature of 60 °C, a reaction time of 6 h, with a 21:1 M ratio of methanol to sunflower oil, and a catalyst amount of 10%. The biodiesel obtained at these conditions met the European norm EN-14214 regarding viscosity and acid value.
CIERMMI Women in Science Engineering and Technology TXV, 2021
The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studi... more The process of carbon dioxide (CO2) reduction to value-added chemicals is being extensively studied worldwide. The main purpose is to decrease emissions to the environment that are associated with global warming, as well as the creation of renewable and sustainable energy sources. In the aforementioned process, the absorption of CO2 is of paramount importance as well as the reactor where the CO2 conversion takes place. In this context, the objective of this chapter is to present and analyze the results of the CO2 absorption in alkaline solutions in capillary reactors. A hydrodynamic study is included in order to establish the operational window of liquid and gas velocities in order to achieve the Taylor flow regime. All experiments were conducted in a capillary reactor (dc = 3 mm). The studied variables were temperature, NaOH concentration (0-0.75 M) and capillary length (300 and 100 mm). It was found that the volumetric mass transfer coefficient of the absorption of CO2 in water in...