RESUMO
El biodiesel es un biocombustible producido a partir de grasas y aceites, y debido a las desventajas del uso de los combustibles fósiles, su producción y consumo ha aumentado en los últimos años. En este trabajo fue estudiada la esterificación por catálisis ácida y la transesterificación alcalina de aceites residuales para obtener biodiesel. Las condiciones de relación aceite-metanol (6:1 y 5:1) y concentración de catalizador fueron variadas para seleccionar las más favorables para el proceso. Los aceites usados fueron recolectados en restaurantes de la ciudad de Cartagena. Se encontró que la variable con mayor efecto en el rendimiento de la reacción fue la relación aceite-metanol, favoreciéndose para bajas concentraciones de metanol (6:1), a las cuales se obtienen rendimientos superiores al 93%. La concentración de catalizador no influyó de manera significado la eficiencia de la esterificación. El biodiesel obtenido presentó buenas características de acidez y bajo contenido de azufre. Adicionalmente, se evidenció la necesidad de un pretratamiento a los aceites y una purificación del biodiesel para lograr el cumplimiento de estándares internacionales.
Biodiesel is a biofuel produced from fats and oils and because of the disadvantages of fossil oils use, its production and consumption has increased in recent years. In this work the esterification of waste oil by acid catalysis and alkaline transesterification to obtain biodiesel was studied. The oil-methanol (6:1 and 5:1) ratio conditions and catalyst concentration were varied to select the most favorable for the process. The oils used were collected in restaurants in the city of Cartagena. It was found that the variable to greater effect on the reaction yield was the oil-methanol ratio, favoring low concentrations of methanol (6:1), from which yields higher than 93% are obtained. The catalyst concentration did not affect significantly the efficiency of esterification. The biodiesel obtained had good acidity characteristics and low sulfur content. Additionally the need for a pretreatment to oils and biodiesel purification to achieve compliance of international standards was evidenced.
Assuntos
Humanos , Biocombustíveis , Óleos , Esterificação , Óleos LubrificantesRESUMO
Aims: The study analyzes the carbon footprint of the waste oil management system operating in Portugal to ensure the sustainable operation in the future. The analysis was carried out in 2011for the system that is composed of a treatment procedure collecting the treated oil for re-refining, followed by the production of expanded clay and recycling for electricity production. Methodology: Carbon footprint analysis was conducted by using the Umberto software 5.5 based on the concepts of life cycle assessment with respect to international standards (ISO). Within this context, the substances considered for such carbon footprint analysis are directly relevant to Intergovernmental Panel on Climate Change (IPCC, 2007). Results: The results showed that managing waste oils may contribute to the reduction of carbon footprint due to the avoided emissions of greenhouse gas through the reuse of treated waste oils. The carbon dioxide equivalent emissions from collection and treatment of waste oils would not outweigh such benefit earned from the substitution of virgin lubricant oil even though the use of treated waste oils for producing expanded clay may end up some more carbon dioxide emissions. Conclusion: The carbon footprint analysis in this study has shown the potential for improvements in the waste oil management system in Portugal. The most significant improvement that could be made is the increase of using treated waste oils for the expanded clay production. However, such a strategy would not be consistent with the waste hierarchy principle which dominates the current decision making in managing waste nationally.