Produção de biodiesel assistida por ultra-som

• Ano de defesa: 2009
• Autor(a) principal: Santos, Francisco Francielle Pinheiro dos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Engenharia química; Processos químicos; Biodiesel
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/15769

This work presents the use of a new technology for biodiesel production applying ultrasound, instead of using the conventional method that requires heating and vigorous mixing. The process for biodiesel production applying ultrasound was studied with the esterification reaction of fatty acid of vegetal and animal origin and with the transesterification reaction of vegetal oil. Fatty acids from fish oil and from waste oil (soybean oil), produced by the saponification reaction followed by acid hydrolysis, were used in the esterification studies. The esterification reaction was carried out in a batch reactor subjected to ultrasound, reacting the fatty acid with methanol using sulfuric acid as catalyst. In the esterification studies, the main parameters that affect the reaction were studied: molar ratio of methanol and fatty acid (from 3 to 9), catalyst concentration (between 0.5 to 3.5%) and temperature (between 30 and 90ºC). Soybean oil was used in the transesterification reactions. The transesterification reaction was also carried out in a batch reactor subjected to ultrasonic waves, reacting the oil with methanol using potassium hydroxide as catalyst. In the transesterification reaction, the parameters molar ratio of methanol and oil (between 3 and 9) and catalyst concentration (from 0.2 and 0.6%) were studied. To compare the ultrasound process with the onventional process, the reactions were carried out with both processes. The results showed that the ultrasound process was superior to the conventional process in terms of conversion into biodiesel. The production of biodiesel using fatty acid of fish oil resulted in a conversion of 99.9% of fatty acid into biodiesel and the optimal condition was found applying a molar ratio of methanol to fatty acid of 7, using 4.1% of catalyst. Using the waste oil fatty acid, the highest conversion obtained was at 99.0% and was obtained at a molar ratio of methanol to fatty acid of 11, using 1.25% of catalyst and 60ºC. For the transesterification reaction, the conversion of soybean oil into biodiesel was 98% and was obtained applying a molar ratio of 9 and 0.2% of catalyst. The results showed that the process for biodiesel production using ultrasound is a promising technology that is able to obtain higher conversions compared to the conventional process. The processing time is lower than of the conventional process and for the esterification process, the total processing time (production of the fatty acid and esterification) is 75% lower. The process also required less catalyst, reducing reacting problems such as soap formation during transesterification