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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Síntese e caracterização de biocombustíveis obtidos a partir do arroz e seus derivados

Silva, Tatiana de Oliveira Magalhães da January 2008 (has links)
Made available in DSpace on 2013-08-07T18:54:12Z (GMT). No. of bitstreams: 1 000398972-Texto+Completo-0.pdf: 1270520 bytes, checksum: c981dc4ef6d67b9a25e1efbb0fef41df (MD5) Previous issue date: 2008 / This work presents a comparative study of different catalytic systems for the transesterification reaction of rice brain oil whith methanol. The transesterification of rice brain oil refined with methanol has been studied in the presence of sulfuric acid (H2S04) and of tin compounds such as: tin chloride dihydrate (SnCb. 2H20), tin 2- ethylhexanoate (Sn(CaH1s02h), dibutyl tin oxide ((C4H9)2SnO) and dibutyl tin dilaurate ((C4H9)2Sn(C12H23O2)2),commercially known as DBTDL. The products of the reactions were characterized by gas chromatography (GC). Through comparative analysis between the catalysts, it was observed that the complex DBTDL presented the best performance, with a yield of 99. 9 % in 4h using a molar ratio of 480:100:5 (methanol:oil:catalyst). The results show the viability of using metallic compounds as catalysts to obtain biodiesel, an interesting alternative to basic and acid catalysis. In the process optimization, alcoholysis with methanol and ethanol were evaluated, the molar ratios were changed and as primary oils it was used in addition to refined oils, degummed oils and crude oils. / Este trabalho apresenta um estudo comparativo entre sistemas catalíticos para a reação de transesterificação dos óleos de farelo de arroz. A transesterificação do óleo do farelo de arroz refinado com metanol foi avaliada na presença de acido sulfúrico (H2SO4) e compostos de estanho como: cloreto de estanho (SnCl2. 2H2O), 2-etilhexanoato de estanho (Sn(C8H15O2)2), conhecido comercialmente como DBTDL. Os produtos das reações foram caracterizados através da analise comparativa entre os catalisadores, verificou-se uma melhor performance para o DBTDL, com rendimento de 99,9%, no tempo de 4h e relações molares de 480:100:5 entre álcool, óleo e catalisador, respectivamente. Estes resultados demonstram a viabilidade do uso de compostos metálicos como catalisadores na obtenção de biodiesel, uma alternativa interessante a catalise acida e básica. Nas otimizações do processo, foram avaliadas alcoolizes com metanol e etanol, as razoes molares foram variadas e foram utilizados como óleo de partida, alem dos óleos refinados, também óleos degomados e brutos.

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