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Estatísticas | Formato DC |



Título: KINETIC EVALUATION OF BIODIESEL ADDITIVES
Autor: FLAVIA ALICE PRACA NOGUEIRA
Instituição: PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO - PUC-RIO
Colaborador(es):  MARIA ISABEL PAIS DA SILVA - ADVISOR
Nº do Conteudo: 65976
Catalogação:  06/02/2024 Idioma(s):  PORTUGUESE - BRAZIL
Tipo:  TEXT Subtipo:  THESIS
Natureza:  SCHOLARLY PUBLICATION
Nota:  Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
Referência [pt]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=65976@1
Referência [en]:  https://www.maxwell.vrac.puc-rio.br/colecao.php?strSecao=resultado&nrSeq=65976@2
Referência DOI:  https://doi.org/10.17771/PUCRio.acad.65976

Resumo:
Biodiesel, a promising option for fuels, has a relevant disadvantage when compared to diesel fossil: like all fatty acid derivatives, it is susceptible to rancid oxidation. This process transforms biodiesel into products with low or no capacity for producing energy. This reaction may be delayed by several compounds which have been used as antioxidants. The majority of commercially available antioxidants are phenolic compounds, which generally presents a level of toxicity. In order to better understand different antioxidant options and their effects on the final fuel, this study was developed. A group of 5 families of compounds were studied regarding their abilities to delay the oxidation reaction. Curcumin and derivatives family focused on the curcumin molecule, which has good antioxidant capacity, but poor solubility in biodiesel, and two others molecules derived from it, with better dissolution capacity. The objective of the family of halogenated curcuminoids was to study a group of compounds that were presented in literature as antioxidant for biodiesel. The family of natural extracts studied two freeze-dried extracts (from beetroot and jabuticaba), in addition to betanin, a compound also extracted from beetroot. The family of essential oils, which is already used as an additive for biodiesel, as an antifreeze additive, was studied in order to understand the impact of these essential oils on the induction time of the final biodiesel. Finally, a diphenol family was also studied, and the compounds 1,2-diphenol, 1,3-diphenol and 1,4-diphenol were compared both in direct analysis of induction time and in aging conditions. From the study of the curcumin family, it was determined that the compound octohydrocurcumin (OHC) has good solubility, both in biodiesel and diesel, and great potential as an antioxidant to be used in pre-dilution with diesel or with a synergistic antioxidant. The same can be said about the brominated compound (in para position) from the halogenated curcuminoid family, which showed promising results in improving the induction period, even at low concentrations, with good solubility in biodiesel. Regarding the natural compounds family, induction time results from the freeze-dried jabuticaba juice powder showed an increase in induction time of 25 percent compared to pure biodiesel. Further studies on antiochionins extraction from jabuticaba aiming its use as antioxidants may bring good results. Essential oils essays demonstrated that Tahiti lemon oil, in addition to increasing induction time, improves the clogging point and viscosity of biodiesel, also acting as a synergistic antioxidant. Finally, 1,4 diphenol isomer showed a better ability to increase the induction time of biodiesel, while the 1,2 isomer seems to stabilize the induction time over time.

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