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Previous issue date: 2013-07-18 / The objective of this study was to analyze the oxidative stability of biodiesel from jatropha
obtained from different purification processes, three wet processes with different drying (in a
vacuum oven, conventional oven and in anhydrous sodium sulfate) and dry (purification with
magnesium silicate adsorbent). Raw materials of different qualities (jatropha crop ancient and
recent crop) were used. The Jatropha oil was extracted by mechanical extraction and refined.
The Jatropha biodiesel was obtained by the transesterification reaction in ethyl route using
alkaline catalysis. The biodiesel samples were characterized by analysis of water content,
carbon residue, Absorption Spectroscopy in the Infrared Region and Thermogravimetry.
Thermogravimetric curves of purified PUsv* PUsq* and had higher initial decomposition
temperatures, indicating that the most stable, followed by samples PU* and PUSC*. Besides
the sample SP* is a smaller initial temperature, confirming the sample without purification to
be less thermally stable. The percentage mass loss of the purified samples showed conversion
of about 98.5%. The results of analyzes carbon residue and infrared suggested that
contamination by impurities is the main factor for decreased oxidative stability of biodiesel.
The oxidative stability was assessed from periodic monitoring, using the techniques of
Rancimat, peroxide index, acid value and Pressurized Differential Scanning Calorimetry.
Samples of biodiesel from jatropha which showed better oxidative stability were of the best
quality raw material and wet scrubbing: PUsq* with dry chemical, using anhydrous sodium
sulfate and PUsv* with vacuum drying, which had oxidative stability 6 hours in Rancimat
time 0 days, within the limits established by the Technical Regulation No. 4/2012 of the ANP,
without the addition of antioxidant, suggesting that these procedures the least influence on the
oxidative stability of biodiesel / O objetivo deste trabalho foi analisar a estabilidade oxidativa do biodiesel de pinh?o manso
obtido a partir de diferentes processos de purifica??o, sendo tr?s via ?mida com processos de
secagens diferentes (em estufa a v?cuo, em estufa convencional e com sulfato de s?dio
anidro) e um via seca (purifica??o com adsorvente silicato de magn?sio). Mat?rias primas de
diferentes qualidades (pinh?o manso de safra antiga e safra recente) foram utilizadas. O ?leo
de pinh?o manso foi extra?do por extra??o mec?nica e refinado. O biodiesel de pinh?o manso
foi obtido pela rea??o de transesterifica??o na rota et?lica, utilizando cat?lise alcalina. As
amostras de biodiesel foram caracterizadas por an?lises de Teor de ?gua, Res?duo de carbono,
Espectroscopia de Absor??o na Regi?o do Infravermelho e Termogravimetria. As curvas
termogravim?tricas das amostras purificadas PUsv* e PUsq* apresentaram as maiores
temperaturas iniciais de decomposi??o, indicando serem mais est?veis, seguidas das amostras
PU* e PUsc*. Al?m da amostra SP* apresentar a menor temperatura inicial, confirmando a
amostra sem purifica??o ser a menos est?vel termicamente. Os percentuais de perda de massa
das amostras purificadas indicaram convers?o em torno de 98,5%. Os resultados das an?lises
de res?duo de carbono e infravermelho sugeriram que a contamina??o por impurezas ? o
principal fator para diminui??o da estabilidade oxidativa do biodiesel. A estabilidade
oxidativa foi avaliada a partir de monitoramento peri?dico, utilizando as t?cnicas de
Rancimat, ?ndice de Per?xido, ?ndice de acidez e Calorimetria Explorat?ria Diferencial
Pressurizada. As amostras de biodiesel de pinh?o manso que apresentaram melhor
estabilidade oxidativa foram as da mat?ria prima de melhor qualidade e purifica??o por via
?mida: PUsq* com secagem qu?mica, utilizando sulfato de s?dio anidro e PUsv* com
secagem a v?cuo, as quais obtiveram estabilidade oxidativa de 6 horas no Rancimat no tempo
0 dias, no limite estabelecido pelo Regulamento T?cnico N? 4/2012 da ANP, sem a adi??o de
antioxidante, sugerindo ser estes procedimentos os que menos influenciam na estabilidade
oxidativa do biodiesel
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17727 |
| Date | 18 July 2013 |
| Creators | Cordeiro, Diego Oliveira |
| Contributors | CPF:42314070453, http://lattes.cnpq.br/1595902438130772, Ara?jo, Ant?nio Souza de, CPF:35530502415, http://lattes.cnpq.br/9770622597949866, Silva, Denise Domingos da, CPF:90380150468, http://lattes.cnpq.br/7952952676209702, Concei??o, Marta Maria da, CPF:80542131404, http://lattes.cnpq.br/3141068978315035, Fernandes J?nior, Valter Jos? |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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