Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-08-01T11:57:07Z No. of bitstreams: 1 KeversonGomesDeOliveira_DISSERT.pdf: 1451007 bytes, checksum: 6336e55175d2d79eeb0023f6b024fb45 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-08-02T14:34:52Z (GMT) No. of bitstreams: 1 KeversonGomesDeOliveira_DISSERT.pdf: 1451007 bytes, checksum: 6336e55175d2d79eeb0023f6b024fb45 (MD5) / Made available in DSpace on 2017-08-02T14:34:52Z (GMT). No. of bitstreams: 1 KeversonGomesDeOliveira_DISSERT.pdf: 1451007 bytes, checksum: 6336e55175d2d79eeb0023f6b024fb45 (MD5) Previous issue date: 2017-04-10 / O aumento gradativo do uso de biodiesel na matriz energ?tica brasileira, como combust?vel em misturas biodiesel/diesel, tem incentivado a pesquisa por m?todos mais eficazes de obten??o e controle dos processos oxidativos deste biocombust?vel, buscando maior qualidade do produto. Neste trabalho, foram sintetizados biodiesel de oleaginosas do algod?o e da soja, e antioxidantes naturais (Passiflora edullis, Punica granatum, Syzygium aromaticum, respectivamente, maracuj?, rom? e cravo). O biodiesel proveniente da Refinaria Potiguar Clara Clamar?o, RPCC, foi utilizado para compara??o. A s?ntese dos biodiesel deste trabalho, ocorreu por cat?lise homog?nea, com KOH e, cat?lise heterog?nea, com catalisadores baseados em s?licas impregnadas por metais s?dio e pot?ssio, denominados CAT1 e CAT2. Os biodiesel produzidos foram utilizados em misturas combust?veis biodiesel/diesel, na propor??o volum?trica de 10% e 15%. As propriedades f?sico-qu?micas dos combust?veis produzidos, tais como, viscosidade e densidade (ASTM D7042), ponto de fulgor (ASTM D93), ponto de n?voa (ASTM D2500), ponto de fluidez (ASTM D97) e ponto de entupimento (ASTM D6371) foram determinadas segundo as normas da American Society for Testing and Materials ? ASTM, de acordo com as especifica??es definidas pela Ag?ncia Nacional de Petr?leo, G?s Natural e Biocombust?vel ? ANP. Os antioxidantes obtidos, atrav?s de extra??o alco?lica com octanol, foram caracterizados por espectroscopia na regi?o do infravermelho com transformada de Fourier (FTIR). Os espectros de FTIR apresentaram bandas em torno de 3000 cm-1 referentes ? deforma??o axial C-H de arom?ticos, 1601 cm-1 e 1460 cm-1 atribu?das ? deforma??o axial de C=C do anel arom?tico, que s?o t?picas de compostos fen?licos que comp?e os principais antioxidantes. O m?todo Rancimat foi utilizado para determinar o Per?odo de Indu??o (PI), do biodiesel de soja e o de algod?o com os antioxidantes naturais. O antioxidante obtido da esp?cie Passiflora edullis (maracuj?) apresentou PI de 5,23 h e 3,68 h, respectivamente, para o biodiesel de soja e algod?o. Os catalisadores produzidos neste trabalho foram caracterizados por difra??o de raios X (DRX), espectrometria de fluoresc?ncia de raios X (FRX) e FTIR. O CAT 1, apresentou tempo reacional de 30 min e rendimento de 85% para o biodiesel de soja produzido. O catalisador CAT2, produziu o biodiesel de soja em maior tempo reacional e rendimento de 75%, por?m apresentou elevada capacidade de reutiliza??o. Os antioxidantes naturais apresentaram atividade no biodiesel similar aos sint?ticos, contribuindo com metodologia de f?cil execu??o e menor custo. As misturas antioxidante/biodiesel/diesel permaneceram dentro dos limites de especifica??o exigidos pela ANP para comercializa??o do combust?vel. / The gradual increase in the use of biodiesel in the Brazilian energy matrix, as a fuel in biodiesel/diesel blends, has encouraged the search for more effective methods to obtaining and controlling the oxidative processo of this biofuel, looking for higher product quality. In this work we were synthesized biodiesel from cotton and soybean oil, and natural antioxidants (Passiflora edulis, Punica granatum, Syzygium aromaticum, respectively, passion fruit, pomegranate and clove). The biodiesel from the Potiguar Clara Clamar?o Refinery, RPCC, was used for comparison. The biodiesel synthesis occurred by homogeneous catalysis, with KOH, and heterogeneous catalysis, with catalysts based on silica impregnated with sodium and potassium metals, called CAT1 and CAT2. The produced biodiesel was used in biodiesel/diesel blends, in the volumetric proportion of 10% and 15%. The physicochemical properties of the produced fuels, such as kinematic viscosity and specific mass (ASTM D7042), flash point (ASTM D93), cloud point (ASTM D2500), pour point (ASTM D97) and cold filter plugging point (ASTM D6371) were determined following the American Society for Testing and Materials (ASTM) standards, according to the specifications defined by the Nacional Agency of Petroleum, Natural Gas and Biofuels (ANP). The antioxidants obtained through alcoholic extraction with octanol were characterized by Fourier transform infrared spectroscopy (FTIR). The FTIR spectra presented bands around 3000 cm-1 relative to C-H deformation of aromatic, 1601 cm-1 and 1460 cm-1 attributed to the axial deformation of C=C in the aromatic ring, which are typical from phenolic compounds that composes the antioxidants. The Rancimat method was used to determine the Induction Period (IP), of the biodiesel with the antioxidants. The antioxidant obtained from Passiflora edulis (passion fruit) showed IP of 5.23 h and 3.68 h for soybean and cotton biodiesel, respectively. The produced catalysts in this work were characterized by X-ray diffraction (XRD), X-ray fluorescence spectrometry (XRF) and FTIR. CAT 1 presented a reaction time of 30 min and yield of 85% for the produced soybean biodiesel. The catalytic converter CAT2, produced the soybean biodiesel in a longer reaction time and yield of 75% but presented a higher reused capacity. The natural antioxidants presented activity in the biodiesel similar to the synthetic ones, contributing with an easy execution and low cost methodology. The antioxidant/biodiesel/diesel blends remained within the specification limits required by the ANP for fuel commercialization.