The production of fatty acid methyl esther (FAME) via transesterification was studied, assessing the influence of CaO heterogeneous catalysts obtained from four different fishery residues: sururu, crab, clam and mussel. Characterization and properties of the residues were obtained via thermogravimetric analysis, X-ray diffraction, X-ray fluorescence, Fourier transform infrared (FTIR) spectra, nitrogen adsorption/desorption, chemical composition and scanning electron microscopy (SEM). Catalytic activities and reaction kinetics of FAME synthesis from the transesterification of soybean oil were performed. FAME yield was determined by 1H nuclear magnetic resonance (NMR). A higher efficiency and reaction rate were observed for the catalysts obtained from the sururu residues with 93.7% FAME yield after 3.5 h of reaction at the first usage, reducing only to 91.0% after four consecutive cycles of reuse. The best activities were assigned to the presence of SrO, to smaller particle size, higher pore volumes and the higher Ca leaching, yielding Ca-diglyceroxide which is an important active phase for transesterification.

ABSTRACT Biodiesel appears to be a likely substitute to conventional diesel. However, the main challenge has been the creation of a competitive advantage for the biodiesel production process in terms of innovation and efficiency. The reactive distillation technique for biodiesel production is possibly a key force to overcome this technological issue because it combines chemical reaction and the separation process inside the same unit. This work presents kinetic data for biodiesel production via the ethylic route and compare them with the methylic one. It also compares experimental results in a 1.5m reactive distillation pilot plant with simulated ones in ASPEN PLUS for ethylic biodiesel production with a molar ratio 6/1 (alcohol/oil). Kinetic parameters obtained for the ethylic study were ko = 8173dm3/(mol.min) and Ea =27.48 kJ/mol. Indeed, at the bottom of a six stage column overall the ethylic and methylic biodiesel accounted for 60.1% and 67.8%, respectively. Following this, a sensitivity analysis considering 20 stages of equilibrium showed an ester conversion above 97%. The total energy required to produce biodiesel via a conventional batch reactor was 1210W/h for the ethylic route and 2430 W/h for methylic one, while it amounted to approximately 1000W/h for both routes in the reactive distillation process.

A pirólise rápida do ácido oleico foi estudada sobre catalisadores com 10% Ni suportados em sílica e alumina. Os catalisadores foram impregnados com 10% m/m de ácido oleico. Os precursores secos e os catalisadores contendo ácido oleico foram caracterizados por análise termogravimétrica. Os catalisadores calcinados foram analisados por difração de raios X (XRD) e redução à temperatura programada (TPR). As amostras com ácido oleico adsorvido foram submetidos à pirólise rápida a 650 °C. A pirólise de ácido oleico puro levou a 10% de conversão, enquanto a pirólise catalítica resultou em praticamente completa conversão. O catalisador NiO/alumina produziu mais hidrocarbonetos do que o NiO/sílica. Os principais produtos obtidos com NiO/sílica foram 1-alcenos, enquanto que os principais produtos obtidos com NiO/alumina foram isômeros de alcenos e aromáticos, e pequenas quantidades de compostos oxigenados, principalmente álcoois. A pirólise rápida de ácido oleico adsorvido em catalisadoras representa um método útil para distinguir as propriedades dos catalisadores e suas diferentes atividades.

Flash pyrolysis of oleic acid was studied over 10 wt.% nickel catalysts supported on silica and alumina. The catalysts were impregnated with 10 wt.% oleic acid. The dried precursors and the catalysts containing oleic acid were characterized by thermogravimetric analysis. The calcined catalysts were analyzed by X-ray diffraction (XRD) and temperature programmed reduction (TPR). Samples containing adsorbed oleic acid were submitted to flash pyrolysis up to 650 °C. Whereas pyrolysis of oleic acid without catalyst converted only about 10%, the pyrolysis of oleic acid adsorbed on catalysts allowed practically a complete conversion. NiO/alumina yielded a higher amount of liquid hydrocarbons than NiO/silica. The main products obtained with NiO/silica were 1-alkenes, whereas the main products obtained with NiO/alumina were alkene isomers and aromatics. Small amounts of oxygenated compounds were also observed, principally alcohols. The flash pyrolysis of oleic acid adsorbed on different catalyst surfaces appears as a useful way to distinguish activity trends of different catalyst samples.