Avaliação da obtenção de biodiesel a partir do óleo de soja e de seus ácidos graxos, empregando sistemas catalíticos alternativos a base de estanho (iv) e estudo da espécie pinhão-manso para geração de energia (obtenção de biodiesel e avaliação de folhas e caule para aplicação em queima direta)

Abstract

This study was divided into two parts. In the first part, the biodiesel obtention from soybean oil and its fatty acids was evaluated using alternative catalytic systems, based on tin(IV). Therefore, the catalytic activity of two metal complex exhibiting Lewis acid character was investigated. The catalysts contain different groups coordinated to the metal center: dimethyl-bis(pentane-2,4-dionato) tin(IV) - Sn-CH3and dichloride-bis(pentane-2,4-dionato) tin(IV)- Sn-Cl. For the experiments we used a stainless steel reactor with mechanical controlled stirring and temperature. The reactions were performed at 80 °C, 120 °C and 150 °C, and the reaction time varied from 1h to 10h. Before, the reaction product was analyzed by gas chromatography (GC) and acid-base titration. In all transesterification experiments the complex Sn-CH3 showed superior performance when compared to Sn-Cl complex. For esterification, the complex Sn-Cl showedbetter results than Sn-CH3. In the second part, jatropha species was investigated for energy generation, evaluating its oil and its fatty acids, to obtain biodiesel (using catalytic systems developed in the case of soybean oil), and some parts (leaves and stem) for application in direct burning. The oil was obtained by extraction, purified and characterized by gas chromatography, and then it was used for esterification and transesterification reactions. The reactions were conducted at 120 °C with reaction time ranging from 1 to 6 hours. The results obtained were comparable to those observed when employed soybean oil and its fatty acids. In parallel with these reactions were carried out physico-chemical characterizations of the leaves and stem of Jatropha(density, moisture content, ash content, volatile content and fixed carbon content), aiming their integrated use for energy production, and these results showed that relative humidity, the leaves and twigs of Jatropha presented within the expected values for combustion in appropriate equipment. Regarding density can be observed that compared to some biomasses it can be considered light. In terms of ash content, we can see that the leaves had a level exceeding the level of the stem, with the stem that hás a potential energy rather than the leaves.