Extraction and characterization of passion fruit and guava oils from industrial residual seeds and their application as biofuels

The Brazilian legislation requires the addition of biodiesel in commercial diesel at a current content of 8%, tying the biodiesel production to diesel consumption. The food industry relies in a great diversity fruits to obtain different products such as juices, sauces and foods. However, the high quantities of fruits processed leads to tons of residues.1 The aim of this work is the oil extraction and characterization from two popular industrial residues, guava seeds and passion fruit seeds. Another goal is to study their potential application as raw materials for biodiesel and bio-oil production. The oil content of passion fruit seeds and guava seeds were 25 % and 9 %, respectively. Both oils were predominantly composed of polyunsaturated fatty acids, as can be seen on Table 1. The biodiesel obtained by esterification/transesterification of both seed oils match most of the criteria adopted by Brazilian regulation. The bio-oils obtained by thermal cracking of the oils were mainly composed by hydrocarbons similar to those observed in petroleum diesel. We have shown that it is possible to extract oils from both residues and use them for biofuels production. The biodiesel obtained from both oils match the specified parameters for this biofuel in Brazil. However, the bio-oils from both seeds need a further upgrading process to remove oxygenated compounds and, thus, be used as diesellike biofuel.