Potential of tilapia oil and waste in biodiesel production

Fish oil shows up as an alternative for the recovery of waste from processing of tilapia as a way of adding value to this raw material for biodiesel production. Thus, this study aimed to evaluate the yield and acid number of tilapia oil according to the type of waste used as well as to estimate its potential for biodiesel production as a function of the oil obtained. The waste consisted of fish viscera, fins, heads, skin, scales and mix of all residues mentioned. Such residues were provided by COPACOL's (Consolata Agro industrial Cooperative) fish refrigerator and kept refrigerated for 24 h. Then oil was obtained by means of cooking and waste pressing. It was not possible to obtain oil from the scales and skin of tilapia by the method used. Fish viscera presented oil content of 22% and the mix of residues had a content of 6.12%. The oil obtained from the viscera showed unsuitable acidity for the production of biodiesel by transesterification, requiring a process of neutralization in order to be processed into biodiesel. The remaining residues, except waste mix, were suitable for the acid transesterification and biodiesel production. Fish oil has potential for biodiesel production from tilapia processing waste. The oil obtained from the viscera presented the highest potential to produce biodiesel per ton of waste processed (217 l), followed by the oil obtained from fish heads (91 l) and mixed waste (60 l), showing that it is possible to convert waste into biodiesel, which can totally or partially replace the use of diesel.