Nile tilapia industrialization waste: Evaluation of the yield, quality and cost of the biodiesel production process

• Published in: Journal of cleaner production 2021-03, Vol.287, p.125041, Article 125041
• Main Authors: Moraes, Paola Silveira, Engelmann, Jênifer Inês, Igansi, Andrei Vallerão, Sant’Anna Cadaval Jr, Tito Roberto, Antonio de Almeida Pinto, Luiz
• Format: Article
• Language: English
• Subjects: Biodiesel; Fish oil; Transesterification; Waste processing
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2020.125041

The biodiesel produced from Nile tilapia waste consists of an alternative material for sustainable energy production, meeting the growing energy demand without damaging the environment, being this fish waste is often disposed in the inadequate form. The aim of this work was to investigate the biodiesel production from fish oil extracted from Nile tilapia processing waste (heads), through a full factorial experimental design. The biodiesel production was carried out by homogeneous alkaline transesterification using ethanol, and potassium hydroxide (KOH) as the catalyst. The best condition of biodiesel production was evaluated as a function of the catalyst concentration, oil:ethanol molar ratio and reaction time, according to the factorial design and the responses were yield, production cost, acid value, and kinematic viscosity. The maximum yield of biodiesel was 92% (w w−1), this result was obtained with KOH 2% (w w−1), molar ratio of 1:12 (oil: ethanol) and reaction time of 4 h. This condition also ensured a product with lower VA (0.63 mgKOH g−1), lower kinematic viscosity (2.78 mm2 s−1), and a low cost of biodiesel production (0.17 US$ kg−1). TLC and FTIR analyses pointed out that the triglycerides of the fish oil were converted into biodiesel. The fatty acids profiles for the crude oil, bleached oil and biodiesel from Nile tilapia oil were determined by gas chromatography and, they have not presented significant differences in their percentage values. Based on the lipid profile obtained, Nile tilapia oil showed suitable characteristics, being a promising source for biodiesel obtainment. This study showed that bleached oil from Nile tilapia heads stands out as a promising source for producing biodiesel with high yield, positive economic potential, and better physicochemical properties. [Display omitted] •Nile tilapia waste proved to be a potential raw material for biodiesel obtainment.•Lipid profile of tilapia oil had suitable characteristics for biodiesel production.•Biodiesel yield from tilapia heads oil was 92% in the best conditions.•Biodiesel showed positive economic potential and better physicochemical properties.