Biofuels from fish processing plant effluents – waste characterization and oil extraction and quality

Fish harvesting and processing is a significant economic force in remote and rural coastal communities across Canada. The sustainability of this industry is governed by the ability maximize product utilization while mitigating environmental impacts. In this study, the feasibility of using oil derived from fish processing waste as a biofuel for on-site application in lower grade fuel applications (e.g. heating oil) was analyzed. The effluent quality, recoverable/quality of oil, and further processing required were assessed. Effluents from farmed Atlantic salmon viscera were used due to high triacylglycerides of 40–70% and monounsaturated fatty acids of 47% in lipids. However, the presence of polar and other lipid impurities (e.g. phospholipids) indicate further processing may be required prior to use as a fuel. A modified fishmeal process recovered 17.8 wt.% oil from the effluent, with 57–66% TAG, 0.6–1.5% straight chain hydrocarbons, 29–35% polar and other impurities, and high MUFA (47.3) in lipids. The oil had viscosity (29 cP), density (913 kg/m3), specific heat capacity (1.72 kJ/kg °C), and cold flow properties similar to No. 6 fuel oil and marine vessel fuels, and sulphur (<10 ppm) was much lower than petroleum fuels.