Seaweed Biofuel Derived from Integrated Multi-trophic Aquaculture

Abstract

Abstract—Aquaculture contributed 23.8 million tonnes of aquatic algae globally in 2012. Increasing consumption of seaweed (as food, for the production of hydrocolloids, and for production of third generation biofuels) will lead to an upward trend in its production and cultivation. Aquaculture contributed 66.6 million tonnes of fish in 2012, 42 % of global production. Fish demand globally is rising to meet food and nutritional requirements; aquaculture for fish will grow. However fish farms are marred by criticism of pollution caused by discharge of waste. Integrated multitrophic aquaculture can reduce pollution through coculture of several species such as seaweed and mussels that utilise waste disposed from fish farms for their growth and development. A model is investigated which would provide 1.25% of energy in transport in the EU from seaweed. This would involve annual production of 168Mt of seaweed (in excess of present world harvest) integrated with 13Mt of farmed salmon. Themodel proposes 2603 anaerobic digesters, each treating 64,500 t/a of Saccharinalatissima in coastal digesters adjacent to natural gas infrastructure for downstream use in natural gas vehicles. Index Terms—Biomethane, gaseous biofuel, hydrocolloids, integrated multitrophic aquaculture, seaweed.