SeaGas Collaboration Farms UK’s Largest Seaweed Harvest

SeaGas is jointly funded by Innovate UK and the Biotechnology and Biological Sciences Research Council (BBSRC), and is assessing the viability – both technical and financial – of farming sugar kelp seaweed for bioenergy production through anaerobic digestion. The world population is growing rapidly and as a result there is a global increase in per capita energy demands. In order to cater for this demand, sustainable feedstocks are needed for the production of bioenergy. The SeaGas project will deliver a strategy to meet this growing need, using farmed seaweed as a feedstock, helping to achieve a sustainable future.

Anaerobic digestion processes traditionally use crops such as maize and beet as well as agricultural and food wastes. However, over the coming years these resources will become increasingly scarce and better used to produce food for human consumption. Seaweed could be a suitable feedstock replacement as it is a sustainable source of biomass that does not require fertiliser, fresh water or agricultural land for production. Furthermore, seaweeds have high productivity, fast growth rates and high polysaccharide content, all of which are important qualities for biofuel biomass. Despite these benefits, only one per cent of the world’s seaweed is farmed in Europe, with Asia responsible for 96.6% of the global seaweed production. The partners of the SeaGas project are collaborating to build a viable supply chain for farming and storage of seaweed in the UK, initially for the production of biomethane from seaweed through anaerobic digestion, but ultimately to stimulate the market and for higher value products from this sustainable feedstock.

The three-year project brings together expertise in anaerobic digestion process development, seaweed growth and storage, economic modelling, environmental and social impact, and the supply chain – from seabed access for seaweed farming through to biogas injection into the national grid. It hopes to be a platform for further exploitation of seaweed in other applications. The project, which is on track for completion in June 2018, involves the collaboration of six partners including CPI, The Crown Estate, the Centre for Environment, Fisheries and Aquaculture Science (CEFAS), the Scottish Association for Marine Science (SAMS), Queen’s University Belfast and Newcastle University. The project also involves two companies on subcontracts, ADAS and Eunomia.

The technical focus of the project is divided into three key areas: seaweed storage to ensure year-round supply, the potential for biomethane production and anaerobic digestion operational factors, and the environmental and socio-economic effects. The financial impact is also being assessed through a financial model created for SeaGas to include the specifics of seaweed cultivation, harvesting and storage. A novel storage system is being developed that will support 12-month anaerobic digestion operation and to counter seaweed availability and variability. The project has progressed from operating a series of 5‑litre reactors, investigating the operating parameters, to now running two 800-litre anaerobic digestion reactor vessels on a pilot scale. The project has recently reached a significant milestone, producing and harvesting the largest batch of farmed seaweed from UK shores to date. This gives promise that bioenergy could be produced from seaweed using anaerobic digestion at a commercial scale.