Abstract
Seaweeds (macroalgae) have been recently attracting more and more interest as a third generation feedstock for bioenergy and biofuels. However, several barriers impede the deployment of competitive seaweed-based energy. The high cost associated to seaweed farming and harvesting, as well as their seasonal availability and biochemical composition currently make macroalgae exploitation too expensive for energy production only. Recent studies have indicated a possible solution to aforementioned challenges may lay in seaweed integrated biorefinery, in which a bioenergy and/or biofuel production step ends an extractions cascade of high-value bioproducts. This results in the double benefit of producing renewable energy while adopting a zero waste approach, as fostered by recent EU societal challenges within the context of the Circular Economy development. This study investigates the biogas potential of residues from six indigenous Irish seaweed species while discussing related issues experienced during fermentation. It was found that Laminaria and Fucus spp. are the most promising seaweed species for biogas production following biorefinery extractions producing 187–195 mL CH4 gVS−1 and about 100 mL CH4 gVS−1 , respectively, exhibiting overall actual yields close to raw un-extracted seaweed.
Highlights
The world seaweed industry is estimated to be worth US$5.5–6 billion annually, with US$ 5 billion being generated from products destined for human consumption (Roesijadi et al 2010; Walsh and Watson 2011)
They are up to twofold below values reported by (Gurung et al 2012), where raw seaweeds were used. The explanation of this behaviour is the composition of the sample, which may consistently vary across seasons and among seaweed species
The theoretical methane yields obtained were found comparable to un-extracted seaweeds and to popular land-based crops, even following extraction of bioproducts
Summary
The world seaweed industry is estimated to be worth US$5.5–6 billion annually, with US$ 5 billion being generated from products destined for human consumption (Roesijadi et al 2010; Walsh and Watson 2011). Seaweeds are used not just for human food, but in a variety of advanced applications. A wide range of food supplements, fertilizers, cosmetics and pharmaceuticals are produced from seaweeds, and these specialisations hold the greatest opportunity for those involved in the seaweed processing industry in Ireland. Ireland has an estimated national seaweed harvest of 25,400 fresh tonnes per annum, 100% of which is wild (Walsh and Watson 2011). It has been estimated that Ireland has at least 3 million tonnes of standing kelp (Bruton et al 2009), which is not being exploited
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
