title: Valorisation to biogas of macroalgal waste streams: a circular approach to bioproducts and bioenergy in Ireland.
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 thatLaminariaandFucusspp. are the most promising seaweed species for biogas production following biorefinery extractions producing 187-195 mL CH4gVS-1and about 100 mL CH4gVS-1, respectively, exhibiting overall actual yields close to raw un-extracted seaweed.
authors.affiliation: Faculty of Science and Engineering, School of Mechanical Engineering, Manchester Metropolitan University, Dalton Building, Chester Street, Manchester, M1 5GD UK.
authors.forename: Silvia
authors.identifier: 0000-0003-2447-3673
authors.initials: S
authors.lastname: Tedesco
authors.affiliation: Department of Mechanical and Manufacturing Engineering, Dublin City University, Glasnevin, Dublin, 9 Ireland.
authors.forename: Joseph
authors.initials: J
authors.lastname: Stokes
keywords: Algal residues; Anaerobic digestion; Biogas; Integrated biorefinery; Macroalgae; Methane