Thermo-catalytic reforming pyrolysis of ensiled Saccharina latissima dominated macroalgal pellets for bioenergy production

Kirby, Marie E.; Toop, Trisha; Ouadi, Miloud; McEvoy, Lesley; Rolin, Christine; Inkster, Rhiannon; Dyer, Philip W.; Theodorou, Michael K.

Abstract

Marine macroalgae is a biomass resource for the manufacture of fuels and chemicals, which can be sustainably harvested from seaweed farms or from man-made structures where it accumulates as a biofouling organism. However, in temperate regions farmed macroalgae can only be harvested between late Spring and early Summer, limiting year-round availability. Here we show that a conventional grass ensilage procedure preserves Saccharina latissima dominated biomass on the tonne scale for 30 months, enabling year-round use of this biomass. Following processing, the resulting dried and pelletised ensiled macroalgae material was subject to Thermo-Catalytic Reforming™, comprising sequential pyrolysis (450 °C) and either dry or steam catalytic reforming (700 °C) processes. Both processing methods produced a mixture of bio-oil (1.6–1.9 wt%) and hydrogen-rich permanent gases (30.9–31.1 wt%) with higher heating values of 34.8–35.4 MJ/kg and 18.0–24.2 MJ/m3, respectively, together with char (45.5–48.5 % wt). The permanent gases can be used directly for heat generation, while hydro-treatment of the bio-oil would afford a material that can be blended with traditional transport fuels. This work demonstrates that if operated at scale, the combined harvesting, ensilaging and Thermo-Catalytic Reforming™ of preserved macroalgal biomass offers a year-round decentralised energy resource.

Citation

Kirby, M. E., Toop, T., Ouadi, M., McEvoy, L., Rolin, C., Inkster, R., Dyer, P. W., & Theodorou, M. K. (2024). Thermo-catalytic reforming pyrolysis of ensiled Saccharina latissima dominated macroalgal pellets for bioenergy production. Energy Conversion and Management: X, 24, Article 100692. https://doi.org/10.1016/j.ecmx.2024.100692

• Journal Article Type: Article
• Acceptance Date: Aug 18, 2024
• Online Publication Date: Sep 22, 2024
• Publication Date: 2024-10
• Deposit Date: Sep 5, 2024
• Publicly Available Date: Sep 5, 2024
• Journal: Energy Conversion and Management: X
• Print ISSN: 2590-1745
• Electronic ISSN: 2590-1745
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 24
• Article Number: 100692
• DOI: https://doi.org/10.1016/j.ecmx.2024.100692
• Public URL: https://durham-repository.worktribe.com/output/2798674