Bioethanol Production from UK Seaweeds: Investigating Variable Pre-treatment and Enzyme Hydrolysis Parameters

Kostas, Emily T.; White, Daniel A.; Cook, David J.

Abstract

This study describes the method development for bioethanol production from three species of seaweed. Laminaria digitata, Ulva lactuca and for the first time Dilsea carnosa were used as representatives of brown, green and red species of seaweed, respectively. Acid thermo-chemical and entirely aqueous (water) based pre-treatments were evaluated, using a range of sulphuric acid concentrations (0.125–2.5 M) and solids loading contents (5–25 % [w/v]; biomass: reactant) and different reaction times (5–30 min), with the aim of maximising the release of glucose following enzyme hydrolysis. A pre-treatment step for each of the three seaweeds was required and pre-treatment conditions were found to be specific to each seaweed species. Dilsea carnosa and U. lactuca were more suited with an aqueous (water-based) pre-treatment (yielding 125.0 and 360.0 mg of glucose/g of pre-treated seaweed, respectively), yet interestingly non pre-treated D. carnosa yielded 106.4 g g−1 glucose. Laminaria digitata required a dilute acid thermo-chemical pre-treatment in order to liberate maximal glucose yields (218.9 mg glucose/g pre-treated seaweed). Fermentations with S. cerevisiae NCYC2592 of the generated hydrolysates gave ethanol yields of 5.4 g L−1, 7.8 g L−1 and 3.2 g L−1 from D. carnosa, U. lactuca and L. digitata, respectively. This study highlighted that entirely aqueous based pre-treatments are effective for seaweed biomass, yet bioethanol production alone may not make such bio-processes economically viable at large scale.

Citation

Kostas, E. T., White, D. A., & Cook, D. J. (2020). Bioethanol Production from UK Seaweeds: Investigating Variable Pre-treatment and Enzyme Hydrolysis Parameters. BioEnergy Research, 13(1), 271–285. https://doi.org/10.1007/s12155-019-10054-1

• Journal Article Type: Article
• Acceptance Date: Sep 3, 2019
• Online Publication Date: Oct 26, 2019
• Publication Date: Mar 1, 2020
• Deposit Date: Nov 8, 2019
• Publicly Available Date: Nov 12, 2019
• Journal: BioEnergy Research
• Print ISSN: 1939-1234
• Electronic ISSN: 1939-1242
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 13
• Issue: 1
• Pages: 271–285
• DOI: https://doi.org/10.1007/s12155-019-10054-1
• Keywords: Macroalgae; Pre-treatment; Bioethanol; L. digitata; D. carnosa; U. lactuca
• Public URL: https://nottingham-repository.worktribe.com/output/3084220
• Publisher URL: https://link.springer.com/article/10.1007%2Fs12155-019-10054-1
• Additional Information: First Online: 26 October 2019; : ; : The authors declare that they have no conflict of interest.; : No conflicts, informed consent, human or animal rights applicable.