Integration of second and third generation biorefineriesvalorization of fast-growing paulownia wood and invasive macroalga sargassum

Résumé

This thesis was focused on the integral valorization of fast-growing Paulownia wood and the invasive brown macroalgae Sargassum muticum within several biorefinery schemes, paying special attention to the production of bioethanol. For that reason, different biorefinery approaches using eco-friendly pretreatments were employed for the multiproduct valorization of the second generation (2G) and third generation (3G) biomasses. On the one hand, Paulownia wood was fractionated in order to obtain xylooligosaccharides, cellulose suitable for bioethanol production, lignin or even phenolic compounds with antioxidant capacity, whereas Sargassum muticum was pretreated to produce fucoidan-derived oligosaccharides, glucan to produce bioethanol or phenolic compounds with antioxidant capacity. As a final step, the joint valorization of both Paulownia wood and Sargassum muticum was evaluated, producing a great variety of valuable products in different streams, but focusing in the jointly production of 2G+3G bioethanol. This thesis opens the path to a possible valorization of lignocellulosic materials and macroalgae within an integrated fifth generation (5G) biorefinery.