Bioeconomy is a widely accepted strategy in order to mitigate the adverse effects of climate change while addressing economic, societal and ecological concerns. The SUBLUBE project has been conceived in support of the European Strategy of Bioeconomy, the State R&D Program Oriented to the Challenges of the Society of Spain (Programa Estatal de I+D+i Orientada a los Retos de la Sociedad), the RIS3 Castilla y Leon Regional Strategy and the Bioeconomy Institute of Universidad de Valladolid. It aims to contribute to these frameworks by developing green processes that would enable sustainable raw-material-to-product conversions. Specifically, SUBLUBE is envisioned to capture waste streams of the cork processing industry and upgrade the valuable component (suberin) into a useful biochemical (biolubricant). Cork is rich in natural biopolyesters in the form of suberinic acids which can be an alternative to mineral and vegetable oils as a biolubricant base. Conventional chemical pathways for suberin recovery involving alkali hydrolysis and alkali methanolysis reactions are organic solvent-intensive and requires arduous processing, and yet recovers suberin in minimal quantity. Herein, we propose the ultrafast supercritical hydrolysis in a continuous microreactor as a novel process to isolate suberin from cork in high yields, without the use of harsh chemicals and at a shorter reaction time than conventional approaches. Moreover, since supercritical water (SCW) as a low ionic reaction media will allow the hydrolysis of polysaccharides and lignin and will avoid the hydrolysis of biopolyesters, which will lead to the separation of suberin in its intact form. Suberin in its intact form would produce longer-chain structure enriched with multiple functional groups that are more suitable for biolubricant base synthesis in the subsequent processing. SUBLUBE is made possible by the integration of various disciplines such as materials and analytical chemistry, chemical process engineering, and cork chemistry.
