Grape stalk valorization for fermentation purposes

•Integrated valorization of grape stalks generated lignin, fermentable sugars and nanocellulose.•For the first time, xylose was recover from grape stalk.•First cellulose nanocrystals recovered from grape stalk.•First proof of concept of use of a generated stream from an integrated valorization process.•Grape stalks fermentable sugars are consumed to produce bioethanol.•Biorefinery is a sustainable way for the processing of grape stalk.