Effect of hydrothermal pretreatment of sunflower oil cake on biomethane potential focusing on fibre composition

► Hydrothermal pre-treatment at 100 °C is an option for improving the AD (anaerobic digestion) of SuOC (sunflower oil cake). ► T > 100 °C worsen the chemical composition of pre-treated SuOC, decreasing the CH4 yield. ► The kinetic constants of the AD process of the pre-treated solid fraction are related to the lignin concentration. ► Lignin content increases with pre-treatment temperature, while the kinetic constant decreases.