High pressure thermal hydrolysis as pre-treatment to increase the methane yield during anaerobic digestion of microalgae

► High pressure thermal hydrolysis (HPTH) pretreatment enhances algal digestibility. ► HPTH increases methane yield from digestion of algae & lipid extracted algal residue. ► HPTH has no affect on rate of methane production from algae. ► Lipid extracted algal biomass has a higher rate of methane production than raw algae. ► Digestion of algae solubilises nutrients which can be recycled for algal growth.