Co-Hydrothermal gasification of Chlorella vulgaris and hydrochar: The effects of waste-to-solid biofuel production and blending concentration on biogas generation

Abstract This studyinvestigates enhanced biogas production via co-Hydrothermalgasification (co-HTG) of wet Chlorella vulgaris biomass andhydrochar (HC). Hydrothermal carbonization was applied to valorize struvite containing waste microalgae stream into solid bio-fuel with improved combustion properties. The effects of HC quality and mixing ratio are investigated on biogas yield, composition and carbon conversion ratio. The results show that the applicationof blending components promotesH2,CH4 formation and selectivityin hydrothermalgasification.The total co-HTGgasyieldis increasedfrom 19.13to 46.95mol kg..1 at 650.Cand 300 barby applying5wt.%HC blending concentration and reducedlevel of volatile matter content (24.61 wt.%).The obtained highhydrogen, methane yields and carbon conversion ratio (19.49, 2.98 mol kg..1, 82.31%, respectively) indicate effective hydrothermal upgrading potentials in case of wet and waste biomass feedstocks.