Cornstalk degradation and recovery of sugars and VFAs was studied at different HTS.
Highest recovery of reducing sugars and VFAs was 92% of aqueous products.
Rigid cornstalk morphology changed to molten structure via SEM as HTS increased.
Significant changes of organic groups at different HTS identified via FT-IR and TGA.
Hydrothermal treatment might be promising for biohythane production from biomass.