We have investigated the thermochemical conversion of spent grain into fuel
s. Spent grain with a high moisture content (77 wt % before dehydration or
67 wt % after dehydration) was reacted at a high temperature of 200 degrees
C to 350 degrees C, and a high pressure of 7 MPa to 18 MPa through the use
of nickel catalyst or alkali catalyst. When nickel catalyst was used, gase
ous fuel consisting of CH4, H-2, and CO2 was primarily obtained. When alkal
i catalyst was used, the main product was a tar-like residue having a net c
alorific value of approximately 30 MJ/kg. However, its nitrogen content and
viscosity were too high for it to be used as an alternative fuel to heavy
oil. The economic evaluation of the system using thermochemical conversion
suggests that the most promising method is gasification of the spent grain
using nickel catalyst, with no dehydration process.