We have investigated the thermochemical conversion of spent grain into fuels. 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, gaseous fuel consisting of CH4, H-2, and CO2 was primarily obtained. When alkali catalyst was used, the main product was a tar-like residue having a net calorific 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.