Patent ID: 8075643

Claim:
A method for producing a solid fuel, comprising: a mixing step of mixing porous coal with a mixed oil containing a heavy oil and a solvent oil to prepare a raw material slurry; an evaporation step of heating the raw material slurry to promote dehydration of the porous coal while impregnating pores of the porous coal with the mixed oil to obtain a dehydrated slurry; a solid-liquid separation step of separating a resulting upgraded porous coal and the mixed oil from the dehydrated slurry; a final drying step of drying the separated upgraded porous coal with a carrier gas, and subsequently condensing a vaporized mixed oil in the carrier gas by cooling, while capturing the porous coal in the carrier gas by atomization of the condensed mixed oil, thereby recovering the mixed oil; and a circulation step of returning the mixed oil separated and recovered in said solid-liquid separation step to said mixing step, wherein the method further comprises a supply step A of supplying the mixed oil recovered in said final drying step to said solid-liquid separation step.