Patent ID: 8734544

Claim:
An apparatus for producing a solid fuel, comprising: a mixing tank for obtaining a raw slurry by mixing porous coal with mixed oil containing a heavy oil content and a solvent oil content; an evaporator for obtaining a dewatered slurry by heating the raw slurry to evaporate water; a solid-liquid separator for separating upgraded porous coal and the mixed oil from each other in the dewatered slurry; a circulation element for returning the mixed oil, having been separated and recovered by the solid-liquid separator, to the mixing tank; and a mixed oil heating heat exchanger for heating the mixed oil being returned to the mixing tank by the circulation element, wherein the circulation element for returning the mixed oil is a circulating flow channel connected between the solid-liquid separator and the mixing tank, and wherein the mixed oil heating heat exchanger is provided at a location along the circulating flow channel.