A process for converting waste fibers to solid fuel is provided, including providing a supply of animal waste including the waste fibers in a predetermined quantity; washing the supply of animal waste for a predetermined washing period; dewatering the supply of animal waste by separating water from the waste fibers for a predetermined dewatering period; shedding the waste fibers for separating liquids from solids; compressing the dewatered and shed waste fibers to generate a plurality of briquettes; torrefying at least one of the plurality of briquettes in a torrefaction reactor using a heat source at a predetermined torrefying temperature for a predetermined torrefying period; removing the at least one of the plurality of briquettes from the reactor; and cooling the torrefaction reactor to reach a predetermined cooling temperature.