PROBLEM TO BE SOLVED: To realize a method for easily deoiling a used hydrogenation catalyst by using an inexpensive furnace.SOLUTION: A volatile oil component vaporized from a hydrogenation catalyst by means of heating during a deoiling process is extracted from a rotary kiln, and the volatile oil component is then combusted within an air atmosphere outside the rotary kiln. Effects exerted onto the intra-furnace temperature by the combustion of the volatile oil component are thus abated. The intra-furnace temperature control is accordingly facilitated. Heat generated as a result of the combustion of the volatile oil component can, furthermore, be used for heating the rotary kiln.
