A method for recovering a disused oil refinery to obtain a plant adapted to produce xylitol from xylose, said refinery comprising at least one plant for the catalytic hydrotreatment of oil products provided at least with the following components: - at least one supply pump; - means for introducing hydrogen; - heat exchange means comprising at least one preheating unit and at least one furnace; - at least one reactive section which comprises at least one reactor; - gas/liquid separation means; - at least one column for stripping the reacted product; said method being characterized in that it provides for a step of reusing at least partly said components in order to obtain a plant for continuous hydrogenation of xylose to xylitol, and it provides for: - removing, in said reactive section, the catalyst that is present and replacing it with a catalyst that is adapted to facilitate xylose hydrogenation reaction to obtain xylitol; - keeping substantially as they are at least said at least one supply pump, said hydrogen input means, said at least one preheating unit, said gas/liquid separation means, and the corresponding mutual interconnection ducts, and removing said furnace and replacing it with a heat exchanger supplied with hot fluid; and - supplying xylose in input to said supply pump. said refinery comprising at least one plant for the catalytic hydrotreatment of oil products provided at least with the following components: - at least one supply pump; - means for introducing hydrogen; - heat exchange means comprising at least one preheating unit and at least one furnace; - at least one reactive section which comprises at least one reactor; - gas/liquid separation means; - at least one column for stripping the reacted product; - at least one supply pump; - means for introducing hydrogen; - heat exchange means comprising at least one preheating unit and at least one furnace; - at least one reactive section which comprises at least one reactor; - gas/liquid separation means; - at least one column for stripping the reacted product; said method being characterized in that it provides for a step of reusing at least partly said components in order to obtain a plant for continuous hydrogenation of xylose to xylitol, and it provides for: - removing, in said reactive section, the catalyst that is present and replacing it with a catalyst that is adapted to facilitate xylose hydrogenation reaction to obtain xylitol; - keeping substantially as they are at least said at least one supply pump, said hydrogen input means, said at least one preheating unit, said gas/liquid separation means, and the corresponding mutual interconnection ducts, and removing said furnace and replacing it with a heat exchanger supplied with hot fluid; and - supplying xylose in input to said supply pump. - removing, in said reactive section, the catalyst that is present and replacing it with a catalyst that is adapted to facilitate xylose hydrogenation reaction to obtain xylitol; - keeping substantially as they are at least said at least one supply pump, said hydrogen input means, said at least one preheating unit, said gas/liquid separation means, and the corresponding mutual interconnection ducts, and removing said furnace and replacing it with a heat exchanger supplied with hot fluid; and - supplying xylose in input to said supply pump.