Method and apparatus for producing diesel fuel oil from waste edible oil

Abstract

A production method of diesel fuel oil from waste oil, in which a vegetable diesel fuel oil can be obtained by utilizing as a raw material a waste edible oil dumped from restaurant, food industry, home, etc. and scarcely utilized. The production method comprises the steps of: removing solid materials contained in a waste edible oil; heating the waste edible oil from which solid materials have been removed to a predetermined temperature, thereby removing moisture and materials of odor contained in the waste edible oil by evaporation; dissolving in alcohol a catalyst composed of alkaline material, thereby preparing an alcoholic solution containing the catalyst; mixing the waste edible oil with the alcoholic solution containing the catalyst and stirring the waste edible oil and alcoholic solution, thereby obtaining a reaction product; separating said reaction product into a light solution and a heavy solution; mixing the light solution with a solid absorbent, thereby impurities contained in the light solution being absorbed by the solid absorbent; separating and removing the solid absorbent from a mixture of the solid absorbent having absorbed the impurities and the light solution; and mixing the heavy solution with a neutralizer to neutralize the catalyst composed of alkaline material contained in the heavy solution.