A process for extracting oil from oil-bearing materials, such as vegetable oil bearing seeds and plant materials, is disclosed. The process comprises adding crude oil, water and a reagent to the oil-bearing materials to form a slurry. Subsequently, a resultant oil is extracted from the slurry. The process provides for treating the oil-bearing materials in a screw extruder. In addition, the process teaches sparging the slurry with steam to remove impurities contained therein.
A substantially toxic-free feed is obtained by maintaining the oil-bearing materials in acid reagents for about 5 minutes to hydrolyze glucosinolates to carbon dioxide and ammonia. The ammonia and carbon dioxide are subsequently stripped therefrom.