Solvent Extraction

Solvent extraction is the preferred method for the final separation of oil from oleaginous materials containing less than 30% oil by weight. For oleaginous materials with less than 30% oil by weight, such as soybeans, cottonseed, dry process corn germ and rice bran, the material is mechanically and thermally prepared and then sent to the solvent extraction process for oil separation. This approach is commonly referred to as direct solvent extraction. For oleaginous materials with more than 30% oil by weight, such as rapeseed, sunflower, ground nuts, and copra, the material is mechanically and thermally prepared, mechanically deoiled to approximately 20% oil by weight and then sent to the solvent extraction process for oil separation. This approach is commonly referred to as prepress solvent extraction. Solvent extraction is an integrated process involving five key unit processes: the solvent extractor, meal desolventiser, meal dryer/cooler, miscella distillation and solvent recovery.