Edible Oil Extraction Plant Manufacturers

Solvent extraction in vegetable oil production

Solvent extraction is used in large-scale vegetable oil production to achieve higher oil recovery than mechanical pressing alone. The process uses food-grade hexane (a petroleum-derived solvent) to extract residual oil from pre-pressed cake or directly from conditioned and flaked oilseeds. In a pre-press plus solvent extraction system: conditioned, flaked oilseeds are first pressed in a screw expeller to extract the bulk of the oil (leaving approximately 12–18% oil in the press cake); the press cake (expeller cake) is then fed to the solvent extractor where hexane is used to wash out the remaining oil, reducing residual oil in the spent meal to typically 1% or below. The miscella (hexane + oil mixture) is separated from the extracted meal by distillation, recovering both the solvent (recycled) and the crude oil. The extracted meal is treated in a desolventiser-toaster to remove residual hexane and to toast the meal (important for soybean meal quality). The use of hexane requires ATEX-rated equipment, appropriate containment and ventilation, and fire and explosion prevention systems throughout the extraction facility.