Oil Extraction Machine Suppliers — Screw Press, Expeller & Solvent Extraction

Types of oil extraction machines and how to choose the right technology

Oil extraction is the core mechanical process in edible oil production — separating oil from oilseed material using pressure (mechanical extraction) or solvent washing (chemical extraction), or a combination of both. The technology choice depends primarily on production capacity, desired oil yield, available capital, and the intended oil grade (cold-pressed premium vs refined commodity). **Screw press / expeller press (mechanical extraction):** The most widely used oil extraction machine for small-to-medium scale production worldwide. A rotating screw (the worm shaft) inside a barrel cage mechanically compresses the oilseed material, squeezing oil out through the barrel gaps and discharging a pressed cake (meal). Standard screw presses process 1–100 tonnes of seed per day. Residual oil in the press cake is typically 6–15% depending on press design, seed type, and operating conditions — leaving extractable oil in the cake compared to solvent extraction. Advantages: relatively simple operation and maintenance, no chemical inputs, lower capital cost, suitable for small-scale and artisan production. Disadvantages: lower oil yield compared to solvent extraction; mechanical wear on barrel bars and the worm shaft requires periodic replacement. **Cold-press expeller:** A variant of the screw press designed to keep oil temperature below 40–50°C during pressing — used for premium cold-pressed oil production (cold-pressed rapeseed, cold-pressed sunflower, virgin olive oil-equivalent applications). Lower capacity and higher residual oil in cake than standard hot-press expellers. Premium oil commands higher market price justifying lower yield. **Continuous solvent extraction plant:** Used for large-scale operations (typically 50 TPD+) to extract remaining oil from pre-pressed cake or directly from flaked oilseed material. Hexane solvent is used to wash the flaked or pressed material in a continuous countercurrent extractor — typically a loop extractor, basket extractor, or rotocel extractor. After extraction, the oil-hexane miscella is distilled to recover the hexane for reuse, leaving crude extracted oil. The desolventised meal is processed for animal feed. Solvent extraction achieves residual oil in meal below 1%. Requires significant additional capital for hexane recovery, safety systems, and steam generation. Not appropriate for cold-pressed or premium oil applications. **Two-stage pre-press + solvent extraction:** The dominant configuration for medium-to-large scale commercial oil production — mechanical pre-pressing reduces oil content to 12–18% in the pre-press cake, then solvent extraction completes the extraction to <1% residual. This combination maximises oil yield while reducing solvent plant size compared to direct extraction.