For small and medium-sized oil processing plants, selecting between secondary pressing and single-stage solvent extraction is one of the most critical decisions affecting profitability, efficiency, and product quality. With daily capacities ranging from 1 to 10 tons, operators must balance initial investment, energy consumption, residual oil levels, and downstream refining complexity.
| Factor | Secondary Pressing | Single-Stage Solvent Extraction |
|---|---|---|
| Residual Oil (%) | 6–8% | 1–2% |
| Energy Consumption (kWh/kg oil) | ~1.8 | ~1.2 |
| Initial Equipment Cost ($) | $25,000–$50,000 | $60,000–$120,000 |
| Refining Difficulty | Moderate (higher free fatty acids) | Low (cleaner oil stream) |
These figures are based on real-world data from over 70 mills across India, Brazil, and Southeast Asia. While single-stage solvent extraction offers higher yield and lower energy use per kilogram of oil, it demands significant upfront capital and specialized maintenance skills — a challenge for many smaller operations.
Cottonseed: High oil content (~20%) but tough seed coat makes pre-treatment essential. Secondary pressing works well here because the first press removes bulk oil efficiently, while the second press recovers more from the fiber cake. One mill in Gujarat, India, increased its cottonseed throughput by 25% after switching to a two-stage system using ZY24 screw press units.
Peanuts: Easier to press initially but prone to oxidation during storage and processing. For peanuts, single-stage solvent extraction is preferred due to faster processing time and reduced exposure to air — crucial for maintaining flavor and shelf life. A Malaysian processor reported a 30% reduction in rancidity complaints after adopting this method.
As one plant manager noted: “If you’re running peanuts at 3 tons/day, don’t waste time trying to squeeze out every drop with manual presses — go for the extractors. You’ll save labor, reduce spoilage, and get cleaner oil.”
In continuous pressing systems, stability and consistency matter more than peak capacity. The ZY24 screw press delivers consistent torque and temperature control, reducing downtime and improving meal quality for further processing. Unlike older batch presses that require frequent adjustments, ZY24 maintains uniform output even when feedstock moisture fluctuates — a common issue in tropical climates.
A case study from a Vietnamese soybean mill shows how integrating ZY24 into their secondary pressing line boosted overall productivity by 18%, with no increase in operator workload. “It’s not just about pressing,” said the engineer. “It’s about creating a stable foundation for everything else — drying, degumming, and bleaching.”
Whether you're evaluating equipment for a new facility or optimizing an existing setup, understanding these trade-offs helps avoid costly mistakes. Many small mills overlook the importance of matching process flow to both production scale and ingredient characteristics — leading to inefficiencies that persist for years.
Ready to explore how the ZY24 screw press can support your specific workflow? Discover the full technical specs and real-world performance metrics.
