Deacidification is a crucial step in the edible oil refining process. Its primary purpose is to remove free fatty acids (FFA) from crude oil – key factors affecting oil quality, taste, and shelf life . High FFA levels cause undesirable flavors, accelerate rancidity, lower smoke point, and may even cause digestive irritation .
National standards require acid value below 0.3 mg/g for most edible oils. Since crude oil cannot meet this standard, deacidification is essential.
Two Main Deacidification Methods
Chemical Deacidification (Alkali Refining)
This method operates on the principle of acid-base neutralization. Alkali is added to the crude oil to neutralize free fatty acids, generating fatty acid salts (soapstock) for subsequent removal. Chemical deacidification has relatively lower equipment requirements and can further remove some pigments and gums. It is suitable for oils with high FFA content and multiple oil types.
Physical Deacidification (Steam Stripping)
This method involves the removal of free fatty acids through distillation under high-temperature (250-270°C) and high-vacuum (1-2mbar) conditions. Physical deacidification offers lower oil loss (typically 0.1-0.3% vs 1-2% for chemical), produces no wastewater, and achieves over 98% deacidification efficiency . However, it demands higher equipment performance and superior oil pretreatment. It is ideal for high acid value oils with low colloid content. Some refineries combine both methods for optimal results.
Benefits of Effective Deacidification
- Extended Shelf Life: FFA removal eliminates the primary substrate for oil oxidation, significantly slowing rancidity
- Improved Oxidative Stability: The process also reduces phosphorus content and trace metal ion concentrations
- Enhanced Safety: Lowers smoke point issues and removes potential digestive irritants
- Compliance: Meets national Grade 1 oil standards (acid value ≤0.2 mgKOH/g for premium oils)
Parameter Control is Critical
Minor changes in temperature, alkali concentration (as precise as ±0.1%), mixing intensity, and reaction time significantly affect deacidification efficiency and refining losses . Huatai's automatic alkali preparation system ensures accuracy, while online monitoring allows real-time adjustment of process parameters. The continuous alkali refining process shortens oil-alkali contact time, reducing saponification and improving efficiency.
Advanced deacidification towers use 316L corrugated packing for efficient mass transfer, achieving low residual FFA (<0.05%) with a compact design. Proper vacuum control (1-2mbar) and steam distribution ensure thorough stripping of FFA while minimizing oil loss and nutrient destruction (preserving tocopherols and sterols).
Why Choose Huatai
- With 38+ years of grain and oil machinery expertise and serving 70+ countries worldwide, Huatai provides:
- High-efficiency packing deacidification towers (316L stainless steel, residual FFA ≤0.05%)
- Fully automated continuous refining lines with PLC control
- Custom capacity from 1 to 5000+ TPD
- National "Little Giant" Enterprise certification & National Green Factory
- Complete turnkey solutions: design, manufacturing, installation, commissioning, and training
Huatai customizes production line equipment based on user needs, providing process design, free installation, and debugging services to ensure optimal production efficiency and oil quality. Good quality, time & fast delivery, perfect after-sales service, and reasonable price.
