Soybean Oil Extraction Plant | Complete Soybean Oil Mill Plant

Modern soybean oil mill plants integrate advanced soybean pretreatment, mechanical pressing or solvent extraction, and edible oil refining processes to ensure high oil yields and excellent product quality. As one of the most widely used vegetable oils, soybean oil production requires a series of complex mechanical and chemical processes. The two primary extraction methods are mechanical pressing and solvent extraction.

Soybeans have relatively low oil content, making solvent extraction with food-grade hexane typically more efficient. This method achieves an oil yield of approximately 19%, compared to about 13% for mechanical pressing. For household or small-scale use, cold-pressing with a small oil press can produce crude soybean oil. However, for industrial production, solvent extraction remains the most cost-effective method due to its higher oil yield and lower residual oil content in the soybean meal.

Flow chart of soybean oil processing:

Soybean → Cleaning → Crushing → Softening → Flaking → Extracting → Evaporating → Stripping → Crude Oil → Filtering → Degumming → Neutralizing → Bleaching → Deodorizing → Refined Soybean Oil

This flow chart applies to most soybean oil production lines and is compatible with both medium and large-scale soybean oil extraction plants.

Key Processing Steps in Soybean Oil Mill Plants

1. Soybean Pretreatment & Flaking

Pretreatment directly impacts extraction efficiency and oil quality. Critical factors include:

• Flake thickness: Ideal flakes should be thin and uniform to maximize surface area.
• Moisture and Temperature Control: Properly softened soybeans (using softening or conditioning tanks) prevent cracking and ensure maximum oil extraction.
• Roll Mill Performance: Consistent pressure and rotational speed ensure uniform flake quality.

Carefully prepared soybean flakes significantly enhance solvent permeability, thereby increasing final oil yield.

2. Solvent Extraction Process

This core process in soybean solvent extraction plants requires precise control:

• Extractor loading: 80–85%
• Solvent temperature: 50–55°C
• Immersion temperature: 50–55°C
• Preferred spray method: Dry-type large droplet spray
• Solvent ratio: 1:0.8–1.1 (solvent : raw flakes)
• Solvent requirements: Must be non-toxic, volatile, chemically stable, non-corrosive, and suitable for edible oil production.

Maintaining proper temperature and liquid level ensures maximum solvent absorption and optimal extraction efficiency.

3. Mixed Oil Processing & Evaporation

The mixed oil (micellar oil) extracted from the soybean meal must undergo the following steps to remove solvents:

• Evaporation
• Stripping
• Condensation & solvent recovery

If concentration does not meet requirements, the oil undergoes repeated evaporation cycles to achieve pre-refining solvent removal standards.

4. Soybean Oil Refining

Refining ensures the oil meets food-grade standards. Refining typically includes:

• Degumming (Hydration): Hydrates phospholipids using hot water (55–75°C).
• Neutralization (Deacidification): Removes free fatty acids.
• Bleaching: Using activated clay to remove pigments and impurities.
• Deodorization: Conducted at high temperatures (approximately 140°C) and high vacuum (approximately 93325 Pa).

Post-refining solvent residue in soybean oil should be below 50 mg/kg, meeting international edible oil standards.

Main Equipment Used in a Soybean Oil Extraction Plant

A complete soybean oil mill plant includes the following machinery:

1. Seed Cleaning Equipment
   Removes stones, dust, metals, and impurities to protect downstream equipment.
2. Seed Cracker / Crushing Mill
   Breaks soybeans into uniform particles to increase surface area for extraction.
3. Softening / Conditioning Equipment
   Adjusts moisture and temperature to improve flaking quality and oil yield.
4. Flaking Machine (Roller Mill)
   Produces thin flakes to facilitate solvent penetration.
5. Solvent Extraction Machine / Extractor
   The heart of the plant—extracts oil using hexane or other food-grade solvents.
6. Evaporator & Stripping Tower
   Removes solvent from the crude oil and recovers hexane for reuse.
7. Oil Refinery Equipment
   Includes degumming, neutralizing, bleaching, and deodorizing machines for edible-grade oil.
8. Meal Desolventizer-Toaster (DTDC)
   Removes solvent from soybean meal, ensures safety, and improves protein quality.
9. Storage Tanks & Oil Filling Line
   Stores crude and refined soybean oil before packaging.

This configuration may vary depending on the capacity and layout of the soybean oil processing plant.

Why Invest in a Soybean Oil Mill Plant?

Soybean oil ranks among the world’s most popular edible oils due to its numerous health benefits:

• Rich in polyunsaturated fatty acids (60%)
• Rich in monounsaturated fatty acids (24%)
• Cholesterol-free
• Ideal for frying, baking, and food processing

With the continuous growth in global demand for edible oils, investing in soybean oil extraction machine and complete soybean oil production lines represents a profitable and sustainable business venture.

Your Trusted Partner for Soybean Oil Extraction Solutions

Huanyang provides complete turnkey oil mill plant projects, including:

• Customized plant design (50-1000 tons/day)
• High-efficiency soybean oil extraction equipment
• Installation, training, and commissioning
• Long-term after-sales service
• Energy-saving and environmentally friendly solutions

With extensive industry experience and a robust engineering team, we help you achieve high oil yield, low operating costs, and stable production.