Introduction
Solvent extraction is an efficient method of recovering oil from prepared oil-bearing materials. The process works by allowing a suitable solvent to penetrate the oil-bearing cells of the raw material and dissolve the oil, producing an oil-solvent mixture known as miscella.
Hexane is widely used as the extraction solvent because of its suitable boiling point, effective oil-solubilizing properties, commercial viability, and suitability for producing edible oils. The complete solvent extraction process is designed for efficient oil recovery, controlled solvent handling, and effective solvent recovery.
The process is broadly divided into three main sections:
1. Preparatory Section
Proper preparation of the raw material is essential for achieving efficient extraction. The material must be processed to an optimum size that allows effective solvent penetration while maintaining good solvent percolation through the material bed.
The preparation method depends on the type and physical characteristics of the raw material:
Oil Cakes
Materials such as soybean, sunflower, rapeseed and canola cakes are sized and cracked to obtain the required particle size while minimizing fines.
High-Oil-Content Seeds
Soybean, sunflower, rapeseed and canola are subjected to operations such as cracking, cooking and flaking. Expansion and conditioning may also be incorporated to improve extraction efficiency.
Floury Materials
Materials such as rice bran require special conditioning before extraction. Pelletizing or expansion systems are used to convert the material into a suitable form for efficient solvent percolation.
2. Main Extraction Section
The prepared material enters the extractor through a controlled feeding system. An air-seal arrangement and material-level control help maintain stable and continuous operation.
Within the extractor, hexane is uniformly distributed over the prepared material through a dedicated spraying system. The extractor is designed to provide sufficient contact time for the solvent to penetrate the material, dissolve the oil and form miscella.
The main extraction section incorporates the following operations:
Oil Extraction
Recovery of oil from the prepared raw material using hexane.
Desolventization
Removal of solvent from the extracted meal.
Miscella Distillation
Separation and recovery of oil from the oil-solvent mixture.
Condensation
Condensation of solvent vapours for reuse.
Final Solvent Recovery
Recovery of residual solvent to minimize losses and improve overall process efficiency.
3. Meal Bagging Section
After extraction and desolventization, the recovered meal is conveyed to the meal handling section. Cooling arrangements are provided to bring the meal to a suitable temperature before storage or packing.
The cooled meal is then transferred to the bagging and packing system for convenient handling, storage and dispatch.
Complete Solvent Extraction Solutions
Our solvent extraction systems are engineered to provide an integrated solution from material preparation through extraction, solvent recovery, meal cooling and bagging. The system is designed to achieve efficient oil recovery, reliable operation, effective solvent recovery and consistent meal quality.
Plant Technologies International provides complete solvent extraction solutions tailored to the characteristics of different oilseeds, oil cakes and other oil-bearing materials.
Contact us now for Edible Oil manufacturing equipment, Turnkey Engineering solutions or Technical consultation.
