1. Degumming

• Purpose: To remove phospholipids, proteins, and mucilaginous substances. These impurities can affect oil stability, appearance, and the efficiency of subsequent steps.
• Process: The crude oil is pumped into the kettle and heated to a specific temperature (e.g., 60-70°C). A small amount of water or food-grade phosphoric acid is added. Agitation ensures thorough mixing, causing the hydratable gums to coalesce and precipitate. The mixture is then allowed to settle, and the bottom layer of “gum oil foots” is drained off.

2. Neutralization (Deacidification)

• Purpose: To remove Free Fatty Acids (FFA), which are a primary cause of off-flavors and rancidity. This is the most critical step for reducing the oil’s acidity.
• Process: The degummed oil is heated to a higher temperature (e.g., 70-90°C). A precisely calculated amount of caustic soda (NaOH solution), known as lye, is added. The lye neutralizes the FFAs, forming soapstock (soap foots). After intense agitation and a long settling period, the heavier soapstock is separated from the neutralized oil and drained.

3. Bleaching

• Purpose: To remove color pigments (e.g., chlorophyll, carotenoids) and residual soap traces.
• Process: The neutralized oil is transferred to a bleaching vessel (which can be the same kettle or a separate one). Under a slight vacuum and at elevated temperature (e.g., 90-110°C), it is mixed with an adsorbent material, typically activated bleaching earth (clay). The clay adsorbs the pigments and impurities. The oil is then passed through a filter press to separate the spent bleaching earth, resulting in a clearer, lighter-colored oil.

4. Deodorization

• Purpose: To remove volatile compounds that cause off-flavors and odors, such as aldehydes, ketones, and residual FFAs. This step produces a bland, stable oil.
• Process: This is a high-temperature (e.g., 180-260°C), high-vacuum process. The bleached oil is heated in a deodorizer vessel. Live steam is sparged through the oil, which acts as a stripping agent to carry away the volatile odoriferous compounds. After the process is complete, the oil is cooled under vacuum and discharged as the final Refined, Bleached, and Deodorized (RBD) oil.

Note: Depending on the quality of the crude oil and the desired final product, some steps may be modified or omitted. For example, physical refining combines deacidification and deodorization for high-FFA oils like palm oil.

Advantages of Our Refining

• High Flexibility and Adaptability
  • It can easily process different types of crude oils (e.g., peanut, sunflower, specialty oils like olive pomace or avocado oil) by simply adjusting process parameters, without requiring equipment changes.
  • Ideal for small-batch production and frequent product changeovers, as the system is easy to clean between batches, minimizing cross-contamination.
• Low Capital Investment
  • The equipment is relatively simple, requires fewer vessels, and has a smaller footprint, leading to significantly lower initial setup costs compared to a continuous refining plant.
• Operational Simplicity
  • The process is straightforward and easier to control, requiring less sophisticated automation. It is easier to train personnel on a batch system.
  • Each batch can be treated as a separate unit, allowing for fine-tuning and easier quality tracking.
• Suitable for Poor-Quality or High-FFA Oils
  • Batch refining is very effective for treating crude oils with high levels of free fatty acids or complex impurities, as the lye concentration and amount can be precisely adjusted for each batch to maximize oil yield.
• Easier By-Product Handling
  • Soapstock and gum by-products are collected in discrete batches, making them easier to manage and process for neutral oil recovery or other uses.