In oil fractionation, dry fractionation has become the mainstream technology for palm oil deep processing due to its solvent-free operation, environmental friendliness, and moderate investment. Ocean's oil fractionation production line adopts dry fractionation technology to further separate RBD palm olein into high-value super olein and stearin.

Feedstock and Products

The process uses RBD palm olein as feedstock, requiring an iodine value ranging from 56 to 57, a slip point of 22 to 23 degrees Celsius, and free fatty acid and impurity content not exceeding 0.1%. The incoming feedstock temperature is approximately 45 degrees Celsius.

The final product, super olein, achieves an iodine value of 58 to 60, a cloud point of 8 to 10 degrees Celsius, and a yield of 80% to 85%.

Crystallization Section

Crystallization is the core of dry fractionation. The feedstock is first heated to 60 to 75 degrees Celsius in the feed oil heater to completely eliminate any existing crystal nuclei, preventing undesired crystallization during subsequent cooling.

Multiple crystallizers are provided, with individual effective volumes determined by capacity requirements. Each crystallizer is equipped with double-layer cooling coils and a mechanical agitator, with agitation speed controlled by variable frequency drives. The cooling process follows a pre-programmed temperature profile automatically — initially using cooling tower water, then switching to chilled water when the temperature differential becomes insufficient. The complete cooling program is determined by feedstock and product specifications, ultimately producing a slurry containing stearin crystals in liquid olein.

Filtration Section

After crystallization is complete, the slurry is fed by a progressive cavity pump to a membrane filter press for solid-liquid separation. The membrane filter press is equipped with multiple filter chambers. During filtration, liquid olein passes through the filter cloth to become the super olein product, while stearin crystals are retained in the filter chambers.

Subsequently, the membranes are inflated to squeeze the filter cake, further extracting residual liquid olein. After compressed air blow-drying, the residual oil in the cake is reduced to a low level. When filtration is complete, the filter press automatically opens, and the stearin cake drops into a stearin tank equipped with a cutter and steam heating coils, where it is melted into liquid form before being transferred to storage.

The filter press typically requires regular cleaning, using hot wash oil circulated through the filter to maintain filtration efficiency.

Refrigeration and Utilities

The refrigeration system consists of a packaged chiller unit equipped with variable-frequency-driven screw compressors. Utility consumption is determined by specific capacity requirements. Steam is primarily used for heating and heat tracing, cooling water for temperature reduction during crystallization, and electricity for driving all process equipment.

Automation Control

The entire plant is controlled by a PLC system with a graphical operator interface. Operators can monitor and control all process parameters in real time via computer, including crystallization temperature profiles, filter press status, flow rates, liquid levels, pressures, and alarms. A single operator can handle routine operations, with only occasional assistance required during cleaning.

Ocean provides full-chain services from process design and equipment manufacturing to installation and commissioning, delivering efficient, stable, and automated dry fractionation production lines.