Palm oil fractionation is a process for further processing refined palm oil. By exploiting the differences in melting points and solubility of various triglycerides in palm oil at specific temperatures, the oil is separated into two solid and liquid components: olein and stearin. This palm oil fractionation process is of great significance in the oil and fat processing industry and is widely used in industries such as food, cosmetics, and biodiesel. Currently, dry fractionation is the most commonly used palm oil fractionation process in palm oil production plants. The process primarily involves heating and crystallizing the refined palm oil, crystallizing and growing the crystals, and filtering, ultimately yielding palm oil olein and stearin products.

Heating Crystallization: The First Step in Fractionation

Palm oil is semi-solid at room temperature and cannot be directly fractionated. Therefore, the refined palm oil must first be heated and dissolved into a liquid state using steam. Before crystallization, the palm oil is generally heated to approximately 70°C to break down any existing crystals, a process known as thermal crystallization. Thermal crystallization is the initial step in the palm oil fractionation process, laying the foundation for subsequent crystallization and growing the crystals, allowing the palm oil to enter the fractionation process smoothly.

Crystallization and Crystallization: A Key Step in Fractionation

The core of the palm oil fractionation process lies in cooling crystallization. Cooling crystallization conditions directly affect the number and size of crystals, and thus the separation quality. Successful crystallization makes the separation process relatively easy. In practice, the cooling process is typically controlled by precisely adjusting the temperature difference between the palm oil and cooling water, as well as the cooling time, under stirring and circulating water cooling conditions. This promotes the formation of palm oil crystal nuclei and their slow growth, enabling effective fractionation. The palm oil fractionation equipment used in the crystallization and crystallization stage is primarily a crystallization tank. The tank is equipped with a refrigeration coil and cooled by a cooling circulation system using an outdoor cooling tower and a refrigeration unit. When the palm oil reaches the desired temperature, cooling is stopped, preparing it for subsequent filtration and separation.

Filtration: Separation of oleoresin and stearin

After crystallization and crystallization, the RBD palm oil is pumped to a membrane filter via a filter pump. A membrane filter consists of filter plates, a filter membrane, and interstitial plates. Its working principle is to allow the palm oil slurry to gradually enter the interstitial space through the filter plates. During the filtration process, the soft fat is pumped into a storage tank by an oil pump, while the hard fat falls directly into the solid fat recovery tank below the filter. Filtration is a key step in physically separating the palm oil after crystallization and growth. The filtration action of the membrane filter effectively separates the soft fat and hard fat, yielding the desired oil products.

Palm oil fractionation processes and equipment play a vital role in palm oil processing. Dry fractionation, a common process in palm oil production plants, achieves palm oil fractionation through heating, crystallization, and filtration. With the continuous advancement and innovation of palm oil production technology, palm oil fractionation processes and equipment are also constantly improving and developing, providing related industries with higher-quality products and more convenient production methods.