
The oil emitted from expeller presses contains varying levels of solid particles, depending on the type of oil seed and the condition of the press. Operators typically feed the oil into a settling tank to remove larger solids. The tank also serves as a buffer. In some installations, operators use a vibrating screen for pre-cleaning, or they direct the oil straight from the press to the oil clarification unit.
To enhance the separation process, operators spray the solids with hot water. Typically, they use 1 percent water by weight in relation to the oil quantity. The water mixes with the oil in the feed pump and then moves to the decanter. The decanter, a horizontal scroll-type centrifuge, continuously separates the solids from the oil, improving the efficiency of the process.
Adding water also hydrates and removes any phosphatides present, which then leave with the solids. This process helps clean the oil and remove unwanted impurities. To prevent oil loss, operators return the solids to the press. The purified oil either undergoes further processing or gets stored and dried in a vacuum to maintain its quality.
In some systems, the press oil clarification unit and decanter process combine, improving efficiency. The plant can then streamline operations and reduce equipment requirements. Operators may also subject the purified oil to additional treatments, such as degumming, neutralization, or deodorization, to meet quality standards for various applications, like cooking, biodiesel production, or industrial uses. These treatments remove flavors, odors, and impurities, ensuring the oil meets the necessary specifications.
Once clarified, operators can use the oil immediately or store it until needed. Storing the oil in a vacuum helps preserve its stability and prevent spoilage. The oil can then serve various industries, including food production and renewable energy, supporting sustainable supply chains. This entire process ensures high-quality oil with minimal waste and maximum yield.

Also check out, “Biodiesel Distillation“