Oil bleaching is a step in the process of crude oil refining. In the bleaching technology, bleaching earth is applied to crude oil, minimizing its content of pigments (e.g., carotenes and chlorophylls), heavy metals, and the phosphorus remaining after degumming. This improves the appearance and taste of the oil.
Bleaching is based on the principle of adsorption of unwanted substances onto bleaching earth. Reactions in the bleacher occur in conditions of deep vacuum and high temperature. The oil is pumped into the bleacher through the regenerative heat exchanger. Bleaching earth is dosed into the bleacher and mixed intensively for a determined time period.
The vacuum is maintained by vacuum pumps or ejectors that have their own cooling systems and storage tanks for the working liquid (water).
After bleaching, the oil is pumped into a filter, where bleaching earth is retained and subsequently dried. The filter then releases bleached oil and bleaching earth falls out at specific intervals.
The basic goal of vegetable oil bleaching is to remove all colourants (pigments) in order to obtain oil that is nearly transparent. Oil quality at output depends on incoming oil quality and the amount of added bleaching earth. Transparency (or colouration) at output does not usually exceed the value of 12 indicated in the sampler, or measured with a spectrometer. Line performance can be modulated between 1 and 10 tons of oil per hour.
The bleaching line also adsorbs a portion of residual hydratable phospholipids, which positively influences final phosphorus content.
The company Farmet offers optional accessories that will satisfy even the most demanding customers. However, the most convenient solutions are usually our turnkey deliveries, which are optimized from both the technical and economic perspectives, meet all your requirements and include the automatization of the entire process.