After they are brought from the field or silo, the oil seeds cannot be immediately pressed and extracted – first they need to go through preparation phase. The goal of this phase is the weakening of oil-containing cells and the reshaping of the material into such form, which opens up these cells in order to reach the desired yield and quality, while keeping the production costs down. The first step of the processing is cleaning the seeds from impurities. Next step is the production of flakes – a shape that opens up the cells for pressing. Before the cleaned seeds are flaked, they pass through a pre-conditioning step, in which they are heated to optimal temperature for flaking. The flaking itself weakens the cell walls and lowers the viscosity of oil. Afterwards, the flakes undergo conditioning, where they are heated to the optimal temperature for pressing.

During pressing both oil and a solid residue called oilcake is produced. Mechanical impurities which mix with the oil are separated in the next step, called cleansing, which results in clean, crude pressed oil, which still needs to be dried. The solid parts are returned back to the main process before the press. The fresh oilcake is rather fragile and crumbly – it needs to be air-cooled in the oilcake cooler.

Extraction is a continuous technological process, in which residual oil is extracted from the oilcake by using a chemical solvent – hexane. The processed cake is thus converted to rapeseed meal, which is subsequently ridded of hexane, dried and cooled. Hexane is removed from the oil in the evaporator. Rapeseed meal is transported to storages. The produced crude vegetable oil is dried and transported to tanks, in which it mixes with the oil from the pressing process. Hexane, which is used in the extraction process, is recovered and returned back into the process.

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