Edible Oil Decolorizing Equipment Adsorption Bleaching Clay Filtration Line

The Edible Oil Decolorizing Equipment improves the colour of edible oil so that it meets the appearance required of a finished product. Pure triglyceride liquid is colourless, but ordinary oil takes on different colours because of the amount and variety of pigments it contains. Those pigments fall into three broad groups: organic pigments such as chlorophyll, carotenoids and gossypol; organic degradants such as proteins, carbohydrates and phospholipids; and a range of chromogens. Not all pigments are harmful, but the harmful ones damage oil quality and threaten health and so must be removed.

The purpose of bleaching is not to remove every pigment in theory but to improve the colour of the oil and to provide qualified material for deodorization, while also avoiding colour reversion and extending the shelf life of the finished oil. In industrial cooking oil plants the decolorization methods include adsorption decolorization, heating decolorization, oxidation decolorization and chemical reagent decolorization, and among them adsorption decolorization is by far the most common method used in oil refining.

• Adsorption decolorization: bleaching earth, activated clay and activated carbon adsorb pigments and impurities.
• More than colour: also removes gum, trace metal ions and substances that poison hydrogenation catalysts.
• High temperature adsorption: the oil is held at about 110 degrees Celsius with stirring for good adsorbability.
• Closed filtration: an automatically closed filter removes the spent clay for a clean and safe process.
• Protects the finished oil: prevents colour reversion and improves the shelf life of the product.
• Complete method range: adsorption supported by thermal, air and reagent decolorization where required.

The decolorizing equipment is applied after degumming and deacidification and before deodorization. It handles oil from soybean, rapeseed, peanut, sunflower, cottonseed, palm and rice bran, and it is used in refineries of all capacities. Thermal and air decolorization are reserved for low value oils such as palm and coconut that contain heat sensitive dyes, while reagent decolorization may be used where an oxidation step is acceptable and the reagent residue is strictly controlled.

The bleaching section is shipped with the bleaching vessels, pre-filtration dryer, filter and dosing system protected and braced for sea transport. We supply the dosing schedule, filter maintenance guide and an operating manual, together with a twelve month warranty on the bleaching vessels, dryer and filter units.