Oil Refining Process

Oil Refining Process Split Column Continuous Physical Refining Process Freshly extracted crude oils contain a diverse group of undersirable impurities such as : • Naturally-occuring compounds, including pigments and phosphatides • Contaminants from the extraction process, such as metals The phosphatides and metals are commonly present as gums, which are not easily handled. By the time you receive the oil, it will contain more, objectionable degradation products, including: • Peroxides, aldehydes, ketones, fatty acids and fixed pigments.

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Dry Degumming: Incoming crude oil from storage is continually heated to degumming temperature by outgoing refined oil, or by preheater during start-up. Food grade acid is constantly dosed and mixed with the oil. The oil-acid mixture flows to a degumming vessel for the degumming reaction to proceed. Gums in the oil decompose on contact with the acid to liberate metals and phosphatides, which are removed during adsorption bleaching. Adsorption Bleaching: Degummed oil continues to a slurry tank under vacuum. Bleaching earth is concurrently metered to the slurry tank and a slurry of degummed oil and earth forms. This slurry continues to flow through a two-stage bleacher vessel. In the first stage, the slurry is heated to bleaching temperature. In the second stage, the bleaching reaction proceeds and impurities, especially metals, phosphatides, pigments and peroxides, are trapped on the earth or decompose. The slurry is continually discharge from the bleacher through the bleaching and polishing filters, which separate the earth from the oil and ensure complete removal of all solid impurities.

Deodorisation: Bleached oil is further de-aerated. Next, it is heated to deodorising temperature in two steps by the outgoing refined oil, or start-up heater, and then by a high-pressure steam generator. The oil then flows under high vacuum through a sequence of three vessels to complete the removal of impurities: • In the flash vessel, around 1/3 of fatty acids evaporate from the oil • In the pre-stripper, which features structured internal packing, aldehydes, ketones and the bulk of fatty acids are carried from the oil by stripping steam • In the deodoriser, removal of aldehydes, ketones and fatty acids is complete and remaining carotenoid pigments decompose The outgoing refined oil is cooled in three steps by bleached oil, incoming crude oil and cooling water. Antioxidant may be dosed and the refined oil is sent to storage. Fatty acids leaving the deodoriser in the vacuum vapour mixture are condensed in a scrubber and collected as fatty acid distillate for other applications. Dry Fractionation Process Fractionation is a physical modification process - so there is no chemical change to the products. And of course in the dry fractionation process, there is no use of costly of hazardous chemical additives, no yield loss and no contamination of the oils. Because it produces no effluent, the dry fractionation process is also environmentally friendly.

Hydrogenation Plant A measured quantity of catalyst-in-oil is pumped into the convertor containing the fully deaerated and dried feedstock oil. Heating and agitation continue until the desired operating temperature is reached. At this point, air evacuation is stopped; hydrogen gas is bubbled into the heated oil at a controlled rate and pressure. The amount of hydrogen required to reach the specifed IV is preset on the gas counter. The hydrogen pressure at the head space is controlled by a pressure controller. Meanwhile, the exothermic heat of reaction developed during the reaction between the oil and hydrogen is removed by water cooling, which is regulated by a temperature controller.

Interesterification Process

The process is as follows: • Neutral feedstock is pmped batch-wise to the interesterification vessel, or crude feedstock may be neutralised in the vessel if suitably equipped. • The oil is heated under vacuum and dried. • A catalyst is added and the reaction proceeds. • After the reaction is complete, the catalyst is deactivated by dilute aqueous citric acid solution • The finished oil is washed with water to remove soap by-products and then dried under vacuum. • A light post-bleaching step is carried out to remove residual soaps. Continuous Physical Refining Process Crude edible oils contain a variety of undesirable impurities comprising: • Naturally occuring compounds (e.g. phosphatides, pigments) • Contaminants (e.g. metals) • Degradation products (e.g. peroxides, aldehydes, ketones, fatty acids, fixed pigments) Phosphatides and metals may be present as problematic gums. Transforming these oils into quality food products requires a manifold approach. Our Continuous Physical Refining Plant integrates three specialised processes to produce a pure, stable, refined edible oil that is bright and lightly coloured and free of odour and taste. Dry Degumming: Incoming crude oil from storage is continually heated to degumming temperature by outgoing refined oil, or by preheater during start-up. Food grade acid is constantly dosed and mixed with the oil. The oil-acid mixture flows to a degumming vessel. There, on contact with the acid, gums in the oil decompose to liberate phosphatides and metals, which are removed during adsorption bleaching. Adsorption Bleaching: Degummed oil continues to a slurry tank under vacuum. Bleaching earth is concurrently metered to the slurry tank to form a slurry of oil and earth. This slurry flows through a two-stage bleacher vessel. In the first stage, the slurry is heated to bleaching temperature. In the second stage, the bleaching reaction proceed and impurities, such as metals, phosphatides, pigments and peroxides are trapped on the earth or decompose. The slurry is continually discharge from the bleacher through the bleaching earth and polishing filters, which separate the earth and its trapped impurities from the oil. Deodorisation: Bleached oil is further de-aerated. It is then heated to deodorising temperature in two steps, firstly by outgoing refined oil, or start-up heater, and secondly by high-pressure steam generator. The oil flows under high vacuum through two vessels: • The flash vessel, where around 1/3 of fatty acids evaporate from the oil • The deodoriser, which features an integrated pocked-column tower. Here, impurities such as aldehydes, ketones and fatty acids are stripped from the oil by steam and remaining carotenoid pigments decompose. The oil is continually discharge from the deodoriser and cooled in three steps by bleeched oil, incoming crude oil and cooling water. Antioxidant may be dosed and then the refined oil sent to storage. Fatty acids leaving the deodoriser in the vacuum vapour mixture are condensed in a scrubber into fatty acid distillate for other applications.

Reference: http://www.oiltek.com.my/products.html