Oil Refining Deacidification System Alkali Neutralization Disc Centrifuge Unit

The Oil Refining Deacidification System removes the free fatty acids (FFA) that give crude oil an irritating odour and accelerate the hydrolysis and rancidity of the neutral oil. Deacidification is necessary in every edible oil refinery, and alkali refining has long been the method with the greatest economic benefit for the crude oil refining process. It is the most critical step of the whole refinery, and it creates the conditions for decolorizing, deodorizing, hydrogenating and further deep processing of the oil. After alkali refining the oil quality is improved, the oil stability is raised and the storage time is extended.

The alkali refining method neutralizes the FFA with lye to form soap, and the soap adsorbs impurities as it is generated. The soap and impurities are then separated from the oil by gravitational sedimentation or, more commonly, by a disc centrifuge. The disc centrifuge consists of a fuselage, a drum, a transmission and a water distribution device. The mixture enters the drum, passes through the discs and slides towards the drum wall, where the flushing water dilutes it. Under the action of the centripetal pump the heavy phase is discharged from the heaviest phase outlet and the light oil phase from the light phase outlet.

• Alkali neutralization: lye reacts with the FFA to form soap that also adsorbs other impurities.
• Disc centrifuge: a high speed separator that splits oil and soap stock cleanly and continuously.
• Controlled reaction: oil warmed to 20 to 40 degrees Celsius, then mixed with phosphoric or citric acid and lye.
• Full work sequence: pre-treatment, neutralization, soap stock separation, washing, dehydration and filtration.
• Efficient washing: process water 3 to 5 degrees Celsius warmer than the oil, added at 10 to 15 percent of oil volume.
• Intermittent and continuous: the intermittent type suits concentrated low temperature alkali refining.

The deacidification system is applied in the middle of the edible oil refining line, after degumming and before bleaching and deodorization. It handles degummed crude oil from soybean, rapeseed, peanut, sunflower, cottonseed, corn germ and rice bran, and it is used in both small intermittent refineries and large continuous refineries that supply first and second grade edible oil.

The system is shipped with the reaction vessels, disc centrifuge, heater, mixer and pumps protected and braced for sea transport. We supply the process parameters, a valve and piping layout and an operating manual, together with a twelve month warranty on the centrifuge, reaction vessels and pumps.