In the traditional process ,after alkali refining and deodorization, corn oil then go through crystal, filtering, dewaxing, due to adding the diatomite which partial acid into the filter to help filting. , it will cause the increase of finished product acid value , affect the quality of the product, and can make products with obvious soil odor. New refining of
corn oil extraction process put dewaxing process between bleaching and deodorization section, deodorization tower can remove fatty acid to reduce the acid value, and odor removal soil in diatomite, then control the quality of the product effectively .
Traditional corn oil refining process is to add filter aid which the quantity is 0.2% of the deodorization oil to the oil.And need to cooling the deodorization oil temperature to 20 centigrade, keep 48 hours, with stirring, the wax oil slowly cohesion, wax with filter finally separated out from the oil. New corn oil refining process is add the same filter aid, rapid cooling to 5-10 ℃, and with the rate of 10-13 slow mixing r/min, under this condition, keep 7 to 8 hours, and then use a horizontal filter to remove wax.
Practices show that, the new type of corn oil refining technology of dewaxing process does not affect the product quality and the process time is short, can improve the quality, so as to improve the economic benefits of enterprises, reduce the investment cost.
The deodorization section of new corn oil refining technology using soft tower equipment, the purpose is to use the soft tower system do as principle of "first stripping,then keeping" .firstly, stripping in the packed tower, to remove free fatty acids and other volatiles, odor material, and as far as possible to reduce the loss of vitamin E and the possibility of the formation of trans acids. Use soft tower can make deodorization and deacidifying process to realize the low temperature, the shorter time of processing. Deodorization tower can not only reduce the production cost, and to inhibit the generation of trans fatty acids and maintain vitamin F remaining amount. General operating temperatures is around 230 degrees Celsius.
Stripping section and tray completely separate can prevent the generation of free radicals and pigmentation. Free radicals are produced oil flavor deterioration and one of the reasons for the darker color. In addition, the presence of free fatty acids may induce pigmentation and letter of the production of free fatty acids, single soft deodorization tower and deacidification system can complete stripping operation in 5 minutes , so the oil colour and lustre is low, and at the same time, thin oil layer tower dish, holding time is short, can inhibit the generation of trans fatty acids.
Under a certain vacuum condition, different stripping steam content will have different effects of vitamin E in the distillate of capture. The less stripping steam, the more vitamin E will remained is the oil. Due to the use of soft systems, need not use steam to turn reservoir, its stripping pressure drop is lower, so less stripping steam can be used to deal with, to improve the remaining quantity in the oil, vitamin E energy consumption is low.
