In the process of edible oil refining, physical refining and chemical refining have their own application scenarios, and the choice of which process mainly depends on the acid value of oil, impurity types, nutrient retention requirements and process costs.

In terms of acid value, oils with low to medium acid value are more suitable for physical refining, such as coconut oil and palm oil; Oils with high acid value are more suitable for chemical refining, such as cottonseed oil and rapeseed oil.

From the type of impurities, if the impurities in oil are mainly free fatty acids (such as palm oil), physical refining can be efficiently treated; However, if the oil contains special toxins (such as gossypol in cottonseed oil) or high colloid (such as soybean oil), it is more suitable to use chemical refining to remove these harmful or unfavorable components more thoroughly.

As far as the demand for nutrient retention is concerned, the physical refining of oils with high requirements for nutrient retention, such as coconut oil and rapeseed oil, is more advantageous because of its mild technological conditions. Chemical refining can also meet the needs of oils with general nutrient retention requirements, such as soybean oil and peanut oil.

From the perspective of process cost, the equipment for physical refining is relatively simple, and the amount of wastewater generated is small, so the cost is low; However, chemical refining needs to treat alkali liquor and wastewater, which has more process links and relatively high cost.

From the perspective of oil products, oils suitable for physical refining include palm oil, coconut oil and pretreated rapeseed oil; Oils suitable for chemical refining include cottonseed oil, rice bran oil, corn oil and soybean oil.

To sum up, when selecting refining process, enterprises should comprehensively consider the acid value level, impurity characteristics, nutrition retention target and cost budget of oil,etc., so as to make the best decision.