Soya oil is an important vegetable oil with its advantage of high smoke point, affordability and health benefits. Obtained from soybean, soya oil has a faint green color or dark yellow. As a popular standard vegetable oil, 80% of commercial oil used in America is soya oil. Besides used as the most widely used cooking oils, it is also used as a drying oil in paint industry.
There are 3 stages to produce soya oil including cleaning, extraction, and purification. Soybeans are first cleaned, dried, and heated to coagulate the soy proteins for the preparation of extraction. Then it is cut into flakes and combined with a solvent into percolation extractors to separate hexane and soybean oil mix from the flakes. Then evaporator is used to separate oil and hexane to obtain crude soybean oil. In the last step, impurities are removed through filtration, degumming, and neutralizing.
Paint and Coating Industry
Soya oil is a renewable resource and widely used to manufacture alkyd resins for inks and paints. It can be incorporated into a range of polymers including polyacrylates, polyesters, and polyurethanes. Polyacrylates are used for latex paints with low cost. Polyesters are commonly used in painting and synthetic fabrics. Polyurethanes are more costly than the others but have a better performance.
The high smoke point of soybean oil allows it to be used as frying oil. Soybean oil is often hydrogenated to increase its shelf life or to produce a more solid product. It is also used by the food industry in a variety of food products including salad dressings, sandwich spreads, margarine, bread, mayonnaise, non-dairy coffee creamers and snack foods.
Soybean oil is also used as renewable raw material to produce a variety of non-food products including bio diesel, inks, plasticizers, crayons, paints and soy candles.