Citric Acid Anhydrous

About Citric Acid Anhydrous
Citric acid is a weak organic acid with formula C6H8O7, which occurs naturally in citrus fruits. It is part of the citric acid cycle which occurs in the metabolism of all aerobic organisms. Globally, more than a million tons of citric acid are produced annually, and more than 70% of the total production is used in the food and beverage industry as an acidifier or antioxidant to preserve or enhance the flavors and aromas of fruit juice, ice cream, and marmalades. Citric acid exists in the form of anhydrous, which is crystallized in hot water, or monohydrate, which is crystallized in cold water. The anhydrous form of citric acid can be produced by heating citric acid monohydrate.
Manufacturing Process
Citric acid is produced by submerged fermentation using fungus from different sources of carbohydrates, such as molasses and starch-based media. As precipitation, calcium oxide is added to form the slightly soluble tri-calcium citrate tetrahydrate. The precipitate is removed by filtration and washed to remove impurities. It is treated with sulphuric acid to form calcium sulfate and filtered off. The citric acid liquid is then treated with active carbon and passed through a cation and anion exchanger. Finally, the liquid is concentrated in vacuum crystallizers at 20-25℃, forming citric acid monohydrate. A higher temperature in this step will result in citric acid anhydrous.