Food grade phosphoric acid

Phosphoric Acid. This acid is the primary acidulant in cola beverages. Phosphoric acid is stronger than most organic acids and weaker than other mineral acids. The dibasic properties of phosphoric acid provide minor buffering capacity in the beverage. Food-grade phosphoric acid is commercially available in concentrations of 75%, 80%, and 85% and is one of the most economical acidulants. 

Figure 5. One-gallon, low density polyethylene liner in a corrugated carton. Used with various chemicals, including food grade phosphoric acid.

Uses The highest value inorganic acid marketed in the U.S. and second in value to sulfuric acid. Used primarily for the preparation of salts used as fertilizers (ammonium and calcium salts), water softeners and detergents, animal feeds, and baking powder. Food-grade phosphoric acid is used to acidify soft drinks, e.g.. Coca Cola. Organic phosphates are used in flame retardants. 

Crude Oil Conditioning—Crude oils with high levels of phosphatides and trace metals are usually treated with food-grade phosphoric acid for 4 to 8 hours before refining. The purpose of the acid pretreatment is to (1) help precipitate phosphatidic materials (2) precipitate natural calcium and magnesium as insoluble phosphate salts (3) inactivate trace metals, such as iron, copper, and others that may be present in the oil (4) reduce the neutral oil losses and (5) improve the color and flavor stability of the finished deodorized oil. 

Dicalcium phosphate is used as a supplement to animal food. Food-grade phosphoric acid is used as an antioxidant and acidulant, for example, giving a sharp taste to soft drinks. U.S. 3,988,420 (to Israel Chemicals Ltd.) describes a process for making both products from phosphate rock and hydrochloric or nitric acid. Determine which acid leads to the highest net present value for a plant that produces 5000 metric tons per year of food grade dicalcium phosphate. 

Derivation From food-grade phosphoric acid and commercial soda ash by a thermal process. 

TABLE 10.6 Partial Analysis of a Typical Food-grade Phosphoric Acid Produced by Phosphorus Combustion (75.0% H3PO4 54.3% P2O5 equiv.)"... 

To produce a food-grade phosphoric acid, a few additional purification steps may be required (Table 10.5). Overall phosphate recoveries from the rock are normally about 90%. 

Phosphoric acid and phosphate salts are produced either by oxidation of elemental phosphorous or by extraction of the phosphate mineral Ca3(P04)2 (apatite) with sulfuric acid. Production from elemental phosphorous is energetically more demanding and therefore capacities are increasingly shifting towards the extraction process. However, the production of food grade phosphoric acid from the natural mineral apatite requires additional separation and purification steps to remove heavy metals (such as e.g., Cu or As) from the crude phosphoric acid. Precipitation techniques and countercurrent extraction with organic solvents, such as n-butanol or diisopropyl ether, are applied for this purpose. 

TABLE 15.1 Official Chemical Name, E Numbers, Synonyms, and Chemical Formulas of Food-Grade Phosphoric Acid and Phosphates... 

Food-grade phosphoric acid and phosphates have an important impact on various products flavor and physical appearance. The measurement of their concentration, separately or as total phosphorus, in all phases of the food production can be used to track potential variations in pH, flavor, odor, and product appearance (Boyles, 1992). 

Hot, food grade phosphoric acid All chemicals In the neutral pH range... 

Digestion of the phosphate ore using sulfuric acid yields the insoluble calcium sulfate (gypsum), which is filtered and removed as phosphogypsum. Wet-process acid can be further purified by removing fluorine to produce animal-grade phosphoric acid, or by solvent extraction and arsenic removal to produce food-grade phosphoric acid. 

Food grade phosphoric acid is found in cola. 

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