Citric acid has chemical formula C6H8O7. Its exact name conforming to requirements of the chemical nomenclature - 2-hydroxy-1,2,3-pro-pan-tricarboxylic acid. Represents itself the white crystals easily soluble in water. It is well soluble in methyl alcohol, it is slightly worse – in ethyl, it is very weak – in ethyl air of acetic acid (ethyl acetate), it is almost insoluble in chloroform. How it is possible to receive this chemical?
Instruction
1. Originally this acid was called tsitronovy (the instruction on a source from which it was received). Respectively, its salts were called and continue to call citrates.
2. The oldest and checked method is an extraction of citric acid from vegetable raw materials. It, for example, as rustic tobacco. It is a grassy plant of family of a nightshade family which leaves contain from 8 to 14 percent of citric acid. Or from pulp of a citrus. But now this way is considered outdated and not too justified from the economic point of view.
3. More modern and profitable method is production of citric acid by means of certain strains of Aspergillus niger (black mold mushroom), by a sbrazhivaniye at its cultivation on molasses (withdrawal of sugar industry, fodder treacle) in tight tanks fermenters.
4. By means of achievements of microbiology and technology, it was succeeded to mechanize and automate this process that, respectively, led to decrease in prime cost of a target product. Now, the selected strains of Aspergillus niger provide an exit of citric acid about 97-99% counting on the used sucrose.