CHEMICAL FORMULA C3H8O3

The three hydroxyl groups enable a high chemical reactivity of glycerin. When oxidized, glycerin aldehyde and dihydroxyacetone are formed. When reacting with nitric acid, glycerin acid is formed. In conjunction with concentrated sulfuric acid and a nitrifying acid from fuming nitric acid, the OH groups esterify to glycerol trinitrate, better known as the explosive nitroglycerin.

When glycerin reacts with dried potassium permanganate, the first results are fume and heat. The latter causes an exothermic reaction as strong that a darting flame shoots out. The reaction products are manganese compounds such as potassium manganate(VI), manganese(VI)oxide and manganese (III)oxide. In this process, glycerin oxidates to water and carbon dioxide. When adding aqueous potassium permanganate, it only oxidizes up to mesoxalic acid. 

When glycerin is heated under lack of oxygen, it decomposes to the well water-soluble aldehyde propanal, also known as acrylic aldehyde or acrolein.

The discovery of glycerin is attributed to Carl Wilhelm Scheele, a Swedish chemist. In 1779, he obtained an oily, sweet-tasting liquid from the impact of lead(II)oxide on olive oil, which he initially called the “sweet principle of fat”. The Englishman George Fergusson Wilson was the first to develop a method for producing C3H8O3 on an industrial scale in 1854.

Today, glycerin is mainly produced through esterification of vegetable oils with methanol (better known as biodiesel). Furthermore, C3H8O3 is produced by hydroxylation of allyl alcohol with hydrogen peroxide and a tungsten oxide catalyzer used as add-on.

On a large scale, glycerin is used in the production of plastics and colorants. In ointments and creams, it serves as a humectant. With vehicles, it is contained in antifreeze and brake fluid. Furthermore, it is used as a hygroscopic additive for copying ink, dye baths as well as stamp-pad and printing inks.

Glycerin is of high importance in medicine as well, where it is used, for example, for the production of suppositories or as a drug for treating cerebral edemas. Under the designation E 422, it also plays an important role as an additive for the food industry, for instance as a solvent for flavorings, as a softener or as a humectant.