Acetic acid, CH3COOH, is a colorless, volatile liquid at ambient temperatures. The pure compound, glacial acetic acid, owes its name to its ice-like crystalline appearance at 15.6°C. As generally supplied, acetic acid is a 6 N aqueous solution (about 36%) or a 1 N solution (about 6%). These or other dilutions are used in adding appropriate amounts of acetic acid to foods. Acetic acid is the characteristic acid of vinegar, its concentration ranging from 3.5 to 5.6%. Acetic acid and acetates are
Acetic Acid is a common chemical reagent used in a multitude of organic reactions. It is the primary constituent of vinegar, contributing to its distinct taste and odor. It is used in the synthesis of dye-sensitized solar cells.
Methods of Manufacturing
1. Acetic acid is widely distributed in nature. For example in fruit or vegetable oils, mainly in the form of esters; in the tissues of animals, excretions and blood are present in the form of free acids. Many microorganisms can convert different organisms into acetic acid by fermentation. In ancient China there was a record of vinegar, as early as BC, humans were able to use alcohol by a variety of acetic acid oxidation of fermentation vinegar, the late 19th century found that wood distillation could get acetic acid. In 1911, in Germany, the world's first set of acetaldehyde oxidation of acetic acid production plants. And soon the development of low carbon hydrocarbon oxidation of acetic acid production methods. In 1960 the former Federal Republic of Germany used methanol at high pressure (20MPa) by carbonylation of acetic acid method. Subsequently, the United States Monsanto rhodium complex catalyst (to iodide as a catalyst), the carbonylation of methanol to acetic acid pressure dropped to 0.3-3.0MPa, and in 1970 the production capacity of 135kt acetic acid methanol low-pressure carbonylation industry Device. As the method of advanced technology and economy, from the mid-seventies, the new manufacturers used more low-pressure methanol carbonylation methods. In 1984 the world's annual production capacity of acetic acid reached 6Mt, of which low-pressure carbonylation of about 40%. 1. Fermentation of starch fermentation using light liquor (containing 3-6% ethanol), the role of vinegar in the mother of bacteria, at about 35 ℃ for fermentation, light wine is air oxidation to vinegar. In addition to vinegar containing 3-6% acetic acid, it still contains other organic acids, esters, and proteins. Fermentation is mainly used to make food vinegar.