Phenol (also known as carbolic acid, benzenol, hydroxybenzene, and phenic acid, amongst others) is an organic compound with the formula C6H5OH. It is a naturally occurring substance that is found in organic matter and animal wastes but is now manufactured for commercial use.
Pure phenol is a colourless-to-white crystal which can darken on exposure to light, however the commercial product is a colourless, mobile liquid. It is moderately soluble in water and has a distinctive, sweet, carbolic odour.
Phenol was first extracted from coal tar but the development of the petrochemical industry has led to a different production route today. The dominant process for the production of phenol is via the partial oxidation of cumene. Benzene and propylene are reacted to form cumene which is then oxidised and this is followed by acid catalysed cleavage which yields phenol and acetone.
Storage and Distribution
Phenol is transported in stainless steel tank trucks, or carbon steel lined tank cars. It should be stored out of direct sunlight and separately from reactive or combustible materials. Phenol is labelled as Toxic and Corrosive and has a hazard class rating of 6.1 and a pack group of II. It is flammable and has a flash point of 79oC (closed cup) and a specific gravity of 1.075.
Phenol is utilised primarily, as a chemical intermediate and is employed in a range of processes. One major derivative of phenol is phenolic resin. These resins can be used in the moulding of heat resistant components for household appliances, in counter-top and flooring laminates, and in brake linings. The resins can also be used as a binding agent for sand moulds and foundry castings in the industrial sector, and are found in the construction sector where they are employed as wood-binding adhesives.
Phenol can also be condensed with acetone to produce bisphenol A (BPA) which is a precursor to both polycarbonate resins and epoxy resins. Polycarbonate resins are used in the electrical and engineering industries, and in optical media. Epoxy resins are employed in high performance coatings, adhesives, flooring and paving applications, and in composites.
Phenol is also employed in the production of caprolactam which is then itself used in the production of Nylon 6 and other synthetic fibres.
Phenol is relatively inexpensive to produce so it is also used in a smaller scale, across a range of industries. Phenol derivatives may be used in the preparation of cosmetics, for example; sunscreens, hair dyes, and skin-lightening preparations. It can also be employed as a disinfectant and antiseptic and thus can be found in medicinal products such as throat lozenges and mouthwash. It is also used in slimicides, which are chemicals that kill bacteria and fungi in slimes. It is also a valuable intermediate in the production of detergents, agricultural chemicals, medicines (e.g. aspirin), and hydraulic fluids.