Adiponitrile is the organic compound with the formula (CH2)4(CN)2. This dinitrile, a viscous, colourless liquid, is an important precursor to the polymer nylon 66. It is the key molecule for nylon 66 production. In the original DuPont process it was produced from adipic acid, but this synthesis was uncompetitive. Adiponitrile (also called 1,4-dicyanobutane) is a clear to yellow liquid, melting point at 1-3oC. It is slightly soluble in water but soluble in alcohol and chloroform. It is derived from 1,4-Dicyanobutylene, which is yielded by dichlorobutylene with sodium cyanide. The main identified use of adiponitrile is as an intermediate for the production of hexamethylenediamine, used for the manufacture of Polyamide 6-6. Adiponitrile is used as intermediate for the synthesis of adipoguanamine, corrosion inhibitors, and rubber accelerators. APPLICATIONS: Adiponitrile (ADN) is a critical intermediate used to manufacture nylon 6,6. Adiponitrile (ADN) is used almost exclusively to make hexamethylene diamine (HMDA), which is used to make nylon 6,6 fibres and resins. ADIPONITRILE PURIFICATION: The principal use of adiponitrile is as an intermediate for the manufacture of hexamethylene diamine (1,6-diaminohexane) which is a co-monomer for the manufacture of Nylon 6,6. There are several different manufacturing processes for adiponitrile including direct addition of HCN to butadiene, electrodimerization of acrylonitrile, and amidation and dehydration of adipic acid. Impurities that are produced by these processes can be converted to cyanoketones or cyanoimines by contacting the adiponitrile product with a strong acid catalyst such as Amberlyst 15. These compounds are then removed by contact with a strong base anion exchange resin in the hydroxide form. Finally, residual ammonia or amine can be removed by contacting with a polishing bed of strong acid cation exchange resin. MARKET SCENARIO: World demand is estimated at 1.2 million metric tonne per year. Demand growth is about 1.5% per year, entirely accounted for by a 1.5% per year growth in nylon 6,6 engineering resin. There is some demand growth for nylon 6,6 fibre in Asia, mainly for tyre cord, but this is balanced by declining demand for textile filament in developed countries where textile industries are under siege from low-cost production in Asia, especially China. Nylon 6,6 has been losing market share to nylon 6 in recent years because it has been marketed as a premium product and is sold at higher price compared with nylon 6. Global capacity for hexamethylene diamine was about 1.62 million metroc tones per year and worldwide ADN capacity was about 1.46 million metric tonnes per year.