Hydrogen cyanide, from ammoxidation

Approximately 80% of all hydrogen cyanide is manufactured by the reaction of air, ammonia, and natural gas over a platinum or platinum-rhodium catalyst at elevated temperature. The reaction is referred to as the Andrussow process. Hydrogen cyanide is also available as a by-product from aciylonitrile manufacture by ammoxidation (20%). 

Acrylonitrile. Acrylonitrile, an important monomer in numerous polymerization processes, is produced mainly from propylene by ammoxidation (see Section 9.5.3). In the traditional process, the major industrial route in the 1950s and 1960s, an aqueous solution of copper(I) chloride, NH4C1 and HC1 was reacted with acetylene and hydrogen cyanide 180 197... 

Ammoxidation, a vapor-phase reaction of hydrocarbon with ammonia and oxygen (air) (eq. 2). can be used to produce hydrogen cyanide (HCN), acrylonitrile, acetonitrile (as a by-product of acrylonitrile manufacture), methacrylonitrile, benzonitrile, and toluinitriles from methane, propylene, butylene, toluene, and xylenes, respectively. See also Acrylonitrile and Methacrylic Acid and Derivatives,... 

Hydrogen cyanide is also available as a by-product from acrylonitrile manufacture by ammoxidation. 

The initial drive for acrylonitrile (AN) production (6.2 Mt/a in 2004 worldwide) was the discovery, in the late 1930s, of the synthetic rubber Buna N. Today nitrile rubbers represent only a minor outlet for AN which is utilized primarily for polymerization to give textile fibres (50%) and ABS resins (24%), and for dimerization to adiponitrile (10%). Early industrial processes depended on the addition of hydrogen cyanide to acetylene or to ethylene oxide, followed by the dehydration of intermediate ethylene cyanohydrin. Both processes are obsolete and are now supplanted by the ammoxidation of propylene (Equation 34) introduced in 1960 by Standard Oil of Indiana (Sohio). The reason for the success stems from the effectiveness of the catalyst and because propylene,... 

Although substantial amounts of hydrogen cyanide are produced and recovered as a byproduct from the manufacture of acrylonitrile by the ammoxidation of propylene, some hydrogen cyanide is also made on purpose from methane. Basically, two main approaches are available. ... 

The major process currently operated on the commercial scale is known as the acetone cyanohydrin (23) (ACN) process [14]. This process uses readily available cheap raw materials (Scheme 2.3). Acetone is produced from propylene and hydrogen cyanide or can be obtained as a byproduct from acrylonitrile production. Acrylonitrile is manufactured via propylene ammoxidation or by catalytic ammoxidation of natural gas. Sulphuric acid is readily available but constitutes the major environmental problem of the acetone cyanohydrin process since a large excess is required to effect the hydrolysis of acetone cyanohydrin to form the methacrylamide sulphate intermediate. 

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