Hydrogen cyanide (HCN) is a chemical precursor used in the production of several industrially relevant compounds, such as adiponitrile for nylon production, methyl methacrylate for polymer manufacturing, sodium cyanide for gold recovery and for the production of methionine, which is used as a feed additive.
HCN is mainly produced though the Andrussow process, named for developer Leonid Andrussow. The method involves reacting ammonia, natural gas and air over a platinum catalyst to form HCN. Alternatively, HCN can be produced by the BMA process, which uses ammonia and natural gas only.
HCN production via the Andrussow process is depicted in Figure 1 and described below, based on information available in the literature. The process can be divided into three main areas: reaction, ammonia recovery and product purification.
Reaction. Natural gas, ammonia and air are fed into the reactor, where HCN is formed through a catalytic reaction. The product stream, containing HCN and unreacted ammonia, must be cooled down to avoid HCN decomposition. This is accomplished in a waste-heat boiler located below the reactor. The waste-heat boiler generates steam that can be used elsewhere in the process.
Ammonia recovery. The product stream…