Greener Industry - Ammonia

Ammonia is basically produced from water, air and energy, the latter usually from hydrocarbons, which provide hydrogen as well. However, coal and electricity can be used in place of hydrocarbons. Natural gas is likely to be the main feedstock for the next 50 years given present reserves of fossil fuels. As such, ammonia can be viewed as a petrochemical, with about 2% of all natural gas supplies being used to make ammonia.

Major modern plants can easily produce 1000 tonnes of ammonia per day, requiring some 35 million cubic feet of methane. Hence production is moving to low cost hydrocarbon sources, closer to the major markets in developing economies.

In the longer term, coal may be the likely source, though countries with available cheap electricity, such as Iceland (geothermal) and Norway (hydroelectricity) may also be at an advantage.

Energy costs have decreased constantly over the past 100 years, with a typical modern plant consuming 30 - 38 GJ per tonne of ammonia produced.

Long Term

In the longer term, if fossil fuel reserves become depleted, they are likely to become more expensive. As the major cost (as much as 55%) of ammonia production depends on the energy source used, there may be a trend towards the electrolysis of water as a major source of hydrogen. This would depend on cheap and renewable electricity supplies, which may come from hydropower, geothermal power or solar power, amongst others. Ammonia would no longer be a petrochemical, but could be produced from renewable energy sources.