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.