Ammonia manufacture consists of three important stages. Firstly hydrocarbons (either naphtha or natural gas) are reformed with the help of steam to form hydrogen and this hydrogen is fed into a scrubbing unit where other gases like CO2 are separated from hydrogen gas. Further the hydrogen gas enters the ammonia reactor where nitrogen gas is also fed and ammonia is produced. This ammonia can be fed into the urea making unit along with CO2 and urea is formed. The urea formed is decomposed further to eliminate ammonium carbamate compound and this decomposed urea is further concentrated and then granulated to form urea granules.

For producing 1 ton of urea about 0.188 ton of naphtha, 0.79 ton steam, 1 ton of N2 gas, 0.731 ton of CO2 are required. Steam, natural gas and electricity are the important energy consumed. CO2 is a secondary output that is used from the scrubbing unit in to the urea making unit.