The Harber Process is a method of producing ammonia, the method is a reversible reaction.
The reaction used to produce ammonia is a reversible reaction between nitrogen and hydrogen. The reaction can reach an equilibrium, where the forward and backward reaction happens at the same rate.
The Harber Process:
Nitrogen (extracted from the air) and hydrogen (from natural gas) are pumped together through pipes
The pressure of the pipes is increased to the optimum pressure for the reaction which is around 200 atmospheres
The gasses are now heated to their optimum temperature which is around 450 degrees Celcius
When the mixed gasses are heated and pressurized they are passed through pipes with an iron catalyst
The reaction mixture is then cooled down to let the ammonia liquefy so it can then be extracted
The unreacted nitrogen and hydrogen can be recycled for further production of ammonium