The Haber process, discovered by Fritz Haber in the early 1900s, is the industrialized production of ammonia gas via
N2(g) + 3 H2(g) ⇌ 2 NH3(g) + 92 kJ.
This reaction is extremely slow at room temperature; in order to increase the rate, we must raise the temperature. The catalyst Fe2O3(s) is also used to speed it up, but this itself requires a high temperature to be efficient. The problem here is that LCP tells us that an increase in temperature will cause the system to shift left, lowering the yield.
Haber discovered a balance: a temperature of 500 ºC to increase the rate (along with the catalyst) and a pressure of 30 MPa to shift the system right. In addition, ammonia is removed from the system once produced, causing the equilibrium to shift further right and allowing the unreacted gases to be recycled.
Billions of kilograms of ammonia are produced every year. It is used as a crop fertilizer, and it is also used in the production of bombs.