Haber Process

Overview

The Haber Process involves the use of nitrogen (from air) and hydrogen (from natural gas) to produce ammonia.
The reaction for the process is N2 + 3H2 ⇌ 2NH3. The reaction is reversible, hence the indication with a double arrow.
Ammonia is crucial for the production of fertilisers and nitric acid.

High pressure (200 atm) and moderate temperature (450°C) are ideal for the Haber process. Higher pressure favours the forward reaction, while the moderate temperature ensures a feasible rate without excessive equipment cost.
Iron catalyst is used to speed up the reaction without altering the position of the equilibrium.

The high pressure required demands strong, expensive equipment, raising the cost.
Although lower temperatures would favour the forward reaction, they would make the reaction too slow. So a moderate temperature is chosen for a good rate of reaction and yield.
The unused hydrogen and nitrogen are recycled back into the reaction, conserving resources.

The Haber Process consumes a significant amount of energy, contributing to carbon emissions.
Ammonia from fertilisers can run off into water sources, causing eutrophication - an excessive richness of nutrients in a lake or other body of water.
It is essential to balance economic factors, production efficiency, and the environmental impact when running the Haber process.

In the context of the Haber process, Le Chatelier’s principle states that the system will attempt to counteract changes in pressure or temperature.
Increasing pressure or decreasing temperature would push the equilibrium towards the side with fewer molecules, which in this case is the ammonia side (forward reaction). Conversely, decreasing pressure or increasing temperature pushes it towards the side with more molecules, the nitrogen and hydrogen side (backward reaction).