Question

Describe the industrial manufacture of ammonia by Haber’s process with a labelled diagram.

Hint: Haber’s process is one in which ammonia is produced. In this, the atmospheric nitrogen is reacted with hydrogen and converted to ammonia .Here, high temperatures and pressures are maintained a metal catalyst is used

- Let’s see the raw materials required for the process:
Air is required which supplies the nitrogen. Iron which is the catalyst is required. Water and natural gas, that are found to supply the energy and hydrogen needed to heat the reactants.
- Let’s see the diagram of Haber’s process:

- Let’s discuss about the process in brief:
- We can see in the diagram that in the Haber process, we take nitrogen gas from air and combine it with hydrogen, which is obtained from natural gas. We do this in the ratio of 1:3 by volume.
- In this the gases are allowed to pass through four beds of catalyst (it is a substance that increases the rate of a reaction, without getting consumed in the reaction). In this promoters are used like Molybdenum, which is added to a catalyst to improve its performance in the reaction. Here, cooling takes place in each pass. During this equilibrium constant is maintained.
- In each pass unreacted gases are evolved that are recycled.
- In this process, an iron catalyst is used, pressure of 150 – 200 atm and a temperature of around $400-{500}^{\circ }C$$400-{{500}^{\circ }}C$ is maintained.
- There are various steps involved in this process like, carbon dioxide removal, shift conversion methanation and steam reforming.
- We can see that finally; the ammonia gas is cooled down to form a liquid solution. Which is then collected and stored in storage containers.
- Now we will discuss about the rate of reaction:
- We can say that the reaction of nitrogen and hydrogen takes place during this process. The chemical reaction is given below. The reaction is an exothermic reaction, in that there is a release of energy.
${N}_{2}\left(g\right)+3{H}_{2}\left(g\right)\to 2N{H}_{3}\left(g\right)$${{N}_{2}}\left( g \right)+3{{H}_{2}}\left( g \right)\to 2N{{H}_{3}}\left( g \right)$
- It is found that Hydrogen gas is obtained from natural gas by a steam reforming process. Nitrogen is obtained by liquefaction, that is by separating nitrogen from the air.
$C{H}_{4}\left(g\right)+{H}_{2}O\to {H}_{2}\left(g\right)+CO\left(g\right)$$C{{H}_{4}}\left( g \right)+{{H}_{2}}O\to {{H}_{2}}\left( g \right)+CO\left( g \right)$

Note: It is found that the reactions in this process is affected by changes in various factors like that of temperature, pressure and catalyst that are used mainly in the composition of the equilibrium mixture. It was the first process that made people mass-produce plant fertilizers due to the production of ammonia.