Contact processStep 1:Preparation of sulphur dioxide:

SO2is prepared by burningsulphurin the presence of excess air so that the product combines with oxygen which is helpful for the next stage.

S(s) + O2(g) → SO2(g)

Step 2:Preparation of sulphur trioxide:

Sulphur trioxide is formed when sulphur dioxide reacts with oxygen in a ratio of 1:1 at a temperature of 400°C – 450°C and a pressure of 1-2 atm in the presence of N2O5as a catalyst. This reaction is reversible in nature.

2SO2(g) + O2(g) ⇌ 2SO3(g)

Step 3:Preparation of concentrated sulphuric acid:

The sulphur trioxide formed is first made to react with concentrated sulphuric acid. Sulphur trioxide cannot be dissolved in water directly as it leads to the formation of fog. The product obtained after this reaction is known as oleum. The oleum obtained is then dissolved in water to obtain concentrated sulphuric acid.

H2SO4+ SO3(g) → H2S2O7(l)

H2S2O7(l) + H2O(l) → 2H2SO4

Haber ProcessNitrogen from the air is combined with hydrogen. The hydrogen is often obtained through a reaction with natural gas and steam. Sometimes it is obtained from cracking, or when a larger molecule is broken down into smaller molecules.

The hydrogen and nitrogen gases are sent to the compressor where they are subjected to 200 atmospheres (or 200 times the pressure you're used to right now)

The pressurized gases are then sent to the converter, which heats the gases to around 450 degrees C. The converter contains iron, which is acatalyst, meaning it aides in the reaction but it isn't used up in the reaction. More specifically, the nitrogen and hydrogen react on the iron's surface. Approximately 15% of the hydrogen and nitrogen become ammonia at this point.

The next stop is the cooling tank where ammonia, hydrogen, and nitrogen are cooled, causing the ammonia to turn into a liquid. This ammonia is collected.

The hydrogen and nitrogen then go back into the converter where more ammonia is produced. It's cooled again and the ammonia is collected. This is repeated several times until most of the hydrogen and nitrogen have been transformed into ammonia.