How is BIG N made

BIG N ® is manufactured at Gibson Island in Brisbane and Kooragang Island in Newcastle.

The process involves bringing nitrogen and hydrogen together under high temperature and pressure.

Chemists describe this process as (N₂ + 3H₂ = 2NH₃).

The first stage is to prepare the natural gas. The gas is mixed with steam and passed through a primary reformer, which is an apparatus used for cracking oils or gas to form specialised products.

The correct proportion of air is added as it passes through a secondary reformer. More steam at high and low temperatures is used to remove carbon monoxide and carbon dioxide from the gas mixture.

The final stage is when the gas mixture is passed over special metal catalysts at pressures of 20,000 to 30,000 kPa and temperatures of up to 7000°C.

The resulting BIG N is then stored in bulk refrigerated tanks.

Incitec Pivot Limited can manufacture up to 1,500 tonnes of BIG N per day.