Inert Gas Residues

Inert gas residues is a general term that refers to particles (soot) from the incomplete combustion of a hydrocarbon (e.g. Gasoil).

During unloading of flammable cargoes, tankships must use inert gas to avoid explosive mixtures. Some tankers, especially in the CPP trade have a so-called exhaust gas system installed for this purpose. These units are burners where hydrocarbons are burnt. The exhaust gas contains to less than 5% Oxygen, hence the requirements for inert gas are fulfilled.

The inert gas from such systems can contain impurities. The impurities are carbon particles and sulphur compounds from incomplete combustion. These particles could lead to clingage of black or sometimes red soot on the surface of tanks, which have been inertized. This soot could contaminate a sensitive next cargo.

A typical example of this contamination risk is the loading of Vegetable Oil after Gasoline or Gasoil.

For removal of this soot wash the tank by recirculation with an Inert Gas Remover (sometimes also called Soot Remover).
If the next cargo requires a water white cleaning standard, the listed cleaner type(s) in step -Recirculation- can be replaced by a soot remover.
Follow the manufactures recommendation regarding concentration and cleaning temperature and cleaning time.