Chemical combination of nitrogen and hydrogen (NH3). Ammonia is a very efficient refrigerant and identified as R-117.
Produced by combustion of hydrogen and nitrogen under large pressure. Ammonia is a poisonous and irritating gas, it has TLV of 25 ppm and the odour threshold is on 20 ppm. It responds to water and there are special rules for vessels that transport Ammonia. We can locate the rules in the IMO Gas Code, chapters 14, 17 and 19.

When ammonia gas is mixed with water, a decreased pressure is formed by 1 volume part water absorbing 200 volume parts ammonia vapour. A decreased tank pressure will occur if there is water in the tank when commence loading ammonia and the tank hatch is closed. With an open hatch, we can replace the volume, originally taken up by the ammonia gas, with air.

One must not mix ammonia with alloys: copper, aluminium, zinc, nor galvanised surfaces. Inert gas that contains carbon dioxide must not be used to purge ammonia, as these results in an carbamate formation with the ammonia. Ammonium carbamate is a powder and can blockage lines, valves and other equipment.

The boiling point for ammonia at atmospheric pressure is -33 deg C, and must be transported at a temperature colder than -20 deg C. One can cool ammonia with all types of cargo cooling plants. Ammonia is transported with atmospheric pressure gas carriers or semi-pressurised gas carriers. Gas carriers carrying Ammonia must be constructed and certified in accordance with IMO's IGC code for transportation of liquefied gases. The definition for ammonia tanker is LPG/NH, carrier.

Ammonia is utilised as raw material for the fertiliser industry, plastic, explosives, colours and detergents.

There is a lot of transportation from the Black Sea to USA, from USA to South Africa and from Venezuela to Chile.



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