Frequently Asked Questions
What is the Marine Urea Solution solution?
- Marine Urea Solution or technically known as AUS40 is 40% Urea Solution used for the purpose of reducing Nitrogen Oxides (NOx) emission from the vessel exhaust.
Why is it important to use Marine Urea solution to control NOx emission from the marine vessel?
- It’s important to reduce Nitrogen Oxides (NOx) emission from the marine vessel as well as vehicle exhaust because it’s known to cause lung cancer.
How can a Marine Urea solution reduce your marine engine’s NOx emissions?
- The Marine Urea Solution enters the flue gas steam. The hot exhaust breaks the marine urea solution into various components. Of which, ammonia is the active component that reacts with the nitrogen oxides (NOx) to form harmless nitrogen and water molecules.
Can we choose not to use any Selective Catalytic Reduction (SCR) system to control the marine vessel emission?
- The answer is no. Unless your vessel fulfils the conditions set by MARPOL.see URL.
Why is Marine Urea Solution used for SCR and why is it 40%?
- Urea Solution is chosen because it’s non-hazardous (this depends on the country jurisdiction) and relatively safer to handle than other alternatives. 40% is chosen by most marine Selective Catalytic Reduction (SCR) system makers because it’s most efficient. For the same volume of urea solution, 40% will be able to treat more exhaust compared to 30%. This means that the same volume will last you longer
What’s the alternative to Marine Urea Solution (AUS40)?
- Ammonia solution is the alternative. It’s highly corrosive and very dangerous to handle. In most countries, special licenses and permits are required to transport, supply and handle ammonia. That’s the reason why Marine Urea Solution (AUS40) is still the preferred and safer choice to control NOx emission.
Why is good quality Marine Urea Solution (AUS40) important?
- In a marine Selective Catalytic Reduction (SCR) system, one of the very expensive components is the catalyst. When bad quality Marine Urea Solution (AUS40) is introduced to the SCR System, the impurities will clog up the SCR catalyst and render it less effective and eventually (and rapidly) useless.
Following may happen:
- The Marine SCR catalyst will need to be changed before it’s due
- The clogged Marine SCR catalyst may cause problems to other system components.
- At the next port call, the vessel would fail the NOx emission test and subject to penalties or delays (depending on the marine/port authorities)
Therefore it’s important to pick reliable Marine Urea Solution (AUS40) suppliers.
How should urea be stored onboard a ship?
- Urea will be stored inside a tank inside the vessel. The tank will be made of compliant material or coating stipulated by ISO 18611.
What will happen in the case of a spill or someone is splashed with Marine Urea Solution (AUS40)?
- Always refer to the Marine Urea Solution (AUS40) supplier’s Safety Data Sheet (SDS).
- In case of spillage, wipe the area dry and rinse the area with plenty of water.
- In case someone is splashed with Marine Urea Solution (AUS40), immediately rinse the affected area with water and change out of the wet clothes.
Why does the Marine Urea Solution (AUS40) smell like urine?
- A small amount of the urea solution has decomposed into carbon dioxide and ammonia. It’s the ammonia that smells like your urine.
Some urea solution smells really bad, is the concentration higher?
- This is a very common misconception. The smell is definitely not an indicator of urea concentration. Everyone’s smell is subjective and highly inaccurate. It’s always better to rely on scientific methods to determine the urea solution concentration. You can refer to the supplier Certificate of Assessment (COA) to find out the marine urea solution concentration.
What’s the freezing point of Marine Urea Solution (AUS40)?
- The freezing point of Marine Urea Solution (AUS40) is approximately around 0 (zero) degree Celsius.