EPA Tier 4 emissions regs and the IMO III regs



During a factory visit at the engine manufacturer Moteurs Baudouin, based in Cassis, a beautiful fishing port in southern France, I took the time to quiz their design team, and one of the main things we discussed was a big challenge affecting them as marine engine manufacturers and the operators of those engines.

I imagine you’re aware of the introduction of the EPA Tier 4 emissions regulations in the US and the IMO III regulations in other parts of the world?

These regulations are so demanding that some main engine manufacturers are questioning whether it’s worth continuing in the marine market.

The OEMs looking for a solution to the demanding regulations – such as MTU, Scania and Baudouin – prefer the SCR (Selective Catalyst Reduction) process, which injects ammonia into the exhaust and can reduce the harmful NOx gases by up to 90%. 

If you haven’t seen the SCR system, here is a diagram showing the vaporiser and catalyst; though the ammonia tank is missing.

From a manufacturer’s perspective, there are some key concerns in designing the best SCR system to meet these standards:

  • Can it be retrofitted?
  • Will the engine still operate if the system fails?
  • How much room will it need? – We have seen how space is a premium in some engine rooms, especially in the windfarm vessels
  • How readily available is the ammonia going to be?
  • How near / far from the engine do the components need to be installed?
  • What will be the knock-on costs?

One advantage is that this system does allow the engines to be set for better fuel consumption, though the savings will be needed to offset the cost of the ammonia.

Are you seeing these regulations restricting your choice of engines?

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