Selective Catalyst Reduction (SCR) technology is Caterpillar’s marine-specific solution to Tier 4 Final/IMO III emission standards. Jason Spear, Caterpillar Marine product definition engineer, discusses common questions Caterpillar receives on SCR installation and support.
HOW EASY OR DIFFICULT IS IT TO INSTALL THE SCR SYSTEM?
The SCR system takes up more room – you have to have space for the [DEF] tank and for the system itself. But we knew that upfront when we started the design phase so we made it as small and as flexible as we could. It’s still a space claim but it’s a really flexible one. Everyone we’ve met with so far has been able to design around it, even in some tight confined engine rooms. We service 13 different market segments with probably three or four different vessel types within each, and every engine room is slightly different. Making it adaptable was our goal. To keep the DEF tank size down, we have a closed loop dosing system, which minimizes the amount of DEF consumed. What is does is senses the NOx values coming in and out of the SCR system, so we’re able to fine tune the amount of dosing required to remain emissions compliant.
WHAT ARE THE MAINTENANCE REQUIREMENTS FOR THE SCR SYSTEM?
The overhaul life of the SCR system certainly depends on the load profile, but we’ve aligned that with the major overhaul of the engine. It’s a long life type component that’s designed to have the same overhaul life as the engine.
WHO SHOULD VESSEL OWNERS CONTACT FOR SCR SYSTEM PURCHASES OR INSTALLATIONS?
Definitely their local Cat dealer. The EPA requires that the OEM supply the system as a serialized system. It’s an emissions component in the eyes of the EPA so from a serialization standpoint they require Caterpillar to provide that. On the IMO side, talking about vessels outside of the U.S., that is not a requirement. A customer could take an existing engine and put a third-party aftertreatment system behind it, legally, but it’s probably not the best solution. The way we’ve integrated Cat engines with the SCR has a lot of advantages – and it’s mostly in terms of total cost of ownership and fluid consumption costs.
IS THE SCR SYSTEM SUPPORTED BY CAT DEALERS? AND WHAT SORT OF WARRANTY COMES WITH IT?
It is fully serviced and supported by Cat dealers worldwide, and has the same standard warranty that we provide for all other Cat Marine engines today.