Tier III NOx certification for MaK M 25 E

10 Nov 2017
The MaK M 25 E with SCR, factory certified for Tier III NOx

The MaK M 25 E with SCR, factory certified for Tier III NOx

Caterpillar’s MaK M 25 E engine platform has received notice of compliance with IMO’s Tier III NOx regulations from class society DNV GL.

The company claims it is one of the first engine manufacturers to release a factory-certified Tier III medium-speed engine group for propulsion and auxiliary applications.

“Customers seeking an IMO III-certified engine solution now have the choice to select a serialised, certified engine, which guarantees safe and reliable vessel operation while meeting the latest emission standards,” said Detlef Kirste, product definition specialist, Caterpillar Marine.

The M 25 E, with a power output range of 1.8-3.15MW, uses selective catalyst reduction (SCR) to reduce N)x emissions, combined with exhaust gas temperature management. The SCR unit is a closed-loop system that senses required NOx reduction, adjusting the amount of urea injected appropriately. Combined with engine combustion calibration, this ensures exhaust gas temperatures are within tolerances for efficient SCR use.

The engine also features a charge air system optimised for increased back pressure capability, allowing for a much smaller SCR system. Scheme A pre-certified M 25 E engines can be installed and commissioned without onboard emission verification tests. This allows the shipyard to avoid testing and certification related costs and to plan for shortest commissioning times.