Wärtsilä's 34DF dual-fuel engine has been awarded the USA Environmental Protection Agency’s (EPA) Tier III certification for diesel mode operation when installed together with the Wärtsilä NOx Reducer (NOR) system.
The Wärtsilä NOR is a selective catalytic reduction (SCR) system that converts nitrogen oxides (NOx) with the aid of a catalyst into diatomic nitrogen (N2) and water. Wärtsilä is the first engine manufacturer to be awarded this certification.
The 34DF has already been awarded EPA Tier III certification of emissions compliance from the EPA in 2017 for operating in gas mode without an SCR system.
Tier III
The US EPA Tier III NOx requirements entered into force in 2016 for Category 3 engine sizes (engines with a cylinder displacement at or above 30 liter/cylinder) to be installed in USA flagged or registered vessels.
At the same time, the International Maritime Organization’s (IMO) NOx Tier III requirements also entered into force in North American and US Caribbean emission control areas (ECAs) from January 2016 for vessels with a keel-laying date on or after 1 January 2016 and an engine output of ≥ 130kW.
The Wärtsilä 34DF engine is now certified for both the EPA Tier III and the IMO Tier III emission standards in diesel mode operation when installed together with the Wärtsilä NOx Reducer SCR system, as well as in gas mode without exhaust after-treatment.
Wärtsilä 34DF Engine
For marine applications, the 34DF engine is manufactured in configurations from 6 to 16 cylinders covering a power range of 2880–8000 kW. Based on the Wärtsilä 32 diesel engine introduced in the mid-1990s, the 34DF’s fuel flexibility means that the engine can be optimised for constant speed generating sets, as well as variable speed mechanical drives for main engine applications.
Picture: A 6-cylinder Wärtsilä 34DF dual-fuel engine.
