Finnish technology group Wärtsilä said its Wärtsilä 34DF dual-fuel engine has been awarded the USA Environmental Protection Agency’s (EPA) Tier III certification for diesel mode operation.
The certification has been awarded 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 said in its statement.
The company added that shipyards now need only a single party to certify both the engine and the SCR system for full compliance with the latest emission regulations.
The Wärtsilä 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.
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 1st 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.