Wärtsilä has released its 20DF dual-fuel engine for sale in the US market. The engine meets the strict emissions compliance criteria of the United States Environmental Protection Agency (EPA) Tier 4.
In addition to the environmental benefits attained from burning gas, the choice of fuel can be made on the basis of price and availability since the dual-fuel (DF) technology allows engines to use either natural gas or diesel oil.
US ECA
Since August 2012 the US enforces the North American Emissions Control Area (ECA), which is meant to achieve stricter control on emissions of sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter from vessels. ECA's have also been established in the Baltic Sea and North Sea.
Engines supplied to the US market will operate primarily on natural gas, with marine diesel oil (MDO) as a pilot fuel or as an emergency backup fuel.
20DF Engine
The Wärtsilä 20DF (picture) power spans the range from 1056 kW to 1584kW per engine. The 4-stroke dual-fuel engine portfolio has the widest power range in the market. The 20DF, 34DF and 50DF output ranges from 1056 kW to 17,550 kW per engine.
Low Percentage of Diesel Pilot Fuel
Wärtsilä's lean burn, low pressure dual-fuel engine technology utilises a very low percentage diesel fuel as a pilot ignition source, amounting to about 1 per cent of total energy when compared to other engines. This results in lower operational costs and reduced emissions.
