Wärtsilä was contracted by Finland-based Arctia Offshore Oy to carry out modification work to two of the company's vessels. The contract was signed in September 2011. The turnkey project involves the fitting of combined Wärtsilä NOx Reducer (NOR) and Oxidation Catalysts (OXI) to the MSV Fennica and MSV Nordica, both of which are multi-functional vessels based on a modified icebreaker design. The ships will also be converted to enable the use of Ultra Low Sulphur Diesel fuel. When this conversion work is completed, the vessels will fulfil the United States Environmental Protection Agency's (EPA) emission requirements for operating in the Arctic Ocean. This opens up the possibility for Arctia Offshore to participate in arctic oil exploration projects in an environmentally sustainable manner. The work will involve fitting the combined Wärtsilä NOR/OXI solution to each of the eight engines that drive the two vessels. The installation schedule is divided into two parts, with the first set scheduled for completion by the en d of December 2011, and the second set by the end of April 2012. The emission control device consists of a combined abatement system designed to reduce nitrogen oxides (NOx) and to enable the oxidation of carbon monoxide and unburned hydrocarbons. The NOR is a customized solution specifically engineered to meet the EPA's emission standards.
"This represents yet another example of Wärtsilä's competence in designing integrated solutions that are both technically advanced and environmentally sustainable. The conversion work that we will carry out on these two offshore servicevessels will not only reduce their environmental impact, but will notably enhance their operational capabilities by allowing them to work in the sensitive environment of the Arctic Ocean," says Leonardo Sonzio, Director EnvironmentalServices, Wärtsilä.
Wärtsilä NOx Reducer (NOR) and Oxidation Catalyst (OXI)
The Wärtsilä NOx Reducer is based on Selective Catalytic Reduction (SCR) technologies, and achieves a reduction in NOx emissions of 85-95 per cent. The new SCR product range caters for the needs of all four-stroke engines in Wärtsilä'sportfolio, and is seamlessly integrated into the Wärtsilä engine control system. The units come with a complete prefabricated ancillary system. Wärtsilä has gained considerable field experience in running SCR on its own engines in marine, as well as power plant applications, since the early 1990s. As a result of this experience, Wärtsilä has developed a standard selection of modularized SCRs under the Nitrogen Oxides Reducer (NOR) product name in close co-operation with a major catalyst manufacturer. The solution is designed to combine efficiency with minimal investment and operational costs.
The Wärtsilä Oxidation Catalyst oxidizes unburned components with the help of the residual oxygen in the flue gas, and forms carbon dioxide and water as end products.