By
Michele Witthaus |
Japanese classification society ClassNK has issued its first ever Statement of Fact for Tier III nitrogen oxide (NOx) reductions in respect of a marine diesel engine incorporating a Selective Catalytic Reduction (SCR) system.
The document, issued for a cargo vessel but with implications for all types of ships, states that the NOx emission measurement results for the engine meet the NOx Tier III emission limits stipulated in amendments to Annex VI of the International Convention for the Prevention of Pollution from Ships 1973 (MARPOL).
The engine in question was fitted as the propulsion system for a 37,800 dwt general cargo ship, built by Naikai Zosen Corporation for Nissho Shipping Co., which entered service on 31 October 2011.
The significance of this step for the industry is twofold: not only is this the first time that ClassNK has issued such a document for a marine diesel engine fitted with an SCR system, it is also the first Statement of Fact issued by the Society for Tier III NOx reduction compliance of any kind.
SCR systems offer the potential for independent reductions in emissions of more than the 80 per cent required under Annex VI. ClassNK has released a document, Guideline for SCR (Selective Catalytic Reduction) Systems and Reductant Agent Supply Systems, to assist manufacturers, shipyards, and owners in installing such systems on their commercial vessels.