MAN B&W型低速機関におけるSCRの運転実績と新しいNOx排出低減技術

抄録

This paper concerns the SCR (Selective Catalytic Reduction) for NO_x emission reduction on the MAN B&W two-stroke diesel engine, used for marine applications. There are clear limitations in practice; this was well demonstrated. The latest development with alternative“internal methods” (in-engine methods) to reduce emission will also be described. Especially, our expectations for other than SCR, NO_x reduction methods are described.
We are confident that internal methods; like EGR, WFE, HAM/SAM, and/or combinations of these internal methods will bring our two-stroke engine to a position to fulfil coming IMO Tier 3 regulations; those regarding NOx emission. This is before the due time fore the IMO Tier 3 to come into force. These methods work without using agents, such as urea or ammonia. Compared to SCR some of these new methods have other advantages. As opposed to SCR, low-load operations are possible as exhaust gas temperature limitations are eliminated.