World Bunkering > News > Summer 2011 > Meeting Tier III

IMO’s Tier-III legislation on NOx is due to come into force in 2016; how to achieve compliance is likely to become a prominent issue of the coming two years. Machinery manufacturer MAN Diesel & Turbo says that its MAN B&W 6S46MC-C8 type fitted with Selective Catalytic Reduction (SCR) meets the Tier-III regulations.

The first SCR-fitted unit, with an output of almost 7 MW, was constructed in the autumn last year by Hitachi Zosen Corporation at its Ariake works in southern Japan. The engine is to be fitted in a general cargo ship, to be built at the Nakai shipyard and scheduled to enter service later this year for operation by Nissho Shipping. The first engine-start took place in January and MAN Diesel & Turbo sent a team to Japan to commission the engine-control system – the first in a series of planned visits. The team also optimised the integration of the SCR system.

The SCR system features: more than 80% NOx reduction based on the load cycle; more than 70% NOx reduction on each load point in the load cycle; and easy switching between on/off modes for optimal emission performance on high seas and coastal waters. MAN Diesel & Turbo says that, when bringing two-stroke engine performance up to Tier-III standard, it had considered both SCR and EGR (Exhaust Gas Recirculation) techniques but, based on a general evaluation of two-stroke MAN B&W engines, a high-pressure, ureabased SCR configuration was chosen as the optimal solution.

Vice President Research & Development, Marine Low-Speed MAN Diesel & Turbo, Søren Jensen, said: “We haven’t just provided an engine and added an SCR system to it. On the contrary, we have delivered a bespoke system. As engine designer, builder and catalyst designer, MAN Diesel & Turbo and Hitachi Zosen comprise a group of specialists that have delivered an optimised propulsion/emissions package of engine, engine-control system and SCR system.”

Mr Jensen added: “In the future, MAN Diesel & Turbo wants not only to develop engines but also to design engines with complete emission-reduction systems. To that end, we envisage collaborating with many other partners in times to come in the same successful fashion as we have seen in Japan.”