VATIS UPDATE Article

Kawasaki Heavy Industries, Japan, has reported a successful sea trial of an arrangement employing a combination of exhaust gas recirculation and emulsion fuel to reach Tier III NOx emission levels with no fuel penalty. The Kawasaki Ecology & Economy System (K-ECOS) – employing EGR, emulsion fuel, water treatment, a turbocharger cut-out system and integrated controls – was installed on a Kawasaki-MAN B&W 7S60ME-C8.2 main engine driving Kawasaki Kisen Kaisha’s pure car/truck carrier ‘Drive Green Highway’.

After a successful sea trial before the vessel’s entry into service early this year, the system will now be tested in service over a two-year period. Performance in shop tests, which were confirmed during the sea trial, showed that the system in ‘NOx Tier III mode’ – employing the EGR and running on emulsion fuel – achieved NOx emissions of 3.3 g/kWh, under the Tier III limit of 3.4g for low-speed engines. The scrubber successfully removed 97% of the fuel sulphur content from the exhaust.

Fuel consumption in NOx Tier III mode – with the full K-EOCS system active and running on emulsion fuel – was greater than in basic mode with regular diesel fuel by 0.4-0.8g/kWh, but was still similar to the performance of the current engine. In ‘auto turbocharger cut-out mode’, which uses emulsion fuel and sequential turbocharger control but does not activate EGR, the fuel saving compared to basic mode reached a maximum of 4.8% at around 60% engine load.