Green SCR system for German cruise ship

MAN PrimeServ Augsburg, part of MAN Energy Solutions, has completed the retrofitting of dual selective catalytic reduction (SCR) systems aboard the cruise ship MS Amadea.

The vessel is chartered by Germany’s PHOENIX Reisen GmbH Bonn and managed by BSM Cruise Services. Also known as ‘Das Traumschiff’, the Amadea is well-known in Germany as the main filming set for a popular television series.

The retrofit developed by MAN PrimeServ Augsburg integrated an SCR system into both of the Amadea’s four-stroke MAN 7L58/64 propulsion-engines to ensure optimal performance.

According to MAN ES, the retrofit reflects a general desire by PHOENIX Reisen to enhance its environmental friendliness and, more immediately, enables the vessel to meet emission standards in the key Norwegian Heritage Fjord market.

For the project, MAN PrimeServ prioritised keeping hazardous emissions to a minimum while maintaining engine performance and propulsion efficiency.

“This has been an important pilot project for MAN PrimeServ that ultimately proceeded smoothly despite the restrictions imposed by the Covid-19 pandemic,” Bernd Siebert, Head of Retrofits & Upgrades, MAN PrimeServ, said.

“Notably, we also successfully delivered the SCR systems pre-equipped with honeycombs in order to maintain the tight schedule. Besides some minor, technical adjustments post-installation, we easily reached the required exhaust-gas temperatures for SCR operation and regeneration of the honeycombs in testing. We still need to determine the exact urea consumption required to achieve the necessary NOx reduction, but, fortunately, the engines have been more recently equipped with new MAN turbochargers such that safe operation of the SCR systems is guaranteed.”

The Amadea project required steel work to free space for installation of the SCR systems and ancillary units; the modular SCR system typically installed aboard newbuildings was not 100% transferable to a retrofit and required some adjustments in the case of the Amadea. Mechanical and electrical integration, and system parameterisation, also required some resources.

The formal handover of the Amadea to PHOENIX Reisen took place in mid-January 2022 after classification society acceptance.

Technical Superintendent BSM CS, Bosse Berg, and his Engine Team verified the successful emission reductions during commissioning of the system and stated that they were convinced by its performance.

“This SCR solution establishes PHOENIX Reisen and BSM CS as trailblazers within the cruise segment in terms of emission reduction. Increasingly, we are receiving requests from cruise and ferry companies that want to improve their green credentials and who desire to become sustainable without the need for mandated industry legislation. We have learned many lessons and gained valuable commercial experience from the entire Amadea project that will serve us in good stead on similar projects in the future,” Siebert added.

The SCR

MAN PrimeServ Augsburg previously retrofitted the Amadea’s turbochargers – in the process improving engine efficiency and significantly reducing CO2 emissions.

Now, the MAN SCR solution has brought the Amadea’s engines from Tier 0 status to Tier III emission level, and has reduced NOx emissions by 90%, equivalent to savings of 600 tons per annum. According to MAN ES, the SCR system is currently the greenest solutions available on the market.

The SCR will be available from just 15% engine load, enabling clean operation, also during slow-sailing in the fjords as well as close to port and populated areas.

The fully modular SCR solution has also been fullly integrated into the Amadea’s engine-control set-up. With its closed-loop system and a weather station that uses environmental data, the NOx-reduction rate is maximised and ammonia-slip minimised to just 10 ppm, comparable to that of a car.

Low ammonia slip is not just good because ammonia is a greenhouse gas and affects the climate, but also because it reduces urea consumption, enabling the urea-tank size to be minimised.

A feasibility study by MAN PrimeServ at the project’s beginning confirmed the compact, modular SCR system’s suitability for the limited space available aboard the vessel. Its integration into the narrow funnel is only possible due to the special 87cpsi honeycombs and their high reactivity in a two-layer slim reactor design.