MAN Energy Solutions’ (MAN) after-sales division – MAN PrimeServ Augsburg – has completed a retrofit of dual SCR systems on board the ‘Amadea’, a cruise ship chartered by Phoenix Reisen and managed by BSM Cruise Services.
The retrofit involved the integration of an SCR system into both of ‘Amadea’s’ 4-stroke MAN 7L58/64 engines to ensure optimal performance.
This retrofit 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.
Bernd Siebert, Head of Retrofits & Upgrades, MAN PrimeServ, said: “This has been an important pilot project for MAN PrimeServ that ultimately proceeded smoothly, despite the restrictions imposed by the Covid-19 pandemic.
“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,” he said.
The project required steel work to free space for the SCR system’s installation together with the ancillary units; the modular SCR system typically installed on board newbuildings was not 100% transferable for a retrofit and required some adjustments in the case of the ‘Amadea’, MAN explained. 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 class society acceptance. BSM CS’ Technical Superintendent, Bosse Berg and his engine team, verified the successful emission reductions during the system’s commissioning and said that they were convinced by its performance.
Siebert added: “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,” he said.
MAN PrimeServ Augsburg previously retrofitted the ‘Amadea’s’ turbochargers and in the process improved her engine efficiency and significantly reduced CO2 emissions.
The 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 tonnes per annum. The SCR will be available from just 15% engine load, enabling clean operation, also during slow steaming in the fjords, as well as close to port and populated areas.
The fully modular solution has also been fully integrated into the ‘Amadea’s’ engine-control system. 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 reduces urea consumption, enabling the urea-tank size to be minimised, as well as being advantageous to the environment.
At the beginning of the project, a feasibility study by MAN PrimeServ confirmed the compact, modular SCR system’s suitability for the limited space available on board the vessel.
Its integration into the narrow funnel was only possible, due to the special 87 cpsi honeycombs and their high reactivity in a two-layer slim reactor design.