Classification society awards SCR system emissions certificate
MAN Diesel & Turbo has been awarded a Tier III-compatibility certificate by the DNV-GL classification society for MAN 8L21/31 four-stroke engine aboard a DFDS Seaways ship with a retrofitted SCR (Selective Catalytic Reduction) system. While the engine alone meets IMO Tier II emission criteria, the SCR
system for NOx reduction raises the whole system to the standard demanded by IMO Tier III rules.
NOx emissions
The vessel in question, the ‘Petunia Seaways’ is a cargo ship that sails a
regular North Sea route between Gothenburg, and Immingham, respectively
Ghent for DFDS Seaways. Its SCR system greatly reduces the level of
nitrogen oxides (NOx) from the engine’s exhaust gas.
Since September 2012, when one of Petunia Seaways’ 8L21/31 auxiliary
engines was retrofitted with a SCR system, it has played a major role in the
testing of this new technology. As such, the system has proven daily that
freight ships can now meet the strict emission levels laid down by IMO Tier III
where NOx emissions have to be reduced in certain areas by 75% compared
to current limits.
Proven technology
MAN Diesel & Turbo is the first company to successfully make four-stroke
marine engines IMO Tier III-compliant, based on a fully modular SCR-kit that
is covering the entire MAN Diesel & Turbo four-stroke engine portfolio. “For
the last 8, 800 hours, this particular auxiliary engine of the Petunia Seaways
has consistently met Tier III NOx limits under real life operating conditions and
in full accordance with the rules, ” said Dr. Daniel Struckmeier, Senior Project
Manager Emission 2016 at, MAN Diesel & Turbo.
The SCR method injects urea into the exhaust gases and passes them
through a catalytic converter at a temperature of 300 to 400 degrees Celsius.
The subsequent, chemical reaction reduces the undesired nitrogen oxides
(NOx) by over 80%. The SCR system in its entirety consists of a catalytic
converter with several control units and a surveillance and control unit.
Technology of the Future already available
Results on the test bed and at open sea have been impressive and shown
that SCR technology is reliable and ready for commercial production and
operation. Accordingly, MAN Diesel & Turbo has already made the basic
version of the SCR system available for all four-stroke engines, from those
powering the largest cruise ships, to ferries and specialised ships, to small,
coastal vessels.
“It is important that we have proven to fulfil the same high standards that will
be demanded by Tier III in the future”, said Prof. Dr. Gunnar Stiesch, Head of
Advanced Engineering & Exhaust After treatment Four-Stroke Engines.
DFDS Seaways also views the collaboration with MAN Diesel & Turbo as a
success: “I am happy that we have helped develop a new, environmentally
friendly technology. DFDS and other operators are definitely going to benefit
from SCR meeting international standards”, said Poul Woodall, Director of
Sustainability & Public Affairs at DFDS Seaways.
About MAN Diesel & Turbo
MAN Diesel & Turbo SE, based in Augsburg, Germany, is the world’s leading provider of large-bore diesel engines and turbomachinery for marine and stationary applications. It designs two-stroke and four-stroke engines that are manufactured both by the company and by its licensees. The engines have power outputs ranging from 450 kW to 87 MW. MAN Diesel & Turbo also designs and manufactures gas turbines of up to 50 MW, steam turbines of up to 150 MW and compressors with volume flows of up to 1.5 million m³/h and pressures of up to 1, 000 bar. The product range is rounded off by turbochargers, propellers, gas
engines and chemical reactors. MAN Diesel & Turbo’s range of goods includes complete marine propulsion systems, turbomachinery units for the oil & gas as well as the process industries and complete power plant solutions. Customers receive worldwide after-sales services marketed under the MAN PrimeServ brand. The company employs around 14, 500 staff at more than 100 international sites, primarily in Germany, Denmark, France, Switzerland, the Czech Republic, India and China. MAN Diesel & Turbo is a company in the Power Engineering business area of MAN SE.
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