The NOx reduction system integrated into the marine diesel engine
reduced NOx by more than 80%.
NIIGATA Power Systems Co., Ltd., (NPS) completed on-board tests of an
environmentally friendly technology compliant with the NOx Tier III
enforced by the International Maritime Organization (IMO) in January
2016. As on-board tests, a marine SCR (selective catalytic reduction)
(*) was integrated into the main engine (output: 1,491 kW) of a cargo
coastal vessel currently in service to evaluate the NOx reduction
efficiency and durability under actual service conditions. The test
revealed that the system reduced NOx emissions by more than 80%,
comparing to without SCR.
NPS has been engaged in on-board tests of the marine SCR compliant with
the Tier III since last July. The requirement of the Tier III is
difficult to meet by improving the engine combustion alone, and
furthermore additional exhaust gas after treatment technology, such as
integration of SCR into the marine engine, had to be developed. In
research and development, the conventional SCR used for stationary power
generation was downsized and optimized to suit ship environments, and
the SCR was improved to obtain the optimal control of reducing agents,
such as urea water solutions, to be installed for the test. As a result,
the NOx reduction efficiency required by the Tier III was achieved.
Since 2007, NPS has been subsidized by the Nippon Foundation for
research in SCR system for the downsizing and optimization of the
de-nitrification reactor, which is the key system in complying with the
Tier III, as part of the Super-Clean Marine Diesel research and
development project initiated by the Ministry of Land, Infrastructure,
Transport and Tourism and Japan Marine Equipment Association. On-board
test was conducted based on the results obtained from research and
development. In the past, NPS was subsidized by the Nippon Foundation
and worked in cooperation with the Ship & Ocean Foundation to develop
marine SCR system. Then, Niigata delivered Japan’s first marine SCR as a
product in 1995.
NPS will stay committed to studying performance, durability and other
properties based on the results from actual ship tests while working on
developing technologies compliant with the Tier III and promoting
research in environmentally friendly solutions.
* SCR: A system that converts NOx emissions into harmless nitrogen and
water by mixing emissions with ammonia as a reduction agent and forcing
the mixture to pass through a catalyst layer.
 Diesel Engine with SCR system |
 SCR Reactor (left) |