Combination with the improved fuel injection valves, achieved about 50% NOx reduction.
For NOx reduction in the future, a de-NOx system based on a selective catalytic reduction (SCR) process similar to those used in factories is considered necessary. In fiscal year 1995, KHI experimentally placed a compact de-NOx system (300 to 500 Nm3/h gas processing capacity) using urea-water solution as a reducing agent on board the car carrier "Olympian Highway". A performance test of the de-NOx system was conducted in cooperation with Kawasaki Kisen Kaisha, Ltd. (K-Line) and Kobe Nippon Kisen Kaisha Ltd. KHI achieved more than 90% reduction of NOx in the test; and established the technology to realize a marine use de-NOx system.
Under the contract with the Association for Structural Improvement of the Shipbuilding Industry (ASIS), KHI has also produced a new type SCR de-NOx system (400 Nm3/h gas processing capacity) using hydrocarbon as a reducing agent. The new de-NOx system aims at a smaller size of system, application to lower temperature exhaust gas and lower operation cost. It was also installed on board "Olympian Highway" for the performance test which was conducted in 1997. KHI achieved about 70% NOx reduction with exhaust gas temperature about 250℃.
The de-NOx system will contribute to the prevention of the global environment pollution, in combination with KHI's energy-saving measures such as improvements in hull form, propeller and Kawasaki Rudder Bulb System with Fins (RBS-F), which can bring about a marked improvement in propulsion efficiency and reduce fuel consumption (some 10% for large container ships when compared with ships built by other companies) and the resulting exhaust emissions over the long term.
The Technological Research Association of Super Marine Gas Turbine, headed by KHI and supported by ASIS as well as the Nippon Foundation, is currently conducting R&D on marine gas turbine with the same level of thermal efficiency as the current high-speed diesel engines and with only 1/10 in the NOx emission.
