1. TOP
  2. Csr Activities
  3. What Hitachi Zosen Can Do For the Earth, for People
  4. Protecting the Environment
  5. 3. Reducing NOx emissions from marine diesel engines 2

Protecting the Environment

3. Reducing NOx emissions from marine diesel engines 2

Reducing NOx emissions from marine diesel engines

International Maritime Organization (IMO) has introduced tougher NOx standards

The International Maritime Organization (IMO) has regulated NOx emissions from marine vessels in order to reduce air pollution caused by NOx. The IMO’s Tier III standards require that marine vessels setting sail in 2016 or later reduce NOx emissions by 80 % relative to 2010 levels.
In order to comply with the strict standard, marine diesel engine manufacturers and ship builders need to work together in the development and application of new technologies.

Compliant with the Tier III NOx emission standards

Hitachi Zosen has developed a marine selective catalytic reduction (SCR) system for marine diesel engines compliant with the strict standards. Marine engines using this SCR system will be mounted on a ship built by Naikai Zosen Corporation with plans to go into service in autumn 2011 with the assistance of the ship owner, BOT Lease Co., Ltd., and the operator, Nissho Shipping Co., Ltd.

Environmentally-friendly marine diesel engines

The marine SCR system that Hitachi Zosen has developed is significantly different from conventional SCR systems. The system can be installed in front of the turbo charger of the engine instead of after it. Since it utilizes high-temperature exhaust gases discharged before they pass through the turbo charger, excessive CO2 is not emitted. And since the exhaust gas is still at a high pressure, gas density remains high and less catalysts are necessary so the entire system can be more compact.

Hitachi Zosen's NOx removal system

Hitachi Zosen started to develop NOx removal catalysts to remove NOx in the late 1960’s when air pollution became a social problem and first manufactured a NOx removal system in 1973. Currently, approximately 330 Hitachi Zosen’s NOx removal systems are used in approximately 150 plants in Japan, US, China, South Korea, Taiwan, and Middle East countries. The company’s abundant expertise and advanced technology lead to the development of the marine SCR system.