100th order intake of marine SCR system

Sep 29, 2021

Hitachi Zosen Corporation has received an order for the 100th marine SCR (Selective Catalytic Reduction) system in total. In 2009, our Company developed the product that reduces NOx (nitrogen oxides) emitted from marine diesel engines by catalytic reaction during ship operation.
From the perspective of preventing air pollution, the IMO (International Maritime Organization) has been promoting the emission control of NOx that cause photochemical smog and acid rain and have an adverse effect on humans and plants.
NOx Tier III emission control * was applied to ECA (Emission Control Areas) in North America in 2016, and the new ECA has been expanding to the North Sea and the Baltic Sea in January 2021, and more to come in the future. With the expansion of these emission regulations, the marine SCR market has grown at an average of 113% per year over the past four years. **

  • * NOx Tier III NOx emission control regarding the reduction of NOx emissions during ship operation set by IMO requires a further 80% reduction from the Tier I (17.0g / kWh) enforced in 2005.
  • ** Source: MAN Energy Solutions

We are a pioneer of the SCR system, started the development of the SCR system in 2009, and in 2014 awarded FTA(First Time Approval)from MAN Energy Solutions (Germany) for the first time in the world, a licensor of marine diesel engines.
Besides, for ships that will be equipped with the SCR system, an SCR system will be additionally installed on the existing marine engine, however, due to the limited space in the engine room, there was a great demand to downsize the equipment. To meet this demand, our Company has developed the second-generation marine SCR system, the "Hitz Green SCR Mk-II" (hereinafter "Mk-II"), and started selling it in 2019. The Mk-II has downsized the equipment by reducing the installation area by about 40% compared to the conventional model and made the SCR system available to various ships.
Our Company is the only supplier in the world that manufactures both marine engines and NOx removal catalysts ***, and we have developed the optimum SCR system for ships leveraging our technologies both in marine engine and NOx removal catalyst.

  • *** NOx removal: A method of adding ammonia to NOx to convert it into harmless nitrogen and water.
Outline and features of our SCR system:

Our SCR system sprays urea solution on the exhaust gas containing NOx and passes it through a NOx removal catalyst to decompose NOx into nitrogen and water, reducing NOx emissions.
The features of the product are as follows.

  • We utilize our unique NOx removal catalyst technology that has many achievements in NOx treatment in Japan and overseas, such as thermal power generation and Energy-from-Waste.
  • To remove NOx from the exhaust gas emitted from an engine, there is almost no adverse effect on fuel oil consumption.
  • By using urea solution as the reducing agent that decomposes NOx, it can be operated safely on board.
  • Regarding urea solution that is used in the SCR system, we also offer an optional urea dilution skid that automatically produces urea solution after adding urea. An appropriate amount of urea solution can be produced depending on the usage status of SCR and it contributes to the reduction of operating costs and the capacity of the urea solution storage tank on board.
Hitz Green SCR Mk-Ⅱ

Number of orders by country



China and South Korea


(By countries of engine manufacturers)

Our Company will continue to contribute to climate change countermeasures and the realization of a sustainable society by providing the SCR system.