NOx Reduction by SCR Catalyst on Ships
NOx reduction for a cleaner shipping
H+H Engineering & Services meets every challenge and delivers flexible NOx reduction solutions for your application.
For perfect final results, we focus on excellent planning. For us, customer satisfaction begins with consultation and
with detailed planning that takes your requirements into account from the very beginning. This is how we create innovations
and solutions that are perfectly customized to your needs and guarantee reliability for our customers.

Perfect planning from the very beginning
This is ensured by competent employees who support you throughout the entire project phase and
combine extensive know-how with the best advice.
H+H SCR Marine Systems will be different approach for new building and retrofit systems.
Thanks to almost 30 years of experience in this highly specialized field of business,
gained from more than 300 ships in service we can provide the perfectly engineered solution for a perfectly
engineered ship – this all with competitive price level.
The high performance SCR Systems by H+H are for new build and retrofit vessels for operation on
GO, MDO and HFO being designed to meet Tier III NOx, U.S. EPA Tier 4 Final and Stage V limits.
Why H+H makes the difference and should be your first choice for marine SCR solutions
» Compatible for all engines from 200 kW to 60 MW
» All components made in Germany - quality out of one hand!
» Fully extruded catalyst designed by H+H with best mechanical stability
» Urea mixer and 2-phase nozzle for fine atomization and even distribution of urea
» In-house competence of PLC Programming based on Siemens
» High spare parts availability
» Worldwide service locations and representations
Flexibility in design
Design is made in house
Our engineers are trained to design the catalyst housing tailor-made to adapt the SCR
system to your specific space requirements.
Very good mechanical stabilityCatalyst design by H+HSpecific know-how and well experienced. |

01
Staff is trained by catalyst manufacturer
No catalogue solution
The in-house catalyst design allows us to adapt backpressure to the special project
needs. Vertical or horizontal reactor design for easy installation and highest flexibility
inside the ships hull.02
Fit equipment in ship
No ship built around equipment
H+H Marine SCR system offers the possibility to combine the catalyst housing or
the urea injection unit with a silencer to optimize space. The special designed
mixing and urea injection unit allow very short distance from nozzle to catalyst.
- Bulletproof due to In-House CFD analysis -03
Small solution for Bypass
One ship – one engine
H+H Marine SCR comes with an integrated bypass solution.
This is class demand on single propulsion projects.04
Adapting is our expertise
Enabling retrofits and newbuilds
H+H Marine SCR has no other than technical and chemical operation limits, thus we are
able to deliver systems that are in compliance with IMO Tier III, EPA Tier 4 and Stage V
emission limits - also on existing ships!
Emission laws
Ship engines produce harmful nitrogen oxides during combustion. These emissions from maritime shipping have serious consequences for human
health. For this reason, strict national and international legal requirements must be observed. The NOx limits are being reduced step by step by the IMO.
These limits apply in the so-called ECA (Emission Control Area) zones. There are already plans to expand the zones. In Norwegian waters, a tax on NOx
emissions is due. The NOx Fund (www.nho.no) raises a tax and finances the installation and operation of measures to reduce emissions.
- The Environmental Ship Index
International
» Learn more - Global IMO Tier III NOx Regulations
International
» Learn more - Differentiated Port and Fairway Dues
Sweden
» Learn more - NOx Tax and NOx Fund
Norway
» Learn more
Global references speak for themselves
Our References
Marine SCR Systems
Offshore
AKOFS SeafarerEngine Producer: Wärtsilä Type: 6L32 / 8L32 Power: 2880 / 3840 kW Fuel: MGO Marine SCR Systems
Fishing
Hovden VikingEngine Producer: Rolls Royce Type: C25:336LP Power: 1900 kW Fuel: MGO Marine SCR Systems
Fish Farming
TaupoEngine Producer: Caterpillar Type: 3512C Power: 1350 kW Fuel: MGO Marine SCR Systems
Wind Supply Vessel
Edda PassatEngine Producer: MTU Type: 16V4000M63 Power: 2000 kW Fuel: MGO Marine SCR Systems
Cruise
Silja SymphonyEngine Producer: Wärtsilä Type: 8R32E Power: 3200 kW Fuel: MGO