8,500 TEU container vessel study
During 2009, the partners of Green Ship of the Future worked together on concept studies of so-called ‘low emission ships’.
The purpose of the studies was to investigate the possible overall emission reductions when the various available technologies from the Green Ship of the Future project were implemented already during the design phase of a new ship.
The studies were carried out for two different ship types, an 8,500 TEU container vessel and a 35,000 DWT handy size bulk carrier.
The basis for the container vessel was an A-Type vessel from Odense Steel Shipyard
In the study of the container vessel, only available and proven ‘green’ technologies were used, which meant that it was possible to build the ships as specified and documented by Odense Steel Shipyard.
The concept study was carried out to benchmark the new technologies in relation to the goal of Green Ship of the Future (reduction of exhaust gas emissions) and in relation to the coming international regulations on NOX and SOX emissions and most probably also CO2 emissions by introduction of the Energy Efficiency Design Index (EEDI) for new ships.
Designing a ship is a very complex process because many aspects and constraints have to be taken into account simultaneously. Very often demands interfere with each other in a negative way so that by fulfilling one demand, another demand cannot be fulfilled or is even counteracted.
This interference means that it is not always possible just to accumulate the savings from each individual technology to get the total possible saving or reduction.
In the study of the container vessel, focus has been on the following technologies:
- Water in fuel system (WIF)
- Exhaust gas recirculation system (EGR)
- Waste heat recovery system (WHR)
- Power and Steam turbine technology
- Exhaust gas scrubbers
The overall goal of the container vessel concept study was to achieve
- 30 % reduction of CO2 emissions
- 90 % reduction of NOX emissions
- 90 % reduction of SOX emissions
In the concept study we have been able to demonstrate and document that by implementing the above technologies on the 8,500 TEU container vessel it is possible to achieve
- 11-14 % reduction of CO2 emissions
- Achieved 80 % reduction of NOX emissions
- Achieved 90 % reduction of SOX emissions
The extra cost for these reductions is 10 million EURO (approximately 10% increase compared to a ‘standard ship’ without ‘green technologies’ in 2009)
Regarding the emission reductions, the results on the NOX and SOX are very promising. When it comes to the reduction of CO2 the results are good, but not as high as the target of 30%.
To ensure that the two concept ships fulfil the relevant Class regulations, all calculations and drawings have been approved by Lloyds Register, and each ship has thus been given a Class Notation.
Conclusion in short
- With respect to NOx and SOx we have reached our goals
- Reducing NOx and SOx will in some case cost increased CO2 emission
- With respect to CO2 the study shows that we still need to work with technical solutions and operation to meet the goal of a 30 % reduction
- Further reduction in CO2 must be obtained through continued efforts to reduce vessel resistance, optimised operation (slow steaming, weather routing etc), more effective propulsion systems, more fuel efficient engines, alternative fuel (LNG, Biofuel etc) and addition of alternative green means of propulsion (fuel cells, wind, solar etc)
- Further reductions in CO2 will also reduce NOx and SOx emissions
- Challenges with retrofitting