35,000 DWT bulk carrier
During 2009, the partners of Green Ship of the Future worked together on concept studiesof 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 bulk carrier was a Seahorse 35 bulk carrier from Grontmij with a capacity of 35,000 DWT.
In the concept studies, only available and proven ‘green’ technologies were used, which meant that it was possible to build the ships as specified and documented by Grontmij.
The concept studies were 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 bulk carrier, focus has been on the following technologies:
- Water in fuel system (WIF)
- Exhaust gas recirculation system (EGR)
- Waste Heat Recovery system (WHR)
- Exhaust Gas Scrubbers
- Ducted/direct air intake for main engine
- Optimised coolers and cooling pumps
- Auxiliary engine operation on marine diesel oil (MDO)
- Speed nozzle/optimized propeller
- Twisted spade rudder with Costa Bulb
- Installation of Ballast Water Treatment System (BWT)
The overall goal of the bulk carrier 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 35,000 DWT bulk carrier it is possible to achieve.
- 7.2% reduction of CO2 emissions
- 79.1% reduction of NOX emissions
- 98.6% reduction of SOX emissions
The extra costsdue to the above mentioned technologies are 3.5 million EURO making the price rise to approximately 20 million EURO (approximately 20% increase compared to a ‘standard ship’ without ‘green technologies’ in 2009)
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