Progress status November 2011 One goal in this project was to document emission reductions possible for a new dedicated design for a construction/intervention vessel in the Arctic. A fairly new conventional supply vessel was chosen as a reference vessel to which the new design was compared. Emissions to air and water were taken into account in the environmental footprint case study where two fuel and engine options (diesel engines with MDO and dual fuel engines with LNG and MDO) for the project vessel were evaluated.
Life Cycle Assessment (LCA) method was applied to estimate the emissions to air. The study supports the need for LCA when evaluating the environmental impact of fuel selection. When evaluating the fuel options the focus should be in the whole GHG entity instead of single parameter. Calculating the global warming potential enables the comparison between CO2 and CH4 emissions. Equally, the NOx and SOx emissions comparison is possible by calculating the acidification potential.
Figure: The impact assessment was restricted to calculation of global warming potential (GWP) and acidification potential (AP)
The preliminary results for the project vessel are slightly in favour to dual fuel engine option instead of conventional diesel engines. The differences in impact potentials between the two options are not outstanding. The results indicate that installing SCR also in DF engines would be feasible since gas mode will not be used in DP operations. The results also indicate that the new design is very competitive regarding the emissions compared to the reference vessel, keeping in mind the great difference in installed engine power (reserve for ice navigation is needed only for the project vessel).
Waste water emissions were covered qualitatively.The nutrient load from waste water discharges can be minimised by using AWT designed for nutrient removal or by using PRF when possible. The adverse effects of the ballast water discharges can be minimised by installing a type approved, state-of-the-art treatment technology onboard while keeping in mind the challenging operational environment of the vessel and restrictions it may pose.
Traditional LCA does not include accidental impacts. Acute oil spills in Arctic waters and oil combating technologies have been reviewed as a separate task. The final report will also include considerations for oil spill response options in the CIV Arctic vessel. Objective:Document emission reductions possible for a new dedicated design for an Arctic construction/intervention vessel
Content:Review of work related to handling of acute maritime pollution in Arctic waters. Review international initiatives on environment friendly shipping. Specify ways of reducing emissions to air and water. Define how to evaluate environmental footprint for vessels operating in Arctic waters (workshop where non-governmental environmetalist organisations are invited). Specify cases for comparison of emission footprint for present vessels and vessel optimized in WP 4. Calculate and compare environmental footprints for conventional and “optimal” vessel.
Published September 19, 2008