Energy Transition and Emission Compliance Options for Dredging Vessels
CEDA Dredging Days 2021
B.T.W. Mestemaker, M.B. Gonçalves Castro, and E.C. van der Blom
The future emission regulations and the maritime energy transition are major challenges for dredging vessels. The technical, economic and environmental aspects require balancing to decide which combination of fuel, prime mover technology and exhaust gas after-treatment systems is the most suitable. This is a complex process and each type of vessel has its unique solution that cannot be simply transferred to other types of vessels.
Decisions on fuel and drive systems are made at an early design stage. Therefore, early stage design assessments are essential to make the right choices, as choices made in design phase affect the performance of a vessel for its entire lifetime. The Life Cycle Performance Assessment (LCPA) method developed for the maritime sector is a useful tool for this purpose, as only a limited amount of information is required. This method includes the well to-tank aspect of fuel production, which is very important in determining which design alternative is truly sustainable.
Five vessel designs, compliant with 0.1% fuel sulphur limit and IMO NOX Tier III are evaluated using the LCPA method. These concepts are a diesel fuelled vessel with a selective catalytic reduction (SCR) system (benchmark), a heavy fuel oil fuelled vessel with wet scrubber and a SCR system, a liquefied natural gas fuelled vessel, a methanol fuelled vessel and a hydrogen fuelled vessel with fuel cells.
The five vessel designs are assessed using three different future policy scenario's that vary in terms of fuel prices and emission costs. This paper shows that these policy scenarios have a large influence on the economic viability of the different design alternatives. It also shows that exhaust gas after-treatment systems are not viable for new built vessels in a number of future scenarios and that choosing for cleaner fuels and more efficient vessels is the most robust choice in the uncertain path of the maritime energy transition.
Keywords: Life Cycle Performance Assessment, Maritime Energy Transition, Alternative Fuels, Exhaust Gas After Treatment Systems, Emission Eegulations.