In a bid to tackle the maritime industry’s air pollution challenge, a recent study has put two sulphur abatement strategies under the microscope, offering valuable insights for aging cruise vessels. The research, led by Luis Alfonso Díaz-Secades from the Department of Marine Science and Technology at the University of Oviedo, Spain, and published in the Journal of Marine Science and Engineering (Ciencias Marinas e Ingeniería), compares the environmental and economic impacts of installing scrubbers versus switching to low-sulphur fuels.
The study focuses on a 1998-built cruise vessel, a typical example of the global fleet’s average age of 21.8 years. With international regulations tightening, such vessels must find ways to comply with emission requirements, and this research provides a data-driven comparison to guide decision-making.
The two strategies evaluated were the installation of open-loop scrubbers with fuel enhancement devices and a switch to marine diesel oil (MDO) as the main fuel. The environmental assessment, based on real operational data and using a Tier III hybrid emissions model, revealed some interesting findings. “Scrubbers reduce SOx emissions by approximately 97% but increase fuel consumption by 3.6%, raising both CO2 and NOx emissions,” Díaz-Secades explained. Particulate matter also saw a modest decrease of only 6.7% with scrubbers.
On the other hand, switching to MDO achieved over 99% SOx reduction, an 89% drop in particulate matter, and a nearly 5% reduction in CO2 emissions. This strategy seems to have a more favorable environmental profile, but what about the economics?
From a commercial perspective, the study found that despite a capital expenditure (CAPEX) of nearly USD 1.9 million, scrubber installation provides an average annual net saving exceeding USD 8.2 million. The deterministic and probabilistic analyses, including Monte Carlo simulations under various fuel price correlation scenarios, consistently showed high profitability for scrubber installation. The net present values (NPVs) surpassed USD 70 million, with payback periods under four months.
This research offers a compelling case for cruise operators to consider scrubber installation, especially for vessels nearing the end of their service life. The significant cost savings and relatively short payback period make a strong commercial case, even as the environmental benefits are somewhat mixed.
For maritime professionals, this study underscores the importance of evaluating both environmental and economic factors when deciding on sulphur abatement strategies. It also highlights the potential for significant cost savings and profitability in adopting scrubber technology, a factor that could drive industry-wide adoption and shape the future of maritime air pollution control.
As the industry continues to grapple with regulatory pressures and environmental concerns, such data-driven insights will be invaluable in navigating the complex landscape of maritime emissions abatement.