On October 27, the International Maritime Organization (IMO) confirmed the date of application of its new global regulation, aimed at reducing the sulfur content of marine fuels from 3.5% to 0.5% by 2020 (outside the SECA zone). This reduction in sulfur emissions should prevent the premature death of 40,000 people a year worldwide due to this pollution1.

This reminds us that, even if sea transport has the lowest GHG emissions per Tonne.km of all modes of transport, its pollutant emissions are still quite high, particularly those of sulphur. This is due to the fuel widely used in deep-sea shipping, HFO (Heavy Fuel Oil), whose sulfur content is generally between 1 and 3.5%.

This reduction in pollution will require a financial effort on the part of hauliers. To adapt their fleets to the new regulations, they will have two options

• Use lighter, but more expensive fuels: MDO (Marine Diesel) or MGO (Marine Gasoil). HFO with a sulfur content in line with the new standard represents only 0.5% of current HFO supply, and will therefore not be able to satisfy all demand.
• Invest in scrubbers to filter exhaust gases. Regulations allow the continued use of HFO in the presence of these devices, provided that sulfur emissions are equivalent to or lower than those of a compliant fuel.

These solutions are similar to those used in the SECA zone. However, the much greater worldwide demand for fuel is likely to drive up the price of MDO and MGO, which are already more expensive than HFO, making investment in these devices more attractive.

More economical purifiers. The use of more expensive fuels will undoubtedly prompt carriers to take steps to reduce their fuel consumption, notably by increasing slow streaming (i.e. operating below rated speed). Although these two scenarios enable compliance with regulations, they do not have the same consequences in terms of pollutant and GHG emissions.

To analyze the impact of these solutions, TK'Blue Agency compared three configurations: an HFO-powered 1900-3849 TEU container ship with SSD Tier 2 engines; the same ship using a scrubber system; and a ship using MGO. The external costs of pollutant and GHG emissions are shown in the graph below, and the costs per ton of pollutant in the table below. Costs in the use phase have been detailed, while those in the upstream phase have been grouped together for greater clarity.

*HFO consumption = 96.13 kg/km; MGO consumption = 90.54 kg/km; Average tonnage =18490 T

Even with a scrubber, sulfur emissions from HFO remain slightly higher than those from MGO. MGO, on the other hand, generates higher emissions in the upstream phase, due to its more complex refining (HFO being a residue). As a result, the HFO configuration with scrubber achieves costs equivalent to those of MGO, although it is much less popular: in addition to the complexity of the operation involved (computerized emissions monitoring, residue collection, etc.), uncertainty about the future fuel market situation makes investment decisions difficult. This trend is confirmed by Lloyd's List's opinion survey of owners, operators and manufacturers in the sector (2015), where 27% of respondents consider the return on investment for a scrubber system "uncertain", and only 32% are confident about the industry's ability to adapt to regulations in 2020.

What's more, pollutant emissions are also reduced through lower fuel consumption: if MGO ships use more fuel-saving devices because of the high price of this fuel, then switching to MGO would be the least costly scenario for society.

Lastly, NOx emissions remain high in all scenarios: their reduction would require specific purification technologies for this pollutant, or the construction/conversion of more ships to LNG, a major investment today, but one that would effectively reduce emissions of all the pollutants studied.