VERY low sulphur fuel oil blends face a potential ban after a new study suggests they result in greater black carbon emissions than conventional heavy fuel oil or distillates.

Four NGOs are calling on the International Maritime Organization to change its rules and ban VLSFO blends that increase black carbon emissions, in a new proposal to the sub-committee on pollution and prevention response — a technical environmental body that meets in late February in London.

The group will advise the Marine Environment Protection Committee, the ultimate decision-making authority for environmental issues to “amend Marpol Annex VI to prohibit the use of low-sulphur heavy fuel oil blends that increase BC emissions,” according to their proposal.

The hard-line position taken by the Clean Shipping Coalition, Friends of the Earth International, Pacific Environment and the WWF, follows the release of the initial results of a study into the effect of different types of fuel on BC emissions, which is an important component of particulate matter.

These initial results, submitted to the IMO by Germany and Finland, show the high aromatic content found in 0.5% sulphur blends lead to higher BC emissions than HFO or distillates produce.

“The results clearly indicate that new blends of marine fuels with 0.5% sulphur content can contain a large percentage of aromatic compounds, which have a direct impact on BC emissions,” the report said.

Specifically, the hybrid fuels had aromatic compounds in a range of 70% to 95%. This led to a 10% to 85% increase in BC emissions compared with HFO and a 67% to 145% increase compared with distillates.

“The measurement study has demonstrated that the combustion of fuels with higher aromatic content emits higher concentrations of BC,” the submission said.

Aside from demanding a prohibition on the VLSFO blends that lead to increases in BC emissions, the NGOs want the IMO to encourage relevant stakeholders to “observe a voluntary prohibition on the use of any marine fuel whose aromatic content is likely to lead to BC emissions greater than those commonly associated with distillate fuels,” until a ban comes into effect.

They further took issue that a potential link between desulphurised fuels and BC had been brought up as a possible issue before this latest study was unveiled.

“It is extremely difficult to believe that oil refiners and the oil industry in general were not aware of the potential impact of aromatic compounds on BC emissions when developing new low-sulphur marine fuel blends,” the NGOs added.

Mandatory fuel switch to distillates in the Arctic Sea

The potential of VLSFO blends to increase BC emissions will be alarming for an industry that has been touting the 2020 sulphur cap as big watershed in its environmental endeavours.

The four NGOs that want a ban of the blends, are especially concerned about VLSFO impact on the Arctic Sea region, warning there is a “much greater warming impact when shipping occurs near reflective snow and ice”.

“It is therefore of the utmost urgency that IMO should agree immediately to a mandatory switch to distillates for all ships operating in or near Arctic waters,” they said in their proposal.

Last year, the IMO rejected the same call by NGOs for mandatory immediate fuel switch to distillates in the Arctic. Governments chose instead to discuss again in future meetings to how to reduce BC emissions from shipping in the Arctic.

While waiting for the Arctic distillate switch to come into effect, IMO should call on shipowners, charterers and others to voluntary switch to distillates in the Arctic and to encourage Arctic governments to similar develop national legislature for their coastal waters, according to the NGOs.

The IMO is also working towards a ban on heavy fuel oil in the Arctic, a move supported by governments and NGOs, albeit with disagreements on potential delays.

This problem of BC emissions in the Arctic has been acknowledged beyond the maritime world, with Arctic Council last year highlighting the significance of combating them last year.