IBIA and ISO contribute to IMO discussions on Black Carbon control measures

The IMO has been wrangling for over a decade with how to reduce the impact on the Arctic from emissions of Black Carbon (essentially soot) from international shipping. The subject was on the agenda again at the 10th session of the IMO’s Sub-Committee on Pollution Prevention and Response (PPR 10) which took place during last week (April 24-28).

The meeting had a range of proposals to discuss, including the outcome of long and complex deliberations in the Correspondence Group on Prevention of Air Pollution from Ships. IBIA has taken part in this Correspondence Group and expressed our views on various aspects and ideas put forward for consideration.

Environmental NGOs represented at the IMO have focused their efforts on insisting that the IMO should adopt a mandatory switch to distillate fuels or other cleaner alternative fuels “in or near the Arctic” as an immediate measure to reduce Black Carbon (BC) emissions, highlighting the climate impact of BC being deposited on snow and ice in the Arctic, contributing to accelerating ice melt and global warming.

PPR 10 saw proposals to define “near the Arctic” to include areas well beyond the area defined as “Artic waters” in IMO regulations. The IMO’s heavy fuel oil (HFO) use and carriage ban that is due to take effect in July 2024 will prohibit the use and carriage for use HFO as fuel by ships in Arctic waters.

Member States at the IMO preferred, however, to focus on further developments of voluntary measures in the short term, building on Resolution MEPC 342(77), Protecting the Arctic from shipping Black carbon emissions. Longer term measures may include new regulations, but that would require more work, including BC emission data collection.

“IBIA has on several occasions said we could support Resolution MEPC 342(77) calling for ships to use distillates or other safe, clean fuel and technologies as a short-term measure to reduce Black Carbon emissions in the Arctic. While fuel is only one of the factors influencing Black Carbon formation, with all else being equal, a shift from HFO to distillates should produce less Black Carbon,” IBIA’s Director and IMO Representative, Unni Einemo, told PPR 10. She continued: “We have also expressed confidence that sufficient distillates would be available for ships operating in the Arctic. However, when discussing extending the geographic scope for BC reduction measures to areas near the Arctic, this would have a significant impact on the amount of distillate fuels being required to meet demand and would need careful consideration.”

After further discussion on the geographic scope of potential BC mitigation measures, the Chair of PPR concluded that this was in fact outside the scope of the sub-committee, and that any further discussion on defining a geographical scope would have to be proposed and discussed at MEPC.

After extensive discussion, both in plenary and the Working Group on Air Pollution convened during PPR 10, the sub-committee agreed to establish a Correspondence Group to “further develop, with a view to finalization, draft guidelines on recommendatory goal-based control measures to reduce the impact on the Arctic of Black Carbon emissions from international shipping,” and submit a report to PPR 11 (scheduled to meet in February 2024).

The guidelines under development are recommendations for collection and reporting of BC emission data, and recommendatory goal-based, technology-neutral control measures, ideally also being able to quantify their effectiveness. This means discussion will continue in the Correspondence Group but with a reduced scope compared to earlier. It will now develop draft recommendatory guidelines on goal-based control measures, and not discuss potential regulatory measures. Potential BC control measures that have been discussed in the Correspondence Group previously have included setting up and Arctic emission control area, engine certification for new ships, the use of BC reduction technology such as particulate filters, and a new fuel standard based on aromatic content.

The role of fuel quality

Those who have been involved in the BC discussion at the IMO for a while will recall a debate about the impact of aromatic content in the fuel used. This became particularly heated when, in late 2019, a study was published suggesting that the very low sulphur fuel oil (VLSFO) blends being developed to meet the 0.50% sulphur limit in 2020 would have a very high aromatic content and hence would emit even more BC than the high sulphur HFOs they were replacing.

This theory was debunked by IBIA and other industry groups with representation at the IMO during PPR 7 in February 2020.

There was, however, been calls for a new fuel standard based on aromatic content to help indicate a fuel’s propensity for emitting BC during combustion.

ISO has taken this into account and during PPR 10, gave an update on the work undertaken on the ISO 8217 standard by ISO/TC 28/SC 4/WG6 (ISO WG6) to provide the maritime industry with an indicator to characterise whether a marine fuel tends to be more paraffinic or aromatic in nature. The approach taken was to find – and apply – a well-established method already used by the petroleum industry to characterise fuels in terms of their paraffinic or aromatic nature. ISO WG6 has identified the ‘Viscosity Gravity Constant’ (VGC) as a straightforward approach as it can be calculated using routinely analysed parameters (viscosity and density). ISO told PPR 10 that the intention is to incorporate this indicator in the 7th edition of ISO 8217, which is expected to be published in the first quarter of 2024.

Despite this update from ISO, some Member States asked ISO to reconsider, and insisted that a H/C ratio should be included in the ISO 8217 revision as an indicator of fuel aromaticity.

Developing a fuel standard based on aromatic content is one of several proposals for potential ways to regulate BC emissions in the future. While some are supportive of developing a fuel standard, it has been pointed out that it would require additional data on fuel characteristics. At the same time, in a related agenda item aimed at protecting the Arctic from HFO spills, proposals have been put forward to specify “polar fuel oils” that are acceptable for use and carriage in the Arctic.

PPR 10 will ask MEPC 80 to extend the target completion year for the work on reducing the impact of Black Carbon emissions on the Arctic to 2025, including to allow for further work on potential control measures.

Given the complexity of working out the actual extent of BC emissions, and identifying and quantifying feasible and effective ways to reduce them, that extra time will be needed.

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