Black carbon misunderstandings thoroughly discussed and addressed

Delegates to an IMO meeting in mid-February were greeted by demonstrators outside calling for a ban on “dirty fuels” to protect the Arctic. They had arranged a crime scene with dead polar bears which they said had been killed by black carbon emissions.

A few weeks prior to this IMO meeting that was due to discuss measures to reduce the impact on the Arctic of black carbon emissions from international shipping, a group of environmental NGOs, as part of the Clean Arctic Alliance, begun a media campaign asserting that the new fuel blends meeting the 0.50% sulphur limit should be banned because they would increase black carbon emissions.

The campaign reflected conclusions they had drawn on the basis of a measurement study submitted to the IMO, investigating the potential link between 0.50% sulphur fuel specimens with high aromatic content and the formation of black carbon (BC). The study, submitted by Germany and Finland to the seventh session of IMO’s Sub-Committee on Pollution Prevention and Response (document PPR 7/8), said the results “clearly indicate that new blends of marine fuels with 0.50% sulphur content can contain a large percentage of aromatic compounds, which have a direct impact on Black Carbon emissions.”

Environmental NGOs have called for ban on HFO in the Arctic

This caused alarm and led the aforementioned group of environmental NGOs to assume that “the refining industry has created a range of new blended fuels that could overnight send ship-sourced BC emissions soaring” according to one of their submissions to PPR 7. They called for an immediate ban on the use of 0.50% sulphur fuel blends and mandate a switch to distillates in the Arctic in PPR 7/8/2 and to “prohibit the use of low sulphur heavy fuel oil blends that increase BC emissions” in PPR 7/8/3.

In one of their PPR 7 submissions, and in public prior to the PPR 7 meeting where the impact on the Arctic of BC emissions would be discussed, they insinuated that experts in the refining and bunker supply sector should have known about this and had failed to address it. IBIA was among the organisations criticised in a public letter from the Clean Arctic Alliance (CAA) for not having sounded the alarm about “elevated aromatics” in 0.50% sulphur fuel blends and an associated increase in black carbon emissions because IBIA was among the co-authors of the Joint Industry Guidance (JIG) on “The supply and use of 0.50%-sulphur marine fuel” published in August 2019. In a response to the CAA letter, co-sponsors of the JIG made it clear that the remit of the JIG was solely to support the industry in preparing for and implementing the use of 0.50% sulphur fuels as safely as possible. JIG co-authors also made it clear, prior to PPR 7, that one of the key points we identified in the JIG were that 0.50% sulphur fuels were expected to be much more variable in terms of composition and characteristics than had been experienced previously, and that we expected there to be a greater tendency for 0.50% sulphur fuels to be more paraffinic, as opposed to more aromatic, in nature.

When the various papers submitted to PPR 7 regarding BC emissions were discussed at the IMO in February, the following points were made:

The BC measurement study in PPR 7/8, although using fuel specimens with specific aromatic content to investigate the correlation with BC emissions, did not draw conclusions about market distribution of fuel types with specific aromatic content.
Both PPR 7/8, which contained the study, and PPR7/8/1 from Euromot, proposed to ask ISO to consider incorporation of parameters in the ISO 8217 standard that may help determine impact on ignition and combustion performance and impact on BC emissions. The proposals were for ISO to consider including aromatic content, a hydrogen/carbon ratio, and estimated cetane number.
Formation of BC, the product of incomplete combustion of carbon-based fuels, is complex to understand and depends on multiple and variable factors and how they interact, including the engine type, engine load, engine condition and the fuel used, and more research is needed.
The fuel specimens used in the BC measurement study are not representative of most 0.50%S fuels that are actually in the market, which in general are more paraffinic and less aromatic than the HSFOs they have replaced.
Suppliers are still developing products complying with the 0.50% sulphur limit so we do not know exactly how these fuels will evolve in the long term.
Global restrictions on 0.50%S fuel blends are not justified on the basis of the evidence presented, and it would have a huge negative impact on the recent implementation of the 0.50% sulphur limit.
There was support from several delegations to expedite measures to reduce the impact of BC emissions from shipping in the Arctic, for example by calling for ships operating there to use only distillate fuels.
More research is required both to understand how BC is formed and the impact of potential policy measures to reduce BC emissions on availability and cost of fuels.

We have shared the statement delivered by the International Organization for Standardization (ISO) to PPR 7, which was of particular interest to the meeting (link here), and a statement made by IBIA (link here). The ISO and IBIA statements, and other statements at PPR 7, stressed that fuel testing data seen for very low sulphur fuel oil (VLSFO) seen so far strongly supports industry expectations that most of the fuels supplied to meet the 0.50% sulphur limit would be less aromatic and more paraffinic in nature than most high sulphur fuel oil (HSFO), meaning the ignition/combustion performance is expected to be improved and hence result in lower BC emissions.

We also share a figure from Lloyd’s Register FOBAS here below, showing the CCAI of fuels with maximum 0.10% sulphur (ULSFO), max 0.50% sulphur (VLSFO) and HSFO tested during January 2020, indicating that some 85-90% of the VLSFOs tested were more paraffinic than HSFO.

The co-sponsors of PPR 7/8/2 and 7/8/3 have submitted essentially the same papers to the 75^th meeting of the IMO’s Marine Environment Protection Committee to call for urgent restrictions on the use of VLSFO. Although the subject was thoroughly discussed at PPR 7 and hopefully better understood now, IBIA and IPIECA have submitted a commenting paper to MEPC 75, which is scheduled to start on March 30. Our paper, MEPC 75/5/7, documents why claims that VLSFO blends introduced to meet the 0.50% sulphur limit would be highly aromatic and lead to an increase in black carbon emissions are based on flawed assumptions.