With the varied parameters in VLSFO there is a need to revise the ISO 8217 marine fuel standard, which could take three years to complete
International marine fuel standards are set to be revised over the next three years in reaction to the increased use of very low sulphur fuel oil (VLSFO). The uptake of VLSFO with less than 0.5% sulphur content was driven by IMO legislation that came into force on 1 January 2020.
Since IMO’s 2020 sulphur cap regulations were implemented, VLSFO is the most frequently purchased marine fuel.
Bureau Veritas (BV) VeriFuel global technical manager Charlotte Røjgaard told attendees of Riviera Maritime Media’s ‘Fuel Testing – no easy answers’ webinar, part of Marine Fuels Webinar Week, that an International Standards Organisation working group had begun revising ISO 8217, which was last updated in 2017.
“The ISO 8217 committee is currently evaluating VLSFOs in the market and this information will be used in the work revising the specification,” she said in answers to question from attendees. “The ISO 8217 committee has kicked off the work on the next revision and it takes a minimum of three years to develop an ISO standard,” she added.
This process involves discussions covering the requirements for changes. “The ISO 8217 committee evaluates whether the existing specification meets the industry needs, whether new parameters should be added and whether the existing limits need an update,” said Ms Røjgaard.
VPS group commercial and business development director Steve Bee explained what is likely to be included in this process.
“The next revision of ISO 8217 is expected around 2023,” he said. “Hopefully, it will include many more fuel types. Plus, the ISO standard for LNG as a marine fuel will be developed separately alongside the new ISO 8217,” he said.
A new revision would need to account for the high variation in VLSFO parameters as its viscosity varies from 2.3 cSt up to 678.6 cSt at 50° with an average of 107.4 cSt, according to BV VeriFuel. Its density ranges 828-995 kg/m3 at 15°, its micro carbon residue varies from less than 0.1% to 16.35%, and its aluminium plus silicon content can be less than 0.1 mg/kg up to 121 mg/kg.
“VLSFOs vary greatly in their density, viscosity, cat-fine levels, cold-flow properties and stability, due to the wide variation in their component make-up,” said Mr Bee. “The only true commonality is the sulphur level of 0.50% and their energy content tends to be higher than heavy fuel oil.”
Revisions over time
There were revisions to ISO 8217 in 2005, 2010, 2012 and 2017. This brings varied fuel standards that ship operators need to manage. Mr Bee said at least 24% of all fuel samples VPS tested were to the ISO 8217:2005 revision, with 66% tested to ISO 8217:2010/12 and just 10% to ISO 8217: 2017. He expects more owners will insist on the later revision in the future.
“ISO 8217:2017 will provide the best protection with regard to purchasing and using today’s fuels,” said Mr Bee. But bunker costs seem to be limiting this. “As with all things, the more work which goes into producing a product, usually the higher the cost,” he said.
Higher demand for marine fuel to the 2017 revised standard will encourage more production. “If fuel buyers insisted on the latest standard, I am sure the supply chain would accommodate the demand to retain business,” said Mr Bee.
“ISO 8217:2017 is a good standard and is the best we have available at this time in offering protection for today’s fuels,” he added. But fuels evolve over time and standards require updating.
Revisions to ISO 8217 can be subtle and require brief modifications just months after an update such as the revision in 2012 after a 2010 standard version was introduced.
Ms Røjgaard explained there was an update to hydrogen sulphide (H2S) testing after the 2010 update was released. “As per ISO regulations this was a significant update that could not be covered by an addendum,” she said. “Instead, the full specification had to be revised.”
But there are few differences between 2010 and 2012 revisions. “The critical parts of the specifications are identical,” said Ms Røjgaard.
Test method for H2S was changed to vapour phase processor testing, said Mr Bee. “This change improves the accuracy of the test,” he said. “But the parameter limit was unchanged at 2.00 mg/kg.”
The ISO 8217:2010 revision had the greatest level of change from the 2005 specification. One of the minor amendments made in 2012 was removing pour point limits for DMX gasoil.
Watch the ’Fuel testing, no easy answers’ webinar in our webinar library