Biofuels received an important vote of confidence at IMO MEPC 78, when a new unified interpretation was approved, potentially clearing the way for their broader use as ‘drop-in’ fuels for ships to lower CO2 emissions.
“This regulatory hurdle is now set to be cleared thanks to a new ‘Unified Interpretation (UI)’ approved by the IMO’s Marine Environment Committee in June 2022 on the application of regulation 18.3 Marpol Annex VI in relation to biofuels,” said the International Bunkering Industry Association (IBIA), adding “This UI means that biofuel blends up to 30% (B30) will be regarded in the same way as regular oil-based fuels.”
The sticking point for biofuels has been the NOx Technical Code. Regulation 184.108.40.206 of Marpol Annex VI requires biofuels shall not “… cause an engine to exceed the applicable NOx emission limit …”. But as ABS explained in a technical brief, the UI “indicates that a fuel oil which is a blend of not more than 30% by volume of biofuel should meet the requirements of regulation 18.3.1 of Marpol Annex VI”. This means it is “considered to be fuel oil of blends of hydrocarbons derived from petroleum refining and verification of the NOx impacts is not required; and a fuel oil which is a blend of more than 30% by volume of biofuel should meet the requirements of regulation 18.3.2 of Marpol Annex VI. It may also be used without verification of the NOx impacts where the engine is already certified to Annex VI regulation 13 on a DM or RM grade fuel, and biofuels can be burnt without changes to the NOx critical components or settings/operating values outside those as given by that engine’s approved NOx Technical File.”
Experience to date indicates no engine setting changes have been needed to operate on up to B100 biofuels, according to Lloyd’s Register.
“No engine setting changes have been needed to operate on up to B100”
A Lloyd’s Register Technical Report on NOx from marine diesel engines using biofuels covered data from multiple biofuel sea trials with FAME or FAME-type fuels from 20% through to 100% bio-component. The report concluded that NOx emissions were not significantly increased in any instance.
The UI will be issued as MEPC.1/Circ.795/Rev.6, replacing MEPC.1/Circ.795/Rev.6 but is essentially already in effect. There may be a delay in taking this new UI into account in some countries, so owners planning to use biofuels should contact their respective flag administrations about the individual administrations’ formal positions in applying the new UI.
In the wake of the IMO MEPC vote, a consortium led by the Global Maritime Centre for Decarbonisation (GCMD) announced in July an US$18M biofuel drop-in fuel pilot to establish a supply chain for the sustainable fuel.
GMCD chief executive Lynn Loo said: “By facilitating and creating an optimised drop-in green fuels supply chain, this pilot will help to shape national and international standards for biofuel bunkering and lower the barrier for their wider adoption to reduce greenhouse gas emissions from a lifecycle perspective.”