Classification society ABS on Friday (19 January) released a regulatory news brief providing background information and guidance for the use of biofuel bunkers for Class, EU and IMO regulatory requirements as well as summarises what operators must consider in the transition to biofuels.
The following are excerpts from the brief:
INTRODUCTION
With new regulations aimed at reducing air pollutants and greenhouse gases (GHGs), there is increased interest in biofuels. Zero and low carbon fuels, such as hydrogen, ammonia, and biofuels with negligible sulfur can lower particulate matter, gaseous and carbon emissions. MARPOL Annex VI has dealt with the use of biofuels by fuel oil quality regulations under Regulation 18.3.2, while the ISO standard
8217 “Petroleum products – Fuels (class F) – Specifications of marine fuels” was modified in 2017 to widen tolerance for use of biofuels in existing and new fuel oil grades.
CLASS AND STATUTORY REQUIREMENTS
Safety – SOLAS Flash Point
Liquid biofuels, or biofuel blends, intended as “drop-in” fuels to replace conventional residual or distillate fuel oils are to meet the SOLAS requirement for a flashpoint of not less than 60° C.
Safety – ISM Requirements
The IMO International Safety Management Code (ISM Code) provides an international standard for the safe management and operation of ships and the prevention of pollution. With respect to biofuels, the fuel supplier’s fuel specifications, Bunker Delivery Note (BDN), SDS sheets, equipment manufacturer’s
recommendations and industry stakeholder guidelines provide the basis for operators to undertake their ISM Code obligations. While there are some risks to equipment and operation with certain
biofuels, the ‘drop-in’ nature and similarity to conventional residual or distillate fuels makes application relatively simple.
Environment – MARPOL Annex VI NOx Implications
IMO fuel oil quality requirements of MARPOL Annex VI regulation 18 classify fuel oils into two main categories:
- Regulation 18.3.1.1: addresses blends of hydrocarbons from petroleum refining.
- Regulation 18.3.2: addresses fuel oil derived by methods other than petroleum refining.
Within the latter, Regulation 18.3.2.2 indicates that such fuel is not to cause an engine to exceed the applicable NOx emission limit. Biofuels may be considered to fall under either category since they may be a blend of bioderived product with conventional petroleum derived sources or be solely bioderived.
There have been ongoing discussions within the industry and in the IMO on how Regulation 18.3.2 should be applied to biofuels. The outcome of these discussions is a revision 8 of MEPC.1/Circ.795 “Unified Interpretations to MARPOL Annex VI” approved by the Marine Environment Protection Committee, at its eightieth session (MEPC80) which now provides a Unified Interpretation (UI) on the application of biofuels to marine engines and, in many cases, allows the use of biofuels without the need to validate the NOx impacts.
Class Requirements
All machinery and equipment intended to consume marine fuel oils are to be designed to burn all intended fuels and meet ABS’ Class requirements. However, biofuels or “biodiesels” are still liquid fuels and therefore are not a type defining parameter (please refer to ABS Marine Vessels Rules 4-2-1/13.5.2 and Table 4 “Type Defining Parameters”) of an internal combustion engine. Furthermore, not all internal combustion engines are designed for the wide variety of residual and distillate marine fuels that are available for marine application.
The suitability of the engines to burn all marine fuels is also demonstrated through the engine designer internal testing, which forms part of the manufacturer’s MARPOL Annex VI Technical File Stage A type testing. Engine type tests (and NOx certification testing) are typically undertaken on distillate grade marine fuels, and this is acceptable for all liquid fuels, under the type defining parameters, that an engine may operate on in service.
The suitability of a particular engine design to burn biofuels should be confirmed by the engine designer, who will typically issue generic guidance or provide specific acceptance of a particular biofuel. Makers have issued service letters or operational guidelines for biofuels.
Where engines are intended for burning residual fuel oils, or other special fuel oils which may be interpreted as applicable to biofuels, the suitability for that is to be demonstrated during shipboard trials as per Marine Vessels Rules 4-2-1/13.9.6.
Note: The full version of ABS Regulatory News on ‘Biofuels as Marine Fuels Under The IMO’s and EU’s Regulatory Framework’ and relevant reference links can be viewed here.
Photo credit: ABS
Published: 23 January, 2024
