FOBAS: IMO publishes interim guidance on calculations of biofuel carbon conversion factor for IMO DCS and CII calculations

Lloyd’s Register Fuel Oil Bunkering Analysis and Advisory Service (FOBAS) on Thursday (13 July) released a bulletin on biofuels for marine use, which was discussed at MEPC 80, specifically in relation to defining the calculation methodology for biofuel’s Conversion Factor (CF) for IMO DCS and CII calculations.

IMO produced an interim guidance with the application date recorded as 1st October 2023. FOBAS outlines the methodology with practical examples:

MEPC 80 concluded last week where GHG emissions from shipping was a top agenda item. One of the key issues under consideration was to provide clarity on the conversion factor (CF) for marine biofuels blends. MEPC 80 came up with an interim guidance (MEPC.1/Circ.905) addressing this aspect. 

As per MEPC.1/Circ.905, biofuels will be considered ‘sustainable’ that have been certified by a sustainability certification scheme (e.g., ISCC or RSB), and providing a well-to-wake GHG emissions reduction of at least 65% compared to the well-to-wake emissions of fossil MGO of 94 gCO2e/MJ (i.e., achieving an emissions intensity not exceeding 33 gCO2e/MJ). The well-to-wake GHG emissions value of the fuel mentioned on the sustainability certificate (expressed in gCO2eq/MJ) is multiplied by its lower calorific value (LCV, expressed in MJ/g) for the purpose of regulations 26, 27 and 28 of MARPOL Annex VI to determine a CF value. For blends, the CF should be based on the weighted average of the CF for the respective amount of fuels by energy. 

Biofuels not certified as ‘sustainable’ or not fulfilling the well-to-wake emission factor criterion should be assigned a CF equal to the CF of the equivalent fossil fuel type. Please see below (Appendix A) few examples which explains the calculation methodology. 

Please note that the application date of this circular has been recorded as 1st October 2023. In view of current variants between flag administrations on the calculation of the CF value, ships should check with their respective flag as to their planned adoption of the MEPC.1/Circ.905. Moreover, this interim guidance will be rescinded upon operationalization of a well-to-wake GHG methodology through the IMO LCA Guideline which is currently under development. 

We trust you will find this guidance document useful and if you are planning to use biofuel blends on your ships, FOBAS can provide further advisory support and comprehensive fuel quality testing service to characterise biofuels to ensure smooth ship operations

Note: The full bulletin, which includes Appendix A and case examples, can be downloaded here. 

Photo credit: Hans Reniers on Unsplash
Published: 14 July, 2023