The use of biofuels in maritime transport has good potential to reduce greenhouse gas (GHG) emissions in shipping, but its supply may become tight in the future, according to Norwegian classification agency DNV.
A vast majority of biodiesel production is currently routed towards the road sector, as most European countries have biofuel blending requirements for road diesel and gasoline. DNV's report said that the percentage of marine biodiesel used in shipping accounted for 0.3pc of the sector's total energy use in 2023 — according to data from the International Energy Agency (IEA).
Fatty acid methyl ester (Fame) and hydrotreated vegetable oil (HVO) are currently the primary types of biofuels used in marine biodiesel blends, with Fame most prominent. The report acknowledged that waste-based Fame biodiesel can be utilised to meet regulations such as FuelEU Maritime, which came into effect this year, and potential International Maritime Organisation (IMO) mid-term measures in 2027 — which DNV expects to significantly boost demand for marine biodiesel.
But with increasing demand and incentives to switch to marine biodiesel from conventional bunker fuels, the report pointed to potential supply limitations in the long term. These include scarcity of advanced waste-based feedstock and competition with other sectors such as aviation. Feedstock challenges could revolve around sources such as used cooking oil (UCO), and as a result DNV said that some suppliers are "investigating" the viability of alternative waste feedstocks that can feed into the marine sector. Biofuels produced from food and feed crops are not viable for regulations such as FuelEU Maritime, and it remains unclear whether they can meet the sustainability criteria under upcoming IMO mid-term measures.
Further to feedstock scarcity are concerns around competition with other sectors, which have been voiced by market participants. But some participants have also said that while biodiesel suppliers may channel their feedstock towards aviation fuels because of higher margins, a potential source of fuel for marine could stem from by-products of sustainable aviation fuel (SAF) production.
DNV's report also advised caution when using biofuels that do not comply with ISO 8217:2024. This is more specifically relevant to off-spec biofuel blends or blends comprising novel feedstocks such as cashew nut shell liquid.
