It has long been a known technology that biofuel, with minor modifications, can be used as fuel in certain types of engines. In order for biofuel to be used as fuel and for it to contribute to achieving Denmark's climate goals, it is important that the biofuel is sustainable and reduces the total CO2 emissions over its entire lifecycle compared to fossil oil.
For several years, shipping has, on an experimental basis and with special permission, used biofuels, either as a mix with the oil already onboard the ship or in its pure form. The reason it being on an experimental basis is due to the requirements for the fuel in accordance with MARPOL, and whether the biofuels could meet these requirements without damaging the technical installations onboard the ship and without compromising the safety of the ship, the environment, and the onboard crew.
It is based on these successful experiments that the IMO has issued a circular (MEPC.1/Circ.795/Rev.8), which is an interpretation of MARPOL Annex VI. The Danish Maritime Authority has chosen to recognize these interpretations, so that special permissions are no longer required for the use of biofuels, when the use of these follows the interpretations in the mentioned circular.
The following general rules apply:
- Ships can blend up to 30% biofuel, and this is considered "conventional fuel" according to rule 18.3.1. (a test permit is no longer required here).
- Ships that are NOx certified and where there have been no changes to the engines' critical components or critical parameters can blend/use 30 – 100% biofuel, and
- Ships that are not NOx-certified, typically older ships – or ships where there have been changes in the critical components or parameters, must document that they do not exceed the NOx limits through measurements in accordance with NOx Technical Code 2008 rule 6.3 or 6.4 and rule 18.3.2.2. (a test permit is still required here).
Furthermore, the biofuel must meet the applicable standards for fuel, ISO 8217, and be certified according to a recognized standard for sustainable origin, such as RED II, ISCC, RSB, or equivalent.
The entire area is jointly regulated by the Maritime Authority and the Environmental Protection Agency. Fundamentally, it is divided so that the Environmental Protection Agency is responsible for the emission rules, and the Maritime Authority is responsible for the regulations concerning technical installations on board the ships, including logs and plans.