Although there is no internationally agreed definition of biofuels, it is generally referred to as a fuel which can replace traditional fossil fuels, made from biomass as a raw material, and has similar properties to petroleum products. It is a low-carbon fuel because its carbon content is relatively low compared to traditional fossil fuels, and it is classified as a carbon-neutral fuel because it uses biomass that has absorbed carbon dioxide from the atmosphere. Because of this carbon neutrality, the use of biofuels is expanding in all industry sectors. While it has the advantage of being easier to store and use than other alternative fuels from the point of view of utilization, it should be noted that storage conditions and periods may differ depending on the type of biofuel. Biofuels are receiving attention as a "drop-in" fuel that can be used immediately without the need for significant modification or alteration of internal combustion engines used as main propulsion or electric power generation on ships. If a sufficient supply is available, they can also be used as pilot fuels for dual-fuel engines, ensuring complete carbon neutrality in ships.
Biofuels can be produced from various materials and manufacturing methods, mainly biomass sources. The representative biofuels are as follows:
Straight Vegetable Oil(SVO) | Fuel extracted from various biomasses such as palm, soybean, and rapeseed |
Fatty Acid Methyl Ester(FAME) | Fuel made from vegetable oil, animal fat, or waste cooking oil through transesterification |
Hydrotreated Renewable Diesel(e.g., HVO) | Renewable fuel produced by adding hydrogen to non-edible raw materials such as waste cooking oil and byproducts of palm oil |
Fischer-Tropsch(FT) Diesel (or BTL : Biomass to Liquid) | Natural gas, coal, and biomass can be used as raw materials. For BTL fuels using biomass as raw material, the fuel is produced through gasification, refining, and F-T synthesis processes. |
Biofuels can be classified according to the raw materials used. First-generation biofuels can use crops for food and animal feed, which can have a negative impact on food production and indirect land-use changes (ILUC) such as assigning pasture or croplands for biofuel production can increase greenhouse gas emissions. Accordingly, it is expected that 2nd generation or higher generation biofuels produced from raw materials with relatively low environmental impact will be used as sustainable fuels.
1st generation | Manufactured from food crops such as corn, palm oil, and soybean oil |
2nd generation | Manufactured mainly using waste biomasses such as waste cooking oil, animal fat, and agricultural waste |
3rd generation | Manufactured using non-food raw materials such as microalgae |
The price of biofuels can vary depending on the raw materials and manufacturing process, and it is known that biofuels with higher generations have a higher price range compared to traditional fossil fuels. In addition, the availability of biofuels as a fuel may vary depending on the limitations of available raw materials and the demand for biomass in other industrial sectors (power generation industry, land and air transport, etc.). Biofuels can be produced worldwide, but infrastructure for bunkering biofuels may be limited. However, with the increasing demand and use of biofuels for sustainable fuel from a life cycle perspective due to strengthened GHG regulations, the number of ports capable of bunkering is expected to increase. In addition, for existing "drop-in" biofuels that can replace traditional fossil fuels without requiring significant investment, existing bunkering infrastructure can be used.
