What are biofuels?
'Biofuel' is a term used to describe a fuel, gas or liquid that derives from biomass or biomass residues.
At the moment, the biofuels that are considered the promising ones for use in the maritime industry are fatty acid methyl ester (FAME) & hydrotreated vegetable oil (HVO). These types are drop-in biofuels and can be used in existing engines and fuel infrastructure.
However, biofuel covers a large range of other products too, making the overview of different biofuel products, generations, feedstocks, and blends rather complex.
There are three different generations of biofuels, depending on the source from which the fuel is derived from.
1st generation biofuels are produced directly from food crops, such as corn, wheat, soybeans, and sugar cane, while 2nd and 3rd generation biofuels are not produced from food crops but non-edible plants and are classed as sustainable.
Which biofuel feedstocks result in which end products?
Vegetable oils derived from food crops, such as palm oil or soy oil, support the production of 1st generation FAME- and HVO biodiesel. They are less expensive feedstocks but are not sustainable.
Waste fats, oils, and greases (FOGs), such as used cooking oil, support the production of 2nd generation FAME- and HVO biodiesel and are unlike 1st generation classified as sustainable.
Other 2nd generation productions include purpose-grown energy crops, like grass or seed, and agricultural residues, like corn stover and wheat straw, resulting in FT diesel, DME, and methanol as end products.
Lastly, natural gas can also be used to produce FT diesel, DME and methanol but since these fuels are fossil-based, they do not contribute to a reduction in greenhouse gasses.
