As the world grapples with climate change and the need for sustainable energy, biofuels have emerged as a promising alternative to conventional fossil fuels.
These fuels, derived from biomass (plant or animal material), offer a renewable energy source that can significantly reduce our carbon footprint.
But not all biofuels are created equal. In fact, there are three generations (G) of biofuels.
We look at them briefly.
1G Biofuels: conventional biofuels from food crops
These biofuels are produced directly from edible biomass, primarily food crops rich in sugar, starch, or vegetable oil.
Common examples include bioethanol from corn and sugarcane, and biodiesel from soybean, rapeseed or palm oil.
Bioethanol is typically produced through fermentation, similar to brewing. While biodiesel is made via a process called transesterification, where vegetable oils react with alcohol.
Although these processes are readily available and the feedstocks are widely cultivated, the biggest drawback is the direct competition with food production.
Using valuable agricultural land and edible crops for fuel can drive up food prices and raise concerns about global food security, particularly in developing nations.
2G Biofuels: advanced biofuels from non-food biomass
Responding to the limitations of first-generation biofuels, the second generation focuses on utilizing non-food biomass.
These biofuels are derived from lignocellulosic biomass, which includes agricultural residues (like corn stover, wheat straw), forestry waste (wood chips, sawdust), dedicated non-food energy crops (switchgrass, miscanthus), and even municipal solid waste.
Examples include cellulosic ethanol, synthetic diesel and bio-hydrogen.
Production often involves more complex processes like thermochemical methods (gasification, pyrolysis) or biochemical methods (enzymatic hydrolysis followed by fermentation) to break down the tough lignocellulosic material into usable sugars or syngas.
2G biofuel utilises non-edible plant parts and waste, which alleviates concerns about food security and also offer a better net reduction in greenhouse gas emissions due to less intensive land use change and utilization of waste materials.
3G Biofuels: future biofuels from algae and microorganisms
The third generation takes a leap into the microscopic world, leveraging the power of microorganisms. These are biofuels derived from algae and other microorganisms.
These tiny powerhouses can produce various types of fuel, including biodiesel, bioethanol, butanol and even jet fuel precursors.
Algae can be cultivated in controlled environments (like photobioreactors or open ponds) using sunlight, water and CO2.
They are then harvested and their high lipid content (oil) is extracted and converted into fuel. Some microorganisms can also be genetically engineered to produce specific biofuels directly.
Algae can produce significantly more oil per unit area than traditional crop-based feedstocks
3G biofuels don’t require arable land and can be grown in non-potable water, including brackish or wastewater, reducing competition for resources.
Future outlook
Each generation of biofuel represents a step further into sustainable energy.
Airlines in the Western Hemisphere look to make biofuel a part of their sustainable aviation fuel (SAF).
Big oil companies like TotalEnergies and Eni are doubling their investments in biofuels production.
In June 2025, Eni entered into an agreement with Côte d’Ivoire to explore the potential for cultivating biofuel crops in the West African country.
Eni is targeting to grow oilseed crops on marginal and degraded lands, thereby avoiding competition with food production and existing forest ecosystems.
Global production of SAF is projected to double this year, reaching 2 million tonnes. That’s just 0.7% of total fuel consumption by airlines.
While first-generation biofuels offers a starting point, the focus is increasingly shifting towards second and third-generation technologies that mitigate environmental and social concerns.