Introduction — Produced from biomass, biofuels are mainly used in transport, either alone or blended with petroleum fuels. Ethanol, biodiesel, renewable diesel and sustainable aviation fuels use different processes and feedstocks. Their value depends on the entire chain: cultivation or collection, processing, transport, land use and emissions avoided compared with the fuel they replace.
Key facts
- Origin: agricultural biomass, oils, fats, residues, waste or organic materials.
- Main categories: bioethanol, biodiesel, renewable diesel and sustainable aviation fuels.
- Uses: road transport, aviation, shipping, heating and sometimes electricity generation.
- Caution: ‘bio’ does not automatically mean sustainable or carbon-neutral.
What is a biofuel?
A biofuel is a fuel produced from recent organic matter, known as biomass. This material can come from cultivated plants, agricultural by-products, used oils, animal fats or certain wastes. The term covers several different products whose characteristics determine compatible engines, infrastructure and blending proportions.
Biofuels are sometimes described as renewable because their feedstock can regenerate over relatively short cycles. This property is not enough to establish their sustainability. Energy used in fields and factories, land-use changes, water consumption, fertilisers and transport emissions must be considered. The overall impact therefore varies by product and production method.
Main categories
Bioethanol
Bioethanol is an alcohol obtained by fermenting sugars. It is generally blended with gasoline in proportions defined by national standards and vehicle characteristics. Sugar cane, maize, sorghum and other sugar- or starch-rich plants can serve as feedstocks. Sugar cane is notably used in Brazil, where the industry is widely integrated with agriculture and the automotive sector.
Biodiesel
Biodiesel is made from vegetable oils, animal fats or used cooking oils. A chemical reaction called transesterification converts these materials into esters suitable for blending with diesel. Biodiesel properties depend on the feedstock and can affect fuel storage, low-temperature behaviour and compatibility with certain equipment.
Renewable diesel
Renewable diesel, sometimes called hydrotreated diesel, is produced from oils and fats through a process that uses hydrogen, among other inputs. Its composition is close to petroleum diesel and, when it meets the necessary specifications, it can be used in existing equipment without the same blending limits as conventional biodiesel. Manufacturing emissions depend particularly on the origins of the hydrogen and feedstocks.
Sustainable aviation fuels
Sustainable aviation fuels (SAF) are made from various renewable materials or wastes through certified pathways. They are designed to be blended with fossil kerosene within the limits permitted by aviation specifications. Aircraft cannot currently operate on 100% biological kerosene in routine commercial use. Feedstock availability, costs and production capacity remain major challenges.
How are they made?
Production depends on the feedstock type. Sugar and starch crops can be fermented to produce ethanol. Oils and fats are converted into biodiesel or hydrotreated to produce renewable diesel. Lignocellulosic residues, such as straw, bagasse, wood chips and certain organic materials, require more complex processes: pretreatment, advanced fermentation, gasification or pyrolysis.
So-called first-generation pathways mainly use food crops or oils. Advanced pathways make use of residues, waste or resources that do not directly compete with food, subject to availability and sound management. They often remain more costly and harder to deploy at scale. Regulatory categories vary between countries: the same fuel may be considered sustainable under one regime yet fail to meet another's criteria.
What are the advantages and limitations?
Biofuels can reduce oil consumption, diversify supply and support local agricultural or industrial value chains. They are particularly relevant to certain uses where direct electrification is advancing more slowly, including aviation, shipping and some heavy vehicles. They can also be blended with existing fuels, limiting the need to rapidly replace engines and infrastructure in some cases.
Their limitations are equally important. Dedicated crops can compete with food production, land access and water resources. Agricultural expansion can cause deforestation or degrade carbon-rich ecosystems. Combustion emits CO₂; the climate benefit therefore depends on carbon reabsorbed during regrowth and all life-cycle emissions. A fuel made from waste or residues does not automatically guarantee a low impact if collection, processing or transport are energy-intensive.
The International Energy Agency forecasts significant growth in renewable energy used in transport by 2030, driven by both electricity and biomass-derived fuels. Blending policies, standards and public support strongly influence the pace of deployment. Traceability criteria and life-cycle assessments are essential to distinguish a real emissions reduction from merely shifting impacts elsewhere.
What is the potential for Africa?
Several African countries have sugar cane, cassava, maize and sorghum residues, used oils or organic waste that could supply local industries. Bagasse can provide heat to sugar mills and, in certain configurations, electricity. Fuels produced close to feedstocks could reduce some imports and create opportunities for farmers, collectors and processing industries.
The priority is to select feedstocks and sites according to local needs without undermining food security, soils or water resources. Projects must also demonstrate profitability, secure equipment access and guarantee fuel quality. For aviation, potential will additionally depend on certification, lasting purchase agreements and the ability to produce at an acceptable cost.
Frequently asked questions
Are biofuels always less polluting?
No. The outcome depends on feedstocks, land-use changes, energy consumed in processing and the fossil fuel replaced. A life-cycle assessment can evaluate net emissions.
What is the difference between biodiesel and renewable diesel?
Biodiesel mainly consists of esters obtained from oils or fats. Renewable diesel is a hydrocarbon produced through hydrogenation and may be closer to petroleum diesel in its properties and uses.
Can biofuels replace all oil?
Sustainable biomass potential is limited by land, water, available residues and competition between uses. Biofuels complement other solutions, such as energy efficiency, electrification and synthetic fuels.
Pourquoi la demande mondiale progresse
La croissance des biocarburants tient à plusieurs facteurs. Les obligations d’incorporation dans l’essence et le gazole créent des débouchés réguliers, tandis que les objectifs climatiques poussent les États à chercher des solutions utilisables dans les véhicules et les infrastructures existants. La sécurité d’approvisionnement compte également : produire une partie des carburants à partir de ressources locales peut limiter l’exposition aux importations de pétrole, à condition que les filières agricoles et industrielles soient disponibles.
Les usages s’étendent au-delà des voitures. L’aviation et le transport maritime cherchent des carburants à plus faible intensité carbone, car leur électrification directe est difficile à court terme. L’Agence internationale de l’énergie a relevé, dans son rapport Renewables 2025, que ses perspectives de croissance de la demande mondiale de biocarburants liquides jusqu’en 2030 avaient été révisées à la hausse de 50 % par rapport à l’édition précédente. Cette révision intègre notamment l’évolution des besoins de transport et de nouvelles politiques de mélange.
Dans un scénario accéléré, l’AIE estime que la demande pourrait atteindre 310 milliards de litres par an en 2030, soit environ 30 % de plus que dans son scénario principal, si les mesures annoncées ou en préparation étaient pleinement appliquées. Les volumes supplémentaires dépendraient à la fois de mélanges plus élevés dans les carburants routiers et de nouveaux débouchés, dont les carburants d’aviation durables et les carburants maritimes. Il s’agit d’un scénario conditionnel, et non d’un résultat déjà acquis.
La croissance ne garantit pas la durabilité
À mesure que les volumes augmentent, la disponibilité de matières premières durables devient un enjeu central. Les huiles alimentaires, les cultures énergétiques, les résidus agricoles et les huiles usagées n’ont ni les mêmes coûts ni les mêmes effets sur les terres et les chaînes alimentaires. Le recours aux déchets et résidus peut améliorer le bilan de certaines filières, mais leur collecte et leur transformation exigent des infrastructures et une traçabilité crédible.
Les politiques publiques influencent fortement l’investissement. Un changement des critères d’éligibilité, des quotas ou des subventions peut modifier la rentabilité d’une usine et la valeur de ses matières premières. Pour les producteurs, l’enjeu est de sécuriser des contrats d’approvisionnement cohérents avec les normes de durabilité ; pour les pouvoirs publics, il est de soutenir les filières dont les réductions d’émissions sont mesurables sur l’ensemble du cycle de vie. La progression de la demande mondiale ouvre ainsi des débouchés, mais elle rend aussi plus nécessaire l’évaluation des impacts agricoles, énergétiques et climatiques de chaque filière.