Enjeux - Biofuels
Greenhouse gas reduction
In Europe, biofuels have been developed mostly for their environmental merits, as they are a possible response for reducing greenhouse gases. Burning them does release carbon gas (CO2), one of the main greenhouse gases, but this gas was absorbed by the plants during growth from CO2 that was already present in the atmosphere.
The reduction in pollutant emissions in the atmosphere is also a major argument used by the biofuel industry. CO2 and water vapour are practically the only emissions produced by biofuels, and, unlike fossil-based fuels, they emit zero or very little nitrogen oxide and sulphur oxide (NOx and SOx).
Apart from its properties as a lubricant, then, using biodiesel in diesels has enabled petroleum companies to stop adding sulphur to their fuels. Also, bioethanol improves petrol combustion by increasing the octane rating.
Spending less on oil
The third argument of biofuel advocates is that biofuel reduces our dependence on oil imports. Each tonne of biofuel produced saves on a tonne of petrol or diesel produced from imported oil. This is the main objective of the two biggest bioethanol producers, Brazil and the USA, who see their energy supply as a strategic issue, especially as the largest share of oil production is in the hands of politically unstable countries.
Petrol accounts for 80% of French energy imports by value (source: Pégase database of the Ministry of the Economy, Finance and Industry). All new energy sources help to diversify supply and reduce our dependence on imported oil. Biofuel manufacture also results in plant-based co-products such as spent grain and oil cakes, which are rich in protein. This is another way of reducing our trade deficit, since France and Europe lack proteins for animal feeds and import considerable quantities every year.
Les autres dossiers :
BIOFUEL LIFE CYCLE
According to a very recent study on the “field to wheel” biofuel life cycle produced by the French Environment and Energy Management Agency (ADEME) and BIO Intelligence Service:
- Compared with petrol, bioethanol reduces atmospheric emissions of greenhouse gases by 58% (for wheat) to 73% (sugar beets).
- The energy yield (energy produced/non-renewable energy consumed) for the production of wheat and sugar beet ethanol is an average 1.7. In other words, bioethanol produces 1.7 times more energy than it takes to produce – compared with 0.8 for petrol.
- Compared with diesel, biodiesel reduces greenhouse gas emissions by 60% (for rapeseed) to 73% (sunflower).
- Incorporating 7% biodiesel in the diesel fuel sold at pumps in France in 2010 reduced atmospheric emissions of greenhouse gases by the equivalent of 6 million tonnes.
- Biodiesel supplies 2.2 times more energy than the fossil fuel used to produce it (versus 0.8 for diesel).