Enjeux - Biofuels

Biofuels

With the inevitable dry-up of oil reserves, volatile barrel prices and the impact of carbon emissions on global warming, everyone agrees that we need to find alternative sources of energy. Biofuels, developed on a significant scale in the USA and Brazil for 30 years and in Europe since the mid-1980s, are a renewable energy source that can be used immediately. After an initial wave of enthusiasm in France, they have been widely criticised over the last two or three years. Let’s take a closer look at the viability of biofuels and try to understand today’s criticism in an attempt to determine whether the charges are justified.

THE CONCEPT

Definition

Biofuels, also known as agrifuels, result, like oil, from the transformation of organic plant matter. But unlike petrol, produced from fossilised matter produced and accumulated over hundreds of millions of years, biofuels are produced from yearly crops, which makes them a renewable source of energy. Biofuels are made by transforming sugar cane, sugar beets, wheat, corn, sunflower and soya bean, all of which are annual crops. In the future, if technological progress allows, the raw material will come from coppices of short-rotation trees and plants like miscanthus, crops that grow over several years. They may also be produced from by-products or waste, including straw, sawdust and green waste. 

Two types of biofuel exist: bioethanol and biodiesel. The best known brand of biodiesel in France is diester.

Bioethanol

Bioethanol today is produced mainly from sugar cane in Brazil, corn in the USA, and sugar beets, wheat and corn in Europe.  But it can also be produced from any source with a high content of sugar or starch, effectively long carbonaceous chains. The sugar contained in the raw material is transformed into alcohol through fermentation.  Bioethanol can be mixed with petrol, in blends containing 5% (in E5 fuel), 10% (in E10), 85% (E85) and even up to 100% bioethanol content in E100. Normal vehicle engines can run on blends containing up to 10% ethanol with no modifications necessary. Beyond that percentage, vehicles need to be fitted with flexfuel engines running on conventional petrol or petrol/ethanol mixes. E100 can only be used with special engines.

Biodiesel

Biodiesel is made from oil seeds with high oil content, including rapeseed and sunflower in Europe, soya bean in the USA and palm oil in Asia. It is the result of a chemical reaction called esterification between the vegetable oil extracted from the plants and an alcohol (methanol or ethanol), to the tune of one tonne of oil to 100 kg of alcohol. Biodiesel can be blended directly with diesel and used by all diesel-powered cars without engine modifications. The average content in diesel available at service stations in France today is 6%. Local authorities and businesses in the country have been using a 30% biodiesel/70% diesel blend for over ten years.

BACKGROUND

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.   

Clean fuels

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.

CRITICISMS

Challenged as petrol alternative

In a context of climate change and sharp rises in oil barrel prices in recent years, biofuels are often presented by their advocates as an alternative to petrol and as the best-adapted sustainable energy source for vehicles. But critics attack biofuels for their mixed environmental performance and excessive cost, for the way they reduce biodiversity and, most of all, because they take up too much agricultural land – land that was previously used to make food.  

Deforestation and reduced biodiversity

The production of biofuels from agricultural products has increased the surface of cultivated land in countries such as Brazil and Malaysia. Critics point to deforestation, reduced biodiversity, increased risks of soil erosion and excessive water use, accusing biofuel-producing countries of being guided purely by economic imperatives.

Strong competition with food production

Although the price of foodstuffs has fallen sharply since, in 2007 the growth of the bioethanol industry was presented as one of the factors responsible for the strong rise in the price of agricultural commodities on world markets, which led to food crises and hunger riots. The significant development of bioethanol production in Brazil using sugar cane had no particular effect on the price of sugar. However, the price of tortillas, a basic food in Latin America, rocketed in Mexico because the country’s corn producers preferred to export their crops at a high price to the USA, where they are transformed into bioethanol. 
Countries that are dependent on cereal imports – Egypt, for example – fear that such incidents will repeat and that the increase in land area used to cultivate cereals for biofuel production will once again threaten their food supply.

Environmental credentials called into question

While everyone agrees that we need to develop alternative solutions to petrol, the environmental credentials of biofuels are regularly called into question. Some people challenge the objectivity of the studies assessing their energy performance and their contribution to the reduction of greenhouse gases. They also denounce the sector’s overwhelming emphasis on high productivity.

OUTLOOK AND SOLUTIONS

Limited agricultural land in France

According to a 2007 study by ONIGC, now France AgriMer, France’s objective to incorporate 7% bioethanol in petrol by 2010 to reduce our dependence on oil imports will require just 2.5% of the land used by the country to produce cereals and 12% of that used for sugar beets. This represents less than 300,000 hectares, out of a total 9 million hectares used to farm these crops in France.

First-generation biofuels: a necessary step?

Progress is possible, starting with a better control of the factors that limit yields of these crops. Progress in genetics is regularly increasing yields in wheat, corn, rapeseed, sunflower and sugar beets.

Farmers have increasingly efficient coordination and monitoring tools that help them to cultivate crops with no waste in input. Improvements in industrial processes are also continuously boosting  the energy yield of biofuels at plant exit. For manufacturers in the sector, first-generation biofuels are an indispensable step towards the development of a second generation of fuels.

Second-generation biofuels

The interest in second-generation biofuels would be to use the entire plant, exploiting all of its constituent parts. For an equivalent cultivated area, the productivity of biofuels is set to increase and energy and environmental performances will be improved. To develop this new generation, players are pushing ahead with considerable research programmes, such as the Futurol project coordinated by 11 partners with a budget of 74 million euros.

Imprimer

Les autres dossiers :

• Les OGM au coeur de la controverse
• Les Biocarburants : une voie d'avenir ?
• La PAC est-elle indispensable ?
• Les phytosanitaires : à bannir ?
• L'agriculture : une menace pour la biodiversité ?
• Agriculture et gestion de l’eau, sont-elles incompatibles ?
• Les attaques contre la viande sont-elles justifiées ?