Bioethanol as fuel

Ethanol today is by far the largest and most immediately available renewable alternative to petrol and diesel. The Swedish Parliament has agreed to follow the UN’s recommendations concerning the reduction of carbon dioxide emissions, and as such, Sweden has already significantly reduced its emissions from the burning of oil. It still needs to reduce emissions from transports. One of the few viable large-scale alternatives to petrol and diesel is bioalcohol. To be of benefit in reducing pollution, these bioalcohols must be produced from biological raw materials such as forestry waste products, wood chips, recycled paper, energy forests, grains, sugarcane, corn or sugar beets.

Ethanol can be used in piston engines in the same way as petrol. Ethanol has a higher octane content then petrol and therefore burns more slowly, which provides better fuel efficiency compared with petrol-powered vehicles. For this reason, many racing cars have converted to using ethanol. Ethanol has a lower energy value per litre than petrol, which means more is needed per kilometre.

Nearly all of the petrol sold in Sweden today contains 5 per cent ethanol, which is the highest permissible blend ratio within the EU. However, an increase to a blend ratio of 10 per cent is not far off. It’s this low-grade blending of ethanol in petrol which accounts for the largest part of Sweden’s ethanol consumption. Fuel with a higher concentration of ethanol is used in ethanol-driven cars (fuel-flexible cars), buses and lorries. Read more about this via the links E85 and ED95.

Ethanol-blended fuels cut exhaust emissions and therefore contribute less to the Greenhouse Effect. Bioethanol can also function as an energy carrier, regardless of whether calculations are based on the currently available engines or on the hybrid motors and fuel cells of tomorrow. Bioethanol has gradually been introduced into the current distribution system for petrol and diesel.

Ethanol gives a purer exhaust than petrol when burned in an engine, as it does not contain sulphur or cyclic hydrocarbons such as benzene. No soot is formed, either, in an ethanol engine, as after complete combustion only acetic acid and a very small amount of formaldehyde are produced. Approximately 90 per cent of the non-combusted substance remaining is pure ethanol, which is a part of the natural biological cycle and is therefore insignificant in this context.