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Alternative Fuels. Why do we need alternative fuels?. Most vehicles in the world are powered by petrol or diesel. These fuels are produced from crude oil.
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Why do we need alternative fuels? Most vehicles in the world are powered by petrol or diesel. These fuels are produced from crude oil. Crude oil is a fossil fuel. It is non-renewable, which means it will run out. Some people believe that reserves of crude oil could run out within 30 years. Although fossil fuels are currently a convenient source of fuel, the products released when they are burned can be very damaging to the environment. As a result, some people have already begun using alternative fuels.
What are biofuels? Biofuels are renewable fuels produced from plant material, such as agricultural crops, or animal oils. Bioethanol and biodiesel are types of biofuels used in vehicles to reduce the demand for petrol. Biofuels can be safely combined with normal petrol or diesel and used in conventional engines to reduce levels of harmful emissions without causing engine damage.
Bioethanol Bioethanol is produced by the natural fermentation of the sugars in certain plants, such as sugar cane or sugar beet. Flexible Fuel Vehicles (FFVs) are engineered to run on fuel that is a blend of ethanol and petrol. FFVs have long been popular in Brazil, where farmers are paid generous subsidies to grow sugar cane for bioethanol. Cars that can run on bioethanol are also taxed at a lower rate than cars that cannot.
Biodiesel Biodiesel is produced by chemically reacting vegetable oils or animal fats with alcohol and a catalyst. The process can be completed in 12 hours. Biodiesel can be mixed with conventional diesel, which significantly reduces harmful exhaust emissions (although the fumes from a biodiesel car can smell like fried foods!). There are few garages in the UK that sell biodiesel. Home-made fuels from vegetable oils are not taxed to encourage people to use them.
Hydrogen fuel cells Hydrogen fuel cells are electrochemical energy conversion devices that work by combining hydrogen with oxygen from the air to form water, producing electrical energy in the process. Unlike in a battery, where all the chemicals needed for energy conversion are stored inside, the hydrogen needed for a fuel cell to work can be replenished. Methanol, natural gas and propane have all shown potential for use in fuel cells.
Using electricity Vehicles powered by electricity stored in batteries have been used for a number of years. Provided the electricity used in the battery is generated from a renewable energy source, such as a wind turbine, vehicles powered entirely by electricity produce no harmful emissions. Currently the batteries can be large and heavy, and many may be needed to power a vehicle. They need to be regularly recharged, which can take a long time.
Developing electric cars Scientists are working to develop practical, everyday cars that can run on electricity for longer journeys. More people using electric cars than petrol or diesel cars could dramatically decrease a country’s harmful emissions. Governments are also encouraging people to switch to electric cars – in the UK, people who drive electric cars are exempt from road tax and car parking charges in many areas. However, if a large number of people suddenly converted to using electric cars, the increased demand for electricity could put a strain on the National Grid.
