Methane is produced when vegetable matter decomposes. It forms methane hydrate when conditions are very cold and the pressure of the gas is high. However, a major problem with using methane is that it is a powerful greenhouse gas – 10 times stronger than carbon dioxide.
Most modern cars are fitted with catalytic converters. These are designed to reduce pollution. The first stage converts the oxides of nitrogen into nitrogen and oxygen. The second stage is designed to deal with the pollutant produced as a result of the incomplete combustion of the fuel.
This table shows how the production and consumption of gas in the United Kingdom have changed since 1970.
As oil supplies begin to diminish, alternatives to petrol and diesel for our transport needs are being investigated. One such fuel is bioethanol.
What is bioethanol?
Bioethanol is a fuel that can be used in all vehicles. It can be blended with petrol at 5% without the need to change fuel or engine specifications. It can be easily distributed using existing filling stations. Bioethanol is produced by the fermentation of crops such as cereals, sugar beet and maize. At current oil price levels, bioethanol is more expensive to produce than petrol, but it does have enormous benefits.
Why bioethanol?
The UK government has set its own target to reduce carbon dioxide (CO2) emissions by 20% by
2010. This represents over 80 million tonnes of CO2 per year. The transport sector accounts for 22% of all ‘greenhouse gas’ emissions, which have increased by 5% since 1990. Petrol usage in the UK is now 24 million tonnes per year. Bioethanol reduces greenhouse gas emissions by at least 50% compared with fossil fuels such as petrol. Blending all petrol with bioethanol would reduce annual CO2 emissions in the UK by 3 million tonnes. Also, using bioethanol improves air quality by reducing the amount of carbon monoxide (CO) from older engines. The rural economy is under increasing pressure following foot-and-mouth disease. The production of raw materials for bioethanol would help to create new sources of income and employment in rural areas. At least 20 000 new jobs could be created in support of a UK bioethanol industry. Europe imports almost 80% of its petrol needs and the demand for oil is increasing. The amount of oil needed for transport is forecast to rise by 2% per year. The UK will be a net importer of oil in the near future. Bioethanol produced from sustainable sources within the UK would contribute to having a secure fuel supply.
What is needed to start a UK bioethanol industry?
Because bioethanol cannot be produced as cheaply as petrol, government support will be needed to establish a viable bioethanol industry in the UK. The report Farming and Food – a Sustainable Future recommended that the duty paid on bioethanol be reduced to 4.5p per litre – the same as that for other ‘clean’ fuels such as liquefied petroleum gas (LPG).