Under the Microscope: The modern world is very dependent on transport fuels - petrol and diesel derived from fossil fuel oil, writes Prof William Reville
This causes two major problems. First, fossil fuel is a non-renewable resource. We have already discovered almost all the oil in the earth, we have reached peak oil production, and we will soon live in an oil-scarce world. Second, burning oil increases the carbon dioxide content of the atmosphere, which is dangerously warming our world. We urgently need an alternative to oil for transport. Biofuel will be an important part of that alternative. We have a unique opportunity in Ireland to quickly power up biofuel production for transport by converting and reopening the sugar factories in Mallow and Carlow. This will also deliver the important bonus of reviving the sugar beet industry, helping farmers and preserving our rural heritage.
Biofuel is any fuel derived from biomass - recently living organisms or their metabolic by-products, such as cow manure. Biofuel is a renewable source of energy. In this article I will concentrate on two biofuels suitable for powering cars and trucks, bioethanol and biodiesel. These fuels can be blended with petrol or diesel respectively and used in conventional car engines, or can be burned on their own in specially designed engines. Use of these biofuels will conserve scarce oil resources for future generations and minimise their impact on atmospheric carbon dioxide levels. However, strong government incentives are needed to encourage necessary private investment.
Bioethanol is ethanol derived from agricultural sources. Ethanol is the familiar alcohol found in beer, wine and spirits. It is clear, colourless and fully miscible with petrol. Ethanol, and biodiesel, have been used since the early days of the car industry. The internal combustion engine, invented by Nickolaus Otto, was intended to run on ethanol. Rudolf Diesel, inventor of the diesel engine, conceived it to run on peanut oil. However the biofuels could not compete then with cheaper petroleum based gasoline and fell out of favour.
Biofuels are now back on the agenda and the transition to a biofuel society is probably inevitable. Ethanol production in the US in 1979 was less than 200 million litres per annum (mlpa); today it is 11,000 mlpa and is expected to double by 2012. The largest producer of bioethanol in the world is Brazil (14,000 mlpa), where ethanol is made from sugarcane and helps offset the huge cost of importing crude oil. Ethanol/petrol blends of up to 35 per cent ethanol are used in Brazil.
The technical process of bioethanol production is well established. Bioethanol is the product of the fermentation of sugars. Basically, any plant that stores sugar can be used as raw material for the production of bioethanol - corn, wheat, barley, sugar beet, and so on. The plant is pulped, the sugar extracted and mixed with yeast which ferments the sugar into alcohol. All other components of the plant (fibre, protein etc) end up as by-products of the process and are known as Dried Distiller's Grains and Solubles (DDGS). This is sold as animal feed.
Biodiesel, on the other hand, is made from vegetable oils and animal fats and has properties similar to petroleum-based diesel. The process involves mixing methanol with the oil or fat and allowing the resulting biodiesel layer to separate by gravity from the heavier by-product glycerol layer. The glycerol is also important economically as it is widely used in the pharmaceutical and cosmetic industries. Burning biofuels in car engines releases carbon dioxide but this gas is removed from the atmosphere when the biofuel crop is grown again. Use of biofuels does not add significantly to atmospheric carbon dioxide.
The recently formed Irish Biofuels Initiative (IBI) is promoting the idea of reopening the sugar-beet factories at Carlow and Mallow and using them to produce bioethanol from sugar beet. IBI estimates that the bioethanol potential would be the equivalent of about 14 per cent of current national petrol use. Furthermore, the animal feed potential of the beet pulp and DDGS by-product would produce about 60,000 tons of feed annually.
The IBI proposal makes great sense. The sugar factories at Carlow and Mallow are ideally located and serviced by rail and road transport. The EU would provide 75 per cent compensation when sugar quotas are reduced and the factories converted to ethanol production. Employment could be retained/sustained in both factory areas. We would have a strategic supply of home produced ethanol. Farmers could continue with beet as a cash and tillage break crop. Use of ethanol as fuel would contribute towards our obligations under the Kyoto Protocol. Alternatively, we could sell off the two factories to speculators who would transform them into two more housing estates!
Imagine the excitement that would greet the discovery of an Irish oil field capable of supplying 14 per cent of our annual petrol needs for the foreseeable future. Well, we can easily do better than this by using native sugar beet to produce bioethanol and we will not pollute the atmosphere in the process. The Government is interested in promoting biofuels. Minister Noel Dempsey recently announced a new excise relief programme for biofuels valued at more than €200 million. I would urge Ministers Dempsey and Coughlan to look carefully at the sugar-beet proposal. Anyone interested in contacting the Irish Biofuels Initiative can do so by telephoning Alan Navratil at 021-4613555.
• William Reville is associate professor of biochemistry and public awareness of science officer at UCC - http://understandingscience.ucc.ie