(Waste Treatment Technology News) Nov 2002 - A Staffordshire University(School of Engineering and Advanced Technology, Beacon Building,Staffordshire University, Beaconside, Stafford, Staffordshire, ST18 0AD,U.K.; Tel: +44 (0) 1785 353335) researcher has developed a method forconverting used cooking oil into biodiesel, a cleaner-burning alternativeto fossil-based diesel.The process devised by Tarik Al-Shemmeri, a Staffordshire Reader inEnvironmental Engineering, employs discarded vegetable oil as the base fora sustainable fuel. Unlike conventional diesel, the oil does not releasesulfur dioxide, a contributor to acid rain and one of world's worstpollutants, when burned. When combusted in a conventional diesel engine,biodiesel also reduces unburned hydrocarbons, carbon monoxide andparticulate matter. Compared to petroleum diesel, up to 78.5% of carbondioxide emissions can be eliminated. The biofuel can be used in existingengines with little impact on operating performance.In addition, Al-Shemmeri's biodiesel offers an environmentally friendlyuse for the large volumes of castoff cooking oil continuously produced byrestaurants and hotels worldwide. If not properly disposed off, the usedoil can pollute agricultural land and waterways.Biodiesel is derived from vegetable oil through an esterification process,which uses alcohol and slow heating to convert the oils into biodiesel(alkyl esters), glycerine and traces of water. Each ester chain usuallycontains 18 carbon atoms and retains two oxygen atoms, which gives thefuel unique combustion properties.The Staffordshire researcher has conducted a series of successfulexperiments using the biodiesel in a 10-kW diesel engine mounted on alaboratory test bed. Al-Shemmeri believes one of the best applications forthe biodiesel is fueling small power generators that would create heat andelectricity for small and rural communities around the world. He says,"This fuel would be ideal for use in conventional diesel-poweredgenerators which typically supply electricity to villages in parts ofAfrica or Asia. By collecting unwanted cooking oil, villagers can access areliable and cheap fuel."Al-Shemmeri presented his research findings, "Biodiesel Fuel for CombinedHeat and Power Generation," to the 37th International Universities PowerEngineering Conference held in Staffordshire in early September. Energyexperts representing 36 countries from five continents attended thethree-day conference, which covered topics including power generation andrenewable energy sources.