Photo: Grazer Stadtwerke ...
From the Frying Pan into the Tank - Graz
The environmental programme “Eco City – Local Agenda 21” has put Graz firmly on the path towards sustainable development. The EU award “Sustainable City” has made it clear that this path is also attracting attention at a European level. One part of the overall concept concerns the promotion of public transport.
Since 2005, the 134 buses of the Grazer Verkehrsbetriebe (Graz transport services) have been running on biodiesel produced from waste cooking oil.The idea was originally conceived in the city environmental department that wanted to prevent used cooking oil from being disposed of into the sewage system. According to an assessment conducted in the year 2000, one litre of old cooking oil in the sewage system cost the sewage treatment plant operator 0.44 euros. Since 1990, waste cooking oil from private households is collected, free of charge, at special collection stations for problematic substances. In 1999, a free collection system was also installed for restaurants and catering businesses in Graz. Around 20 % of the 1,200
catering businesses in Graz with an estimated annual capacity of 200,000 litres of used cooking oil are currently collection is run by the non-profit service company Öko-Service that creates useful jobs in ecological areas
for long-term unemployed and disabled people. At present, 50 people are employed by Öko-Service.
The Grazer Verkehrsbetriebe started the project “Eco-diesel from old cooking oil” already back in 1994. The added consumption for buses is at around 5 %, however, the price for biodiesel is lower. As pure biodiesel from waste cooking oil is not suited for the wintertime, it is necessary to switch to mixed operation with diesel oil during the cold season. To improve the air quality, the buses were equipped with particle oxidation catalysts that reduce the total number of particles by 90 %. These catalysts are also suited for engines driven by fossil diesel.
The biodiesel recycling facility is at the South-Styrian energy and protein cooperative SEEG in Mureck. One kilogram of waste cooking oil can be recycled into 0.85 litres of biodiesel. SEEG was the first company in the world ever to produce biodiesel out of waste cooking oil. “Bioenergie-
Kreislauf Mureck” was awarded the World Energy Globe Award in 2001.
04.07.2006,