The two-year project, funded by a Scottish Enterprise grant, is being carried out by Edinburgh's Napier University. The researchers believe the process could play an important part in meeting the demands of the Landfill Directive, which bans the disposal of whole tyres to landfill in July 2003 and shredded tyres in July 2006.
The process will involve grinding the tyres down, removing metals and fibre before adding the rubber to a liquid containing the bacteria. The bacteria, first isolated at Napier University, feeds on sulphur molecules used to vulcanise the original rubber.
Explaining the process, project leader Professor Nick Christofi said: “Rubber gains its strength through a process called vulcanisation which adds sulphur to rubber molecules. The bacteria, which is found naturally on former coal mining and oil production sites, can devulcanise the rubber tyres by eating the sulphur.”
The rubber, claims the university, can then be processed into new rubber products – with the bacteria being killed off by the high temperatures involved in the manufacturing process.
Once their project is complete, the Scottish researchers hope to find a private sector partner to set up a factory to exploit the new technique.
“We already know, from lab tests, that the bacteria feed on sulphur and we are confident it can work in this application,” Professor Christofi said.
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