scientists have devised various methods to recycle old tyres into new ones. Now Kirk Manfredi, a chemist at the University of Northern Iowa, usa , has developed a technique to produce lemon oil from discarded tyres. He produces limonene, which is the main ingredient in the oil of lemons and other citrus fruits ( Discover , Vol 18, No 7).

When old tyres are processed in an airless reactor at around 725