VIDEO: Scientists turn old toothpaste tubes into fuel and precious metal
Nestlé, Kraft Foods and Mondelez International are part-funding a new commercial-scale recycling plant that can turn old toothpaste tubes into aluminium and fuel in just three minutes.
Previously, this type of plastic-aluminium laminate waste – also used in drink pouches and pet-food packaging – was consigned to landfill, meaning around 16,000 tonnes of aluminium was squandered each year in the UK alone.
But researchers at the University of Cambridge have been exploring how laminate packaging would react to intense heating – known as microwave-induced pyrolysis. (Scroll down for video).
Trial by fire
Professor Howard Chase and Dr Carlos Ludlow-Palafox put a pile of particulate carbon and some shredded laminate packaging inside a conventional kitchen microwave, replaced the air inside the oven with nitrogen and turned the microwave up to full power until the temperature increased to about 600°C.
When they opened the door two minutes later, the laminate material had been separated into clean aluminium flakes and hydrocarbon gases and oil.
With funding from consumer-goods companies Nestle, Kraft Foods and Mondolez, the idea has now been successfully scaled up in the form of a commercial plant which will recycle 2,000 tonnes of waste a year.
The aluminium output is used for smelting, while the hydrocarbons are used for fuel with no toxic emissions.
Chase and Ludlow-Palafox expect the plant to pay for itself within three years.
“It was a chicken and egg situation,” said Ludlow-Palafox. “No one is going to buy this technology unless this type of waste is separated for recycling, but the waste wasn’t going to be separated because there has been no process to recycle it. We had to break that negative loop somehow.
“Now we have the commercial-scale plant, we can show waste handlers the benefits and encourage local authorities to implement a selective collecting system.”
Video: Turning waste into aluminium and fuel
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