Recycled aluminum foil could make for cheaper, greener biofuels
According to researchers at Queen's University Belfast, around 20,000 metric tons of aluminum foil is tossed away in the UK each year – enough to stretch to the Moon and back. This prompted chemistry researcher Ahmed Osman to look for new ways to put all that waste to use. Working with the school's engineers, Osman has now come up with a way to turn used tinfoil into a catalyst for biofuel that could not only be more environmentally friendly, but more cost-effective too.
The trouble with recycling aluminum largely stems from how we used it the first time around. While aluminum cans can be taken to treatment plants, cleaned and reprocessed, the foil that accompanies food items is typically contaminated by grease and oils, which cause damage to the plant's recycling equipment. Most of it is dumped in landfill or incinerated.
So for Osman, whose work focuses on developing cheaper and easier ways to produce biofuels from waste, it presented as the perfect material. After rounding up some aluminum foil from the university's building laboratories, he began work on a new kind of crystallization method in an attempt to turn it into something useful.
This new technique involves dissolving the foil in acidic solutions and keeping them there until single crystals form. Ammonia precipitation is then used to turn those into the 100 percent pure single crystals of aluminum salts, a green method the team says produces no emissions or waste.
These aluminum salts can be used as a starting material of alumina catalyst, which in turn can be used to produce dimethyl ether, a clean, non-toxic biofuel. Current approaches to producing alumina catalyst require mining bauxite ore in places like West Africa and Australia, which causes considerable environmental damage.
So further to saving a whole lot of aluminum foil from going to landfill, Osman's method also shapes as a greener approach on the production side of things. And it is cost-effective too. The average cost of commercial alumina catalyst is around US$400 per kg. He says with 265 g (9.3 oz) of foil, he can produce a kilogram for just $156. From here, Osman hopes to continue improving these catalysts and investigate how the process of biofuel production might be commercialized.
"This breakthrough is significant as not only is the alumina more pure than its commercial counterpart, it could also reduce the amount of aluminum foil going to landfill while also sidestepping the environmental damage associated with mining bauxite," he says.
The research was published in the journal Nature Scientific Reports.
Source: Queen's University Belfast