Scientists Figure Out How to Recycle Aluminum Foil Into an Ingredient for Biofuel

A whole lot of aluminum foil ends up in landfills each year—some 22,000 tons in the UK alone. Like cans, aluminum foil can be recycled, but because we tend to use foil to pack food, that’s a tricky proposition. Many recycling centers won’t take dirty aluminum foil, since the contamination from greasy and oily food can damage recycling equipment. New research led by engineers at Queen's University Belfast in Northern Ireland has found another way to make use of that old aluminum foil, even if it does have food stuck to it.

As New Atlas reports, the study in Scientific Reports introduces a crystallization method that allows contaminated foil to be transformed into pure aluminum salt crystals. This can be turned into a chemical catalyst to make dimethyl ether, a biofuel that is considered a promising alternative energy source, especially to run diesel engines.

Essentially, the researchers dissolved the foil in a chemical solution that turned it into crystals, then used another chemical mixture to purify those crystals. The resulting 100 percent pure aluminum salts can be used to create alumina catalyst, a key ingredient for making dimethyl ether.

Alumina catalyst created by the tinfoil process would be cheaper than the current commercial version, according to a press release from the university. It costs about $72 per pound, compared to $183 per pound for the existing commercial catalyst.

In addition, the commercially available catalyst is made from bauxite ore, and like many materials that need to be mined from deep within the earth, obtaining bauxite is a resource-intensive process with major environmental costs. So if this technique lives up to its promise, the benefits of being able to recycle even food-soiled aluminum for a second use would be two-fold. It would save used aluminum from the landfill, and allow researchers to produce more of this biofuel without causing environmental harm.