Scientists at Australia's RMIT have developed a microscopic sponge that they say can convert old dirty cooking oil into biofuel in a much easier and cheaper way than commonly used methods.
The RMIT team says their sponge is a first-of-its-kind development that could convert a variety of other waste products into reusable materials.
An ultra-efficient catalyst
The microscopic sponge developed at RMIT is a new type of ultra-efficient catalyst that turns complex molecules into raw materials with an unprecedented degree of control over the output.
"Catalysts have previously been developed that can perform multiple simultaneous reactions, but these approaches offer little control over the chemistry and tend to be inefficient and unpredictable," co-lead investigator Professor Karen Wilson explained in a press release.
"Our bio-inspired approach looks to nature's catalysts – enzymes – to develop a powerful and precise way of performing multiple reactions in a set sequence. It's like having a nanoscale production line for chemical reactions – all housed in one, tiny and super-efficient catalyst particle," he continued.
Recycling cooking oil and other materials
The micron-sized and highly porous sponge causes molecules that are fed into it to undergo a chemical reaction. Amongst the materials that can be recycled using the new method is dirty cooking oil, which would otherwise typically be disposed of rather than recycled.
Current methods for recycling cooking oil into biofuel would see the oil cleaned through an energy-intensive process to do away with contaminants.
The researchers at RMIT point out that the traditional process can only handle pure feedstocks with 1-2% contaminants, while the new catalyst can make biodiesel from low-grade ingredients, known as feedstock, containing up to 50% contaminants.
As of now, the researchers say their sponge only requires a large container and occasional stirring to turn cooking oil into biofuel. They say that in the future they would like to develop their work to enable it to produce jet fuel from agricultural waste, rubber tires, or algae.
"Our new catalysts can help us get the full value of resources that would ordinarily go to waste – from rancid used cooking oil to rice husks and vegetable peelings – to advance the circular economy," co-lead investigator Professor Adam Lee explains.