Generating energy by purifying the air we exhale; it sounds like a utopia but Belgian scientists from KU Leuven seem to make it possible. They developed, in collaboration with the University of Antwerp, a remarkably simple way to convert polluted air into energy. All it takes is light.
Air pollution still plagues many people: in 2013, as many as 5.5 million people worldwide died from the effects of polluted air. The problem is particularly acute in countries such as China and India. Researchers at KU Leuven have now managed to put a positive spin on air pollution; they developed a technology that allows polluted air to be converted into energy.
The device consists of two chambers separated by a membrane. On one side, air is purified; on the other, hydrogen gas is produced from some of the degradation products.
Hydrogen
"We tried to develop a technology that on the one hand tackles polluted air - so you can breathe clean air and create a clean living environment - and on the other hand is an alternative energy source," explains professor Sammy Verbruggen (UAntwerpen / KU Leuven). "But this is still a proof of concept."
The hydrogen gas produced in one chamber of the device can be stored and later used as fuel, as is already being used in some hydrogen buses of De Lijn, a Belgian transport company, for example.
In this way, the researchers are responding to two major societal needs: clean air and alternative energy production. The core of the solution is at the level of the membrane. That is where the researchers apply specific nanomaterials. "Those catalysts are capable of forming hydrogen gas and breaking down air pollution," explains Verbruggen. "In the past, such cells were mainly used to extract hydrogen from water. We have now discovered that it can also be done, and even more efficiently, with polluted air."
Sunlight
You would think it would involve a complicated process, but nothing could be further from the truth: all the device needs is illumination. The researchers' goal is to be able to make use of sunlight. Indeed, the processes underlying the technology are similar to those of solar panels. "The difference is that here electricity is not produced directly, but air is purified while the generated energy is stored in hydrogen gas."
Scaling up
The device could just be a solution to major world problems. Not only can it tackle air pollution but also the shortage of energy sources. In India, for instance, 240 million people have no access to electricity. In addition, it could help reduce pollution in industry itself. "I imagine many industries have to deal with large waste streams. If you can use this technology to divert waste gases, then the industry can always comply with environmental regulations."
The device is currently so small that it fits in the palm of a hand, but the intention is to change that. "In time, we would like to scale up our technology to make the process industrially applicable. We are also working on improving our materials so that we can make even more efficient use of sunlight to generate the reactions. It is not that we have invented the holy grail. But we have created a new palette of possibilities."
By: Kelly Bakker
Photos: KU Leuven
