#Engineers find neat way to turn waste carbon dioxide into useful material

The researchers say in effect, they are closing the carbon loop in industrial processes that create harmful greenhouse gases. And by making small adjustments to the way the nanoparticles are burned by the FSP technique, they can determine the eventual mix of the syngas building blocks produced by the carbon dioxide conversion.
“At the moment you generate syngas by using natural gas—so from fossil fuels,” Dr. Daiyan says. “But we’re using waste carbon dioxide and then converting it to syngas in a ratio depending on which industry you want to use it in.”
For example, a one to one ratio between the carbon monoxide and hydrogen lends itself to syngas that can be used as fuel. But a ratio of four parts carbon monoxide and one part hydrogen is suitable for the creation of plastics, Dr. Daiyan says.
Cheap and accessible
In choosing zinc oxide as their catalyst, the researchers have ensured that their solution has remained a cheaper alternative to what has been previously attempted in this space.
“Past attempts have used expensive materials such as palladium, but this is the first instance where a very cheap and abundant material, mined locally in Australia, has been successfully applied to the problem of waste carbon dioxide conversion,” Dr. Daiyan says.
Dr. Lovell adds that what also makes this method appealing is using the FSP flame system to create and control these valuable materials.
“It means it can be used industrially, it can be scaled, it’s super quick to make the materials and very effective,” she says.
“We don’t need to worry about complicated synthesis techniques that use really expensive metals and precursors—we can burn it and in 10 minutes have these particles ready to go. And by controlling how we burn it, we can control those ratios of desired syngas building blocks.”
Scaling up
While the duo have already built an electrolyser that has been tested with waste CO₂ gas that contains contaminants, scaling the technology up to the point where it could convert all of the waste carbon dioxide emitted by a power plant is still a way down the track.
“The idea is that we can take a point source of CO₂, such as a coal fired power plant, a gas power plant, or even a natural gas mine where you liberate a huge amount of pure CO₂ and we can essentially retrofit this technology at the back end of these plants. Then you could capture that produced CO₂ and convert it into something that is hugely valuable to industry,” says Dr. Lovell.
The group’s next project will be to test their nanomaterials in a flue gas setting to ensure they are tolerant to the harsh conditions and other chemicals found in industrial waste gas.