A proven “wonder material” – thin sheets of graphene could be used as inexpensive filters in water treatment and lead to methane-fuelled public transport, among other things.
Researchers from the University of New South Wales, Sydney have demonstrated graphene as a viable filter for removing valuable methane from the biogas produced in wastewater plants, potentially serving as a source of renewable energy.
The thin graphene membrane was originally developed by the research team as a means to purify drinking water. Under that application, it is capable of removing more than 99 per cent of the ubiquitous natural organic matter left behind during conventional treatment of drinking water.
Now, the technology is being converted in collaboration with Sydney Water into a cost-effective, easy-to-operate retro-fitable technology to purify the methane from biogas in treatment plants.
For the past four years, the UNSW team has been working towards scaling up the graphene filter for this commercial use. Lead researcher Dr Rakesh Joshi said the group’s recent research indicates it is not only possible to extract the methane, it can also be refined to be recycled and reused as a source of energy.
The process is made possible by the honeycomb structure of graphene’s atoms, which make it stronger than steel, essentially a “wonder material,” according to Dr Joshi.
“This is positive news for the wastewater and the renewable energy industries as it will be possible to use the purified methane for other applications,” he said in a statement.
“The graphene-based membranes show the removal of carbon dioxide from the mixture of gases.”
While Sydney Water already uses biogas produced in the wastewater treatment process to generate energy, principal scientist in treatment Dr Heri Bustamante said this technology will increase capture capability and expand potential uses beyond current requirements.
“Production of methane to fuel buses could be a potential future use, for example,” Dr Bustamante said. “This would contribute to the potential of creating a circular economy at Sydney Water.”
It is expected the graphene membranes will be scaled up and ready for plant trials within the next five years.