UNSW scientists have developed a unique graphene filter to purify methane obtained from municipal wastewater treatment plants.
Dr Rakesh Joshi and his team have successfully demonstrated how lab-grown graphene membranes can be used to extract methane present in wastewater generated biogas.
Mainly composed of methane and other impurities, biogas is produced when bacteria separates biodegradable material through the process of ‘Anaerobic Digestion’ in wastewater treatment plants.
“We are working in close collaboration with Sydney Water Corporation to convert these findings into a retrofittable technology for wastewater treatment plants,” contends Dr Joshi.
The university’s Graphene Team, in partnership with Sydney Water, has already demonstrated a graphene-based, laboratory-scale filter that can remove more than 99% of the ubiquitous natural organic matter left behind during conventional treatment of drinking water.
“Our group’s latest research indicates that it is possible to use graphene to extract and refine methane to be recycled and reused as a source of energy,” notes Joshi.
Dr Heri Bustamante, Principal Scientist in Treatment at Sydney Water, said there was a need to develop more cost effective and easier to operate technologies to purify the valuable methane in biogas:
“Sydney Water currently uses biogas produced in the wastewater treatment process to generate energy.”
“The use of graphene will enable increased capture of methane to expand potential uses beyond the requirements of Sydney Water.”
Producing methane to fuel buses could be a potential future use, for example, notes Bustamante.
“This would contribute to the potential of creating a circular economy at Sydney Water.”
Sydney Water supplies around 1.5 billion liters of drinking water each day which is treated at one of its nine water filtration plants.
Joshi’s team have been working with Sydney Water for the past four years to develop a graphene membrane design that is now being scaled up for commercialization.
The UNSW team is confident that their graphene membranes will be ready for plant trials at Sydney Water within the next five years.
Image and content: Shutterstock/University of New South Wales (UNSW)