New research has shown how Australian energy companies and waste management firms can safely turn organic waste, such as food scraps, sewage and animal waste, into clean gas for homes and businesses.
Led by Professor Mohsen Talei from the University of Melbourne's Faculty of Engineering and Information Technology, the research team identified the critical specifications for optimal biomethane quality, making it more cost effective to produce and informing the latest update of Australian Standards for use by energy producers.
The revised standard now recognises biomethane as a natural gas equivalent and introduces new contaminant limits. It gives distributors, manufacturers and regulators a shared foundation to work from and clears the path for biomethane to enter Australia's gas networks safely and at scale.
"Converting waste into renewable energy supports circular-economy principles, reduces methane emissions and capitalises on existing gas infrastructure serving millions of homes and industries," Professor Talei said.
Funded by Future Fuels CRC, the team used computer modelling and built a custom-made burner to understand how tiny compounds found in biomethane, a renewable gas, affect everyday appliances, in a push to facilitate scaling this repurposed energy source.
Biomethane, or Renewable Natural Gas, is a near-pure source of methane derived from organic waste broken down by microorganisms in oxygen-free tanks, to produce biogas. It can replace fossil natural gas for heating, electricity and transport, significantly reducing greenhouse gas emissions.
The fuel crisis has put pressure on Australia's energy system, driving a 42% surge in EV sales during March, but electrification alone cannot replace all fossil fuels, particularly for heavy transport and industry use.
A NSW demonstration project , the Malabar Biomethane Facility, has proved that biomethane can be upgraded and safely injected into Australia's gas pipelines. According to a Blunomy and Energy Networks Australia study , Australia could potentially recover enough biomethane from waste to offset 96 per cent of the East Coast's demand for gas, purifying biomethane to scale its use nationally is a demanding process.
"One of the main challenges is fully removing a compound named siloxane, which comes from household products like deodorants and shampoos. When burned in biomethane, siloxane leaves a glass-like coating on appliances, making them less effective and damaging them over time," Professor Talei said.
"Our research findings help to determine exactly how much siloxane needs to be removed to nationally scale the use of biomethane as an energy source."
The team simulated how gas flow, temperature and chemical reactions influence the formation of this glass-like coating under a wide range of conditions.
"By combining simulation outcomes and experimental data, we developed a framework to predict how much siloxane can be present for appliances to still run reliably, even at concentrations too low to study experimentally," he said.
Professor Talei and his team are now in discussions with an industry partner to support further research and a wider adoption of biomethane.
