CSIRO’s ventilation air methane (VAM) abatement research has taken another step forward with the world-first trial of high-efficiency catalytic VAM abatement at large scale under real mining conditions.
The trial, at the GM3 Appin mine in southern New South Wales, Australia, used CataVAM™ catalytic oxidation technology.
Every underground coal mine has one thing in common: coal seams leak methane gas into the tunnel network, presenting a serious safety hazard.
The control is the same the world over: continuously pump fresh air through the workings, diluting and pushing out the methane. High-volume mechanical ventilation systems are a cornerstone of mine safety, but they create a stubborn environmental problem, according to CSIRO.
Exhaust air from coal mining, called VAM, carries methane at safe concentrations – typically well below 1%, ensuring a safety margin below the 5% explosive range. Dusty and damp, the VAM is often pumped at hundreds of cubic metres per second.
Methane is roughly 28 times more potent as a greenhouse gas than CO2, with VAM accounting for more than 60% of all fugitive emissions from Australian coal mines and around 15% of the nation’s total methane output. That makes methane a material liability. One that regulators, investors and mine operators are increasingly required to address.
Thermal oxidisers – essentially high-temperature burners – have been used since the 1990s to destroy industrial methane. But they are often bulky, and generally operate above 900°C, using the methane they treat to sustain that temperature. A conventional thermal system requires concentrations of 0.3% and above to work well. Once methane in the VAM drops below this threshold, they typically need supplemental fuel to keep running efficiently, adding cost, complexity and their own emissions.
Too dilute to burn, too voluminous to concentrate easily, low and highly variable levels of VAM have presented an engineering paradox that has defeated every straightforward approach to effective abatement – until now.
Why the problem is getting harder
The VAM challenge has sharpened considerably over the past decade, driven by two converging forces. Australia’s Safeguard Mechanism, established in 2016 and significantly expanded in 2023, now unequivocally requires large emitters, including underground coal mines, to keep net emissions within defined baselines.
Australia is also a signatory to the Global Methane Pledge, which commits more than 120 countries to collectively cut methane emissions by 30% below 2020 levels by 2030. That deadline is approaching fast, and global progress has been disappointing.
At the same time, mine safety practice has tightened risk management. Operators usually pre-drain methane from coal seams removing the majority of the explosive gas. Further government regulatory pressure has driven even lower methane concentration limits through improved gas management and reporting to better protect workers underground.
This means more dilution, with lower average methane concentrations in the VAM stream and higher volumetric flow rates.
Over the past decade, methane concentrations in Australian mine ventilation air streams have declined significantly and now typically range from 0.2-0.4%, with levels below 0.2% occurring for substantial periods.
Older abatement systems that were marginal at these concentrations will inevitably become unfit for purpose.
Two decades of groundwork
CSIRO has been working on the science of VAM abatement for close to two decades. That sustained investment produced a suite of technologies spanning three broad approaches: converting VAM to electricity (VAMCAT), concentrating it for downstream use (VAMCAP), and destroying it via thermal (VAMMIT) or catalytic oxidation (CataVAM).
Dr Yonggang Jin, CSIRO Senior Principal Research Scientist and Team Leader, Environment and Sustainability, leads CSIRO’s R&D in VAM abatement and is the principal inventor of CataVAM.
“The success of CataVAMTM is underpinned by strong science and engineering foundations in catalytic materials and reaction engineering, fluid dynamics, heat transfer and system control, built on CSIRO’s two decades of R&D in methane emissions abatement,” Dr Jin said. “That accumulated expertise is what has made CataVAM possible, underpinning CSIRO’s position as the leading research organisation in this space.”
CataVAM: a technology built for where the industry is heading
CataVAM uses high-performance catalysts on a purpose-designed honeycomb regenerative bed to destroy methane. Like the catalytic converters found in modern cars, it scrubs out methane at concentrations from 0.5% down to as little as 0.1%, without supplemental fuel.
It operates in full auto-thermal mode at temperatures between 450°C to 650°C depending on VAM concentrations – well below the temperatures required by other thermal systems.
Self-sustaining once running and energy-efficient by design, the system uses heat generated by catalytic methane oxidation to preheat incoming gas.
Central to the technology’s performance is a proprietary honeycomb-shaped catalytic regenerative bed, designed to optimise the coupling of catalytic performance, heat transfer and flow dynamics.
“We have engineered the honeycomb bed to destroy methane efficiently while maintaining efficient cross-bed heat transfer for stable auto-thermal operation and keeping bed flow resistance very low to reduce energy consumption,” Dr Jin said. “The lower operating temperature avoids catalyst degradation and prevents issues such as stone dust sintering, supporting long-term bed durability.”
Similarly, moisture in the gas stream – a persistent complication in real mine conditions – has not presented problems in trials.
Critically, the innovative honeycomb bed design delivers more than four times the VAM throughput of comparable conventional thermal systems of the same physical unit size. That significantly improves the commercial and logistical case. For the same airflow capacity, a CataVAM module is much smaller than older technology units making it suited to space-constrained mine sites and practical to relocate between ventilation shafts.
Dr Gareth Kennedy, CSIRO’s Research Director, Sustainable Mining Technologies, said this would make modules genuinely transportable. “Older thermal-based systems are larger, heavy and generally not relocatable in any practical sense,” he said. “A CataVAM set-up will be able to be deployed at one shaft, and when that seam is exhausted, packed up and trucked to the next.”
The economics are shifting too. Catalytic systems have traditionally cost more, but falling VAM concentrations are making thermal technologies less efficient and harder to scale. At lower methane levels, thermal systems need to be much larger to remain self-sustaining. At the same time, advances in catalyst performance and durability, combined with much higher throughput, are making catalytic mitigation a more practical and cost-effective option.
A world-first demonstration
A large-scale pilot CataVAM has been field-trialled at GM3 Appin mine in southern New South Wales using real VAM. The CataVAM technology reached Technology Readiness Level (TRL) 7 following its successful demonstration, processing substantially high ventilation airflows up to 1.38 cu.m/s in extensive trials completed in April 2026.
This represents a world-first demonstration of high-efficiency catalytic VAM abatement at this scale under real mining conditions, CSIRO claims. The successful field validation marks a significant milestone in de-risking the technology for industry adoption and establishes clear pathways toward further scale up and commercial deployment.
“We achieved a world first from trials of the new prototype, demonstrating greater than 98% methane destruction efficiency using real VAM at methane concentrations around 0.2% or less,” Kennedy said.
Mining company GM3 have been an industry collaborator in CSIRO’s VAM abatement research and development since 2014.
“GM3 is committed to exploring practical and innovative opportunities to reduce greenhouse gas emissions from our operations,” Russell Thomas, GM3 Technical Services Manager, said. “Projects such as this provide an opportunity to test emerging technologies under real-world conditions and generate valuable operational data that may help inform future methane abatement solutions for Appin Mine and the mining industry.”
The next step is a trial of a unit designed for approximately 5 cu.m/s and is underway with a commercialisation partner.
“This is the final proof-of-technology phase before moving to full-scale modular development, for which we are actively collaborating with industry partners to achieve,” Dr Kennedy said.
The target commercial module is designed to treat around 20 cu.m/s, with mine deployments using multiple modules in parallel to match the full ventilation flows at a given shaft.
A future-facing technology
CataVAM is not designed for the VAM concentrations of a decade ago. It is designed for the concentrations coal mines produce today, and the even lower concentrations they will have to move towards as safety standards continue tightening, CSIRO explains.
“The mines that currently need this technology are already at or approaching the CataVAM design window, and every new mine developed in Australia to modern safety standards will likely operate there from day one,” Dr Kennedy said. “The science is done. The field performance is documented. The next stage is an engineering up-scale and commercial challenge, and CSIRO is not looking to solve it alone.”
With VAM abatement a priority in Australia’s Net Zero Plan for the Resource Sector, further investment in scale-up could support Safeguard Mechanism baselines and Australia’s Global Methane Pledge commitments.