University of Newcastle: Methane Reduction: Safety Principles
There are numerous safety hazards associated with deploying commercially available Ventilation Air Methane (VAM) abatement technology at an operating underground coal mine.
This project has produced a comprehensive summary of the potential safety hazards and ways to eliminate them as a basis for considering VAM abatement at operating coal mines, recognising that these are general principles that must be adapted to specific conditions at individual mines.
The project investigated how and why methane ignites, how fast a flame can travel through dilute methane-air mixtures within an enclosed duct if the methane does ignite and how and why combustion develops into an explosion.
This research included examining the effects of temperature and pressure in the presence of solid particles (non-combustible dust and combustible coal dust) and other gases such as water vapour and carbon dioxide.
The project also reviewed available devices for:
- detecting methane in a fast-flowing air stream
- preventing explosions using fast-acting valves to divert the air stream away from the abatement unit should a risk of ignition arise
- mitigating the impacts of explosions using rupture discs and explosion arrestors.
The project also assessed control strategies for the prevention and mitigation of explosions using combinations of the above devices.
Achievements and findings
This project represents world-leading research on the behaviour of methane in an underground coal mine environment. The research was conducted in world-leading facilities including:
- a fully instrumented, 30-metre detonation tube (located at the university) for detailed ignition and combustion experiments
- a large-scale duct (100m long, located at Test Safe in Western Sydney), also fully instrumented and incorporating the full range of mitigation devices for testing under full-flow conditions.
While other combustion and explosion testing facilities exist around the world, none has the same level of instrumentation or the range of mitigation devices.
Results of the research are being captured on a University website as a reference for industry and others working in the area.
The project started in July 2013 and the detailed investigations in the laboratory and using the 30-metre detonation tube were completed in November 2016. Construction of the large-scale duct at Test Safe was completed in October 2017 and the test program was completed in March 2018.
The ultimate objective is a full-scale demonstration of VAM abatement at an operating underground coal mine. The further work required has been scoped by the Centennial Coal Methane Reduction Demonstration Project based on the findings from this project.
Download the Project Snapshot