Mine Site Greenhouse Mitigation » Mine Site Greenhouse Mitigation
This multi‐phase project is concerned with the mitigation of mine site greenhouse gases (GHG) and specifically focuses on the development and demonstration of a novel stone dust looping (SDL) process for the abatement of ventilation air methane (VAM). The relevant research and development activities of this multi‐phase program of study are:
- Phase‐I (previously reported) - Examination of the performance characteristics of a laboratory‐scale proof of concept SDL prototype under controlled settings;
- Phase‐II (previously report) - Mine site process integration and bench scale demonstration;
- Phase‐III (this report) - Demonstration of the SDL concept in the once‐through single‐reactor configuration (i.e. no stone dust regeneration) using an existing 1 m3/s fluidised‐bed plant at the University of Newcastle; followed by techno‐economic assessment of the single‐reactor configuration and scale‐up studies;
- Phase‐IV - Piot‐scale demonstration of the SDL concept in the twin‐reactor configuration using a 200 m3/h setup (to be designed, built and commissioned as part of Phase‐IV); followed by techno‐economic assessment of the twin‐reactor configuration and scale‐up studies.
While each phase of the proposed study is the subject of a separate project, they are complementary.
SDL is the only VAM abatement process being developed by an Australian University which provides a near zero emission mining option. SDL process development has positioned Australia in the forefront for the development of innovative zero emission VAM abatement technology.
The work plan for Phase‐III included comprehensive experimental and modelling work. Following successful bench scale demonstration (Phase‐II), the SDL process was demonstrated at scale for proof of concept purposes at the University of Newcastle in a 1 m3/s plant. The optimum SDL process conditions were evaluated in the 1 m3/s plant.
The key outcomes of Phase‐III can be summarised as:
- Demonstration of the SDL process in a single reactor configuration (i.e. representing the version of the process with no drainage gas integration or CO2 capture) at a gas flow rate 1 m3/s using was completed using an existing pilot‐scale fluidised bed reactor constructed as part of the VAMCO research and development project;
- Methane conversion ranged from 100% for all inventory sizes at bed temperatures of 600°C and above to 41% conversion for 2 tonne inventory and 575°C;
- The bed acted as a thermal mass and responded favourably to VAM concentration fluctuations;
- Significantly higher methane conversion can be achieved with stone dust than iron oxide oxygen carriers in the rate 1 m3/s VAMCO unit;
- Scale rules were derived and gas to solids ratios of 0.5 or lower are required;
- A preliminary techno‐economic assessment of the SDL process in the single‐reactor configuration showed that the levelised cost of methane abatement was about $120/t CO2‐e. A similar set of calculations for the twin‐reactor configuration suggested an abatement cost of approximately $14/t CO2‐e, which is the justification for completion of Phase‐IV of the project.
The three reports are provided as a set.