1417 nanoparticle (NP) and comes closest to that of Pd-based catalyst as a comparison. NB performance is even close to that of the Pd-based catalyst (1% Pd supported on Co3O4). Figure 11. CuO nanobelts (NB) catalyst for CH4 oxidation: (a) TEM image of CuO NBs, (b) CH4 catalytic oxidation activity of CuO NB, CuO nanowires (NW) and CuO nanoparticles (NP). A new type of low-cost precious-metal-free catalysts have been developed based on spinel oxides exhibiting outstanding catalytic activity for VAM oxidation and notably exceptional catalytic stability with wet VAM [12]. As shown in Figure 12a, they are highly active at low reaction temperatures with a light-off temperature of T10 (10% methane conversion) as low as 280 oC and T90 (90% methane conversion) at 433 oC. The results of long-term catalytic stability test for over 260 hours reveal the new catalyst can achieve a constant high methane conversion of 93% at 500 oC after initial decline when treating the vapor statured VAM (Figures 12b&c). The team is currently working on developing low-cost honeycomb monolithic catalysts for practical applications in catalytic VAM mitigators by a washcoating process based on these CSIRO developed high-performance precious-metal-free catalysts. Figure 12. Catalytic activity and stability of CSIRO developed low-cost catalysts tested with water vapor saturated VAM. 4. CONCLUSIONS This paper has summarized over two decades of CSIRO research and development in ventilation air methane abatement, encompassing fundamental studies, pilot-scale system development and extensive mine site trials. Four technologies including AMCAT, VAMMIT, VAMCAP, and CataVAM have progressed to TRL 6-7 and have been demonstrated using actual VAM under real operating conditions. Collectively, these technologies address the key constraints associated with VAM mitigation, including low and variable methane concentrations, large airflow rates, dust, and moisture. Together, these technologies provide a flexible portfolio of solutions that can be deployed individually or in combination to enable selfsustaining methane destruction, energy recovery, or methane enrichment, depending on site-specific
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