Techno-economic assessment of coal fugitive methane abatement in Australia using currently available technology

Australia is a signatory to the Global Methane Pledge, which aims to reduce methane emissions by 30% from 2020 levels by 2030. Approximately 21% of Australia's methane emissions are fugitive emissions from coal mines. This paper estimates the practical potential for the abatement of fugitive methane emissions, for both opencut and underground coal mines in Australia, including quantities and corresponding costs. The techno-economic analysis of methane abatement is based on data specific to current Australian coal mines. Only abatement options that are commercially available and demonstrated at mine scale are considered: (a) flaring of drained gas; (b) electricity generation by combusting drained gas using a combined-cycle gas turbine; and (c) ventilation air methane regenerative thermal oxidation. The key result is a marginal abatement cost curve and accompanying sensitivity analysis for fugitive methane abatement from Australian coal mines. For the scenarios examined, costs range from −20 to 50 AUD/t(CO 2 -e) for methane abatement of up to 10 Mt.(CO 2 -e) per annum. Uncertainties in component costs are incorporated through a Monte Carlo approach. Uncertainties in abatement potential result from uncertainties in emissions estimates (±10% for underground mines and ± 33% for opencut mines) and a lack of publicly available data concerning precise emissions characteristics and physical characteristics of individual coal mines. The most cost-effective abatement methods identified in this study are electricity generation (which can be a net financial benefit); flaring, which costs less than 2 AUD/t(CO 2 -e); and regenerative thermal oxidation of ventilation air methane at less than 20 AUD/t(CO 2 -e). • A marginal abatement cost curve for coal-mine methane abatement is estimated. • The result is derived for Australian mines using Australian-specific data. • 6Mt(CO2-e) per annum can be abated with costs between −20 and + 20 AUD/t(CO2-e). • It is likely 10Mt(CO2-e) per annum can be abated for <AUD50/t(CO2-e).