case study

CH4 to CO2 emissions reduction at Buchanan Mine

The methane (CH4) emissions from our Buchanan Mine accounts for 63% of Coronado’s total carbon impact. The Pocahontas 3 seam in southwest Virginia inherently has some of the highest methane gas content in the world.

Since 1992, Coronado has focused on capturing high percentage methane from the Buchanan Mine gas wells and gob wells primarily from the Pocahontas 3 seam geologic horizon and preparing it for market.

Even though Coronado gathers the methane, a high quantity of methane emissions from the mine ventilation shafts remains. The ventilation shafts are used to ventilate fresh air into the mine for the safety of the miners and channels the return gaseous air out of the mine. These ventilation shafts are called bleeder ventilation shafts and contain 0.3 to 1.2% of methane.

This mixture of gaseous air is called VAM (Ventilation Air Methane). Our objective is to reduce the carbon footprint of the remaining portions of the VAM emissions by investigating other possible options.

After detailed investigation and consideration we determined the best technology option to be from NextEra Energy.

In 2021, we entered into a project development agreement with NextEra to assist with installation and sourcing of the infrastructure to channel the VAM from the bleeder shafts to an oxidising system called Regenerative Thermal Oxidiser (RTO) Technology.

Phase One of the project is proposed to be installed at Ventilation Shaft 16 in quarter 2 of 2022 to extract a portion of the VAM and channel through an RTO. The oxidation process converts the methane to carbon dioxide (CO2) which reduces the carbon footprint by 22.25 times.

Phase Two of the project includes the installation of another RTO in 2024.

Overall projections show reduction of the Buchanan fugitive VAM emissions from 2019 of 1,929,624 tCO2e to 12,000 tCO2e (61% reduction) by 2030. If achieved, this alone will cut the overall Coronado tCO2e by over 30%.

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