Spectrometric imaging of sub-hourly methane emission dynamics from coal mine ventilation

Abstract

Anthropogenic methane (CH4) emissions contribute significantly to the current radiative forcing driving climate change. Localized CH4 sources such as occurring in the fossil fuel industry contribute a substantial share to the anthropogenic emission total. The temporal dynamics of such emissions is largely unresolved and unaccounted for when using atmospheric measurements by satellites, aircraft and ground-based instruments to monitor emission rates and verify reported numbers. Here, we demonstrate the usage of a ground-based imaging spectrometer for quantifying the CH4 emission dynamics of a ventilation facility of a coal mine in the Upper Silesian Coal Basin, Poland. To this end, we deployed the imaging spectrometer at roughly 1 km distance from the facility and collected plume images of CH4 column enhancements during the sunlit hours of four consecutive days in June 2022. Together with wind information from a co-deployed wind-lidar, we inferredCH4 emission rates with roughly 1 min resolution. Daily average emission rates ranged between 1.39±0.19 and 4.44±0.76 tCH4/h, 10-min averages ranged between (min) 0.82 and (max) 5.83 tCH4/h, and puff-like events caused large variability on time scales below 15 min. Thus, to monitor CH4 emissions from such sources, it requires measurement techniques such as the imaging spectrometer evaluated here that can capture emission dynamics on short time scales.

Numerical Multifield Coupling Model of Stress Evolution and Gas Migration: Application of Disaster Prediction and Mining Sustainability Development

“…Massive amounts of gas gushed out during this accid and the phenomenon of a gas countercurrent was produced. The gas emission was 11, m 3 , and the gas emission per ton of coal was 38.3 m 3 . According to the accident report, when the accident occurred, the coal body near the excavation face was the first to break and spray out in large quantities, and the support above the roadway in that area was the most severely damaged.…”

“…In recent decades, the coal mining depth in China has been increasing [1][2][3]. Nowadays, the mining depth in some mines has exceeded one kilometer, and it is increasing at a rate of more than ten meters every year [4,5].…”