Closed coal mine shaft as a source of carbon dioxide emissions

Abstract

The closure of coal mines does not terminate their impact on the environment. Gas emissions into the atmosphere are the one of the problems. The closed “Gliwice II” shaft has been selected for a series of measurements to assess greenhouse gas emissions from the closed mine; however, only CO2 emission has been detected. The article compromises obtained knowledge about the rate of emissions and the influence of meteorological parameters on this phenomenon—baric tendency, difference in dry-bulb temperature between flowing gas and the atmosphere (buoyancy effect) and wind speed. In the course of the conducted research, it was detected that the highest amount of carbon dioxide emission was $$V_{{{\text{CO}}_{2} }}$$ = 0.023 m3/s (which is 82.8 m3/h) when baric tendency of pressure drop was 0.57 hPa/h, and the difference between dry-bulb temperatures gas and atmosphere was +4.4 °C (the highest difference in the obtained results). The rate of CO2 emissions varied from 12.7 to 162.3 $${\text{kg}}_{{{\text{CO}}_{2} }} / {\text{h}}$$ . Carbon dioxide was detected up to 43 m from the shaft. The results can be considered as a general conclusion about gas behavior when it flows from the underground sites to the surface in natural conditions and about gas concentrations near a point of emission, especially in the case of former mines. However, it may also be useful for other applications, e.g., the leakages from installations of underground coal gasification, or gas drainage.