Studies on bio-oxidation of coal mine gas by a biofilter

A new biofilter technology was used to control the methane concentration in the coal mine. The results indicate that the biofilter achieves a steady methane removal capacity of 1 470 mg/(L·h) after 30 days start-up. More than 90% of the methane can be removed with an empty bed retention time (EBRT) of 5.6 min when the inlet concentration of methane (IMC) is lower than 70 mg/L (10%, V/V) and about 80% when IMC is at 105 mg/L (15%, V/V). The biofilter is still a reliable method to control methane concentration as an auxiliary means to boost coal mine production safety together with aggrandized ventilation and drainage technologies, even though the removal efficiency of methane is not very satisfactory with a high IMC (>10%) or a short EBRT (<3.8 min).