The effectiveness of demethanation depends on numerous geological and mining as well as technical and technological factors:

• the methane producibility of the mined seam and the seams above and below it,
• the gas permeability of coal seams and the surrounding rocks,
• the choice of a proper demethanation system,
• preparation of a proper demethanation plan,
• determination and calculation of parameters for a demethanation installation,
• the ventilation system of mine workings.

In practice, the impact of individual factors on the efficiency of the demethanation process is difficult to determine unambiguously. Conducting effective and efficient demethanation allows us to reduce the release of methane into the workings, thereby maintaining acceptable concentrations in mine air. The high efficiency of capturing methane from mine workings makes it possible to achieve a high concentration of coal production in the most methaniferous parts of the deposit.

Our experience in the field of conducting the mine demethanation process, the engineering staff and the employees with high qualifications allow us to achieve high efficiencies of demethanation of mine workings, even reaching up to 98%. The demethanation process we have carried out on one of the longwalls in seam 401 allowed us to achieve a demethanation efficiency reaching up to as high as 100% in one of the months of the advancing mining face of the extraction heading. Such a result is due to the correct execution of the technical demethanation plan, the selection of a proper demethanation system, precise calculations of the demethanation network, and the highly specialised human resources.

The demethanation efficiency index for mines, including mine workings, galleries and goafs, is determined from the following relationship: E₀ = V₀ / V_k
E₀ – the mine demethanation efficiency index, including for mine workings, galleries and goafs,
V₀ – the amount of methane captured by demethanation from the rock mass, including mine workings, galleries and goafs,
V_k – the absolute (total) methane content of the mine or its region, including mine workings, galleries and goafs.