Methane is the main greenhouse gas that is related to coal production. It is produced
from underground and surface mines, and as a result of post-mining activities including
coal processing, storage, and transportation. Globally, coal mine methane (CMM)
accounts for 6 percent of total methane emissions caused by human activities. With
a greenhouse potential (GHP) being 21 times higher than that of carbon dioxide,
CMM emissions were estimated to be in the range of 400 million metric tons of carbon
dioxide equivalent (MMTCO2E) in 2005. The energetic utilisation of CMM e.g. by electric
power generation in CHP, co-firing in boilers, contributes to the conservation of
fossil fuels, to the diversification of energy resources, and to the reduction of
climate-relevant emissions. However, today CMM is used only to a very small extent.
This applies especially to the new EU member states and to developing countries.
The main barriers are:
- insufficient knowledge about the different possibilities and concepts for energetic
use of CMM,
- various gas compositions,
- fluctuant and not predictable gas quality and amount,
- lack of economical options for CMM gases with low methane content (< 15%) and
- differing country and site specific infrastructure and administrative conditions
as well as different economic conditions, impeding an easy technology transfer of
already applied technologies and concepts.
Therefore the elimination of barriers as well as the stimulation of enhanced energetic
use of CMM is an important issue related to the reduction of GHG emissions.