THE INFLUENCE OF GEOLOGICAL HISTORY ON COAL MINE GAS DISTRIBUTION IN THE RUHR DISTRICT - A CHALLENGE FOR FUTURE RESEARCH AND RECOVERY

Document(s) associé(s)

Annexes

• Juch.pdf (2,2M)

Abstract

Methane emissions to the atmosphere induced by German hard coal mining in the Ruhr mining district reach nearly 700 Mill. m³ of methane per year. Energetic utilization of this methane is environmentally friendly and an interesting completion to coal mining. Practical experiences with the utilization of coal mine methane (CMM) from abandoned mines showed that the produced gas is highly variable in quantity and quality. Although there is a lot of information about most of the infl uencing factors to the whole system, their mutual interaction still is hardly understood. The pre-mining gas distribution in the coal bearing strata of the Ruhr district is rather irregular due to the geological evolution of the basin. The models of “dynamic adsorption�? and “fossil migration�? explain this situation and may also help to better understand the recent gas dynamics induced by the mining activity. During the transformation of organic matter into hard coal by basin subsidence a large volume of 50-100,000 km³ gas was formed. Most but not all of this gas escaped into the atmosphere. Gas migration in the rocks and storage capacity in the organic matter or coal are controlled by temperature and pressure conditions, which changed considerably in the geological history of the basin. Due to the large adsorptive storage capacity of coal, gas contents of more than 10m³ per ton of coal still can be found in several parts of the Ruhr basin. In combination with data of the geological coal resources the remaining gas potential can be calculated. A considerable gas resource still exists. The utilization of CMM on the local energy market has been stimulated by German legislation. Today, the extraction of the dangerous coal mine gas from still working and abandoned mines pays off and leads to an additional energy recovery, which simultaneously reduces the greenhouse effect of methane otherwise vented to the atmosphere.

Pour citer cet article

A propos de : Dierk JUCH

A propos de : Roland GASCHNITZ

A propos de : Thomas THIELEMANN