Methane-rich gas production through UCG experimentally proven
Methane, the main component of natural gas (NG), is one of the most desirable products of the underground coal gasification (UCG) that significantly contributes to the calorific value of the gas produced. Gasification test conducted in MEGAPlus resulted in high methane yields and the maximum CH4 concentration (average) obtained during the experimental campaign was: 20.6%vol. Two different European coals were used for the tests - hard coal "Wesoła" (Poland) and semi-anthracite "Six Feet" (Wales). Large-scale UCG tests conducted in ex-situ reactor revealed that not only gasification pressure, but also the coal rank had a significant impact on methane formation. Therefore, the feasibility of methane-rich gas production through UCG was demonstrated in the MEGAPlus project.
Unique tests on coal gasification using hydrogen - underground coal hydrogasification
Hydrogasification is gasification in a hydrogen-rich environment, often used for the production of synthetic natural gas (SNG) from coal. It is an exothermal reaction between carbon and hydrogen where the reaction product is methane. Two multi-day underground hydrogasification trials (UCHG) were carried out in MEGAPlus project using a GIG's large scale gasification facilities of the Clean Coal Technology Centre located at Experimental Mine "Barbara" in Mikołów.
Assessment of CBM-UCG end-product scenarios
The economics of UCG is dependent on many components, including but not limited to:
• geological setting of the coal seam,
• land use on the surface,
• selected technology for the downstream syngas utilisation,
• selection of UCG oxidant,
• requirements for carbon dioxide capture and storage (CCS).
Within the MEGAPlus project, economic assessment of the overall process chain from the production of a methane-rich synthesis gas, through its cleaning and further processing, to the end products - SNG and methanol was carried out.
UCG environmental risks minimized - effect of gasification conditions
With regards to underground coal gasification process, there are two key items in analysis of groundwater impacts, namely the potential risk of groundwater contamination and the likelihood for depletion of regional groundwater reservoirs in the vicinity of the UCG site. Pollution of groundwater, however, is considered to be the most serious possible negative environmental impact.