Extraction Study of Lignite Coalbed Methane as a Potential Supplement to Natural Gas for Enhancing Energy Security of Western Macedonia Region in Greece

Abstract

Greek lignite reserves are mainly located in the northwestern part of the country (Region of Western Macedonia, Greece), reaching a total of 5 billion tons. Considering that Greece is planning to stop burning lignite for electricity production, the recovery of the CH4 trapped in lignite coalbed reservoirs can be a valuable alternative for power generation and may help to reduce the direct emissions of methane during mining activities. The aim of the present study was to evaluate the LCBM in the Region of Western Macedonia, Greece (Ptolemaida basin). In order to assess the LCBM that could be extracted, three samples were collected from an active mine and were subjected to desorption experiments at different temperatures (25 °C, 50 °C, 100 °C, and 150 °C) by channeling high purity Ar gas at 1 atm of pressure. According to the results, the highest amount of CH4 was extracted during the desorption process at 50 °C, while the total amount of CH4 from all three samples was 0.82 m3/kg, confirming the presence of CH4 in the lignite deposits. Finally, a SWOT analysis was carried out that shows the strengths and opportunities against the weaknesses and threats of a potential LCBM exploitation in Greece, while also taking into account the social, economic, and environmental nexus.