Renewable and Sustainable Energy Reviews 15 (2011) 1042–1049 Contents lists available at ScienceDirect Renewable and Sustainable Energy Reviews journal homepage: www.elsevier.com/locate/rser Mine ventilation air methane as a sustainable energy source Izzet Karakurt, Gokhan Aydin, Kerim Aydiner ∗ Karadeniz Technical University, Department of Mining Engineering, 61080 Trabzon, Turkey article info Article history: Received 23 June 2010 Accepted 12 November 2010 Keywords: Global warming Greenhouse gases Methane Coal mines Ventilation air abstract Underground coal mines emitting large quantities of methane to atmosphere is one of the sources of methane. Approximately 70% of the methane emitted from coal mines is released as the ventilation air methane (VAM). Unfortunately, due to the low methane concentration (0.1–1.5%) in ventilation air, its effective utilization is considerably low. However, the global warming potential of methane can be reduced up to 95% by oxidizing the methane. Energy recovery may be possible as the products of oxi- dization. In this study, the existing and developing methods, based on the oxidation of methane, are introduced with a discussion of the features of the methods of the mitigation and utilization of VAM. The main operational parameters of the methods such as combustion method, technical feasibility and engineering applicability were also discussed. © 2010 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................................................ 1042 2. Mitigation and utilization of VAM ................................................................................................................. 1043 3. Methane oxidation mechanisms ................................................................................................................... 1044 4. Ancillary uses of ventilation air methane ......................................................................................................... 1044 4.1. Pulverized coal-fired power station ........................................................................................................ 1044 4.2. Hybrid waste/coal/tailings/methane combustion units ................................................................................... 1045 4.3. Internal combustion engines ............................................................................................................... 1046 4.4. Conventional gas turbines ................................................................................................................. 1046 5. Principal uses of VAM .............................................................................................................................. 1046 5.1. Thermal flow reversal reactor technology (TFRR) ......................................................................................... 1046 5.2. Catalytic flow reversal reactor (CFRR) ..................................................................................................... 1046 5.3. Catalytic-monolith reactors (CMR) ........................................................................................................ 1047 5.4. Lean-burn gas turbines ..................................................................................................................... 1048 5.5. Concentrators .............................................................................................................................. 1048 6. Conclusions ........................................................................................................................................ 1048 References ......................................................................................................................................... 1049 1. Introduction Greenhouse gases are released mainly from the activities such as burning of fossil fuels, industrial processes, transportation, agricul- tural facilities and waste management processes. Accumulation of greenhouse gases in atmosphere has led to the increase of earth’s temperature. As a result of the increases in global temperatures, it is expected that important changes affecting socioeconomic sec- ∗ Corresponding author. Tel.: +90 462 377 35 31; fax: +90 462 325 74 05. E-mail address: aydiner@ktu.edu.tr (K. Aydiner). tors, ecological systems and humans’ life would come into existence [1,2]. Carbon dioxide, methane, nitrogen oxide and chlorofluorocar- bons have vital importance on the global warming and the related environmental problems. Carbon dioxide has solely a rate of 74% in total anthropogenic greenhouse gas emissions. Methane, nitro- gen oxide and high global warming potential gases follow carbon dioxide (Fig. 1). Methane can trap the heat about 20 times of CO 2 . In spite of the fact that methane is the second biggest contributor to anthropogenic greenhouse gas emissions, it affects climate changes at least as carbon dioxide does [5,6]. The variation of non- 1364-0321/$ – see front matter © 2010 Elsevier Ltd. All rights reserved. doi:10.1016/j.rser.2010.11.030