Status of worldwide coal mine methane emissions and use

Underground coal mines worldwide Liberate an estimated 29-41 x 10(9) m(3) of methane annually, of which less than 2.3 x 10(9) m(3) are used as fuel. The remaining methane is emitted to the atmosphere, representing the loss of a valuable energy resource. Methane is also a major greenhouse gas and is thus detrimental to the environment when vented to the atmosphere. Coal mine methane recovery and use represents a cost-effective means of significantly reducing methane emissions from coal mining, while increasing mine safety and improving mine economics. The world's ten largest coal producers are responsible for 90% of global methane emissions associated with the coal fuel cycle. China is the largest emitter of coal mine methane, followed by the Commonwealth of Independent States, or CIS (particularly Russia, Ukraine and Kazakhstan), the United States, Poland, Germany, South Africa, the United Kingdom, Australia, India and the Czech Republic. Most of these countries use a portion of the methane that is liberated from their coal mines, but the utilization rate tends to be low and some countries use none at all. Coal mine methane is currently used for a variety of purposes. Methane is used for heating and cooking at many mine facilities and nearby residences. It is also used to fuel boilers, to generate electricity, directly heat air for mine ventilation systems and for coal drying. Several mines in the United States sell high-quality mine gas to natural gas distributors. There are several barriers to decreasing methane emissions by increasing coal mine methane use. Many of the same barriers are common to a number of the subject countries. Technical barriers include low-permeability coals, variable or low gas quality, variations in gas supply and demand and lack of infrastructure. Economic and institutional barriers include lack of information pertinent to development of the resource, lack of capital and low natural gas prices. A possible option for encouraging coal mine methane recovery and use would be international adoption of a tradeable permit system for methane emissions. (C) 1998 Elsevier Science B.V.