1、附录A英文翻译（原文）Status of worldwide coal mine methane emissions and use Abstract: Underground coal mines worldwide liberate an estimated 2941109 m3 of methane annually, of which less than 2.3109 m3 are used as fuel. The remaining methane is emitted to the atmosphere, representing the loss of a valuable e
2、nergy 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 improvi
3、ng mine economics. The worlds 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,
4、 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
5、 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 h
6、igh-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,
7、 variations in gas supply an 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 internat
8、ional adoption of a traceable permit system for methane emissions.Keywords: coalbed methane; global warming; coal mining; natural gas1. Introduction In recent years, coalbed methane has gained attention as a saleable natural gas resource. Methane can be extracted either from coal seams which will ne
9、ver undergo mining, or it can be produced as a part of the coal mining process. This paper focuses on methane which is produced in conjunction with coal mining operations（ coal mine methane） . According to the United States Environmental Protection Agency （USEPA, 1994a） , underground coal mines libe
10、rate an estimated 29 to 41109 m 3of methane annually, of which less than 2.3109 m3 are used as fuel. The remaining methane is vented to the atmosphere, representing the loss of a valuable energy resource. This paper examines the potential for recovering and using the methane which is currently being
11、 emitted from coal mines.There are three primary reasons for recovering coal mine methane. The first reason is to increase mine safety. Worldwide, there have been thousands of recorded fatalities from underground mine explosions in which methane was a contributing factor. Using methane drainage syst
12、ems, mines can reduce the methane concentration in their ventilation air, ultimately reducing ventilation requirements.The second reason is to improve mine economics. By reducing emissions and preventing explosions and outbursts, methane drainage systems can cost effectively reduce the amount of tim
13、e that the coal mine must curtail production. Moreover, recovered methane can be used either as fuel at the mine site or sold to other users.The third reason for coalbed methane recovery and use is that it benefits the global and local environment. Methane is a major greenhouse gas and is second in
14、global impact only to carbon dioxide; methane thus is detrimental to the environment if vented to the atmosphere. Although the amount of carbon dioxide accumulating in the atmosphere each year is orders of magnitude larger than that of methane, each additional gram of methane released to the atmosph
15、ere is as much as 22 times more effective in potentially warming the Earths surface over a 100-year period than each additional gram of carbon dioxide (USEPA, 1994a) . Compared with other greenhouse gases, methane has a relatively short atmospheric lifetime. The lifetime of methane (defined as its a
16、tmospheric content divided by its rate of removal) is approximately 10 years. Due to its short lifetime, stabilizing methane emissions can have a dramatic impact on decreasing the buildup of greenhouse gases in the atmosphere.Coal mine methane recovery and use represent a cost-effective means of significantly reducing methane emissions from coal mines. Methane, moreover, is a remarkably clean fuel. Methane combustion produces no sulfur dioxide or particul
