据《中国煤炭报》2 0 0 4年 4月 13日报道 :煤矿风井排风中含有大量瓦斯。由于瓦斯浓度稀释 ,一般浓度大于 0 .5 %。美国环保总署估计 ,以 2 0 0 2年为例 ,全球全年的煤矿通风瓦斯排放量在 173亿 m3 以上 ,相当于把 2 .37亿吨二氧化碳排放到大气中。其中 11个主要产煤国家占 88 According to “China Coal” reported April 13, 2004: coal mine shaft exhaust contains a lot of gas. Due to gas concentration dilution, the general concentration is greater than 0.5%. The U.S. Environmental Protection Agency estimates that by 2002, for example, the annual global mine ventilation gas emissions will be more than 17.3 billion m3, equivalent to releasing 223.7 million tons of carbon dioxide into the atmosphere. Among them, 11 major coal-producing countries accounted for 88