【正文】 onsite and used as fuel for the Association’s vehicle fleet. The refueling station, which has been operating for more than three years, produces about 1,000 m3 of pressed gas per day. Based on estimated gas reserves it is expected to operate for a total of eight years ( Pudak, 1995 ). While many mines in the CIS are utilizing their methane resources, the majority are not. Certain barriers must be overe before recovery and use of coal mine methane bees widespread. These barriers and their potential solutions are discussed in greater detail in Section 3 of this paper. The United States There are five major coal producing regions in the United States from which hard coal is mined and which have the potential for coalbed methane development. They are: （ 1） the Appalachian Basin, located in Pennsylvania, Ohio, West Virginia, eastern Kentucky and Tennessee, （ 2） the Warrior Basin, located in Alabama, （ 3） the Illinois Basin, located in Illinois, Indiana and western Kentucky, （ 4） the Southwestern region, including the Uinta, Piceance, Green River and San Juan Basins located in Colorado, Utah and New Mexico and （ 5） the Western Interior region, including the Arkoma Basin of Oklahoma and Arkansas. In 1994, an estimated 109 m3 of methane were liberated by underground mining in these regions, of which less than 109 m3 were used（ USEPA, unpublished data） . Currently in the United States, at least 17 mines in six states（ Alabama, Colorado,Ohio, Pennsylvania, Virginia and West Virginia） recover methane for profit, primarily through sale to gas distributors. In 1995, the total methane recovered 7 from these mines, including vertical wells draining methane in advance of mining, exceeded 1109 maximizing the amount of gas recovered via drainage systems, these mines have greatly reduced their ventilation costs, improved safety conditions for miners and have collected and sold large quantities of highquality gas. Following is a brief description of selected coal mine methane recovery activities in the United States. Warrior basin: Alabama Six of the seventeen US mines with mercial methane recovery systems are located in the Warrior Basin of Alabama. Today, energy panies recover methane from the Warrior Basin by horizontal wells, gob wells（ in areas being mined ） and vertical wells（ in both mined and unmined areas） . Most of this gas is sold to regional natural gas distributors, although there is some onsite mine use. In 1995, four mines operated by Jim Walter Resources produced more than 380106 m3 of methane for pipeline sale and USX’s Oak Grove Mine recovered an estimated 117106 m3 of methane for use. Appalachian region Eight mines in Virginia and West Virginia have developed successful methane recovery and use projects. The Consol mines in Virginia are the most welldocumented examples. Consol produces gas from a bination of vertical wells that are hydraulically stimulated, horizontal boreholes and gob wells drilled over longwall panels. In 1995, Consol produced approximately 688106 m3 of saleable methane from three mines. Methane recovery efficiency at these mines is higher than 60%. Southwestern region The Soldier Canyon Mine in Utah recovered about 106 m3 of methane for sale annually until early 1994, when production was curtailed and gas sales ended due to low market prices. Summary While methane recovery has been economically implemented at the abovedescribed mines, safety and high coal productivity remain the impetus for their degasification efforts. Methane drainage at many gassy mines in the United States is limited or nonexistent. Section 3 of this paper discusses potential avenues for increasing methane recovery and use in the United States and other countries. 8 Germany Germany produced nearly 54 million tons of hard coal in 1995, all from underground mines （ Schiffer, 1995） . Of this total, 43 million tons were mined from the Ruhr Basin in northwestern Germany （ Von Sperber et al., 1996） and most of the remainder was mined from the Saar Basin in southwestern Germany. Until recently, hard coal mining was heavily subsidized in Germany, and the industry’s future is in question （ Schiffer, 1995） . Even mines that are closed, however, can continue to liberate methane for long periods of time. An estimated 109 m3 of methane are liberated annually from underground mining activities in Germany, of which 520106 m3, or 30%, are drained（ 63 IEA, 1994） . About 371106 m, or 71% of all drained methane is used, primarily for heating or power generation. Government officials suggest that as much as 45% of the methane emitted from coal mining activities could be drained and used in a variety of applications. The primary barrier to increased methane recovery is low methane concentrations in the gas mixture. Safety regulations in Germany prohibit any utilization if the methane content is less than 25%. If the average recovery efficiency at German mines is to be increased, it will be necessary to adopt practices that will recover methane in a more concentrated form. 3 Barriers to decreasing coal mine methane emissions There are several barriers to decreasing methane emissions by increasing coal mine methane use. Some are technical, such as low coal permeability, while others are Institutional, such as low gas prices. In a few cases, certain barriers are country orregion specific, but most cases, many of the same barriers exist in a number of countries. This section discusses obstacles to increased coal mine methane use, and potential ways to overe these obstacles. Technical issues Lowpermeability coals Coal seams that exhibit low permeability pose special problems for developing successful methane drainage and recovery systems. Methane desorbs and flows through natural pores and fractures until the gas re