Methane liberated in underground coal mines is a severe safety hazard to miners. It is also a major contributor to the build-up of greenhouse gases in the global atmosphere. This report presents an engineering and economic evaluation of several methane recovery and end-use technologies which can remove, purify, and utilize methane from coal seams. The methane recovery technologies evaluated are widely applicable to US underground mines, and include conventional systems such as vertical extraction wells, gob area wells, horizontal boreholes, and cross-measure boreholes. More advanced and developmental technologies, such as the nitrogen injection process, have also been examined. Methane utilization technologies examined include the use of gas turbines for the generation of on-site power, compression and transport systems needed to sell the gas to a national distributor, and the generation of electrical power for off-site sale. The applicability and performance of each technology were assessed at nine representative coal mine sites, and the economic and emissions reduction performance between existing and alternative recovery operations were examined.

ABSTRACT Past efforts to estimate methane emissions from underground mines, surface mines, and other coal mine operations have been hampered, to different degrees, by a lack of direct emissions data. Direct measurements have been completely unavailable for several important coal mining operations. A primary goal of this study was to collect new methane emissions measurements and other data for the most poorly characterized mining operations and use these data to develop an improved methane emission inventory for the U.S. coal mining industry. This required the development and verification of measurement methods for surface mines, coal handling operations, and abandoned underground mines and the use of these methods at about 30 mining sites across the United States. Although the study's focus was on surface mines, abandoned underground mines, and coal handling operations, evaluations were also conducted to improve our understanding of underground mine emission trends and to develop improved national data sets of coal properties. Total U.S.

The Greenhouse Gas (GHG) Technology Verification Center is one of 12 independent verification entities operating under the U.S. EPA-sponsored Environmental Technology Verification (ETV) program. The ETV program tries to accelerate the acceptance and use of improved technologies through the development of third-party technology performance data. The Center focuses on GHG mitigation and monitoring technologies and has completed performance verification testing on one technology and initiated testing on six others. Technologies applicable to the natural gas industry, electricity generation industry, and GHG monitoring industry have been the primary focus of the Center's initial efforts. This paper outlines the Center's verification approach and activities. Final results are presented on a fuel cell technology for which testing has been completed, and preliminary results are presented for two additional types of technologies that have completed the first phase of a two-phase verification test.

The report gives results of EPA research into the emission processes and control strategies associated with underground coal mines in the U.S. Goals of the EPA program have been to assess the economic performance and emissions reductions of methane control strategies for underground coal mines, and to develop modeling tools and data bases that miners can use to conduct their own site-specific methane control analyses. To this end, nine standard or model mines were designed to closely simulate existing mines in the major coal producing regions. Cost performance and methane reductions were then calculated for a number of methane recovery and utilization combinations at these model mines. Algorithms were developed using site-specific mine designs, geologic parameters, and costs, with the assistance of mine operators, mining consultants, degasification system consultants, and the U.S. Bureau of Mines.

The report is a conpilation of quality assured data on gas content and coal-bed reservoir properties for 11 major coal bearing regions in the U.S. The primary source of these data is the U.S. Bureau of Mines (BOM) gas content measurements program conducted during the 1970s and 1980s. In order to enhance the utility of the BOM data, an evaluation was conducted to compile and quality assure the original data, and to adjust the data as needed to improve quality and representativeness. The raw data were digitized to allow a computer to accurately and consistently perform routine quality assurance checks, consistently determine lost gas and total gas contents for each sample, and examine various corrections to the data. In addition, desorption constants for each coal sample were determined from time series desorption curves generated from the original data. Additional data presented include the results of equilibrium adsorptionn isotherm tests performed by the U.S. Department of Energy (DOE) in 1983 for approximately 100 of the BOM coal samples.

Most global methane (CH4) budgets have failed to include emissions from a diverse group of minor anthropogenic sources. Individually, these minor sources emit small quantities of CH4, but collectively, their contributions to the budget may be significant. In this paper, CH4 emissions are estimated for a wide variety of individual minor emissions sources on a country‐specific basis. Emissions from biomass combustion in the residential sector are also examined. The minor sources examined include fuel combustion in furnaces, vehicles, aircraft, ship, rail systems, industrial waste treatment and combustion processes, various industrial manufacturing processes (e.g., chemical manufacturing), on‐site residential waste burning, forest wildfires, and prescribed burning activities, oil refining, and the storage/distribution of oil‐derived products, coke production, and charcoal production. Country‐specific emissions associated with residential wood, charcoal, and dung combustion are also estimated. The total annual CH4 emissions from all sources examined here are estimated to be about 40 Tg. Almost half of this total is due to residential fossil fuel and biofuels combustion.

An auto-positioning open-path Fourier Transform Infrared (FTIR) spectrometer can be used to directly measure vertical concentration profiles in a plume downwind from an emission source. The multi-component analysis capabilities of FTIR spectroscopy allow simultaneous measurement of diverse downwind pollutant species. Using concentration measurements and meteorological data, it is possible to estimate the emission fluxes across the plume and, thus, the emission rates of pollutants from the source. The field assessment goals were to conduct the first in a series of field tests of a new measurements system developed to perform such emission rate determinations, and to evaluate the system's performance and feasibility. For these purposes, a simple volume source simulator was constructed to emulate process equipment leaks encountered at chemical plants, refineries, and other facilities. By metering the release rates from the volume source simulator, "actual" release rates were compared to the "estimated" release rates calculated using the measurements system. Using simple data screening techniques, over 90% of the field tests conducted produced run-average emission rate estimates within 20% of the actual emission rates. Half of the tests were within 10% of the actual emission rates.

The paper summarizes current research on abandoned underground coal mines. It forms an initial basis for developing an inventory of methane emissions from such mines. Early measurements have shown that some abandoned coal mines can liberate large volumes of high quality gas (up to 750,000 cu ft/day: 21,000 cu m/day). The research has focused on developing improved emission factors and relationships, and improving inventories for methane emissions from surface mining, coal handling, and abandoned underground mines. The work has initially focused on coal mining in the U.S., but will be extended to global coal production. Improved emissions inventories for coal mining operations will enhance the ability of researchers to assess the significance of coal mining in global scale processes. Determination of representative methane emissions relationships and mechanisms for coal mining (especialy abandoned mines) will also be useful to researchers and industrial groups exploring for potential sources of energy.

This paper describes a methodology developed for the purpose of estimating emissions factors of organic compounds from a variety of different area sources in a rapid and cost effective manner. The methodology involves the use of an open-path fourier transform infrared (FTIR) spectrometer to measure concentrations of hydrocarbon and other compounds in plumes emanating from area sources. Meteorological measurements are also collected and used in conjunction with an appropriate plume dispersion model to relate measured plume and background concentrations to an emission rate for the source. This study was conducted to validate the performance of the measurements methodology, and to support the development of measurements methodology protocols, field setup guidelines, data analysis procedures, and other information needed to conduct more effective and accurate measurements. Based on the results, it appears that the methodology is capable of estimating the emissions from an area source with an accuracy of at least +/- 25 to 30 percent.

A new measurements methodology has been developed which allows the rapid and efficient measurement of methane (CH4) emissions from surface coal mines. An initial field trial of this methodology has been completed, and results from the field trial revealed that emissions from one surface coal mine in the U.S. are estimated to be 1,735,000 m3/year. The results provide some evidence that CH4 concentrations determined by the FTIR may be low by 20 to 75 percent but the overall effect of this potential bias on the mine emissions estimate cannot be adequately quantified. The initial trial demonstrated that the methodology is an applicable and feasible approach for measuring CH4 emissions from very large surface coal mines. It also highlighted several uncertainties and methodology questions which if resolved could further improve the performance and reliability of the methodology.

This chapter identifies and describes major industrial sources of methane (CH4) emissions. For each source type examined, CH4 release points are identified and a detailed discussion of the factors affecting emissions is provided. A summary and discussion of available global and country-specific CH4 emissions estimates are also presented.

This chapter identifies and describes major industrial sources of methane (CH4) emissions. For each source type examined, CH4 release points are identified and a detailed discussion of the factors affecting emissions is provided. A summary and discussion of available global and country-specific CH4 emissions estimates are also presented. The major emission sources examined include coal mining operations and natural gas production and distribution systems. However, a variety of minor industrial sources are also examined because their collective contributions to the global CH4 budget may be significant. Among the minor industrial sources examined here are: coke production facilities, chemical manufacturing operations, peat mining operations, light water nuclear reactors, fossil fuel combustion equipment (boilers and automobiles), geothermal electricity generation facilities, salt mining operations, residential refuse burning, and shale oil mining operations. (Copyright (c) Springer-Verlag 1993.)

Country-specific emissions of methane (CH4) from underground coal mines, surface coal mines, and coal crushing and transport operations are estimated for 1989. Emissions for individual countries are estimated by using two sets of regression equations (R2 values range from 0.56 to 0.71). The first set is used to estimate the CH4 content of coals in selected countries based on country-specific coal depth and other relevant parameters. The second equation relates this CH4 content and the country's coal production rate to the emissions from coal mining operations. The regression equations developed in this study rely on documented relationships which exist between mine emissions, coalbed CH4 content, coal production rate, and other coal properties. Only those independent variables which could be included at 95 percent confidence or greater were retained in the regression equations. Estimated global CH4 emissions from coal mining axe estimated to be 45.6 Tg for 1989.