USGS Science⌕ Search

USGS · 70022445

Depletion of Appalachian coal reserves - how soon?

Abstract

Much of the coal consumed in the US since the end of the last century has been produced from the Pennsylvanian strata of the Appalachian basin. Even though quantities mined in the past are less than they are today, this basin yielded from 70% to 80% of the nation's annual coal production from the end of the last century until the early 1970s. During the last 25 years, the proportion of the nation's coal that was produced annually from the Appalachian basin has declined markedly, and today it is only about 40% of the total. The amount of coal produced annually in the Appalachian basin, however, has been rising slowly over the last several decades, and has ranged generally from 400 to 500 million tons (Mt) per year. A large proportion of Appalachian historical production has come from relatively few counties in southwestern Pennsylvania, northern and southern West Virginia, eastern Kentucky, Virginia and Alabama. Many of these counties are decades past their years of peak production and several are almost depleted of economic deposits of coal. Because the current major consumer of Appalachian coal is the electric power industry, coal quality, especially sulfur content, has a great impact on its marketability. High-sulfur coal deposits in western Pennsylvania and Ohio are in low demand when compared with the lower sulfur coals of Virginia and southern West Virginia. Only five counties in the basin that have produced 500 Mt or more exhibit increasing rates of production at relatively high levels. Of these, six are in the central part of the basin and only one, Greene County, Pennsylvania, is in the northern part of the basin. Decline rate models, based on production decline rates and the decline rate of the estimated, 'potential' reserve, indicate that Appalachian basin annual coal production will be 200 Mt or less by the middle of the next century. Published by Elsevier Science B.V.Much of the coal consumed in the US since the end of the last century has been produced from the Pennsylvanian strata of the Appalachian basin. Even though quantities mined in the past are less than they are today, this basin yielded from 70% to 80% of the nation's annual coal production from the end of the last century until the early 1970s. During the last 25 years, the proportion of the nation's coal that was produced annually from the Appalachian basin has declined markedly, and today it is only about 40% of the total. The amount of coal produced annually in the Appalachian basin, however, has been rising slowly over the last several decades, and has ranged generally from 400 to 500 million tons (Mt) per year. A large proportion of Appalachian historical production has come from relatively few counties in southwestern Pennsylvania, northern and southern West Virginia, eastern Kentucky, Virginia and Alabama. Many of these counties are decades past their years of peak production and several are almost depleted of economic deposits of coal. Because the current major consumer of Appalachian coal is the electric power industry, coal quality, especially sulfur content, has a great impact on its marketability. High-sulfur coal deposits in western Pennsylvania and Ohio are in low demand when compared with the lower sulfur coals of Virginia and southern West Virginia. Only five counties in the basin that have produced 500 Mt or more exhibit increasing rates of production at relatively high levels. Of these, six are in the central part of the basin and only one, Greene County, Pennsylvania, is in the northern part of the basin. Decline rate models, based on production decline rates and the decline rate of the estimated, `potential' reserve, indicate that Appalachian basin annual coal production will be 200 Mt or less by the middle of the next century.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R. C. Milici. 2000. Depletion of Appalachian coal reserves - how soon?. https://doi.org/10.1016/s0166-5162(00)00013-6

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Characterisation of bituminite and testing reproducibility of vitrinite and bituminite reflectance measurements in organic‑carbon-rich intervals of the Kimmeridge Clay Formation: ICCP Identification of Dispersed Organic Matter Working Group round robin exercises

Three round robin exercises (RRE) aimed at characterizing bituminite and testing the reproducibility of random vitrinite (VR o %) and bituminite (BitR o %) reflectance measurements on samples of dispersed organic matter from organic‑carbon rich shale intervals of Kimmeridge Clay Formation were conducted in 2016, 2018, and 2020. This work was conducted by the Identification of Dispersed Organic Matter Working Group (IDOM WG) of the International Committee for Coal and Organic Petrology (ICCP). The Kimmeridge Clay Formation represents the major marine source rock for the North Sea hydrocarbon province. Samples collected from Kimmeridge Bay, Dorset, England, United Kingdom and Filey Bay, North Yorkshire, England, United Kingdom outcrops and the 16/17–14 well in the Tiffany oil field, Viking Graben, North Sea, were analyzed by 19 to 23 participants in 15 to 17 laboratories from 14 to 15 countries. Samples contain moderate to high organic matter content [5.32 to 12.10 wt% total organic carbon (TOC) content] with thermal maturity ranging from immature to thermally mature (T max 418 to 445 °C). Participants used a standard description sheet to record bituminite morphological characteristics, including its form, size, mode of appearance, and impurities, for use in the revision of the bituminite definition. The usage of previously published classifications of bituminite types (e.g., bituminite I sensu Teichmüller and Ottenjann, 1977 ) in the RRE was not found to be helpful. The indistinct, amorphous character of boundaries of bituminite, and the poor preparation of whole rock pellets for the 2018 and 2020 RRE hampered identification of bituminite. Mean random BitR o %, including outlying values, varied in all three RRE from 0.19 to 0.35% and is reported here for the first time. Application of the criterion standard deviation (SD) < 0.15 × BitR o % to exclude outlying BitR o % values showed virtually no change in modified BitR o % in immature samples (2016 and 2018 RRE) and an unexpected increase to 0.43% BitR o in the thermally mature sample (2020 RRE). Mean VR o values, including outliers in the three RRE, range from 0.47 to 0.71%, confirming the immature to thermally mature nature of samples of the Kimmeridge Clay Formation used in this study. Application of the criterion SD < 0.15 × VR o to exclude outlying values results in a comparable range of modified VR o values and a decrease in group standard deviation. Precision of VR o values (including outlying values) evaluated via the averaged unsigned multiple of the standard deviation rule (< 1.5) showed moderate to high precision comparable to historical values from similar RRE. An average reproducibility limit (RL) of 0.29% (including outlying values) showed an improvement in reproducibility relative to similar historical RRE (0.35%), which was attributed to the application of a common methodology (ASTM D7708, 2014b, 2023) to enhance the quality of data from the reflectance test method.

Kimmeridge Bay↗

Relating systematic molecular and textural properties of graptolite pyrolyzed via gold tube hydrous pyrolysis: Implications for thermal proxies in lower Paleozoic marine shales

A series of gold tube pyrolysis experiments (72 h, 300–550 °C, 50 MPa) conducted on a graptolite-rich lower Paleozoic marine shale generated pyrolysis residues for a comprehensive evaluation of the molecular and structural variability of three types of graptolite periderm. Organic petrology, Raman spectroscopy, and field emission scanning electron microscopy (FE-SEM) with energy dispersive spectroscopy (EDS) were combined to evaluate the thermal evolution process. The three types of graptolite periderm, namely granular, non-granular, and nodular graptolite, were analyzed by Raman spectroscopy wherein point measurements were obtained after the maceral was identified and the location verified by organic petrology. Distinct thermal evolution pathways among non-granular, granular, and nodular graptolite periderms were recorded. The evolution patterns of the Raman parameters, particularly D1 and G bands, highlight the differences in geochemical composition of the graptolite periderm types and the alteration of molecular structure with increasing thermal maturity. Raman parameters D1 (position of the D1 peak), G-FWHM (full width at half maximum of the G peak), and ratios D1-FWHM/G-FWHM (full width at half maximum of the D1 peak ratioed to G-FWHM) and A D1 /A G (ratio of D1 and G peak intensities) showed effectiveness in assessing thermal maturity. Bireflectance with increasing gold tube pyrolysis temperature followed a hierarchy: non-granular > granular > nodular, reflecting different molecular alignment intensities. Qualitative FE-SEM evaluation showed that fine-grained mineral inclusions (primarily Fe-sulfide as determined via EDS) were associated with the graptolite populations, with granular graptolite containing greater amounts of coarser-grained (e.g., ∼300–1400 nm) mineral inclusions relative to non-granular and nodular graptolite, which contain finer-grained (e.g., ∼100–200 nm) inclusions difficult to resolve with optical microscopy. These findings are investigated to highlight the mechanisms that drive organic matter evolution within graptolite during thermal maturation, as well as to explore some of the limitations of using spectroscopic parameters as thermal maturity proxies.

International Journal of Coal Geology↗

Component identification of solid biomass fuels using reflected light microscopy: Interlaboratory study 2

As nations transition toward sustainable energy systems , biomass has become a vital component of global energy portfolios. Derived from organic materials such as wood, agricultural residues, forestry byproducts, and organic waste, biomass is a renewable energy source with significant environmental and economic benefits. Responsible biomass energy production can improve waste management, reduce emissions of greenhouse gases, and mitigate environmental pollution. However, as the diversity of biomass-derived fuels increases, robust quality assessment methods are essential to ensure their efficiency, safety, and minimal environmental impact. Reflected light microscopy (RLM) is one such technique with the potential to complement conventional physico-chemical analyses by enabling a rapid identification of material constituents and impurities. To refine this methodology and evaluate the reproducibility of solid biomass component identification using RLM, an interlaboratory study (ILS) was conducted. The study involved the recognition of 58 components across 45 photomicrographs, with the participation of 65 scientists and students from 25 countries. The participants faced high difficulty identifying some of the marked components, and as a result, the percentage of correct answers ranged from 19.0 % to 98.3 %, with an average correct identification rate of 62.7 %. The most challenging aspects of the identification process included distinguishing between woody and non-woody (agro) biomass, accurately identifying petroleum-derived materials, and differentiating agro biomass from inorganic matter. The results suggest that while RLM is an important tool for characterizing solid biomass, further development of methodology guidelines and training are necessary to enhance its effectiveness. Future research should prioritize preparing detailed, image-rich, microscopic morphological descriptions of biomass fuel components, which could improve the accuracy and reliability of using RLM in biomass fuel characterization.

International Journal of Coal Geology↗