17 research outputs found
Quality Characteristics of the Lower Elkhorn Coal Bed in Eastern Kentucky
Thickness and quality data from the Kentucky Coal Resources Information System (KCRIS) are summarized in this chart for the Lower Elkhorn coal bed (and equivalents). Parameter averages and ranges of values are presented in the two tables, and average values are displayed graphically by county
Overview of Environmental Regulations That Affect Coal Combustion
Environmental regulations have had, and continue to have, an effect on the combustion of coal. These regulations largely affect the electric utility industry, the largest consumer of domestic coal, but they ultimately affect everyone, because we all use electricity, and the cost of compliance is usually passed on to the consumer, resulting in higher electric bills
Quality Characteristics of the Springfield Coal in Western Kentucky
Thickness and quality data from the Kentucky Coal Resources Information System (KCRIS) for the Springfield coal bed are summarized in this chart. Parameter averages and range of values are presented in the two tables, and average values are displayed graphically by county
Compositional Variations in the \u3cem\u3eFire Clay Coal Bed\u3c/em\u3e of Eastern Kentucky: Geochemistry, Petrography, Palynology, and Paleoecology
Bench samples of the Fire Clay coal bed, collected from 28 localities in a study area of eight 7.5-minute quadrangles in the Eastern Kentucky Coal Field, were analyzed geochemically, petrographically, and palynologically to determine any spatial or temporal trends among the studied parameters.
At most sample sites the Fire Clay is split by a flint-clay parting of probable volcanic origin. The upper bench of the Fire Clay coal generally is thick, laterally continuous, low in ash yield and sulfur content, has a moderate to high calorific value, and is high in total vitrinite content. In contrast, the lower bench generally is thin, laterally discontinuous, moderate to high in ash yield and sulfur content, has a low to moderate calorific value, and has high liptinite and inertinite contents. Rider coals, present at two sample sites, are thin, laterally discontinuous, and high in both ash yield and sulfur content.
Fire Clay coal extracted from underground mines typically contains roof and floor rock, which is separated by conventional coal-cleaning methods. The analytical data were grouped into categories of increasing coal purity to approximate a cleaned coal product. Results indicate that some parameters (Btu and total vitrinite content) increase along a trend from higher ash to lower ash coal. Other parameters (ash yield, total sulfur content, and several minor elements) decrease. Still others (thickness and total moisture) show no trend at all. A comparison of these data with previously accumulated data from 64 cleaned coal samples (collected from preparation plants) confirms these trends. This is significant, especially with regard to Titles III and IV of the Clean Air Act Amendments of 1990, in that many deleterious components of coal appear to be removable by conventional coal-cleaning methods prior to combustion in an industrial furnace. Examples of these undesirable constituents include pyrite, chromium, cobalt, and nickel.
The Fire Clay coal was grouped into four compositional categories for paleoecological interpretation. The categories are (1) a Lycospora-dominant group with high vitrinite contents that is interpreted to have formed in areas of the Fire Clay paleomire that were kept very wet, to the point of having standing water, a majority of the time (this group probably developed in areas of the mire that were dominantly rheotrophic and planar); (2) a mixed-palynoflora group with high vitrinite contents that is defined by having a more diverse palynoflora than the first group (increased percentages of small lycopsid, fern, and calamite spores), and high percentages of vitrinite (this group is also interpreted to have formed in areas that were very wet most of the time, and were predominantly rheotrophic and planar); (3) a mixed-palynoflora group with moderate to low vitrinite contents that contains increased percentages of inertinite compared to the first two groups and a diverse palynoflora, possibly because the mire became more ombrotrophic and domed; and (4) a mixed-palynoflora group with high ash yield whose palynoflora is marked by various mixtures of lycopsids (trees and small forms), ferns (tree-like and small forms), calamites, and cordaite spores; samples defined by this group contain elevated percentages of liptinite and inertinite macerals, as well as higher ash yields. The conditions under which group 4 formed probably were rheotrophic and planar. Group 4 defines all the samples in the lower bench of the Fire Clay coal bed
Geochemistry, Petrology, and Palynology of the Princess No. 3 Coal, Greenup County, Kentucky
The high volatile C bituminous-rank, Bolsovian-age Princess No. 3 coal, a correlative of the heavily-mined Hazard No. 7 coal and the Peach Orchard and Coalburg Lower Split coals, was investigated three sites at a mine in Greenup County, Kentucky. The coal exhibits a “dulling upwards” trend, with decreasing vitrinite and a greater tendency towards dull clarain and bone lithotypes towards the top of the coal. The relatively vitrinite-rich basal lithotype is marked by a dominance of lycopod tree spores. The palynology transitions upwards to a middle parting co-dominated by tree fern and small lycopod spores and an upper bench dominated by tree ferns with contributions from small ferns, cordaites, and calamites. The lithotypes generally have a moderate- to high-S content with a variable ash yield. Sulfur, Fe2O3, and certain siderophile elements are highest near the top of the coal. As observed in other coals, uranium and Ge are enriched at the top and bottom margins of the coal. The rare earth chemistry at the top of the coal has a significantly lighter distribution (higher LREE/HREE) than at the base of the coal
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Analysis of Devonian Black Shales in Kentucky for Potential Carbon Dioxide Sequestration and Enhanced Natural Gas Production
Carbonaceous (black) Devonian gas shales underlie approximately two-thirds of Kentucky. In these shales, natural gas occurs in the intergranular and fracture porosity and is adsorbed on clay and kerogen surfaces. This is analogous to methane storage in coal beds, where CO2 is preferentially adsorbed, displacing methane. Black shales may similarly desorb methane in the presence of CO2. Drill cuttings from the Kentucky Geological Survey Well Sample and Core Library were sampled to determine both CO2 and CH4 adsorption isotherms. Sidewall core samples were acquired to investigate CO2 displacement of methane. An elemental capture spectroscopy log was acquired to investigate possible correlations between adsorption capacity and mineralogy. Average random vitrinite reflectance data range from 0.78 to 1.59 (upper oil to wet gas and condensate hydrocarbon maturity range). Total organic content determined from acid-washed samples ranges from 0.69 to 14 percent. CO2 adsorption capacities at 400 psi range from a low of 14 scf/ton in less organic-rich zones to more than 136 scf/ton in the more organic-rich zones. There is a direct linear correlation between measured total organic carbon content and the adsorptive capacity of the shale; CO2 adsorption capacity increases with increasing organic carbon content. Initial volumetric estimates based on these data indicate a CO2 sequestration capacity of as much as 28 billion tons total in the deeper and thicker parts of the Devonian shales in Kentucky. In the Big Sandy Gas Field area of eastern Kentucky, calculations using the net thickness of shale with 4 percent or greater total organic carbon, indicate that 6.8 billion tonnes of CO2 could be sequestered in the five county area. Discounting the uncertainties in reservoir volume and injection efficiency, these results indicate that the black shales of Kentucky are a potentially large geologic sink for CO2. Moreover, the extensive occurrence of gas shales in Paleozoic and Mesozoic basins across North America make them an attractive regional target for economic CO2 storage and enhanced natural gas production
An Exhumed Late Paleozoic Canyon in the Rocky Mountains
Landscapes are thought to be youthful, particularly those of active orogenic belts. Unaweep Canyon in the Colorado Rocky Mountains, a large gorge drained by two opposite‐flowing creeks, is an exception. Its origin has long been enigmatic, but new data indicate that it is an exhumed late Paleozoic landform. Its survival within a region of profound late Paleozoic orogenesis demands a reassessment of tectonic models for the Ancestral Rocky Mountains, and its form and genesis have significant implications for understanding late Paleozoic equatorial climate. This discovery highlights the utility of paleogeomorphology as a tectonic and climatic indicator
Petroleum source rock evaluation of organic black shales in the Paleogene N'kapa Formation, Douala Basin, Cameroon
Black shales outcropping in the Douala Basin were studied using organic petrography and Rock-Eval pyrolysis. The goal of this study was to use organic petrography and bulk geochemical analysis to evaluate N'kapa Formation shales in terms of organic matter (macerals) composition and its relationship to oil and gas productivity potentials. The quantity of organic matter, kerogen type and thermal maturity were determined, and their relationship to oil and gas generation was evaluated. The results of this investigation indicate that the nine samples analyzed had average random vitrinite reflectance values (VRo random) between 0.48 and 0.57% and are indicative of immature source rocks. Calculated maximum reflectance values (VRo maximum) ranged from 0.50 to 0.59%, showing a maximum volatile C bituminous rank and Liptinite macerals were found to fluoresce in the yellow-green to the yellow range, which is consistent with the indicated rank. The total organic carbon (TOC) of the samples ranges from 0.55 to 2.23 wt% (average of 1.18 wt%), implying fair to good concentration of organic matter, while the S1 values range from 0.04 to 0.10 mg HC/g rock (average of 0.07 mg HC/g rock) and S2 values range from 0.10 to 0.91 mg HC/g rock (average of 0.38 mg HC/g rock) and are described as showing poor source potential. Based on Genetic Potential (GP = S1+S2) values (0.18-1.01 mg HC/g rock), the studied N'kapa Formation shales are dominated by type III gas-prone kerogen with a minor association of type IV kerogen. The hydrogen index (HI<50mg HC/g TOC) and oxygen index (OI<75mg CO2/g TOC) values are too low for the shales to have generated hydrocarbons. The low values HI and OI and the absence of type II and mixed type II/III may be due to some degree of weathering of the samples