The major element and Sr isotope systematics and geochemistry of coal fly ash and its interactions with environmental waters were investigated using laboratory flow-through column leaching experiments (sodium carbonate, acetic acid, nitric acid) and sequential batch leaching experiments (water, acetic acid, hydrochloric acid). Column leaching of Class F fly ash samples shows rapid release of most major elements early in the leaching procedure, suggesting an association of these elements with soluble and surface bound phases. Delayed release of certain elements (e.g., Al, Fe, Si) signals gradual dissolution of more resistant silicate or glass phases as leaching continues. Strontium isotope results from both column and batch leaching experiments show a marked increase in Sr-87/Sr-86 ratio with continued leaching, yielding a total range of values from 0.7107 to 0.7138. For comparison, the isotopic composition of fluid output from a fly ash impoundment in West Virginia falls in a narrow range around 0.7124. The experimental data suggest the presence of a more resistant, highly radiogenic silicate phase that survives the combustion process and is leached after the more soluble minerals are removed. Strontium isotopic homogenization of minerals in coal does not always occur during the combustion process, despite the high temperatures encountered in the boiler. Early-released Sr tends to be isotopically uniform; thus the Sr isotopic composition of fly ash could be distinguishable from other sources and is a useful tool for quantifying the possible contribution of fly ash leaching to the total dissolved load in natural surface and ground waters. (c) 2012 Elsevier Ltd. All rights reserved.

PM2.5 mass was measured daily with three batch samplers, a PM2.5 R&P Partisol-Plus FRM, an Andersen RAAS, and a BYU PC-BOSS, and continuously with a TEOM monitor during July and August 2000. PM2.5 composition was also determined. These data are part of an ongoing PM2.5 characterization program centered around a sampling site at the National Energy Technology Laboratory Pittsburgh campus. The composition and concentrations of PM2.5 were both highly variable during this time period. Likely sources of PM2.5 during low concentration periods were transportation, coal-fired boiler, and other emissions generated in the local area. For these periods, the average concentration of PM2.5 was 13 mug/m(3) and 70% of the PM2.5 mass was carbonaceous material, including semivolatile organic material that was lost in varying degrees from both the TEOM and FRM samplers. In contrast, much higher concentrations of PM2.5 were associated with transport of pollutants to the site. Analysis of meteorological and back-trajectory data suggests that these pollutants were emitted elsewhere during a period of high atmospheric pressure and were subsequently transported to the site with the passage of a frontal system. When the PM2.5 collected at the site originated from the west or southwest, the concentrations averaged 31 mug/m(3) and ammonium sulfate averaged 54% of the PM2.5 mass. Scanning election microscopy and trace element analyses are consistent with the association of high concentration PM2.5 episodes with transport of coke and iron processing, coal-fired boiler, and other emissions from the Ohio River Valley region to the NETL site. Preliminary observations on the use of SEM and PIXE data in source apportionment at the NETL site are given.

The overall goal of the DOE fine particulate program is to ensure that the best science and technology is available for any regulatory decision-making related to the health and environmental impacts of ambient fine particulate matter and regional haze. Interest primarily lies in the particulate fraction having aerodynamic diameters of 2.5 microns and less (PM2.5). Particulates of this size are the focus of the newly established National Ambient Air Quality Standards. As such, the Federal Energy Technology Center (FETC) is establishing a fine particulate sampling station at the Center's Pittsburgh site located in South Park Township, PA. This sampling station is one of a group of stations scattered throughout Pennsylvania, West Virginia, and Ohio that constitute the Upper Ohio River Valley Project. The station is equipped with a full complement of fine particulate and gaseous monitors including the following: (1) R and P Sequential FRM sampler, (2) Grimm PM2.5 continuous sampler, (3) TSI Dustrak PM2.5 continuous sampler, (4) R and P TEOM equipped with an AccuSampler, (5) Andersen speciation sampler, (6) MetOne speciation sampler, (7) EcoChem continuous PAH monitor, (8) Total peroxide monitor that employs the Greg Kok method, (9) Burkard 7 day pollen and mold spore sampler, (10) Continuousmore » gas monitors for O{sub 3}, SO{sub 2}, NH{sub 3}, CO, H{sub 2}S, NO{sub y}, NO{sub x}, and (11) Meteorological instruments. The presentation will describe the initial results for the summer 1999 season from the above instruments. The chemical analysis of the aqueous extracts of the FRM filters will be discussed, including the anions present as determined by ion chromatography, and the metals present.« less

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPractical Notes on the Use of N-Methyl-2-pyrrolidinone as a Solvent for Extraction of Coal and Coal-Related MaterialsC. M. White, P. C. Rohar, G. A. Veloski, and R. R. AndersonView Author Information Federal Energy Technology Center, P.O. Box 10940, Pittsburgh, Pennsylvania 15236 Cite this: Energy Fuels 1997, 11, 5, 1105–1106Publication Date (Web):September 18, 1997Publication History Received26 March 1997Revised23 May 1997Published online18 September 1997Published inissue 1 September 1997https://pubs.acs.org/doi/10.1021/ef970050yhttps://doi.org/10.1021/ef970050yrapid-communicationACS PublicationsCopyright © 1997 American Chemical SocietyRequest reuse permissionsArticle Views466Altmetric-Citations33LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Coal,Extraction,Nitrogen,Solvents,Transition temperature Get e-Alerts

Dimethyl polysulfides have been reported in the supercritical methanol extracts of coal and in the pyrolysis products of a high-sulfur Spanish coal that was first extracted with a mixture of dichloromethane and methanol. Dimethyl polysulfides and other products are shown to be formed by the reaction of methanol with elemental sulfur at elevated temperature and pressure. This reaction is a possible source of some of the dimethyl polysulfides observed by others in high-temperature methanol extracts.

Partially coalified, structurally intact latex fibers(''Affenhaar'') found in a low-rank coal have been characterized by various analytical methods. It has been proposed in previous studies, and it appears to be so here, that the latex was ''naturally'' vulcanized during the coalification period. The Affenhaar samples studied here are high in sulfur. However, the sulfur constituents were not extracted in the pyridine solvent used to exact the hydrocarbons. Two fossilized latex samples recovered from different locations within the brown coal deposit were characterized. Pyridine extracts of the samples were analyzed by capillary gas chromatography, combined capillary gas chromatography-mass spectrometry, and high-resolution mass spectrometry. Twelve compounds in the extract were tentatively identified as amyrin and hopane biomarker derivatives by comparing the Kovats retention indices, mass spectra, and order of elution with those in the literature. Three of these identifications were verified by cochromatography with authentic standards. Kovats retention indices for the twelve compounds are reported.

This paper describes a catalyst/wax separation technique based on dense-gas and/or liquid extraction of the soluble hydrocarbon components from the insoluble inorganic catalyst particles. The separation by extraction can also be performed in conjunction with magnetic separation of iron catalyst particles. Extractions of 4.91 wt % catalyst in wax were performed with n-butane, n-pentane, and n-hexane. Up to 91 wt % of the catalyst/wax feed mixture to the extractor could be recovered as a catalyst-free wax (combined yield of the second- and third-stage separators). High-temperature gel permeation chromatography was used to measure the average molecular weight of the extraction fractions. The extraction process separates the wax according to molecular weight. The lower molecular weight wax components are extracted from the catalyst/wax mixture and accumulate in the second-stage separator, while the higher molecular weight wax components remain in the first-stage separator. The low molecular weight wax fraction can be remixed with the catalyst and pumped back into the slurry reactor, reducing the average molecular weight, reducing the viscosity, and improving the transport properties of the reaction media while minimizing the chances of reactor gelation due to buildup of high molecular weight waxes.