Physical Structure Of Coal Research Articles

Production of near Zero ash coal through ionic liquid promoted organo-refining process

ABSTRACT Ionic liquids (ILs) being green solvents have found a wider and interesting applications in modern industries. Presently, three ionic liquids – 1-Butyl-methyl-imidazolium 2(2-methoxy ethoxy) ethyl sulfate (Bmim(ME)ES), 1-Butyl-methyl-imidazolium (BF)4(Bmim(BF)4), 1-Butyl-methyl-imidazolium(Octyl sulfate)(Bmim(OS) were employed for promoting the solvolytic extraction of an Indian coking coal, Bhagabandh coal (BC) and a lignite, Neyveli Lignite (NL) under milder conditions in N-methyl pyrrolidone (NMP) and NMP containing a small amount of ethylenediamine (EDA) (termed as e,N) through prior treatment with ionic liquids. The driving aim was to disrupt the intermolecular associative forces existing in solid coal by using N-based ILs. Swelling studies were carried out to determine the extent of interaction of the ILs with the coal. Interestingly, Bmim(OS) was found to be the best candidate to enhance the extraction yield in NMP (37.6%) as well as in e,N (66.9%). Optical micrographs and ATR-FTIR spectras of BCcoal and NL pre-treated with IL showed the disruption of physical structure of coal.

Effects of Coal Interaction with Supercritical CO2: Physical Structure

It is known that polar solvents swell coal, break hydrogen-bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of drying, interaction with supercritical CO2 and degassing on the physical structure of coal have been studied using gas sorption technique and a scanning electron microscope (SEM). Both drying and interaction with supercritical CO2 drastically change the micropore and mesopore surface area, absolute volume, and volume distribution in both bituminous coal and lignite. Degassing removes debris in the pore space which allows for better analysis of the changes in the morphology that were induced by drying and exposure to supercritical CO2. SEM reveals that interaction of bituminous coal with supercritical CO2 results in an abundance of carbon structures similar to the maceral collinite.

Analysis of pyrolysis and gasification reactions of hydrothermally and supercritically upgraded low-rank coal by using a new distributed activation energy model

Hydrothermal water treatments and supercritical (SC) water treatments of a lignite were performed to examine the feasibility of upgrading low-rank coals. The treatment below 400°C was found to be effective enough to keep high gasification reactivity at high temperature, as well as to suppress spontaneous combustion. The pyrolysis and gasification behaviors of raw and pretreated coals were examined by thermogravimetry (TG). The kinetic analysis was carried out based on a new distributed activation energy model (DAEM) presented by Miura [K. Miura, Energy & Fuels, (12), 864–869 (1998).]. According to this method, thermogravimetric curves measured at two or more different heating rates were needed to obtain the activation energy distribution function f( E) of a given coal sample. It was found that in the case of pyrolysis, the peak values of f( E) curves for upgraded coal samples are nearly 300 kJ/mol, whereas, the peak value of f( E) curve for their parent coal is about 200 kJ/mol. In the case of gasification, where only single reactions occur, the application of this new DAEM can give the changes of activation energy during reaction. Some interesting results occur, which may hint at some changes in the rate-controlling step of reaction or in the physical structure of coal during gasification.

Changes in the physical structure of coal on partial solubilization

Changes in the physical structure of Alberta hvCb coal upon partial solubilization in tetralin, Athabasca bitumen and the oil fraction from the bitumen were determined from gas adsorption measurements, mercury porosimetry and petrographic examination. It was shown that solubilization of the coal generated new micropores, while the macropore structure was degraded. Resistance to extraction due to pore structure is considered to be probably of minor importance. The experimental results suggest that low molecular weight material in the coal was preferentially liquefied.

165. Changes in the physical structure of coal on partial solubilization

165. Changes in the physical structure of coal on partial solubilization

ChemInform Abstract: O‐ALKYLATION CHEMISTRY OF COAL AND ITS IMPLICATIONS FOR THE CHEMICAL AND PHYSICAL STRUCTURE OF COAL

Chemischer InformationsdienstVolume 12, Issue 25 Other Subjects ChemInform Abstract: O-ALKYLATION CHEMISTRY OF COAL AND ITS IMPLICATIONS FOR THE CHEMICAL AND PHYSICAL STRUCTURE OF COAL R. LIOTTA, R. LIOTTASearch for more papers by this authorK. ROSE, K. ROSESearch for more papers by this authorE. HIPPO, E. HIPPOSearch for more papers by this author R. LIOTTA, R. LIOTTASearch for more papers by this authorK. ROSE, K. ROSESearch for more papers by this authorE. HIPPO, E. HIPPOSearch for more papers by this author First published: June 23, 1981 https://doi.org/10.1002/chin.198125353AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume12, Issue25June 23, 1981 RelatedInformation

O-Alkylation chemistry of coal and its implications for the chemical and physical structure of coal

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTO-Alkylation chemistry of coal and its implications for the chemical and physical structure of coalR. Liotta, K. Rose, and E. HippoCite this: J. Org. Chem. 1981, 46, 2, 277–283Publication Date (Print):January 1, 1981Publication History Published online1 May 2002Published inissue 1 January 1981https://doi.org/10.1021/jo00315a010RIGHTS & PERMISSIONSArticle Views275Altmetric-Citations73LEARN 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 InReddit PDF (1018 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Geochemistry of coal

The past decade has witnessed great strides in the accumulation of information about the origin, chemical and physical structure, and composition of coal. These advances were made possible in part by the development of new analytical techniques, and in part by cooperative research between geologists, chemists, physicists, and biologists.Based on a review of the literature, the consensus is that coal was formed predominantly from lignin. The potential contribution from cellulose or it degradation products is, however, difficult to evaluate. Consideration of sources of energy for the metamorphic processes that convert plant residues into high-rank coals leads to the conclusion that neither bacteria, hydrostatic head, nor localized high temperatures were the geologically active agencies. The application of shear force may provide the energy necessary, but the effectiveness of low-grade thermal activation over long periods of time cannot be overlooked.The relative importance of aromatic and aliphatic structures, and of the various oxygen-bearing functional groups in coal is now understood in considerable detail. Application of such techniques as adsorption, infrared absorption, and X-ray diffraction has enabled the development of a model for the physical structure of coal through which its colloidal characteristics can be reasonably well explained. The conclusion that coal contains a high concentration of free radicals also helps to explain its color and reactivity.The concentrations of germanium, uranium, organic sulfur, phosphorus, vanadium, nickel, chromium, beryllium, and rare gases associated with coal have been studied in less detail. For several elements, notably uranium and germanium, attempts have been made to evolve the geochemical principles underlying the mode of concentration of the elements by coals, and the mechanisms by which they are retained.

Physical Structure of Coal, Cellulose Fiber, and Wood as Shown by Spierer Lens

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhysical Structure of Coal, Cellulose Fiber, and Wood as Shown by Spierer LensReinhardt ThiessenCite this: Ind. Eng. Chem. 1932, 24, 9, 1032–1041Publication Date (Print):September 1, 1932Publication History Published online1 May 2002Published inissue 1 September 1932https://doi.org/10.1021/ie50273a016RIGHTS & PERMISSIONSArticle Views82Altmetric-Citations9LEARN 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 InReddit PDF (2 MB) Get e-Alerts