Download or read book Removal of Sulfur from Coal Using Mild Oxidizing Conditions written by Mingshe Zhu and published by . This book was released on 1990 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Removal of Sulfur from Illinois Coals Via Charring and Partial Oxidation written by Rodney R. Ruch and published by . This book was released on 1985 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Ferric Sulfate written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work has been to investigate the ability of ferric sulfate-acid leach systems to oxidize the sulfur in model compounds of coal. Ferric iron-acid leach systems have been shown to be quite effective at removal of inorganic sulfur in coal. In this study, the oxidative effect of ferric iron in acid-leach systems was studied using dibenzothiophene, diphenyl sulfide, and di-n-butyl sulfide as models of organic sulfur groups in coal. Nitrogen and oxygen, as well as various transition metal catalysts and oxidants, were utilized in this investigation. Dibenzothiophene was found to be quite refractory to oxidation, except in the case where metavanadate was added, where it appears that 40% oxidation to sulfone could have occurred per hour at 150°C and mild oxygen pressure. Diphenyl sulfide was selectively oxidized to sulfoxide and sulfone in an iron and oxygen system. Approximately 15% conversion to sulfone occurred per hour under these conditions. Some of the di-n-butyl sulfide was cracked to 1-butene and 1-butanethiol under similar conditions. Zinc chloride and ferric iron were used at 200°C in an attempt to desulfonate dibenzothiophene sulfone, diphenyl sulfone, and di-n-butyl sulfone. Di-n-butyl sulfone was completely desulfurized on one hour and fragmented to oxidized parafins, while dibenzothiophene sulfone and diphenyl sulfone were unaffected. These results suggest that an iron-acid leach process could only selectively oxidize aryl sulfides under mild conditions, representing only 20% of the organic sulfur in coal (8% of the total sulfur). Removal through desulfonation once selective sulfur oxidation had occurred was only demonstrated for alkyl sulfones, with severe oxidation of the fragmented paraffins also occurring in one hour.
Download or read book Removal of Organic and Inorganic Sulfur from Ohio Coal by Combined Physical and Chemical Process Final Report written by and published by . This book was released on 1989 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project consisted of three sections. In the first part, the physical cleaning of Ohio coal by selective flocculation of ultrafine slurry was considered. In the second part, the mild oxidation process for removal of pyritic and organic sulfur.was investigated. Finally, in-the third part, the combined effects of these processes were studied. The physical cleaning and desulfurization of Ohio coal was achieved using selective flocculation of ultrafine coal slurry in conjunction with froth flotation as flocs separation method. The finely disseminated pyrite particles in Ohio coals, in particular Pittsburgh No. 8 seam, make it necessary to use ultrafine ( -500 mesh) grinding to liberate the pyrite particles. Experiments were performed to identify the ''optimum'' operating conditions for selective flocculation process. The results indicated that the use of a totally hydrophobic flocculant (FR-7A) yielded the lowest levels of mineral matters and total sulfur contents. The use of a selective dispersant (PAAX) increased the rejection of pyritic sulfur further. In addition, different methods of floc separation techniques were tested. It was found that froth flotation system was the most efficient method for separation of small coal flocs.
Download or read book Removal of Sulfur from Coal by Treatment with Hydrogen written by Colorado School of Mines. Chemical and Petroleum Refining Engineering Department and published by . This book was released on 1973 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sulfur Removal from High sulfur Illinois Coal by Low temperature Perchloroethylene PCE Extraction Technical Report December 1 1992 February 28 1993 written by and published by . This book was released on 1993 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this project are to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co.(MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for year-2 study are to verify the possible effect of PCE treatment on coal-derived FeS2, FeSO4, and Fe2(SO4)3 on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample to investigate the proprietary reagent on the oxidation of the organic sulfur model compounds with and without additives, to evaluate this new oxidation on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions. Oxidation study on the organosulfur model compounds alone was completed in first quarter. The oxidation reactions were repeated on the organosulfur model compounds with the presence of hydrocarbon additives. These additives are known to easily produce hydroperoxides during air oxidation. Analysis of the reaction products is in progress.
Download or read book Combined Chemical and Microbiological Removal of Organic Sulfur from Coal written by and published by . This book was released on 1991 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.
Download or read book Sulfur Removal from High sulfur Illinois Coal by Low temperature Perchloroethylene PCE Extraction Quarterly Technical Report March 1 1993 May 31 1993 written by and published by . This book was released on 1993 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purposes of this project are: to independently confirm and possibly to improve the organic sulfur removal from Illinois coals with the PCE process developed by the Midwest Ore Processing Co. (MWOPC), to verify the forms-of-sulfur determination using the ASTM method for evaluation of the PCE process, and to develop a dechlorination procedure to remove excess PCE from the PCE-treated coal. The objectives for the second year are: to verify the possible effects of PCE treatment on coal-derived FeS2, FeSO4, and Fe2(SO4)3 on ASTM coal analysis, to investigate the behavior of sulfur during oxidation and PCE desulfurization using the isotopically signatured coal sample, to investigate the effects of conditions and/or reagents on the oxidation of the organic-sulfur-model compounds, to evaluate the extended oxidation condition on the organic sulfur removal by PCE desulfurization, and to study other innovative pretreatment processes for the removal of organic sulfur from coal under mild conditions.
Download or read book Mild Pyrolysis of Selectively Oxidized Coals written by and published by . This book was released on 1991 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.
Download or read book Extraction Separation and Analysis of High Sulfur Coal written by and published by . This book was released on 1991 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two processes were studied in the period. The first was a study of oxidative desulfurization processes. Earlier research indicated that the use of copper-promoted oxidation of the organic and inorganic sulfur species in coal showed considerable promise. Initial studies utilizing CuCl2 demonstrated that the desulfurization yields were much lower than previously quoted. However, the experiments suggested that the reactant pathway showed promise and further investigations were conducted varying the solvent and replacing the Cl− anion with the OH− species. Ultimate analyses of these reactions are reported in addition to the experimental conditions used. Reactions using Cu(OH)2, CuCl2, and copper cyclohexane butyrate are investigated. The second process discussed was desulfurization using selective solvation. Supercritical ethanol was used to investigate the extent of organic sulfur removal from coal. (VC).
Download or read book Extraction Separation and Analysis of High Sulfur Coal Final Report written by and published by . This book was released on 1992 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work described in this report studies the removal of sulfur by oxidative interaction of various cupric salts with coal and also considers the possibility of removing organic sulfur by the selective interaction of supercritical ethanol with the organic coal matrix. Either one of these methods could potentially be used to pretreat coals before burning. The primary purpose of these studies is to ascertain the nature of the chemical reactions occurring, the chemical composition of the resultant products, and information on possible reaction mechanisms. This information should allow prediction of reasonable reaction conditions for the removal of organosulfur compound from coal.
Download or read book Direct Determination of Organic and Inorganic Sulfur in Coal by Controlled Oxidation written by and published by . This book was released on 1992 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this project is to develop an analytical method to directly measure the forms of organic sulfur in coal. The method will provide a route to monitor the effectiveness of coal preparation research directed toward removal of organic sulfur in coal. The approach involves subjecting diluted coal samples simultaneously to an oxygen flow and a linear increase in temperature. Distinctive sulfur dioxide evolution patterns are observed among coals of different rank and between raw and treated coals. Assignments have been made relating each specific sulfur dioxide evolution to the non-aromatic organic, aromatic organic, and inorganic sulfur present in coals and treated coals. Work is progressing on schedule to optimize experimental conditions and to improve the efficiency of the controlled-atmosphere programmed-temperature oxidation (CAPTO) method by developing a multiple sample instrumental system.
Download or read book Combined Chemical and Microbiological Removal of Organic Sulfur from Coal Technical Report September 1 1990 August 31 1991 written by and published by . This book was released on 1991 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this work is to investigate techniques for chemically converting the sulfur containing organic compounds in coal to compounds that can be treated microbiologically to remove the organically bound sulfur. The goal is to achieve an economically feasible mild chemical oxidation of the organic sulfur in a representative Illinois Basin coal by converting the sulfur to sulfoxides and sulfones; the carbon sulfur bond in the sulfoxides and sulfones would then be broken microbiologically and the sulfur removed from the coal as sulfate.
Download or read book Advanced Development of Fine Coal Desulfurization and Recovery Technology Annual Technical Progress Report October 1 1976 September 1977 54 References written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Work has been carried out to develop and improve several promising methods for desulfurizing and recovering fine-size coal. These methods included froth flotation, selective oil agglomeration, pelletization, and a chemical desulfurization process which involves leaching fine coal with a hot dilute solution of sodium carbonate containing dissolved oxygen or air under pressure. This process is an oxydesulfurization process which utilizes an alkaline solution instead of an acidic solution for leaching coal. The results of experiments with a small autoclave showed that more sulfur, both organic and inorganic, was removed from several high-sulfur bituminous coals when a dilute solution of alkali was used than when a dilute acid solution was used for leaching under the same conditions of time, temperature, and oxygen partial pressure. On the other hand, the heating value recovery was somewhat higher when acidic solutions were used. Also it was shown that pure oxygen is more effective than air, even though the oxygen partial pressure was kept the same, for oxydesulfurization of coal in either acidic or alkaline solutions. In addition it was found that the removal of organic sulfur by alkaline solutions increased as the oxygen partial pressure was raised. Although small concentrations of alkali were beneficial, large concentrations were detrimental. In order to improve the physical separation of coal and pyrite particles by froth flotation or oil agglomeration, various surface chemical treatments were tested. The most successful treatment involved treating the coal or pyrite particles with a warm, dilute alkaline solution which was aerated to provide mildly oxidizing conditions.
Download or read book Coal Desulfurization written by Robert Allen Meyers and published by Marcel Dekker. This book was released on 1977 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyzing Organic Sulfur in Coal written by and published by . This book was released on 1994 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cost effective removal of sulfur from coal has been very difficult to accomplish. Perhaps the single most important reason for this is the fact that the organic sulfur in coal remains very poorly characterized. The overall goal of this study is to improve our understanding of sulfur in coals/chars via the use of combined advanced non-destructive and advanced destructive methods of sulfur analysis. This study combines selective oxidation, analytical pyrolysis, and sulfur X-ray Absorption Near Edge Structure Spectroscopy (XANES) analysis. Examination of samples that were oxidized with peroxyacetic acid using the analytical pyrolysis technique showed that the level of simple thiophene structures observed in the pyrolysis products declines with increasing levels of oxidation. Sulfur XANES spectra of treated samples showed various effects depending on the treatment severity. For the less severely treated samples (demineralization and solvent extraction), the XANES spectra were similar, although not identical, to the untreated coal spectra, whereas the more severe treatments (steam at 450°C; peroxyacetic acid at 25°C) showed preferential oxidation of one or more sulfur-bearing phases in the original coal.
Download or read book Coal Desulfurization written by S. K. Kawatra and published by Taylor & Francis. This book was released on 2001 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book was written to provide a comprehensive survey of the current state-of-the-art information in coal preparation, with particular emphasis on coal desulfrization. The primary audience for this book will be practising coal preparation engineers who need complete information about all of the coal preparation and desulphurization technologies that are available now, or that may be available in the future. It will also be valuable for coal researchers who need details and comparative data for cutting-edge technologies that are still under development. The main emphasis is on physical coal preparation, but chapters also include chemical and biological technologies that are under development, but not yet used in industrial practice. Along with the successful technologies, also included are details of processes and techniques that were attempted, but were subsequently abandoned, along with discussions of the reasons they were abandoned.
