Activity and characterization of anion-modified iron(III) oxides as catalysts for direct liquefaction of low pyrite coals

Pradhan, V.R.; Hu, Jiahao; Tierney, J.W.; Wender, I.

doi:10.1021/ef00040a002

Cited by 20 publications

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“…In the present study, the kinetics of the esterification of oleic acid with glycerol were investigated by using sulfated iron oxide as catalyst. Sulfated metal oxides have been studied in coal liquefaction processes (31)(32)(33) and acid-catalyzed reactions (34)(35)(36). Due to their unusual properties, the most important one being their so-called "superacidity," sulfatepromoted iron oxides seemed to be worth investigating in the reaction between glycerol and oleic acid.…”

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confidence: 99%

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Güner

Sirkecioğlu

Yılmaz

et al. 1996

J Americ Oil Chem Soc

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Esterification of oleic acid with glycerol was investigated in view of the reaction kinetics, using "superacidic" sulfated iron oxide catalysts. A series of different sulfate contents were prepared and characterized by a multitude of techniques prior to their use as catalysts. The sulfated iron oxide reaction was carried out with equivalent amounts of reactants in the temperature range of 180-240~ Effects of the sulfate content and the catalyst amount on reaction kinetics at different temperatures were evaluated.1A0C5 73, 347-351 (1996).

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confidence: 99%

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Güner

Sirkecioğlu

Yılmaz

et al. 1996

J Americ Oil Chem Soc

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“…As shown in Figure and Table , it can be concluded that the 42.3% of oil yield and 75.2% of coal conversion at the S/Fe atomic ratio of 0.6 were probably due to the synergistic effects of higher partial pressure of H 2 S and the catalysis of pyrrhotite at the initial H 2 pressure of 4.0 MPa. It was reported that the increase in oil yield was related to the possible interaction between pyrrhotite and H 2 S for catalyzing hydrogenation reactions during coal liquefaction …”

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confidence: 99%

Effects of sulfur additive on the transformation behaviors of γ‐Fe₂O₃ and coal liquefaction performances under mild conditions

Zhao

Yang

Song

et al. 2018

Asia-Pacific J Chem Eng

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In this paper, the effects of sulfur on liquefaction performances of coal and the transformation behaviors of γ-Fe 2 O 3 at the S/Fe atomic ratio of 0-1.3 under mild conditions were investigated. Compared with traditional liquefaction processes, the oil yield and coal conversion were insensitive to the addition of sulfur under mild conditions (temperature of 430°C, reaction pressure of 8.5-13.8 MPa). The optimum S/Fe atomic ratios at the initial H 2 pressures of 4.0 and 8.0 MPa were 0.6 and 1.0, which were lower than those of traditional liquefaction processes. As the S/Fe atomic ratio increased from 0 to 0.6 (at the initial H 2 pressure of 4.0 MPa), the oil yield and coal conversion increased by 4.0% and 3.8%, and this could be attributed to the synergistic effects between the relatively sulfur-rich structure of pyrrhotite (Fe 0.8917 S) and the relatively high partial pressure of H 2 S. In addition, over 85% of sulfur was retained in the solid products, and the effect of S/Fe atomic ratio on the sulfur distribution was tiny. However, increasing H 2 pressure was conducive to the transfer of sulfur to the gaseous products.

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“…Table I. List of the anion-modified iron oxide catalysts, their preparation routes [10,11] and their particle sizes determined from x-ray diffraction analysis. (NSP= not superparamagnetic up to 300K) In-situ ESR spectroscopy to test the activities of the catalysts:…”

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confidence: 99%

Cooperative research in coal liquefaction. Final report, May 1, 1992--April 30, 1993

Huffman¹

1996

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One step in the synthesis of anion-treated iron and tin oxides is precipitation as hydroxides using either urea or ammonium hydroxide. The catalysts prepared using urea as a precipitation agent were more reproducible than those using ammonium hydroxide in terms of activities and properties. These catalystdcatalyst precursors were characterized by several techniques to determine their physical (size and structure related) and chemical (acidity) properties. Sulfated and mo€ybdated iron oxides were found to have grain sizes as small as 10-20 nm. An attempt was made to correlate the physicochemical properties of these catalysts with their activity for coal liquefaction. SiIron ion-exchanged into lignite from an iron Acetate solution showed excelle activity for direct coal liquefaction. Two lignites were studied, and both exhibite significant increases in both total conversion and oil yields when from 1 t o 7% of ir was incorporated into the coal by cation-exchange. Mossbauer spectroscopy and 0th characterization methods indicated that a substantial percentage of the iron was present in particles o r molecular complexes less than 30 A in diameter. 4An investigation of catalyst dispersion has been made using electron probe microanalysis (EPMA) following impregnation of Wyodak coal with FeC1, and (NH4)2hbS4 in aqueous solutions. Before hydrotreatment, the iron and molybdenum are found coating the coal particles. After hydrotreatment at 350°C and 1500 psig H2, both the Fe and Mo are dispersed throughout the interior of the coal particles.Design, construction and testing of a batch-type tubing bomb microreactor has been completed in the liquefaction laboratory at West Virginia University. Tests of the variation in liquefaction yields for Blind Canyon coal as a function of time, temperature, and agitation speed have been completed. A second system, which is similar in design, but incorporates a hydrogen purge, associated gas preheat and downstream product analysis, has also been designed and constructed. Testing of this system is now in progress.Reaction of ferric chloride at 5°C with sodium sulfide in aqueous solution yielded a black colloid of Fez& On heating to 100 -200"C, the ferric sulfide disproportionates to pyrite, pyrrhotite, and elemental sulfur. Particle sizes of the iron sulfides produced by this method are typically around 200 A. These iron sulfides exhibit reasonable catalytic activity for DCL of Blind Canyon coal at 350"C, increasing total conversion by about lo%, split approximately between increases in asphaltene and oil + gas yields. At 400°C, however, the catalytic conversion and yields are only slightly hig,her than those observed thermally for the DECS-17 coal.A novel aerosol reactor for generation of ultrafine iron sulfide catalysts has been designed and is now under construction.In situ transmission electron microscopy (TEM) studies were carried out to elucidate the basic mechanisms of the catalytic reaction between hydrogen and graphite in the presence of either iron sulfide or molybdenum sulfide...

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Activity and characterization of anion-modified iron(III) oxides as catalysts for direct liquefaction of low pyrite coals

Cited by 20 publications

References 0 publications

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Effects of sulfur additive on the transformation behaviors of γ‐Fe₂O₃ and coal liquefaction performances under mild conditions

Cooperative research in coal liquefaction. Final report, May 1, 1992--April 30, 1993

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Activity and characterization of anion-modified iron(III) oxides as catalysts for direct liquefaction of low pyrite coals

Cited by 20 publications

References 0 publications

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Esterification of oleic acid with glycerol in the presence of sulfated iron oxide catalyst

Effects of sulfur additive on the transformation behaviors of γ‐Fe2O3 and coal liquefaction performances under mild conditions

Cooperative research in coal liquefaction. Final report, May 1, 1992--April 30, 1993

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Effects of sulfur additive on the transformation behaviors of γ‐Fe₂O₃ and coal liquefaction performances under mild conditions