Effect of temperature, catalyst and charge gas on the mean chemical structures of the products from hydrogenation of Liddell coal

Wilson, Michael; Rottendorf, H; Collin, Philip J.; Vassallo, Anthony M.; Barron, Peter F.

doi:10.1016/0016-2361(82)90045-x

Cited by 31 publications

(9 citation statements)

References 13 publications

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“…Results obtained by 13C NMR, combustion analyses and yields are shown in Table III and Figures 1-4. GPC and NMR data have been or will be reported elsewhere (Wilson et al, 1982; Vassallo et al, to be published) and are not repeated here since they are not relevant to the present discussion. Conversion to gaseous and liquid products was calculated as conversion = wt dry ash free residue wt dry ash free coal ) X 100 (1)…”

Section: Methodsmentioning

confidence: 99%

“…An autoclave with a different mixing mechanism was also chosen, since the method of mixing might affect dissolution. The yields and solution NMR spectra of the products from these experiments have been reported elsewhere (Wilson et al, 1982). CP spectra of the residues have also been reported (Wilson et al, 1982) but /a values could not be calculated because of the highly aromatic nature of the residues.…”

mentioning

confidence: 92%

“…The yields and solution NMR spectra of the products from these experiments have been reported elsewhere (Wilson et al, 1982). CP spectra of the residues have also been reported (Wilson et al, 1982) but /a values could not be calculated because of the highly aromatic nature of the residues. Aromaticities from CP/MASS spectra are reported in this work (Figure 4).…”

mentioning

confidence: 92%

“…Bearing in mind these measurements were made without MASS, the results are identical with those obtained in our present study of uncatalyzed reactions. Thus, although conversion can be slightly higher in catalyzed reactions (Rottendorf and Wilson, 1980; Wilson et al, 1982) , catalyst has little or no effect on the aromaticity of the residues.…”

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confidence: 99%

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Changes in aromaticity during coal liquefaction

Wilson¹,

Pugmire²,

Vassallo³

et al. 1982

Ind. Eng. Chem. Prod. Res. Dev.

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any light onto this controversy, so steps B and C have been listed separately.The oberved order of reaction with respect to H+ concentration is empirical in this work, since, according to the mechanism, the order should in fact be unity. However, the evidence of acid-catalyzed aldol condensation of MEK precludes exact first-order acid dependence.Other Results. The findings of Neish et al. (1945) cannot be refuted on the basis of this work. The Neish system contained a very strong acid with no effective water concentration, so a different mechanism is conceivable. Neish also reported the formation of the cyclic ketal, 2ethyl-2,4,5-trimethyl dioxolane, by the condensation of 1 mol each of 2,3-butanediol and MEK. This compound was not detected in our work, presumably because the equilibrium lies in favor of 2,3-butanediol and MEK in aqueous solution (see Fife et al., 1967Fife et al., , 1970Fife et al., , 1971. ConclusionsAqueous 2,3-butanediol was shown to react in a pseudo-first-order reaction in the presence of sulfuric acid to form methyl ethyl ketone. The reaction could be described by a pinacol rearrangement mechanism and had an activation energy of 36 kcal/mol. An empirical order of reaction with respect to H+ concentration of 1.53 was determined. MEK yields exceeding 90 mol % could be consistently obtained, but evidence of acid-catalyzed aldol condensation was noted.The pseudo-first-order reaction incorporated the temperature, acid concentration, and initial reactant concentration, and predicted, a priori, the reaction time course for both MEK and 2,3-butanediol.Dehydration of 2,3-butanediol to MEK in fermentation broths is feasible, and the current model can be used as the first step in the development of a more complete model which is directly applicable to 2,3-butanediol fermentation broths.

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Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 92%

mentioning

confidence: 92%

mentioning

confidence: 99%

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Changes in aromaticity during coal liquefaction

Wilson¹,

Pugmire²,

Vassallo³

et al. 1982

Ind. Eng. Chem. Prod. Res. Dev.

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“…As a measure of hydrogen consumption by the coal, the degree of tetralin dehydrogenation to naphthalene has often been used (Curran et al, 1967; Vlieger et al, 1984). To obtain maximum hydrogenation of a mediumvolatile bituminous coal in excess tetralin, the presence of hydrogen gas was considered necessary (Wilson et al, 1982). However, the dehydrogenation of tetralin in the liquefaction of lignite was reported to be independent of gaseous atmosphere (Philip and Anthony, 1982).…”

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confidence: 99%

Generalized kinetic model for the uncatalyzed hydroliquefaction of coal

Ghosh¹,

Prasad²,

Agnew³

et al. 1986

Ind. Eng. Chem. Proc. Des. Dev.

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A kinetic model, incorporating dehydrogenation of tetralin, for the liquefaction of coals has been developed and tested with data from a variety of lowand medium-rank coals. The model postulates that coal essentially consists of three lumps. Of these, one dissociates almost instantaneously, the second is characterized by slow internal hydrogen shuttling, and only the third lump requires external hydrogen. The reactivity of each lump does not vary between coals; however, different coals are found to contain different fractions of each lump. The rate of reaction of coal is about 3 orders of magnitude faster than the tetralin dehydrogenation reaction. This study clearly shows that it is not only the solvent's capacity to donate hydrogen but also the rate at which hydrogen is donated that is important in coal liquefaction.

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