Comparison of Hydrogenation and Dehydrogenation Behavior and Coal Conversion Activity upon the Addition of Coal for Supported and Unsupported Molybdenum Catalysts

Cugini, A.V.; Rothenberger, K. S.; Ciocco, Michael V.; Veloski, Garret

doi:10.1021/ef960100j

Cited by 9 publications

(6 citation statements)

References 14 publications

(26 reference statements)

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“…The loss in activity probably requires much less than the 60-min reaction time used in these experiments. Results from related experiments in microautoclaves and a microflow reactor indicate the loss in activity is permanent. Thus, after being exposed to coal, recovered and recycled MoS 2 catalysts exhibit much reduced activity for hydrogenation even in the absence of coal.…”

Section: Resultsmentioning

confidence: 98%

Poisoning and Inhibition of Dispersed Liquefaction Catalyst Activity by Exposure to Coal

et al. 1997

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The activity of a dispersed MoS 2 catalyst prepared in situ from ammonium tetrathiomolybdate was measured in octacosane containing various amounts of Argonne Premium Illinois No. 6 coal using microautoclaves. Conversion of 1-ethylnaphthalene (1-ETN) was followed to measure the extent of hydrogenation and/or rearrangement to 2-ETN. The reactors were charged with 1200 psig of hydrogen at room temperature. After a small amount of coal was added, activity for the acid-catalyzed rearrangement was virtually extinguished. Hydrogenation activity was significantly reduced but not eliminated. The effect on hydrogenation activity was divided into two components. One component was assigned to poisoning and the other to competitive inhibition. The weight of coal required to complete the poisoning process was determined to be 6 times the weight of Mo in the catalyst. The activity that remains for hydrogenating 1-ETN after the poisoning process is complete suffered from competitive inhibition as more coal was added. The amounts of H 2 S or basic nitrogen compounds that might be released from the coal during liquefaction were determined to be insufficient to account for the extent of deactivation observed.

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Section: Resultsmentioning

confidence: 98%

Poisoning and Inhibition of Dispersed Liquefaction Catalyst Activity by Exposure to Coal

et al. 1997

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“…Calibration gases (N4, N21, Crystal-mixtures) and H 2 (purity [ 99.999 mol %) were purchased from Air Liquide (Hamburg, Germany). Pt and CoMo catalysts for HDO purposes were applied and have already been widely studied [5,[24][25][26][27][28]. The CoMo catalyst was provided stringshaped in a basket, and the Pt catalyst as a fine powder.…”

Section: Experimental Section Materialsmentioning

confidence: 99%

Hydrodeoxygenation of cracked vegetable oil using CoMo/Al2O3 and Pt/C catalysts

Baldauf

Sievers

Willner

2016

Int J Energy Environ Eng

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During the continuous catalytic hydrodeoxygenation (HDO) of cracked vegetable oil (CVO), CO 2 and CO occur as the main reaction gases, in addition to hydrocarbon gases such as CH 4 and C 2 H 6. The catalysts used were cobalt-molybdenum (CoMo) on an Al 2 O 3 support and platinum (Pt) on an active carbon. All named gas components can result directly from the decomposition of CVO. The results of batch experiments for gas phase reactions (GPRs) under the same 50 bar H 2 atmosphere using the same catalysts (CoMo, Pt) indicate that CO and CH 4 can also be formed by GPRs. CO can result from the reverse water-gas shift reaction (RWGS), and CH 4 from CO-or CO 2-methanation. The found CO-yields from GPRs are within the theoretical thermodynamic limits based on equilibrium. An unexpected inhomogeneity of the gas component concentrations in the reactor during batch investigations was observed despite the elevated temperature (380°C) and high RPM (1100) due to the high density difference compared to H 2, especially in the case of CO 2. Keywords Catalytic hydrodeoxygenation Á Cracked vegetable oil Á Biofuel Á Gas residence time Á Gas phase reactions Á Gas phase inhomogeneity

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“…The removal of mineral matter from coal prior to liquefaction has advantages like an increase in throughputs, a decrease in wear and tear of process equipment, an increase in catalyst life which is otherwise passivated by minerals clogging into its pore mouths, 5,6 and ease in solid liquid separation. The presence of mineral matter, however, has been found beneficial to coal liquefaction 7,8 when no foreign catalyst is used.…”

Section: Introductionmentioning

confidence: 99%

Depolymerization Study of Pakistani Lignite Coal Influence of Pre‐treatments on Product Slate

Ahmad

Khan

Shakirullah

et al. 2004

J Chinese Chemical Soc

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Influence of pretreatments, i.e., demineralization and pre‐soaking in some solvents on the yields of liquefied products obtained from hydro‐depolymerization of Pakistani coal in a pool of hydrogen has been discussed. Results of hydrogenation experiments demonstrated that demineralizing the coal sample prior to liquefaction caused the yields to decrease compared with the virgin coal samples. The contribution of mineral matter of coal has been evaluated by comparing the yields of liquid products of virgin and leached samples. Increase in the yields obtained from the hydrogenation experiments of swollen coal samples was not satisfactorily significant.

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Comparison of Hydrogenation and Dehydrogenation Behavior and Coal Conversion Activity upon the Addition of Coal for Supported and Unsupported Molybdenum Catalysts

Cited by 9 publications

References 14 publications

Poisoning and Inhibition of Dispersed Liquefaction Catalyst Activity by Exposure to Coal

Poisoning and Inhibition of Dispersed Liquefaction Catalyst Activity by Exposure to Coal

Hydrodeoxygenation of cracked vegetable oil using CoMo/Al2O3 and Pt/C catalysts

Depolymerization Study of Pakistani Lignite Coal Influence of Pre‐treatments on Product Slate

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