Hexaaluminate catalysts for the partial oxidation of middle distillate fuels

Gardner, Todd H.

doi:10.33915/etd.2768

Cited by 2 publications

(2 citation statements)

References 33 publications

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“…The water seen in the products is due to the excess oxygen added to fully suppress deposition of carbon. These results can be compared to other reforming studies for gasoline, diesel fuel, JP-8, and easier-to-reform surrogates (for example, Shekhawat et al ., [1] Lee, [21] Haynes, [11] Haynes et al ., [2] Kang et al ., [15] and Gardner [10] ).…”

Section: Resultsmentioning

confidence: 99%

Reforming diesel‐fuel distillates with membrane reactors

Mundschau

Gribble

Henton

et al. 2009

Asia-Pacific J Chem Eng

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A porous-membrane reactor is used to produce H 2 and CO by dry partial oxidation of volatile hydrocarbons distilled from diesel fuel. To eliminate deposition of thermodynamically and kinetically favored carbon onto reactor walls as the fuel is heated, cool air is brought into reactors through porous walls of refractory, zirconia-based ceramic. Flow of air through reactor walls suppresses alkyl-radical polymerization that otherwise leads to formation of tar and soot in the reformer heating zone. Diesel fuel is distilled just below 200 • C to avoid cracking of long-chain n-alkanes. The volatile distillates enter the reformer in the vapor phase, eliminating need for complex liquid-fuel injectors and mixers. Volatile distillates are relatively easily reformed, eliminating soot and most naphthalene in the exhaust, converting 88 mole% of carbon in the distillate into CO, 7% into CH 4 , and 5% into CO 2 . Approximately 75 mole% of the hydrogen is converted into H 2 , 13% into CH 4 , and the remainder into H 2 O. Synthesis gas produced from diesel fuel distillates could fuel solid-oxide fuel cells or regenerate NO x traps used in pollution control.  2009

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Section: Resultsmentioning

confidence: 99%

Reforming diesel‐fuel distillates with membrane reactors

Mundschau

Gribble

Henton

et al. 2009

Asia-Pacific J Chem Eng

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“…These differences are largely due to the ionic radius and/or valence level of the mirror cation(s) used in the synthesis of the hexaaluminate. The investigators chose to employ liquid-phase coprecipitation to synthesize the catalysts (6). The first step of preparing the catalysts was to weigh out the calculated amount of nitrate precursor salts to create the desired hexaaluminate.…”

Section: Hexaaluminate Structure and Propertiesmentioning

confidence: 99%

Characterization of nickel-substituted hexaaluminate catalysts

Hissam¹

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Characterization of Nickel-substituted Hexaaluminate Catalysts Jason C. Hissam A characterization study was performed on two series of hexaaluminate catalysts of the form M I (M II) x Al 12-x O 19-δ ; where M I refers to the mirror cation (M I = Ba, Sr, La) and M II to the cation (M II = Ni) substituted into the lattice. The first series was synthesized for comparison of different mirror cations while holding the Ni substitution level constant at x = 0.4. The second series was developed with the same mirror cation of Ba, but varied x, the level of Ni substitution. Experiments were conducted by means of the following characterization techniques: scanning electron microscopy (SEM), unit-cell refinement (UCR), in situ temperature-programmed reduction and X-ray diffraction (TPR-XRD) and Fourier-transform infrared (FT-IR) spectroscopy. UCR showed that Ni has been incorporated into the hexaaluminate lattice during synthesis. Increasing the Ni substitution level results in an increase in the a and b parameters and a decrease in the c direction. The overall volume of the unit-cell was found to increase with higher Ni substitution level. In situ TPR-XRD studies with La and Sr hexaaluminates have shown that Ni in the lattice upon reduction with H 2 turns into metallic Ni 0 on the hexaaluminate surface of the crystal. Experiments with Ba hexaaluminates were mostly inconclusive due to the hexaaluminate diffraction pattern having intense peaks in the same positions as Ni 0 metal so that the hexaaluminate pattern masks the appearance of Ni 0 metal peaks. Fourier-transform infrared spectroscopy of the absorption of CO on reduced catalysts was performed to distinguish between Ni +2 ions and Ni 0 metal species on the hexaaluminate surfaces. However, the analysis of the FT-IR spectra provided no evidence for CO adsorbed on either Ni +2 ions or metallic Ni 0 on the hexaaluminate surface. During exposure of CO, there was the appearance of multiple peaks that indicate the presence of gas phase CO and CO 2 molecules as well as the formation of carboxylates and carbonates. Upon evacuation of the experimental chamber, the only remaining peaks belonged to those of the appropriate mirror cation carbonate.

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Hexaaluminate catalysts for the partial oxidation of middle distillate fuels

Cited by 2 publications

References 33 publications

Reforming diesel‐fuel distillates with membrane reactors

Reforming diesel‐fuel distillates with membrane reactors

Characterization of nickel-substituted hexaaluminate catalysts

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