Stepwise production of CO-rich syngas and hydrogen via methane reforming by a WO3-redox catalyst

Kodama, Tetsuya; Shimizu, Tadaaki; Satoh, Takaharu; Shimizu, K.

doi:10.1016/s0360-5442(03)00093-8

Cited by 44 publications

(14 citation statements)

References 15 publications

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“…There are also serious safety concerns related to the direct mixing of highly explosive feed gas (methane) with oxygen at high temperature. 12 Other processes in the development for hydrogen production are thermochemical cycles, 13 the steam-iron process, 14 twostep cyclic processes with steam, 15 methane decomposition, 16 catalytic coal gasification, 17 and combustion reforming. 18 More processes, such as photochemical, photoelectrochemical, and photobiological processes, are also being explored.…”

Section: Introductionmentioning

confidence: 99%

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst

Dai

et al. 2006

J. Phys. Chem. B

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A redox cycle process, in which CH 4 and air are periodically brought into contact with a solid oxide packed in a fixed-bed reactor, combined with the water-gas shift (WGS) reaction, is proposed for hydrogen production. The sole oxidant for partial oxidation of methane (POM) is found to be lattice oxygen instead of gaseous oxygen. A perovskite-type LaFeO 3 oxide was prepared by a sol-gel method and employed as an oxygen storage material in this process. The results indicate that, under appropriate reaction conditions, methane can be oxidized to CO and H 2 by the lattice oxygen of LaFeO 3 perovskite oxide with a selectivity higher than 95% and the consumed lattice oxygen can be replenished in a reoxidation procedure by a redox operation. It is suggested that the POM to H 2 /CO by using the lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable. The LaFeO 3 perovskite oxide maintained relatively high catalytic activity and structural stability, while the carbonaceous deposits, which come from the dissociation of CH 4 in the pulse reaction, occurred due to the low migration rate of lattice oxygen from the bulk toward the surface. A new dissociation-oxidation mechanism for this POM without gaseous oxygen is proposed based on the transient responses of the products checked at different surface states via both pulse reaction and switch reaction over the LaFeO 3 catalyst. In the absence of gaseous-phase oxygen, the rate-determining step of methane conversion is the migration rate of lattice oxygen, but the process can be carried out in optimized cycles. The product distribution for POM over LaFeO 3 catalyst in the absence of gaseous oxygen was determined by the concentration of surface oxygen, which is relevant with the migration rate of lattice oxygen from the bulk toward the surface. This process of hydrogen production via selective oxidation of methane by lattice oxygen is better in avoiding the deep oxidation (to CO 2 ) and enhancing the selectivity. Therefore, this new route is superior to general POM in stability (resistance to carbonaceous deposition), safety (effectively avoiding accidental explosion), ease of operation and optimization, and low cost (making use of air not oxygen).

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Section: Introductionmentioning

confidence: 99%

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst

Dai

et al. 2006

J. Phys. Chem. B

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“…This hypothesis was experimentally confirmed for numerous selective oxidation reactions, performed in "anaerobic" conditions, such as oxidation of methane to syngas [3][4][5][6] at transient metal oxides, ethylene to ethylene oxide [7,8] and propylene to propylene oxide [9] at supported silver catalysts, butane to butadiene at Sb/Sn oxide catalyst [10], n-butane to butane and butadiene at vanadia-magnesia catalyst [11], propane to propylene [12][13][14][15][16] and many others.…”

Section: Introductionmentioning

confidence: 71%

“…Although the heat effects of stages (1)(2)(3)(4) were not used in the model directly, it is interesting to consider them for better understanding of the following results.…”

Section: Estimation Of Heat Effectsmentioning

confidence: 99%

Simulation of selective reactions’ performance in transient regimes with periodical separate feeding of reagents

Zagoruiko

2007

Chemical Engineering Journal

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“…(1)]. [3][4][5][6] However, the endothermic thermal reduction reaction of this processp resents major challenges due to the very high temperatures required. [1] WO 3…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the WO 3 /W redox pair system has been proposed as an attractive option for solar energy to fuel conversion [Eq. ] . However, the endothermic thermal reduction reaction of this process presents major challenges due to the very high temperatures required …”

Section: Introductionmentioning

confidence: 99%

Carbo‐ and Methanothermal Reduction of Tungsten Trioxide into Metallic Tungsten for Thermochemical Production of Solar Fuels

et al. 2016

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The WO3/W redox pair is proposed as an alternative option for the production of solar fuels due to high reactivity and selectivity in two‐step thermochemical redox cycles. This study addresses the high‐temperature solar step involving the use of carbonaceous materials (carbon or methane) as reducing agents to lower the temperature of the reduction step in the WO3/W cycle, which makes the process compatible with the use of concentrated solar energy as the source of process heat. The carbothermal reduction of tungsten trioxide to tungsten by using carbon in the form of graphite, carbon black, and activated carbon was investigated with a thermobalance and a packed‐bed tubular reactor, whereas methanothermal reduction was studied by using a solar‐driven thermogravimetric reactor. The WO3/C powder reactivity was analyzed as a function of temperature, carbon type, and stoichiometry of the reactant mixture. The reaction was complete upon heating to 1280 °C when using excess carbon in the mixture, with metallic tungsten and carbon monoxide as the main products. A high specific surface area of carbon favored the solid–gas reaction mechanism, whereas a small carbon nanoparticle size favored the solid–solid mechanism, along with the formation of carbides. Methanothermal reduction of WO3 started from 850 °C and yielded mainly W and WC at 1000 °C with WO3 conversion above 80 %. This study thus indicates that carbo‐ and methanothermal reduction of tungsten trioxide can be used to produce metallic tungsten powder efficiently.

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Stepwise production of CO-rich syngas and hydrogen via methane reforming by a WO3-redox catalyst

Cited by 44 publications

References 15 publications

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst

Simulation of selective reactions’ performance in transient regimes with periodical separate feeding of reagents

Carbo‐ and Methanothermal Reduction of Tungsten Trioxide into Metallic Tungsten for Thermochemical Production of Solar Fuels

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Stepwise production of CO-rich syngas and hydrogen via methane reforming by a WO3-redox catalyst

Cited by 44 publications

References 15 publications

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO3Perovskite Catalyst

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO3Perovskite Catalyst

Simulation of selective reactions’ performance in transient regimes with periodical separate feeding of reagents

Carbo‐ and Methanothermal Reduction of Tungsten Trioxide into Metallic Tungsten for Thermochemical Production of Solar Fuels

Contact Info

Product

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Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst

Hydrogen Production from a Combination of the Water−Gas Shift and Redox Cycle Process of Methane Partial Oxidation via Lattice Oxygen over LaFeO₃Perovskite Catalyst