Effect of Mo and Ce Additives on Redox Behavior for Hydrogen Storage and Release of Iron Oxide Mediums

2012 ◽  
Vol 554-556 ◽  
pp. 616-619
Author(s):  
Young Ho Kim ◽  
Eun Jee Kang ◽  
Su Gyung Lee ◽  
Hyo Sub Kim ◽  
Chu Sik Park
Keyword(s):  
Iron Oxide ◽  
Hydrogen Storage ◽  
Water Splitting ◽  
Atmospheric Pressure ◽  
Hydrogen Reduction ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Redox Behavior ◽  
Good Material ◽  
Reduction And Oxidation

The hydrogen reduction and water-splitting oxidation for hydrogen storage and release on the iron oxide mediums with Ce, Mo or Ce-Mo additives were carried out using a fixed bed reactor at atmospheric pressure. A sole Ce additive was an outstanding material for the improvement of the reactivity in the reduction and oxidation of iron oxide medium, even though the medium with Ce was easily deactivated during repeated cyclic reactions due to sintering. A sole Mo additive was a good material for the improvement for the durability. In the mediums with the Ce-Mo additives, therefore, the degree of deactivation and the reactivity of the mediums were gradually decreased with the increase of the amount of Mo. Among the iron oxide mediums with Ce-Mo additives, a FeCeMo-5 medium exhibited the good durability while the maintaining the considerable reactivity during the cyclic reactions.

Hydrogen Storage and Release by Redox Reaction of Iron Oxide Medium with Mo and Zr Additives

2011 ◽  
Vol 347-353 ◽  
pp. 3317-3320 ◽  
Author(s):  
Young Ho Kim ◽  
Han Sol Je ◽  
Eun Jee Kang ◽  
Su Gyung Lee ◽  
Chu Sik Park
Keyword(s):  
Iron Oxide ◽  
Hydrogen Storage ◽  
Atmospheric Pressure ◽  
Redox Reaction ◽  
Hydrogen Reduction ◽  
Fixed Bed ◽  
Urea Solution ◽  
Redox Cycles ◽  
Chemical Hydrogen Storage ◽  
Theoretical Amount

Chemical hydrogen storage and release of iron-based oxide mediums were investigated by hydrogen reduction and water splitting oxidation (Fe3O4 + 4H2 ⇌ 3Fe + 4H2O). In this study, all metal oxide mediums were prepared by coprecipitation method using urea solution as precipitant. The redox reactions of the mediums were conducted using a fixed bed quartz reactor under atmospheric pressure. The theoretical amount of hydrogen storage that can be obtained from the redox reaction of iron oxide is calculated to be 4.8wt% on the basis of 1g-Fe. However, in case of using the iron oxide medium without additives, the medium was rapidly deactivated due to the agglomeration of Fe metals in the hydrogen reduction step of repeated redox cycles. In this study, therefore, Mo and Zr additives were added to iron oxide to improve the reactivity of the medium and to prevent the agglomeration of that. As a result, the reactivity for oxidation of the mediums was largely improved with the addition of Mo additive. It was concluded that change in the valence of Mo cations affected the redox behavior of the mediums.

scholarly journals Hydrogen Storage in Propane-Hydrate: Theoretical and Experimental Study

2020 ◽  
Vol 10 (24) ◽  
pp. 8962
Author(s):  
Mohammad Reza Ghaani ◽  
Satoshi Takeya ◽  
Niall J. English
Keyword(s):  
Hydrogen Storage ◽  
Storage Capacity ◽  
Fixed Bed ◽  
Hydrogen Uptake ◽  
Hydrogen Release ◽  
Fixed Bed Reactor ◽  
Gas Dispersion ◽  
Fixed Bed Reactors ◽  
Non Equilibrium Molecular Dynamics ◽  
Kinetics Of

There have been studies on gas-phase promoter facilitation of H2-containing clathrates. In the present study, non-equilibrium molecular dynamics (NEMD) simulations were conducted to analyse hydrogen release and uptake from/into propane planar clathrate surfaces at 180–273 K. The kinetics of the formation of propane hydrate as the host for hydrogen as well as hydrogen uptake into this framework was investigated experimentally using a fixed-bed reactor. The experimental hydrogen storage capacity propane hydrate was found to be around 1.04 wt% in compare with the theoretical expected 1.13 wt% storage capacity of propane hydrate. As a result, we advocate some limitation of gas-dispersion (fixed-bed) reactors such as the possibility of having un-reacted water as well as limited diffusion of hydrogen in the bulk hydrate.

Characteristics of Gaseous Produced from Co-Pyrolysis of Municipal Solid Waste and Corn Stalk

2014 ◽  
Vol 1010-1012 ◽  
pp. 947-951
Author(s):  
Jin Wei Jia ◽  
Ming Yuan Lu ◽  
Yue Fu Yuan ◽  
Lu Liu ◽  
Feng Sheng Yang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Atmospheric Pressure ◽  
Fixed Bed ◽  
Pyrolysis Product ◽  
Fixed Bed Reactor ◽  
Corn Stalk ◽  
Product Yields ◽  
Gaseous Products

An experimental study on co-pyrolysis of municipal solid waste and corn stalk was performed in a fixed-bed reactor under atmospheric pressure. The effect of different blending ratio on the pyrolysis product yields and compositions of the gaseous products was investigated. The results indicated that there exist synergetic effects in the co-pyrolysis of municipal solid waste and corn stalk. Under the different blending ratio conditions, the char and liquid yields were lower than the theoretical values calculated on pyrolysis of each individual municipal solid waste and corn stalk, and consequently the gas yields were higher. H2 and CH4 obtained co-pyrolysis at 800°C-900°C of 40% blending ratio conditions were higher than those of municipal solid waste and corn stalk alone.

scholarly journals Characterisation of liquid oil from pyrolysis of waste tyre

2020 ◽  
Vol 3 (1) ◽  
pp. 62
Author(s):  
Rusmi Alias ◽  
Atiqah Mohd Rafee
Keyword(s):  
Aromatic Compounds ◽  
Atmospheric Pressure ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Oil Yield ◽  
Degradation Study ◽  
Aromatic Content ◽  
Waste Tyre ◽  
Increasing Temperature

The aim of this study is to characterise the liquid oil produced from pyrolysis of waste tyre. In this study, a series of experiment were carried out at various process temperature from 300 °C to 500 °C. The degradation study was carried out by using TGA, meanwhile the pyrolysis process was done using a fixed bed reactor. Liquid oil obtained from the pyrolysis was analysed using FTIR and GC-MS. The oil yield was found to decrease with increasing final pyrolysis temperature and the yield of the gas increased. The highest oil yield was 58.3 wt. %. For pyrolysis at 400 °C. The pyrolysis of waste tyre at atmospheric pressure commenced at about 340 °C and completed at 460 °C. An increase in the aromatic content of the oil was observed with increasing temperature. However, the aliphatic content decreased as the temperature increased from 300 °C to 500 °C. It was observed that the amount of aliphatic fraction in the oil decreased from 7.8 wt. % to 5.4 wt. %. In the meantime, the number of aromatic compounds increased from 37.4 wt. % to 51.2 wt. %. The main aromatic compounds were limonene, xylene, styrene, toluene, trimethylbenzene, ethylbenzene and benzene.

Regeneration of Iron Oxide Sorbent Used for Hot Gas Desulfurization

2011 ◽  
Vol 396-398 ◽  
pp. 1170-1173
Author(s):  
Hui Ling Fan ◽  
Hong Sheng Guo ◽  
Li Tong Liang ◽  
Fang Shen ◽  
Jian Ying Lin ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Red Mud ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Gas Composition ◽  
Hot Gas ◽  
Regeneration Condition ◽  
Hot Gas Desulfurization

Iron oxide sorbent was prepared from red mud and the regeneration behaviors were investigated in a fixed bed reactor. Regeneration parameters including temperature and concentration of oxygen have been considered in order to obtain a suitable regeneration condition. XRD and SEM techniques were used to characterize the fresh and regenerated sorbents. The experimental results show that the sulfided sorbent could be regenerated efficiently using a gas composition of 2% O2-15% H2O- balance N2, at the temperature of 700 °C.

scholarly journals Solar-Driven Thermochemical Water-Splitting by Cerium Oxide: Determination of Operational Conditions in a Directly Irradiated Fixed Bed Reactor

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2451 ◽  
Author(s):  
Lucía Arribas ◽  
José González-Aguilar ◽  
Manuel Romero
Keyword(s):  
Water Splitting ◽  
Cerium Oxide ◽  
Radiation Power ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Solar Simulator ◽  
Operational Conditions ◽  
Concentrated Solar Energy ◽  
Production Of Hydrogen ◽  
Temperature Levels

Concentrated solar energy can be transformed into electricity, heat or even solar fuels, such as hydrogen, via thermochemical routes with high exergetic efficiency. In this work, a specific methodology and experimental setup are described, developed to assess the production of hydrogen by water splitting making use of commercial cerium oxide, ceria (CeO2), in a solarized reactor. A fixed bed reactor, directly irradiated by a 7 kWe high flux solar simulator (HFSS) was used. Released H2 and sample temperature levels were continuously monitored. Three tests were carried out consisting of three consecutive redox cycles each, with irradiances in the range of 1017–2034 kWm−2. It was necessary to achieve a compromise between sample temperatures (higher temperatures lead to higher reduction rates) and sample stability, since absorbed radiation can degrade a sample at lower temperature (1280–1480 °C) than in a conventional infrared oven (T > 2000 °C). Irradiating the surface of the sample with an irradiance of 2034 kWm−2 (270 W of total radiation power) during 9.5 min eventually degraded the sample, resulting in a conversion into stoichiometrically reduced oxide (Ce2O3) of 11%. A similar conversion was achieved (9.7%) after 2 min of irradiation at 270 W (100% of radiation), but without irreversibly damaging the sample.

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