Pure hydrogen generation in a fluidized-bed membrane reactor: Experimental findings

2008 ◽  
Vol 63 (10) ◽  
pp. 2752-2762 ◽  
Author(s):  
Andrés Mahecha-Botero ◽  
Tony Boyd ◽  
Ali Gulamhusein ◽  
Nicholas Comyn ◽  
C. Jim Lim ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Membrane Reactor ◽  
Hydrogen Generation ◽  
Pure Hydrogen ◽  
Experimental Findings

Pure hydrogen generation in a fluidized bed membrane reactor: Application of the generalized comprehensive reactor model

2009 ◽  
Vol 64 (17) ◽  
pp. 3826-3846 ◽  
Author(s):  
Andrés Mahecha-Botero ◽  
John R. Grace ◽  
C. Jim Lim ◽  
S.S.E.H. Elnashaie ◽  
Tony Boyd ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Membrane Reactor ◽  
Hydrogen Generation ◽  
Pure Hydrogen ◽  
Reactor Model ◽  
Reactor Application

Hydrogen from an Internally Circulating Fluidized Bed Membrane Reactor

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Tony Boyd ◽  
John Grace ◽  
C. Jim Lim ◽  
Alaa-Eldin M. Adris
Keyword(s):  
Fluidized Bed ◽  
Membrane Reactor ◽  
Gas Flow ◽  
Circulating Fluidized Bed ◽  
Membrane Surface ◽  
Pure Hydrogen ◽  
Heat Of Reaction ◽  
Steam Methane ◽  
External Heating ◽  
Fluidized Catalyst Bed

A novel fluidized bed membrane reactor has been developed for the production of high-purity hydrogen based on steam methane reforming (SMR). The reactor incorporates perm-selective membranes for in-situ removal of hydrogen from the reactor, thus shifting the thermodynamic equilibrium of the SMR reaction. The membranes also eliminate the need for downstream hydrogen purification.The endothermic reaction duty is provided either by external heating of the vessel wall or through direct air injection into the fluidized catalyst bed (autothermal reforming). The gas flow pattern within the fluidized bed induces internal circulation of catalyst particles between the central reaction (permeation) zone and outer heating zones. The circulating hot catalyst particles from the oxidation zone carry the required endothermic heat of reaction for the reforming while ensuring that the palladium membranes are not exposed to high temperatures or to oxygen. Another characteristic of the reactor configuration is that very little of the nitrogen present in the oxidation air reaches the reaction zone, thus maintaining the hydrogen driving force for the perm-selective membranes.The reactor concept was proven in a pilot reactor (0.13 m diameter, 2.3 m tall). A number of variables were studied, including steam-to-carbon ratio, temperature and pressure. The pilot reactor was operated with both external heating and direct air addition. Pure hydrogen (99.999+%) was obtained from the reactor and an equilibrium shift was demonstrated. The maximum pure hydrogen recovery obtained from the pilot reactor was 0.96 mol H2/mol CH4, limited by the installed membrane surface area for these tests.

A Compact Membrane Reactor for Producing Pure Hydrogen From Anhydrous Ammonia

2004 ◽  
Author(s):  
Thomas R. Vencill ◽  
Amand S. Chellappa ◽  
Mike R. Powell
Keyword(s):  
Fuel Cell ◽  
Specific Energy ◽  
Membrane Reactor ◽  
Hydrogen Generation ◽  
Decomposition Reaction ◽  
Reaction Chamber ◽  
Pure Hydrogen ◽  
Total System ◽  
Anhydrous Ammonia ◽  
Subsequent Conversion

A significant barrier to the use of fuel cells for portable and small stationary applications is the lack of a supply of pure hydrogen with high specific energy. Anhydrous ammonia is an attractive fuel because it has very high intrinsic specific energy, requires no water for decomposition, and has established distribution channels throughout the world. A compact membrane reactor hydrogen generation system using anhydrous ammonia as a fuel has been developed which produces greater than 99.95% purity hydrogen at a rate sufficient to power a 100 We PEM fuel cell. Ammonia concentrations in the resultant hydrogen product are non-detectable. Hydrogen recovery through the membrane is as high as 80% and the membrane reactor thermal efficiency (LHV) is 70%. The primary features of this system are a catalytic reactor, a hydrogen separation membrane integrated into the reaction chamber, and a catalytic combustion module to provide heat for the ammonia decomposition reaction and subsequent conversion of trace ammonia reject. The membrane reactor is planar in configuration and allows for a simple, single unit design to provide pure hydrogen for fuel cell applications. The total system can provide specific energies of greater than 500 Wh/kg for a 72 hour run making it an attractive solution of portable and long unattended run time applications.

Techno-economic Assessment of Membrane Reactor Technologies for Pure Hydrogen Production for Fuel Cell Vehicle Fleets

2013 ◽  
Vol 27 (8) ◽  
pp. 4423-4431 ◽  
Author(s):  
Leonardo Roses ◽  
Giampaolo Manzolini ◽  
Stefano Campanari ◽  
Ellart De Wit ◽  
Michael Walter
Keyword(s):  
Fuel Cell ◽  
Hydrogen Production ◽  
Membrane Reactor ◽  
Economic Assessment ◽  
Fuel Cell Vehicle ◽  
Pure Hydrogen

scholarly journals Simulation study of an auto-thermal double-membrane reactor for the simultaneous production of hydrogen and methanol: comparison of two different hydrogen redistribution strategies along the reactor

2017 ◽  
Vol 19 (2) ◽  
pp. 115-124
Author(s):  
Farhad Rahmani ◽  
Mohammad Haghighi ◽  
Pooya Estifaee ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Methanol Synthesis ◽  
Membrane Reactor ◽  
Synthesis Process ◽  
Pure Hydrogen ◽  
Heterogeneous Model ◽  
Double Membrane ◽  
Methanol Production ◽  
Current Configuration ◽  
Production Of Hydrogen ◽  
Counter Current

Abstract In a continuing effort to realize the simultaneous hydrogen and methanol production via the auto-thermal methanol synthesis process, the effect of two different hydrogen redistribution strategies along a double-membrane reactor has been considered. A steady-state one-dimensional heterogeneous model was developed to compare two strategies applied in the operation of the auto-thermal methanol synthesis. It was found that the counter-current configuration exhibited the better performance compared to the reactor operated in the co-current mode from both the economic and environmental points of view. This superiority is ascribed to the establishment of a more favourable temperature profile along the reactor and also more hydrogen extraction from the reaction zone. Moreover, the influence of some operating variables was investigated on the performance of the auto-thermal double-membrane reactor in the counter-current configuration. The results suggest that utilizing this configuration for pure hydrogen and methanol production could be feasible and beneficial.

Hydrogen Generation Facilitates Sintering Atmospheres

2021 ◽  
Author(s):  
David Wolff
Keyword(s):  
Heat Conduction ◽  
Hydrogen Storage ◽  
Thermal Processing ◽  
Hydrogen Generation ◽  
Energy Content ◽  
High Energy ◽  
Pure Hydrogen ◽  
Post Processing ◽  
Hydrogen Supply ◽  
Processing Techniques

Abstract For annealing, brazing or sintering, furnace atmospheres help ensure that metals thermal processors obtain the results they need. Hydrogen-containing atmospheres are used to protect surfaces from oxidation, and to ensure satisfactory thermal processing results. Hydrogen-containing atmospheres make thermal processing more forgiving because the hydrogen improves heat conduction and actively cleans heated surfaces – reducing oxides and destroying surface impurities. For powder based fabrication such as P/M, MIM or binder-jet metal AM, the use of a hydrogen-containing thermal processing atmosphere ensures the highest possible density of the sintered parts without necessitating the use of post-processing techniques. Users of pure hydrogen or hydrogen-containing gas blend atmospheres often struggle with hydrogen supply options. Hydrogen storage may create compliance problems due to its flammability and high energy content. Hydrogen generation enables hydrogen use without hydrogen storage issues. Deployment of hydrogen generation can ease the addition of thermal processing atmospheres to new and existing processing facilities.

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