The basic strategy is to utilize the most effective means of production for any area. If these catalyzed reactors can produce cost competitive H2, they become part of a spectrum of solutions for H2 production. Here are some examples of production methods quoted from the other thread.
Direct production from whole biomass
Gasification
Thermal/Steam/Partial Oxidation
A technical note by Williams (1980) (USA) makes a case for efficient hydrogen production from coal using centrifuge separation of hydrogen from other gases following steam gasification at 1100-5000°C. Recent advances in new materials developed by the aerospace industry made it appear possible to develop such a gaseous centrifuge.
A large number of single research studies have appeared from 1981-2000, from researchers in many countries around the world. Brief notes follow. McDonald et al. (1981) (New Zealand) proposed extracting protein from grass and lucern and using the residue for hydrogen production (among other fuels). Saha et al. (1982, 1984) (India) reported using a laboratory-scale fluidized-bed autothermal gasifier to gasify carbonaceous materials in steam. Further studies with agricultural wastes were planned. Cocco and Costantinides (1998) (Italy) describe the pyrolysis-gasification of biomass to hydrogen. More-or-less conventional gasification of biomass and wastes has been employed with the goal of maximizing hydrogen production. Researchers at the Energy and Environmental Research Center at Grand Forks have studied biomass and coal catalytic gasification for hydrogen and methane (Hauserman & Timpe, 1992, and Hauserman...
Hydrogen from Biomass-Derived Pyrolysis Oils Laboratory work using this approach has been conducted at NREL (USA), starting in 1993 (see Chornet et al., 1994; Wang et al., 1994; Wang et al., 1995; Chornet et al., 1995; and Chornet et al., 1996 a, b, c). Early papers present the concept of fast pyrolysis for converting biomass and wastes to oxygenated oils. These oils are subsequently cracked and steam-reformed to yield hydrogen and CO as final products (Mann et al., 1994). The 1995 Wang report presents the chemical and thermodynamic basis of this approach, the catalysis related to steam reforming of the oxygenates, and the techoeconomic integration of the process...
Six progress reports in 1996 and 1997 document the systematic exploration of the pyrolysis oilto-hydrogen process. In Chornet et al. (1996a) bench-scale experiments determined the performance of nickel-catalysts in steam reforming of acetic acid, hydroxyacetaldehyde, furfural, and syringol. All proceeded rapidly. Time-on-stream experiments were started. In Chornet et al., (1996b), Czernik et al., (1996), and Wang et al. (1997a), the approach of using extractable, valuable co-products with the balance of the oil converted to hydrogen is explored.
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Small scale reformer technologies
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Four types of solar photochemical hydrogen systems have been identified: photochemical systems, semiconductor systems, photobiological systems and hybrid and other systems. Asurvey of the state-of-the-art of these four types has been presented. The four system types (and their sub-types) have been examined in a technological assessment, where each has been examined as to efficiency, potential for improvement and long-term functionality. Four solar hydrogen systems have been selected as showing sufficient promise for further research and development:
1. Photovoltaic cells plus an electrolyzer
2. Photoelectrochemical cells with one or more semiconductor
electrodes
3. Photobiological systems
4. Photodegradation systems
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Photoelectrolytic and Photobiological Production of Hydrogen
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Hydrogen by Catalytic Decomposition of Water:
Researchers at DOE’s National Energy Technology Laboratory and Argonne National Laboratory have patented a "Method of Generating Hydrogen by Catalytic Decomposition of Water." The invention potentially leapfrogs current capital and energy intensive processes that produce hydrogen from fossil fuels or through the electrolysis of water. According to co-inventor Arun Bose, "Hydrogen can be produced by electrolysis, but the high voltage requirements are a commercial barrier. The invention provides a new route for producing hydrogen from water by using mixed proton-electron conducting membranes." Water is decomposed on the feed surface. The hydrogen is ionized and protons and electrons travel concurrently through the membrane. On the permeate side, they combine into hydrogen molecules.
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DENSE CERAMIC MEMBRANES FOR HYDROGEN SEPARATION
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HYDROGEN FROM COAL
See also:
A NATIONAL VISION OF
AMERICA'S TRANSITION TO
A HYDROGEN ECONOMY —
TO 2030 AND BEYOND
February 2002
Based on the results of the
National Hydrogen Vision Meeting
Washington, DC
November 15-16, 2001
http://www.eere.energy.gov/hydrogenandfuelcells/pdfs/vision_doc.pdf
