Potential Applications of Concentrated Solar Energy Proceedings of a Workshop (1991) / Chapter Skim
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6 SESSION 6 - FUEL PROCESSING ADN THERMOCHEMICAL/PHOTOCHEMICAL CYCLES
6 SESSION 6 - FUEL PROCESSING ADN THERMOCHEMICAL/PHOTOCHEMICAL CYCLES
Pages 117-136
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From page 117... ...
Feedstocks include inorganic compounds much as water and carbon dioxide and organic sources such am oil shales, coal, biomass, and methane. The range of approaches to carry out these processes runs the gamut from wellestablished chemical engineering practices with near-term predictable costs, to long-term basic photochemical processes, the details of which are still speculative.
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From page 118... ...
Thun, the technology was fairly well understood for many of the hydrogen production and methane reforming cycles; the principles are known for oil shale processing. An examination of the cost" of fuel production indicated that "olar-derived fuel" were currently significantly more expensive than fuel" derived from nonrenewable resource=.
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From page 119... ...
Further, Bilgen suggested that more research we" necessary to find and evaluate materials that could withstand the high temperature sulfur oxide chemistry, especially in the presence of water. Moshe Levy discussed solar testing experience of oil shale processing and methane reforming reactions for a chemical heat pipe.
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From page 120... ...
A question arose an to the effectiveness of direct radiant heating of coal or oil shale because the radiation could not penetrate to a significant fraction of the feed~tock. In earlier work on solar gasification of coal and shales, a solar driven communition of the feedstock could be used to reduce the material to very fine sizes.
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From page 121... ...
They produce electricity first, before producing gaseous fuels by electrolysis. Although a very long research path remain=, GRI's program made significant progress in different stand-alone systems for photochemical water splitting and in the conversion of water and carbon dioxide to methane and other hydrocarbons.
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From page 122... ...
· Where sunlight produces molecular scale electricity first, through excited-state charge separation, photochemical approaches may not be better than using an appropriate combination of photovoltaic and electrochemical cells. Viable photochemical processes will satisfy a clear need to directly access reactant or photocatalyst electronic excited states with sunlight.
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From page 123... ...
123 could not exceed the value of Having natural gas and any environmental advantages. · Concentrated solar energy may have advantages for providing the high heat transfer rates required for endothermic processes.
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From page 124... ...
IERMAL, T] IERMOC~IQL, AlID HYBRID SOLAR HYDROGEN PRODUCTION Ertugrul Bilgen Ecole Polytechnique Montreal P.Q.
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From page 125... ...
Thermal energy is produced over a wide range of temperatures and at various power rates [8-103. The temperature level of thermal energy is below 1500 K with optical efficiencies of about 60%.
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From page 126... ...
Most of the thermochemical cycle" for water splitting using high temperature nuclear heat are adapted for molar operation. They are based on the Sulfur family processes where the high temperature thermal decomposition of sulfuric acid into sulfur dioxide, water, and oxygen i" the common reaction.
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From page 127... ...
1981. Solar Power Tower Design Guide: Solar Thermal Central Receiver Power Systems, A Source of Electricity and/or Process Heat.
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From page 128... ...
1986. Hydrogen Production by Water Thermolysi=.
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From page 129... ...
We used secondary concentrators to boost the solar flux. Unshod God ~ Oil shales consist of an intimate mixture of minerals and organic matter.
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From page 130... ...
The process i" now being scaled up to a 400 kW unit in the solar central receiver. The forward reforming reaction, which in the endothermal part, was performed mostly in an opaque metal reactor.
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From page 131... ...
1990. Gasification of Oil Shales by Solar Energy.
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From page 132... ...
SERI has three research divisions, including the Solar Fuels Research Division, which includes the Chemical Conversion Research Branch. The branch has a staff of 21 professionals, 1 postdoctoral fellow, 3 administrative assistants, and 6 parttime chemistry and chemical engineering students.
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From page 133... ...
The goal has been elusive because it has been dif f icult to obtain a reproducible technical product at the necessary low cost. Phenol replacements that cure "lower than phenol require a change in press times or temperatures, which are not easily accepted in the United States because they decrease production rates.
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From page 134... ...
The program investigates biomass fast pyrolysis oils; more than 60% of the dry weight of the feedstock is converted into a mixture of controllable products. The SERI vortex reactor (100 pounds per hour)
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From page 135... ...
The staff members of the Chemical Conversion Research Branch at SERI are gratefully acknowledged for their contribution to the work described: J Diebold, J
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From page 136... ...
1990. Process for Fracionating Fast Pyrolysis Oils and Products Derived Therefrom.
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