摘要:

Photochemical methods of generating hydrogen from water by light of wavelengths greater than 185 nm are reviewed. Contrary to the commonly held opinion, solar water photodecomposition reactions are known. Both heterogeneous and homogeneous reactions have been described. Currently, the heterogeneous photolysis involving semiconductors as electrodes in photoelectrochemical cells is a very active field of research. Homogeneous - photoredox reactions are also known to result in water oxidation and reduction. Of these, the Eu2+photolysis occurs in the sea level solar range of wavelengths with a reasonably high quantum yield. Energy is not stored in this reaction, however, and a means to reduce the photo-oxidized Eu3+is not yet in hand. Thermodynamic considerations suggest that the direct photoreduction of aqueous ions is not likely to occur in the visible or neat ultraviolet range. Therefore, indirect routes must be sought for the half of the cycle that provides a reducing agent and generates oxygen, from water. This half of the cycle is probably the crucial one and represents a central problem in photochemical solar energy conversion.

ISSN:0090-8312    

DOI:10.1080/00908317808908048

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The microstructure of coal is determined and characterized by combined scanning election microscope-energy dispersive analysis techniques. Microstructural information on a micrometer-size scale is correlated with microchemical information developed by energy dispersive X-ray microanalyses to establish the presence and distribution of pyrite, the primary sulfur-bearing inorganic phase in coal. Other complementary analytic techniques are also used. This study evaluates particle size, shape, and distribution factors which bear on decisions to try to remove additional sulfide particles to reduce the sulfur content. Subsamples are obtained from complete channel samples or sources such as raw material prepared as appropriate to the major methods of coal conversion.

ISSN:0090-8312    

DOI:10.1080/00908317808908049

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

It is generally recognized that the coal-preparation option for increasing the percentage of compliance coal available should be used whenever that option can be proved favorable on an economic basis. In order to carry out economic evaluations of alternative coal-preparation plants, one should use a revenue requirements approach based on transformations of input coal size distribution vectors into output size distribution vectors containing acceptable Btu, ash and sulfur intensities. Some general procedures are described for tracking energy and other intensities through the more important units used in coal-preparation plants. It is emphasized that there is a need for engineering-oriented algebraic matrix generators paramatized to reflect the steady-state performance of each unit. It is suggested that insufficient attention is being paid to the development of design procedures for plants that process input vectors, and that an interdisciplinary approach would be helpful in order to allow the concepts, models, and methods developed in related disciplines to be shared.

ISSN:0090-8312    

DOI:10.1080/00908317808908050

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

This paper derives fuel-demand equations from a translog profit function, permitting the estimation of elasticities of demand and substitution that are subject only to those restrictions implied by economic theory. The estimated elasticities indicate substantial interfuel substitution in the generation of electric energy.

ISSN:0090-8312    

DOI:10.1080/00908317808908051

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Carbonate rock is considered one of the major sources of carbon dioxide, capable of catalytic conversion to methane, synthetic natural gas (SNG), and other organic products. A brief account of various research reports available in the literature on the catalytic hydrogenation of carbon dioxide is included. Finally, carbon dioxide or, more specifically, carbonate rock is advanced as a potential source of products that might serve either as feedstocks for petrochemical industries or for production of energy.

ISSN:0090-8312    

DOI:10.1080/00908317808908052

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0090-8312    

DOI:10.1080/00908317808908053

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor