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Groundwater in the Navajo sandstone a subset of "Simulation of the effects of coal-fired power developments in the Four Corners region" /Dove, Floyd Harvey. January 1973 (has links) (PDF)
Thesis (Ph. D. - Hydrology and Water Resources)--University of Arizona. / Includes bibliographical references (leaves 128-133).
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Investigating the effects of the 1990 Clean Air Act Amendments on inputs to coal-fired power plants /Lange, Ian. January 2005 (has links)
Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 79-84).
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Analysing fly-ash erosion in coal-fired boilers using compational fluid dynamicsKloppers, Johannes Christiaan 16 April 2007 (has links)
Please read the abstract in the section 00front of this document / Dissertation (M Eng (Mechanical Engineering))--University of Pretoria, 2007. / Mechanical and Aeronautical Engineering / unrestricted
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High temperature interactions of alkali vapors with solids during coal combustion and gasification.Punjak, Wayne Andrew January 1988 (has links)
The high temperature interactions of alkali metal compounds with solids present in coal conversion processes are investigated. A temperature and concentration programmed reaction method is used to investigate the mechanism by which organically bound alkali is released from carbonaceous substrates. Vaporization of the alkali is preceded by reduction of oxygen-bearing groups during which CO is generated. A residual amount of alkali remains after complete reduction. This residual level is greater for potassium, indicating that potassium has stronger interactions with graphitic substrates than sodium. Other mineral substrates were exposed to high temperature alkali chloride vapors under both nitrogen and simulated flue gas atmospheres to investigate their potential application as sorbents for the removal of alkali from coal conversion flue gases. The compounds containing alumina and silica are found to readily adsorb alkali vapors and the minerals kaolinite, bauxite and emathlite are identified as promising alkali sorbents. The fundamentals of alkali adsorption on kaolinite, bauxite and emathlite are compared and analyzed both experimentally and through theoretical modeling. The experiments were performed in a microgravimetric reactor system; the sorbents were characterized before and after alkali adsorption using scanning Auger microscopy, X-ray diffraction analysis, mercury porosimetry and atomic emission spectrophotometry. The results show that the process is not a simple physical condensation, but a complex combination of several diffusion steps and reactions. There are some common features among these sorbents in their interactions with alkali vapors: In all cases the process is diffusion influenced, the rate of adsorption decreases with time and there is a final saturation limit. However, there are differences in reaction mechanisms leading to potentially different applications for each sorbent. Bauxite and kaolinite react with NaCl and water vapor to form nephelite and carnegieite and release HCl to the gas phase. However, emathlite reacts to form albite and HCl vapor. Albite has a melting point significantly lower than nephelite and carnegieite; therefore, emathlite is more suitable for lower temperature sorption systems downstream of the combustors/gasifiers, while kaolinite and bauxite are suitable as in-situ additives.
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Regional economics: a subset of "Simulation of the effects of coal-fired power development in the Four Corners Region."Everett, Wayne Leonari,1945- January 1974 (has links)
The focal point of the quality of life associated with the United States is a strong economy. Growth in the economy means growth in employment. The establishment of stringent environmental legislation is now a reality. However, those responsible for enacting environmental laws, as well intentioned as they may be, must strive to assess the socio-economic consequences of their actions so that the true net benefit of the environmental legislation is established. The main effort in this research centers around the analysis of how a particular resource, energy (i.e., energy in the form of electric power derived from strip-mined coal) is embedded in the economic growth of the Southwest. The basic econometric tool that has been utilized is a regional input-output model which evolved from a California-Arizona linked input-output model developed by H. O. Carter and D. Ireri. The decision space developed, which effectively acted as a mechanism for restricting coal-fired power availability in future years, was based on a schedule of electric energy capacity additions as delineated by the U.S. Department of Interior's Southwest Energy Study. The regional economic analysis, described in Chapter 5 of this dissertation, suggests there is a definite relationship between coal-fired power availability and regional economic growth in the Southwest. Furthermore, the estimates of incremental decreases in regional economic activity associated with certain levels of decreased coal-fired power development are of such a magnitude that one could characterize the relationship as very significant.
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PLUG FLOW REACTOR MODELS FOR COAL COMBUSTION.Kyle, Gary Newton. January 1982 (has links)
No description available.
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Environmental geochemistry and petrology of the recent sediments from lakes in the vicinity of the coal-fired power plants in central Alberta, CanadaSanei, Hamed. 10 April 2008 (has links)
No description available.
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Coal pulveriser maintenance performance enhancement through the application of a combination of new technologies22 June 2011 (has links)
M.Ing. / The dissertation is an investigation on the implementation of new technologies (five off) in a coal pulverising with main aim to optimise mill maintenance interventions. The technologies in question are: • Stationary air throat replaced with a rotating throat assembly. • Hydro-pneumatic mill loading cylinders replaced with airbags. • Classifier cone modification. • Introduction of triton material for the mill spider guide plates. • High chrome mill grinding balls. Every maintenance intervention, even if planned, negatively affects a plant’s availability and reliability. A Babcock and Wilcox (B&W) at Kriel power station (ESKOM) was used for the testing of the mentioned technologies. The mill model/size is a B&W 10.8E mill. The aim of the introduction of new technology on a mill is to optimise the period between required maintenance activities. A higher availability will assist in achieving good plant maintenance performance indicators. It needs to be noted that the dissertation focussed on the financial and technical parameters of a specific modification. This in an effort to increase uptime and reduce costs as part of a business drive for bigger profit margins. The new technologies tested were thus evaluated from a technical and financial point of view. Each technology was implemented at different time periods and nowhere was any tests performed in parallel on a single mill. To get approval from an investment committee for release of money for tests/modifications, technical and financial assumptions need to be made regarding the performance parameters of the modification/change. Once a modification is being tested, actual plant data can be used as inputs into the execution phase of the modification as assumptions can be replaced with test data. A financial model was developed to “test” the financial feasibility of the proposed changes/modifications. With new technology successful implemented in the plant the current maintenance strategies for maintenance interventions can be re-evaluated as the proposed modifications removed historic barriers that determined the current used based maintenance intervals. An example is where a mill is taken from service to replace or repair the stationary air throat (typically every 5 000 operating hours). With the newly applied technology (rotating throat assemblies), there is no need for maintenance interventions every 5 000hrs as a rotating throat assembly can run without major interventions for 60 000hrs.
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A numerical study of solid fuel combustion in a moving bedKo, Daekwun 12 November 1993 (has links)
Coal continues to be burned by direct combustion in packed or moving bed in
small size domestic furnaces, medium size industrial furnaces, as well as small power
stations. Recent stringent restrictions on exhaust emissions call for a better
understanding of the process of combustion of coal in beds.
The present study is a prelude to developing methods of analysis to obtain this
improved understanding. A one-dimensional steady-state computational model for
combustion of a bed of solid fuel particles with a counterflowing oxidant gas has
been developed. Air, with or without preheating, is supplied at the bottom of the bed.
Spherical solid fuel particles (composed of carbon and ash) are supplied at the top of
the bed. Upon sufficient heating in their downward descent, the carbon in particles
reacts with oxygen of the flowing gas.
The governing equations of conservation of mass, energy, and species are
integrated numerically to obtain the solid supply rate whose carbon content can be
completely consumed by a given gas supply rate. The distributions of solid and gas
temperatures, of concentrations of various gas species, of carbon content in solid, and
of velocity and density of gas mixture are also calculated along the bed length. The
dependence of these distributions on the solid and gas supply rates, the air supply
temperature, the size of solid fuel particle, and the initial carbon content in solid is
also investigated.
The calculated distributions are compared with the available measurements
from literature to find reasonable agreement. More gas supply is needed for complete
combustion at higher solid supply rate. At a given gas supply rate, more solid fuel
particles can be consumed at higher gas supply temperature, for larger particle size,
and for lower initial carbon content in solid. The temperature of the bed becomes
higher for higher solid supply rate, higher gas supply temperature, larger solid
particle diameter, or lower initial carbon content in solid. These reasonable results
lead one to encourage extension of the model presented here to more complex
problems involving combustion of coals in beds including the effects of drying and
pyrolysis. / Graduation date: 1994
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Computer modeling of Tennessee Valley Authority's coal based power plant at Kingston to predict the effluent to Emory riverBagchi, Bratendu, January 2006 (has links) (PDF)
Thesis (Ph. D.) -- University of Tennessee, Knoxville, 2006. / Title from title page screen (viewed on Jan. 31, 2007). Thesis advisor: Paul R. Bienkowski. Vita. Includes bibliographical references.
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