Of all coke properties the influence of the catalytic mineral matter on reactivity of metallurgical cokes is least understood. There is limited information about the form of minerals in the metallurgical cokes and no information about their relative concentration. A comprehensive study was undertaken for characterisation of mineral matter in coke (qualitative and quantitative), which enabled quantification of the effect of catalytic minerals on the reaction rate, and establishment of the effect of gasification on the mineral phases. Also, the relative importance of coke properties on the gasification reaction rate was determined. The reactivity experiments were performed at approximately 900??C using 100% CO2 under chemically controlled conditions. The mineralogical composition of the investigated cokes was found to vary greatly as did the levels of catalytic mineral phases. These were identified to be metallic iron, iron sulfides and iron oxides. The gasification reaction rate at the initial stages was strongly influenced by the content of catalytic mineral phases and also by the particle size of the catalytic mineral matter. The reaction rate increased as the contact surface between catalyst and carbon matrix increased. Catalytic mineral phases showed a strong influence on the reaction rate at early stages of reaction. But their influence diminished during gasification. At later stages of reaction the influence of micropore surface area became more important. The influence of the catalytic mineral phases diminished during gasification because the catalyst was inactivated to some degree and the contact surface between the catalyst and carbon matrix diminished due to the strong gasification of the carbon around the catalyst particles. The partial inactivation of the catalytic mineral phases occurred because metallic iron and pyrrhotite were oxidised by CO2 to iron oxide, and in turn iron oxide reacted with other mineral phases, which it is associated with, to form minerals that are not catalysts. It is noteworthy that a significant percentage of the mineral matter present in the investigated cokes was amorphous (44 - 75%). The iron, potassium and sodium present in the amorphous phase did not appear to catalyse gasification, but their potential contribution to gasification could not be completely excluded.

The material properties of the candidate fiber-reinforced composite materials and different fabrication methods for fiber composites were discussed. The improvement of the hand lay-up process for polyurethane impregnated Kevlar was investigated. Testing samples for lab and prototype tests were fabricated by hand lay-up process. The study showed that fiber composites fabricated by the hand lay-up process can achieve good properties, and advanced fabrication methods could be applied In industrial manufacturing processes to improve the fiber composite properties. A nonlinear static analysis was discussed. The ANSYS finite element analysis computer program was used to build stress analysis models, simulate the loading conditions, and perform the nonlinear static analysis. The tensile strength proof test was designed and done by using a microcomputer controlled Instron 4505. It showed that the different types of fiber composites can meet the strength requirements for the application. Polyurethane impregnated Kevlar showed the best strength properties among the different types of fiber composites, which were fabricated and tested. The wear and abrasion properties of the different types of fiber composites were discussed and relevant tests were introduced. An ultraviolet light exposure test and the Oregon Department of Transportation road-cover test were conducted. Moisture and acid resistance and cost analysis were also discussed. Based on the results of the study, a prediction of the optimal fiber-reinforced composite materials was made. Also, various conclusions and recommendations for future research work were made. / Graduation date: 2000

Coal fly ash is a by-product of coal combustion that has drawn renewed public scrutiny due to the negative environmental impacts from accidental release of this waste material from storage facilities. Historically, the leaching of toxic elements from coal fly ash into the environment has always been a major environmental concern. Despite extensive efforts into the characterization of coal fly ash, effective models for the fate and transport of toxic fly ash constituents have remained lacking, making it difficult to perform accurate environmental impact assessment for coal fly ash. To close this critical knowledge gap, the overall objective of this study was to develop a predictive model for the leaching of toxic elements from fly ash particles. First, physical properties of coal fly ash were characterized to evaluate their contribution to elemental transport. Unburned carbon was shown to contribute to the sorption of arsenic to fly ash, which slowed the release of arsenic from fly ash. In parallel, leaching properties of various elements were determined to differentiate species of varying leaching capacities, demonstrating that the majority of toxic elements were not mobile under environmentally relevant conditions. Subsequently, a mechanistic model for the dissolution of fly ash elements was developed and validated with batch kinetics studies. Furthermore, elemental dissolution was integrated with hydrodynamic modeling to describe the leaching of toxic elements from fly ash in dry disposal facilities, which was validated by column studies. The mechanistic model developed and validated in this research represents the first such model that successfully characterized the complex processes underlying the release and transport of toxic elements in coal fly ash, providing a valuable tool to predict the environment impact of coal fly ash and develop more effective management practices for both the industry and regulators.

ABSTRACT This proposal is a study of coal-mining in Southern West Virginia; its impact on the landscape; local economy and culture; and presents an alternative land use to address the loss of a major industry in a rural county. The study began with understanding the process of mining; from the actual extraction to the end product, electricity. Looking at the past provided a historical metric for the Coal Company - Mine Worker dynamic. Case studies created benchmarks for both appreciating and improving upon the issue. Constructing a timeline that tracked political, social and natural occurrences gave scope to the interrelationships of government, industry and the working class. Current reclamation practices take into account the physical changes made to the land, but not the void the loss of industry will create in the local economy. Recognizing coal mining as an important part of Appalachian culture means re-envisioning reclamation, and understanding more than the land needs to be restructured when a mine closes. Coal mining reclamation has been studied by engineers, ecologists and political bodies more so than by the design community: architects, landscape architects and artists. However, the designer’s training for not just research and analysis but synthesis of ideas and collaboration between disciplines that could provide the next step for a changing industry.

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.

Coal mining carries significant impacts for surrounding livelihood practices. Yet, in order to explain how specific impacts become grounded within a particular community, attention must be given to the complex assemblage of socio-political and economic forces operating at the local scale. As such, this paper builds upon 3 months of field research in 2010 to describe the impact of decentralized extractive resource governance at coal mines near the rural coastal village of Sekerat, East Kalimantan. Employing evolutions in political ecology research, the analysis focuses on the evolving governance ‘space’ in order to explain how institutional analyses of resource extraction governance and livelihood governance can be integrated to understand how scalar processes construct a range of real and perceived impacts which condition the decision-making modalities of local villagers. A case is then made for giving greater consideration to the importance of temporality and materiality to explaining how land-based and wage-labour livelihood practices have become ‘reified’ within the local village.

Coal mining carries significant impacts for surrounding livelihood practices. Yet, in order to explain how specific impacts become grounded within a particular community, attention must be given to the complex assemblage of socio-political and economic forces operating at the local scale. As such, this paper builds upon 3 months of field research in 2010 to describe the impact of decentralized extractive resource governance at coal mines near the rural coastal village of Sekerat, East Kalimantan. Employing evolutions in political ecology research, the analysis focuses on the evolving governance ‘space’ in order to explain how institutional analyses of resource extraction governance and livelihood governance can be integrated to understand how scalar processes construct a range of real and perceived impacts which condition the decision-making modalities of local villagers. A case is then made for giving greater consideration to the importance of temporality and materiality to explaining how land-based and wage-labour livelihood practices have become ‘reified’ within the local village.

An emplaced source of coal tar creosote within the sandy Borden research aquifer has provided an opportunity to document the long term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals were extensively sampled seven times using a monitoring network of ~280 14-point multilevel samplers. A model of source dissolution using Raoult’s Law adequately predicted the dissolution of nine of eleven compounds analysed. Mass transformation has limited the extent of the plumes as groundwater flowed more than 500 m yet the plumes are no longer than 50 m. Phenol and xylenes were removed and naphthalene was attenuated from its maximum extent on day 1357. Some compound plumes reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass loss is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. After 10 years the source zone was treated with permanganate in situ to reduce the flux of contaminants into the dissolved plume and to permit natural attenuation to further reduce the plume extent. A sufficient mass of permanganate was injected to oxidize ~10% of the residual source. Laboratory experiments demonstrated that eight of ten of the study compounds were readily oxidized by permanganate. Once treated oxidized compounds displayed a reduced plume mass and mass discharge while they migrated through the monitoring network. Once beyond the monitoring network the mass discharge and plume mass of these compounds returned to pre-treatment trends. Non-reactive compounds displayed no significant decrease in mass discharge or plume mass. Overall the partial in situ chemical oxidation of the coal tar creosote source produced no long-term effect on the dissolved plumes emanating from the source.

An emplaced source of coal tar creosote within the sandy Borden research aquifer has provided an opportunity to document the long term (5140 days) natural attenuation for this complex mixture. Plumes of dissolved chemicals were produced by the essentially horizontal groundwater flowing at about 9 cm/day. Eleven chemicals were extensively sampled seven times using a monitoring network of ~280 14-point multilevel samplers. A model of source dissolution using Raoult’s Law adequately predicted the dissolution of nine of eleven compounds analysed. Mass transformation has limited the extent of the plumes as groundwater flowed more than 500 m yet the plumes are no longer than 50 m. Phenol and xylenes were removed and naphthalene was attenuated from its maximum extent on day 1357. Some compound plumes reached an apparent steady state and the plumes of other compounds (dibenzofuran and phenanthrene) are expected to continue to expand due to an increasing mass flux and limited degradation potential. Biotransformation is the major process controlling natural attenuation at the site. The greatest organic mass loss is associated with the high solubility compounds. However, the majority of the mass loss for most compounds has occurred in the source zone. Oxygen is the main electron acceptor yet the amount of organics lost cannot be accounted for by aerobic mineralization or partial mineralization alone. After 10 years the source zone was treated with permanganate in situ to reduce the flux of contaminants into the dissolved plume and to permit natural attenuation to further reduce the plume extent. A sufficient mass of permanganate was injected to oxidize ~10% of the residual source. Laboratory experiments demonstrated that eight of ten of the study compounds were readily oxidized by permanganate. Once treated oxidized compounds displayed a reduced plume mass and mass discharge while they migrated through the monitoring network. Once beyond the monitoring network the mass discharge and plume mass of these compounds returned to pre-treatment trends. Non-reactive compounds displayed no significant decrease in mass discharge or plume mass. Overall the partial in situ chemical oxidation of the coal tar creosote source produced no long-term effect on the dissolved plumes emanating from the source.

An extensive study of intrinsic and extrinsic factors on biomass pyrolysis reactions is needed if valuable hydrocarbon gases are to be produced from pyrolysis of biomass. In the first phase of this study a spent coffee waste material was pyrolysed in a stainless steel batch reactor at 500 to 900°C with both N₂ and H₂ carrier gases. The use of H₂ gas did not affect the product distribution. Yields of pyrolysis gas products reached 61 and 74 wt% of the feed at 900°C for N₂ and H₂ carrier gases. Corresponding mass balance closures were obtained at 86 and 98 wt% of the feed. Catalytic effect of the stainless steel wall was confirmed. Maximum conversion of CO was found at pyrolysis zone temperature of 700°C. Pyrolysis experiments with spent coffee performed in a quartz (inert) batch reactor proved that the carrier gas had negligible influence on the primary pyrolysis product distribution. Pyrolysis with K₂CO₃ at 650, 700, and 800°C, showed catalysis of cracking reactions of pyrolysis tars and the water-gas shift reaction. Copyrolysis of biomass materials and coals were performed in the quartz reactor with the objective of producing a higher hydrocarbon content gas product. Copyrolysis of spent coffee and lignite coal at 800°C in a hydrogen atmosphere resulted in gas production of more than 45 wt% of the feed, compared with only 27 wt% for pure coal sample. Increases in production of CH₄ and C₂H₄ were 15.9 wt% and 21.3 Wt%. For copyrolysis with sub-bituminous coal, these synergistic increases were 36.5 wt% and 23.9 wt%. In the final phase of this research, a fluidized bed reactor was used to study hydropyrolysis of cellulose, spent coffee, aspen-poplar, bagasse and lignite coal in presence of sand (inert medium), ã-alumina catalyst, Engelhard US-260 (a silica alumina catalyst), 10 wt% nickel-ã-alumina, 10 wt% cobalt-ã-alumina and a 40 wt% nickel-refractory support catalyst. Over the temperature range of 500 to 600°C, the 10 wt% nickel catalyst was most effective in conversion of biomass. Overall it was found that the combination of cellulose with 10 wt% Ni catalyst at 550°C was the optimum catalyst-feed system for conversion of carbon content of biomass to methane. In this case the yield of CH₄ was 46.7 wt% of cellulose. Rate constants for (primary) pyrolysis, (secondary) tar-cracking and (tertiary) hydrogenation reactions at 550°C were determined. Rate constants for the above mentioned reactions were estimated to be k₁=2.88 s^-1 (pyrolysis model), k₁=2.88 and k₂=1.31 s^-1 (pyrolysis-cracking model), and k₁=2.88, k₂=13.1 and k₃=12.96 s^-1 (pyrolysis-cracking-hydrogenation model).