45 research outputs found
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VALIDATION OF FIRESIDE PERFORMANCE INDICES: FOULING/CORROSION EVALUATION OF MDF PARTICLEBOARD AND BLENDS WITH WHEAT STRAW BOARD
Sauder Woodworking currently fires a large portion of all wood wastes in a boiler producing process steam. It is investigating using particleboard made from wheat straw in its manufacturing process and is concerned with the effects of the inorganics on its boiler. Wheat straw board contains higher ash contents and increased levels of potassium, creating concern over fouling characteristics in Sauder's tight boiler design. In addition, the wheat straw board contains high concentrations of chlorine, which may affect boiler tube corrosion when fired in combination with the particleboard wastes currently generated. Sauder has engaged the services of the Energy & Environmental Research Center (EERC) at the University of North Dakota to investigate the potential detrimental effects of firing blends containing wheat straw on boiler tube fouling and corrosion. Additional funding for this project was provided through the U.S. Department of Energy Jointly Sponsored Research Program (DOE JSRP) project ''Validation of Fireside Performance Indices'' to validate, improve, and expand the PCQUEST (Predictive Coal Quality Effects Screening Tool) program. The PCQUEST fuel database is constantly expanding and adding new fuels, for which the algorithms may need refinement and additional verification in order to accurately predict index values. A key focus is on performing advanced and conventional fuel analyses and adding these analyses to the PCQUEST database. Such fuels include coals of all ranks and origins, upgraded coals, petroleum coke, biomass and biomass-coal blends, and waste materials blended with coal. Since there are differences in the chemical and mineral form of the inorganic content in biomass and substantial differences in organic matrix characteristics, analysis and characterization methods developed for coal fuels may not be applicable. The project was seen to provide an excellent opportunity to test and improve the ability of PCQUEST to handle nontypical soil and biomass minerals
Enacting Resilience: A Performative Account of Governing for Urban Resilience
Resilience is an increasingly important urban policy discourse that has been taken up at a rapid pace. Yet there is an apparent gap between the advocacy of social-ecological resilience in scientific literature and its take-up in policy discourse on the one hand, and the demonstrated capacity to govern for resilience in practice on the other. This paper explores this gap by developing a performative account of how social-ecological resilience is dealt with in practice through case study analysis of how protection of biodiversity was negotiated in response to Melbourne’s recent metropolitan planning initiative. It is suggested that a performative account expands the possible opportunities for governing for social-ecological resilience beyond the concept’s use as a metaphor, measurement, cognitive frame or programmatic statement of adaptive management/co-management and has the potential to emerge through what has been called the everyday ‘mangle of practice’ in response to social-ecological feedback inherent to policy processes
Openness in participation, assessment, and policy making upon issues of environment and environmental health: a review of literature and recent project results
Issues of environment and environmental health involve multiple interests regarding e.g. political, societal, economical, and public concerns represented by different kinds of organizations and individuals. Not surprisingly, stakeholder and public participation has become a major issue in environmental and environmental health policy and assessment. The need for participation has been discussed and reasoned by many, including environmental legislators around the world. In principle, participation is generally considered as desirable and the focus of most scholars and practitioners is on carrying out participation, and making participation more effective. In practice also doubts regarding the effectiveness and importance of participation exist among policy makers, assessors, and public, leading even to undermining participatory practices in policy making and assessment
Starfish in the Sundance Sea: Jurassic Asteroidea Fossils from South Montana
In 2010, Jay Gunderson discovered several Jurassic-age (~160 million years old) starfish fossils in the Pryor Mountains of south-central Montana. Starfish fossils are rare and very few have been found in North America. The Pryor Mountain site produced over 20 specimens and at least four different species of starfish, representing one of the most diverse assemblages of Jurassic Asteroidea fossils in the world. This presentation gives an overview of the discovery, collection, and detailed study of these fossils by one of the world\u27s leading Asteroidea experts. Most of the collection is housed at the Field Museum of Natural History in Chicago, but a few specimens have recently found their way to the Montana Mineral Museum
Application of rock physics to an exploration play: A carbonate case study from the Brazeau River 3D
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JV Task 110 - Evaluation of an Acoustic Single-Fluid Nozzle for Oil Combustion
Two residual (No. 6 fuel) oils from Texas and North Dakota with very different chemical compositions and physical properties were burned at similar injection rates ({approx}28 lb/hr) in a pilot-scale (550,000 Btu/hr) combustion test facility unit using conventional dual-fluid and Kimberly-Clark (K-C) acoustic nozzles to compare flame characteristics, gaseous and fly ash emissions, and fly ash morphological and chemical characteristics. The K-C acoustic nozzle supplied a more consistent oil feed rate to the furnace relative to the conventional dual-fluid nozzle. This consistency in oil flow reduced the variability in NO{sub x}, SO{sub 2}, CO{sub 2}, and O{sub 2} flue gas concentrations. K-C nozzle injection, however, produced a more carbon-rich residual oil fly ash (ROFA) relative to the conventional nozzle. The K-C acoustic nozzle promoted oil atomization and extended the flame higher in the furnace so that the residence time of the residual oil was greatly reduced. The lack of oil residence time in the furnace contributed to the incomplete combustion performance of the K-C acoustic nozzle. On average, the K-C acoustic nozzle reduced NO{sub x} emissions from burning the Texas and North Dakota oils by 66% and 33%, respectively. Late in the test program, it was discovered that a significant increase in power to the K-C acoustic nozzle improved combustion efficiency, flame stability, and reduced the amount of unburned carbon in ROFA. The unburned carbon particles were smaller, generally about 50 {micro}m in diameter, as a result of the increase in power to the K-C nozzle. Additional optimization of the K-C nozzle at higher power in a larger furnace has the potential to further improve combustion efficiency
Assessment of Coal Geology, Resources, and Reserves in the Montana Powder River Basin
The purpose of this report is to summarize geology, coal resources, and coal reserves in the Montana Powder River Basin (MTPRB) assessment area in southeastern Montana. This report represents the fourth assessment area within the Powder River Basin to be evaluated in the continuing U.S. Geological Survey regional coal assessment program.
There are four active coal mines in the MTPRB assessment area: the Spring Creek and Decker Mines, both near Decker; the Rosebud Mine, near Colstrip; and the Absaloka Mine, west of Colstrip. During 2011, coal production from these four mines totaled approximately 36 million short tons (MST). A fifth mine, the Big Sky, had significant production from 1969–2003; however, it is no longer in production and has since been reclaimed. Total coal production from all five mines in the MTPRB assessment area from 1968 to 2011 was approximately 1.4 billion short tons (BST). The Rosebud/Knobloch coal bed near Colstrip and the Anderson, Dietz 2, and Dietz 3 coal beds near Decker contain the largest deposits of surface minable, low-sulfur, subbituminous coal currently being mined in the assessment area.
A total of 26 coal beds were identified during this assessment, 18 of which were modeled and evaluated to determine in-place coal resources. The total original coal resource in the MTPRB assessment area for the 18 coal beds assessed was calculated to be 215 BST. Available coal resources, which are part of the original coal resource remaining after subtracting restrictions and areas of burned coal, are about 162 BST. Restrictions included railroads, Federal interstate highways, urban areas, alluvial valley floors, state parks, national forests, and mined-out areas.
It was determined that 10 of the 18 coal beds had sufficient areal extent and thickness to be evaluated for recoverable surface resources ([Roland (Baker), Smith, Anderson, Dietz 2, Dietz 3, Canyon, Werner/Cook, Pawnee, Rosebud/Knobloch, and Flowers-Goodale]). These 10 coal beds total about 151 BST of the 162 BST of available resource; however, after applying a strip ratio of 10:1 or less, only 39 BST remains of the 151 BST. After mining and processing losses are subtracted from the 39 BST, 35 BST of coal were considered as a recoverable resource. Coal reserves (economically recoverable coal) are the portion of the recoverable coal resource that can be mined, processed, and marketed at a profit at the time of the economic evaluation. The surface coal reserve estimate for the 10 coal beds evaluated for the Montana Powder River assessment area is 13 BST.
It was also determined that about 42 BST of underground coal resource exists in the MTPRB assessment area; about 34 BST (80 percent) are within 500–1,000 ft of the land surface and another 8 BST are 1,000–2,000 ft beneath the land surface
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JV Task 108 - Circulating Fluidized-Bed Combustion and Combustion Testing of Turkish Tufanbeyli Coal
Two combustion tests were performed at the Energy & Environmental Research Center (EERC) using Tufanbeyli coal from Turkey. The tests were performed in a circulating fluidized-bed combustor (CFBC) and a pulverized coal-fired furnace, referred to as the combustion test facility (CTF). One of the goals of the project was to determine the type of furnace best suited to this coal. The coal is high in moisture, ash, and sulfur and has a low heating value. Both the moisture and the sulfur proved problematic for the CTF tests. The fuel had to be dried to less than 37% moisture before it could be pulverized and further dried to about 25% moisture to allow more uniform feeding into the combustor. During some tests, water was injected into the furnace to simulate the level of flue gas moisture had the fuel been fed without drying. A spray dryer was used downstream of the baghouse to remove sufficient sulfur to meet the EERC emission standards permitted by the North Dakota Department of Health. In addition to a test matrix varying excess air, burner swirl, and load, two longer-term tests were performed to evaluate the fouling potential of the coal at two different temperatures. At the lower temperature (1051 C), very little ash was deposited on the probes, but deposition did occur on the walls upstream of the probe bank, forcing an early end to the test after 2 hours and 40 minutes of testing. At the higher temperature (1116 C), ash deposition on the probes was significant, resulting in termination of the test after only 40 minutes. The same coal was burned in the CFBC, but because the CFBC uses a larger size of material, it was able to feed this coal at a higher moisture content (average of 40.1%) compared to the CTF (ranging from 24.2% to 26.9%). Sulfur control was achieved with the addition of limestone to the bed, although the high calcium-to-sulfur rate required to reduce SO{sub 2} emissions resulted in heat loss (through limestone calcination) and additional ash handling. A more efficient downstream sulfur scrubber capable of operation at a much lower Ca/S ratio would result in significantly higher boiler efficiency for this coal. At the operating temperature of a typical CFBC, bed agglomeration and convective pass fouling are not likely to be significant problems with this fuel. Compared to pulverized coal-firing, CFBC technology is clearly the better choice for this fuel. It provides more efficient sulfur capture, lower NO{sub x} emissions, better solids-handling capability, and can utilize a wetter feedstock, requiring less crushing and sizing. The lower operating temperature of CFBC boilers (820 C) reduces the risk of fouling and agglomeration. Care must be taken to minimize heat loss in the system to accommodate the low heating value of the coal
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COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS
The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems