Thesis (M.A.)--Ohio State University, 1954. / Available online via OhioLINK's ETD Center

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains ix, 64 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 62-64).

A large-scale pilot plant (0.43 m ID) was extensively modified and converted into an absorber/stripper system to demonstrate CO₂ capture technology using aqueous piperazine promoted potassium carbonate for coalfired power plants. Four pilot plant campaigns were completed. Three campaigns were conducted using 5 m K⁺/2.5 m PZ and 6.4 m K⁺/1.6 m PZ. Flexipac 1Y and Flexipac AQ Style 20 structured packing were used in the absorber. The stripper was tested with 14 sieve trays, IMTP #40 random packing, and Flexipac AQ Style 20 packing. Monoethanolamine (7 m) was tested in the third campaign to establish a base case. An approximate rate analysis showed that 5 m K⁺/2.5 m PZ is two times faster than 7 m MEA and three times faster than 6.4 m K⁺/1.6 m PZ. The location of the temperature bulge moves from the top of the column to bottom as the liquid to gas flow rate ratio is increased. Foaming occurred in the absorber in the first two campaigns and occurred in the stripper in the fourth campaign. Data from the pilot plant was used to develop a K⁺/PZ absorber model in Aspen Plus® RateSep[trademark]. The Hilliard (2005) Aspen Plus® VLE model and the kinetics developed by Cullinane (2005) were incorporated in the model. Data-Fit was simultaneously used to reconcile pilot plant data and perform a regression of the interfacial area and heat loss parameters for the RateSep[trademark] absorber model. The lean loading for the pilot plant data was shifted down by 10% to account for a discrepancy with the Cullinane vapor-liquid equilibrium data. The Data-Fit results showed that the average interfacial area for Flexipac 1Y was 80% of the value measure by the air-water column. The average interfacial area for Flexipac AQ Style 20 for 5 m K⁺/2.5 m PZ was 56% of the air-water measurement. The CO₂ heat of absorption may not have been adequately predicted by the RateSep[trademark] absorber model because the regressed values of heat loss were consistent with forced convection.

There are thousands of subterranean coal fires in the world that, because of incomplete combustion, emit a wide variety of volatile and semivolatile organic compounds to the atmosphere, water, and soil at concentrations that could pose health risks to humans and wildlife. The main goals of this study were to (1) review methods that are used to characterize physical and chemical characteristics of coal-fire sites, (2) determine relationships between gas emissions and physical and chemical characteristics of coal-fire sites, using a combination of regression and multivariate statistical methods, and (3) determine the concentrations of volatile and semivolatile organic compounds in water and soil at two coal-fire sites in eastern Kentucky. More specifically: The objective of Chapter 1 was to review past works and list technologies used over time. Eight years of coal-fire collection technologies were reviewed. A variety of methods and technologies were identified. Qualitative and quantitative preferences were noted. The objective of Chapter 2 was to identify and list uncontrolled coal-fire variables. These variables include complete/incomplete combustion; fire temperature and size; distance to fire; relative humidity and moisture in the system; geology, geochemistry, and age of coal; condition of the mine, sampling time of day; sampling equipment differences; and human error. A secondary objective of this chapter was to determine which coal-fire gases have strong relationships by using the principal component analysis (PCA) software JMP. The strongest relationship was between CO and H2S. Temperature and CH4 were also important. This indicates that incomplete combustion and polynuclear aromatic hydrocarbon (PAH) formation are likely occurring, setting the stage for Chapter 3. The objective of Chapter 3 was to identify and define the extent of soil and water hydrocarbon contamination at the Truman Shepherd and Lotts Creek coal fires in eastern Kentucky. No groundwater contamination was detected at either location. Soil contamination was found at both, but was much higher at Lotts Creek, potentially because of sorption onto soil organic matter (which is reduced at Truman Shepherd by an excavation attempt) and other physicochemical mechanisms. Soil contamination was localized to relatively small areas around coal-fire vents. Based on the results, future studies should consider: Attempting to duplicate these results in other geologic regions Quantifying greenhouse gas emissions from coal fires to consider their contribution to climate change. Coal-fired power plants are regulated, but coal fires, which produce many more harmful gases, are not Determining the feasibility of an oxygen-injection system to engender more complete combustion, therefore possibly reducing harmful gases Determining the feasibility of electricity production from coal fires Adopting a consistent federal coal-fire policy

Pulverized samples of Utah bituminous, Beulah (North Dakota) low Na lignite, Beulah high Na lignite and Texas (San Miguel) lignite coals were burned at a rate of 2.5 kg/hr in a laboratory furnace under various (overall fuel lean) combustion conditions. Particle size distributions (PSD) and size segregated particle filter samples were taken at various positions within the convection section. Temperature and gas concentrations were measured throughout. The evolution of the submicron PSD within the convection section for the four coals was similar, although the location of the initial particle mode at the convection section inlet varied with coal type. While staged (.8/1.2) combustion of the Utah bituminous coal had a variable effect on the volume of submicron aerosol produced, staged combustion of two of the three lignites (Beulah low Na and Texas) caused a definite increase in the submicron aerosol volume. Vapor enhancement due to a localized reducing atmosphere, which would effect coals of higher ash volatility or higher inherent ash content, is thought to explain this behavior. Depressed combustion temperatures associated with the high moisture content of the Beulah high Na lignite are thought to offset the effects of staging. Increased combustion temperatures (through oxygen enrichment) caused staged volume increases for the Beulah high Na lignite. Combustion temperatures are a controlling factor even at more extreme staging conditions. Chemical analysis of the size segregated particle samples show the trace elements, As, Pb, Zn and the major elements, Na and K to be enriched in the submicron aerosol. Auger depth profiles show these small particles to be comprised of a core enriched in Fe, Si, Ca and Mg and surface layers enriched in Na and K. These results point to a mechanism of homogeneous nucleation of low vapor pressure species followed by successive layering of progressively more volatile species. Volatile species are enriched in the submicron aerosol due to the large surface areas provided. Modeling efforts show that while coagulation may be the dominant mechanism to describe the aerosol evolving within the convection section, it cannot be used solely to predict the PSD. Another mechanism, presumably surface area dependent growth (condensation) must be included.

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No description available.

Alternate, cost effective disposal methods must be developed for reducing phosphorous and nitrogen loading from land application of animal waste. Cofiring coal with animal waste, termed dairy biomass (DB), is the proposed thermo-chemical method to address this concern. DB is evaluated as a cofired fuel with Wyoming Powder River Basin (PRB) sub-bituminous coal in a small-scale 29 kW_(t) low NO_(x) burner (LNB) facility. Fuel properties, of PRB and DB revealed the following: a higher heating value of 29590 kJ/kg for dry ash free (DAF) coal and 21450 kJ/kg for DAF DB. A new method called Respiratory Quotient (RQ), defined as ratio of carbon dioxide moles to oxygen moles consumed in combustion, used widely in biology, was recently introduced to engineering literature to rank global warming potential (GWP) of fuels. A higher RQ means higher CO_(2) emission and higher GWP. PRB had an RQ of 0.90 and DB had an RQ of 0.92. For comparison purposes, methane has an RQ of 0.50. For unknown fuel composition, gas analyses can be adapted to estimate RQ values. The LNB was modified and cofiring experiments were performed at various equivalence ratios (phi) with pure coal and blends of PRB-DB. Standard emissions from solid fuel combustion were measured; then NO_(x) on a heat basis (g/GJ), fuel burnt fraction, and fuel nitrogen conversion percentage were estimated. The gas analyses yielded burnt fraction ranging from 89% to 100% and confirmed an RQ of 0.90 to 0.94, which is almost the same as the RQ based on fuel composition. At the 0.90 equivalence ratio, unstaged pure coal produced 653 ppm (377 g/GJ) of NOx. At the same equivalence ratio, a 90-10 PRB:LADB blended fuel produced 687 ppm (397 g/GJ) of NO_(x). By staging 20% of the total combustion air as tertiary air (which raised the equivalence ratio of the main burner to 1.12), NO_(x) was reduced to 545 ppm (304 g/GJ) for the 90-10 blended fuel. Analysis of variance showed that variances were statistically significant because of real differences between the independent variables (equivalence ratio, percent LADB in the fuel, and staging intensity).

No description available.

No description available.