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Enhancing the use of coals by gas reburning-sorbent injection

Description: The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on three coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices; tangential, wall, and cyclone fired. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent in SO{sub x} emissions, by a combination of two developed technologies, gas reburning (GR) and sorbent injection (SI). With GR, about 80--85 percent of the coal fuel is fired in the primary combustion zone. The balance of the fuel is added downstream as natural gas to create a slightly fuel rich environment in which NO{sub x} is converted to N{sub 2}. The combustion process is completed by overfire air addition. SO{sub x} emissions are reduced by injecting dry sorbents (usually calcium based) into the upper furnace, at the superheater exit or into the ducting following the air heater. The sorbents trap SO{sub x} as solid sulfates and sulfites, which are collected in the particulate control device.
Date: December 22, 1988
Partner: UNT Libraries Government Documents Department

An Expression for the Temperature Gradient in Chaotic Fields

Description: A coordinate system adapted to the invariant structures of chaotic magnetic fields is constructed. The coordinates are based on a set of ghost-surfaces, defined via an action-gradient flow between the minimax and minimizing periodic orbits. The construction of the chaotic coordinates allows an expression describing the temperature gradient across a chaotic magnetic field to be derived. The results are in close agreement with a numerical calculation.
Date: December 22, 2008
Creator: Hudson, S.R.
Partner: UNT Libraries Government Documents Department

Growth and Dissolution of Iron and Manganese Oxide Films

Description: Growth and dissolution of Fe and Mn oxide films are key regulators of the fate and transport of heavy metals in the environment, especially during changing seasonal conditions of pH and dissolved oxygen. The Fe and Mn are present at much higher concentrations than the heavy metals, and, when Fe and Mn precipitate as oxide films, heavy metals surface adsorb or co-precipitate and are thus essentially immobilized. Conversely, when the Fe and Mn oxide films dissolve, the heavy metals are released to aqueous solution and are thus mobilized for transport. Therefore, understanding the dynamics and properties of Fe and Mn oxide films and thus on the uptake and release of heavy metals is critically important to any attempt to develop mechanistic, quantitative models of the fate, transport, and bioavailablity of heavy metals. A primary capability developed in our earlier work was the ability to grow manganese oxide (MnO{sub x}) films on rhodochrosite (MnCO{sub 3}) substrate in presence of dissolved oxygen under mild alkaline conditions. The morphology of the films was characterized using contact-mode atomic force microscopy. The initial growth began by heteroepitaxial nucleation. The resulting films had maximum heights of 1.5 to 2 nm as a result of thermodynamic constraints. Over the three past years, we have investigated the effects of MnO{sub x} growth on the interactions of MnCO{sub 3} with charged ions and microorganisms, as regulated by the surface electrical properties of the mineral. In 2006, we demonstrated that MnO{sub x} growth could induce interfacial repulsion and surface adhesion on the otherwise neutral MnCO{sub 3} substrate under environmental conditions. Using force-volume microscopy (FVM), we measured the interfacial and adhesive forces on a MnO{sub x}/MnCO{sub 3} surface with a negatively charged silicon nitride tip in a 10-mM NaNO3 solution at pH 7.4. The interfacial force and surface adhesion of MnOx ...
Date: December 22, 2008
Creator: Martin, Scot T.
Partner: UNT Libraries Government Documents Department

Enhancing the use of coals by gas reburning-sorbent injection. Quarterly report no. 6, September 1, 1988--November 30, 1988

Description: The objective of this project is to evaluate and demonstrate a cost effective emission control technology for acid rain precursors, oxides of nitrogen (NO{sub x}) and sulfur (SO{sub x}), on three coal fired utility boilers in Illinois. The units selected are representative of pre-NSPS design practices; tangential, wall, and cyclone fired. The specific objectives are to demonstrate reductions of 60 percent in NO{sub x} and 50 percent in SO{sub x} emissions, by a combination of two developed technologies, gas reburning (GR) and sorbent injection (SI). With GR, about 80--85 percent of the coal fuel is fired in the primary combustion zone. The balance of the fuel is added downstream as natural gas to create a slightly fuel rich environment in which NO{sub x} is converted to N{sub 2}. The combustion process is completed by overfire air addition. SO{sub x} emissions are reduced by injecting dry sorbents (usually calcium based) into the upper furnace, at the superheater exit or into the ducting following the air heater. The sorbents trap SO{sub x} as solid sulfates and sulfites, which are collected in the particulate control device.
Date: December 22, 1988
Partner: UNT Libraries Government Documents Department

241-A evaporator flowsheet users manual

Description: This supporting document presents a description of the 242-A Evaporator flowsheet. Material balances are calculated for feed, slurry, and effluent streams based on input data for the feed stream.
Date: December 22, 1994
Creator: Larrick, A. P.
Partner: UNT Libraries Government Documents Department