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Water Extraction from Coal-Fired Power Plant Flue Gas

Description: The overall objective of this program was to develop a liquid disiccant-based flue gas dehydration process technology to reduce water consumption in coal-fired power plants. The specific objective of the program was to generate sufficient subscale test data and conceptual commercial power plant evaluations to assess process feasibility and merits for commercialization. Currently, coal-fired power plants require access to water sources outside the power plant for several aspects of their operation in addition to steam cycle condensation and process cooling needs. At the present time, there is no practiced method of extracting the usually abundant water found in the power plant stack gas. This project demonstrated the feasibility and merits of a liquid desiccant-based process that can efficiently and economically remove water vapor from the flue gas of fossil fuel-fired power plants to be recycled for in-plant use or exported for clean water conservation. After an extensive literature review, a survey of the available physical and chemical property information on desiccants in conjunction with a weighting scheme developed for this application, three desiccants were selected and tested in a bench-scale system at the Energy and Environmental Research Center (EERC). System performance at the bench scale aided in determining which desiccant was best suited for further evaluation. The results of the bench-scale tests along with further review of the available property data for each of the desiccants resulted in the selection of calcium chloride as the desiccant for testing at the pilot-scale level. Two weeks of testing utilizing natural gas in Test Series I and coal in Test Series II for production of flue gas was conducted with the liquid desiccant dehumidification system (LDDS) designed and built for this study. In general, it was found that the LDDS operated well and could be placed in an automode in which the process ...
Date: June 30, 2006
Creator: Folkedahl, Bruce C.; Weber, Greg F. & Collings, Michael E.
Partner: UNT Libraries Government Documents Department

BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

Description: The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low volatile fuels with lower reactivities can experience damaging fouling when switched to higher volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early for biomass fuels compared to the design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides, in combination with different flue gas temperatures because of changes in fuel heating value which can adversely affect ash deposition behavior. The goal of this project is to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project are: Modification of an existing EERC pilot-scale combustion system to simulate a grate-fired system; Verification testing of the simulator; Laboratory-scale testing and fuel characterization to determine ash formation and potential fouling mechanisms and to optimize activities ...
Date: October 1, 2001
Creator: Folkedahl, Bruce C.; Schmidt, Darren D.; Weber, Greg F. & Zygarlicke, Christopher J.
Partner: UNT Libraries Government Documents Department

BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

Description: The Energy & Environmental Research Center (EERC) has completed a project to examine fundamental issues that could limit the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC attempted to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience problematic fouling when switched to higher-volatile and more reactive coal-biomass blends. Higher heat release rates at the grate can cause increased clinkering or slagging at the grate due to higher temperatures. Combustion and loss of volatile matter can start much earlier for biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the stoker, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates, various chlorides, and phosphates. These species in combination with different flue gas temperatures, because of changes in fuel heating value, can adversely affect ash deposition behavior. The goal of this project was to identify the primary ash mechanisms related to grate clinkering and heat exchange surface fouling associated with cofiring coal and biomass--specifically wood and agricultural residuals--in grate-fired systems, leading to future mitigation of these problems. The specific technical objectives of the project were: (1) Modification of an existing pilot-scale combustion system to simulate a grate-fired system. (2) Verification testing of the simulator. (3) Laboratory-scale testing and fuel characterization to determine ash formation and potential fouling mechanisms and to optimize activities in the modified pilot-scale ...
Date: September 1, 2002
Creator: Folkedahl, Bruce C.; Gunderson, Jay R.; Schmidt, Darren D.; Weber, Greg F. & Zygarlicke, Christopher J.
Partner: UNT Libraries Government Documents Department

BARRIER ISSUES TO THE UTILIZATION OF BIOMASS

Description: The Energy & Environmental Research Center (EERC) is conducting a project to examine the fundamental issues limiting the use of biomass in small industrial steam/power systems in order to increase the future use of this valuable domestic resource. Specifically, the EERC is attempting to elucidate the ash-related problems--grate clinkering and heat exchange surface fouling--associated with cofiring coal and biomass in grate-fired systems. Utilization of biomass in stoker boilers designed for coal can be a cause of concern for boiler operators. Boilers that were designed for low-volatile fuels with lower reactivities can experience damaging fouling when switched to higher-volatile and more reactive lower-rank fuels, such as when cofiring biomass. Higher heat release rates at the grate can cause more clinkering or slagging at the grate because of higher temperatures. Combustion and loss of volatile matter can start too early with biomass fuels compared to design fuel, vaporizing alkali and chlorides which then condense on rear walls and heat exchange tube banks in the convective pass of the boiler, causing noticeable increases in fouling. In addition, stoker-fired boilers that switch to biomass blends may encounter new chemical species such as potassium sulfates and various chlorides in combination with different flue gas temperatures because of changes in fuel heating value, which can adversely affect ash deposition behavior.
Date: May 1, 2002
Creator: Gunderson, Jay R.; Folkedahl, Bruce C.; Schmidt, Darren D.; Weber, Greg F. & Zygarlicke, Christopher J.
Partner: UNT Libraries Government Documents Department

JV 58-Effects of Biomass Combustion on SCR Catalyst

Description: A portable slipstream selective catalytic reduction (SCR) reactor was installed at a biomass cofired utility boiler to examine the rates and mechanisms of catalyst deactivation when exposed to biomass combustion products. The catalyst was found to deactivate at a much faster rate than typically found in a coal-fired boiler, although this may have been the result of high ash loading rather than a general property of biomass combustion. Deactivation was mainly the result of alkali and alkaline-earth sulfate formation and growth in catalyst pores, apparently caused by alkaline-earth ash deposition on or near the pore sites. The high proportion of biomass in the fuel contributed to elevated levels of alkali and alkaline-earth material in the ash when compared to coal ash, and these higher levels provided more opportunity for sulfate formation. Based on laboratory tests, neither catalyst material nor ammonia contributed measurably to ash mass gains via sulfation. A model constructed using both field and laboratory data was able to predict catalyst deactivation of catalysts under subbituminous coal firing but performed poorly at predicting catalyst deactivation under cofiring conditions. Because of the typically higher-than coal levels of alkali and alkaline-earth elements present in biomass fuels that are available for sulfation at typical SCR temperatures, the use of SCR technology and biomass cofiring needs to be carefully evaluated prior to implementation.
Date: August 31, 2006
Creator: Folkedahl, Bruce C.; Zygarlicke, Christopher J.; Strege, Joshua R.; McCollor, Donald P.; Laumb, Jason D. & Kong, Lingbu
Partner: UNT Libraries Government Documents Department

EERC Center for Biomass Utilization 2006

Description: The Center for Biomass Utilization (CBU®) 2006 project at the Energy & Environmental Research Center (EERC) consisted of three tasks related to applied fundamental research focused on converting biomass feedstocks to energy, liquid transportation fuels, and chemicals. Task 1, entitled Thermochemical Conversion of Biomass to Syngas and Chemical Feedstocks, involved three activities. Task 2, entitled Crop Oil Biorefinery Process Development, involved four activities. Task 3, entitled Management, Education, and Outreach, focused on overall project management and providing educational outreach related to biomass technologies through workshops and conferences.
Date: May 27, 2009
Creator: Zygarlicke, Christopher J.; Hurley, John P.; Aulich, Ted R.; Folkedahl, Bruce C.; Strege, Joshua R.; Patel, Nikhil et al.
Partner: UNT Libraries Government Documents Department