Brekke, DW
1994
Inorganic Phase Characterization of Coal Combustion Products Using Advanced SEM Techniques
Folkedahl, B.C.; Steadman, E.N.; Brekke, D.W. and Zygarlicke, C.J.
The Impact of Ash Deposition on Coal-Fired Plants, Taylor & Francis, Inc., 1994. Funded by US Department of Energy, Brigham Young University, Electric Power Research Institute, Dow, Texaco and Shell.
Scanning electron microscopy/electron microprobe analysis (SEM/EMPA) techniques can quantify the inorganic phases present in complex coal combustion materials, as well as provide information on the morphology of the sample. Recent advancements in SEM instrumentation, data manipulation, and automated image analysis techniques have made the routine analysis of a large number of samples and data points possible. The scanning electron microscopy point count (SEMPC) routine, developed at the Energy & Environmental Research Center (EERC), randomly selects a statistically valid number of points and analyzes them for chemistry. This routine also allows for the concurrent storage of digitized images and the measurement of sample porosity. A mineral classification of the chemical point data is determined using a new data manipulation program, MINCLASS©. This new program uses carbon and oxygen region of interest (ROI) x-ray counts to differentiate between oxides and metals as well as sulfates and sulfides. A user-friendly graphical user interface (GUI) to execute under Windows© has been implemented, which makes the application very easy to learn and use. The GUI allows the user to easily select data sets that may be used to define and classify the chemistries of raw data. Mineral definition data sets have been developed for several types of samples, including coal combustion and gasification. Users may also enter their own mineral definitions for the program to use in the classification of Materials into mineral phases. In conjunction with this new program. MINCLASS©, a viscosity calculation program, VISCALC©, can be used to determine viscosity of silicate materials. This viscosity model will produce visual displays of viscosity distributions. The viscosity calculation also associates a viscosity value with each analysis point in a file. The user can retrieve a stored image and inspect the morphology of the area surrounding each point and relate it to the calculated viscosity. The measurement of porosity, calculation of viscosity, and determination of mineral-phase distribution for a sample are great assets in the characterization and determination of strength development in coal combustion deposits and by-products. The association of chemistry, mineralogy, and morphology is realized, utilizing the SEMPC technique developed at the EERC.
New Analysis Techniques Help Control Boiler Fouling
Karner, F.R.; Zygarlicke, C.J.; Brekke, D.W.; Steadman, E.N. and Benson, S.A.
Power Engineering, 98:35-38, 1994. Funded by US Department of Energy, Brigham Young University and Electric Power Research Institute.
Severe boiler fouling can be controlled. But, it demands a thorough understanding of how minor changes in the chemical and physical properties of coal and ash and operating conditions can cause hardened deposits. Traditional analytical techniques have helped reveal some of these mechanisms in the past, but limitations inherent to the analysis left many questions unanswered.
Now, however, scanning electron microscopy and electron microprobe analysis (SEM/EMPA) provide researchers with the analytical tools necessary to truly understand deposit formation mechanisms. These new techniques are exposing the size, shape, and chemistry of the myriad individual ash particles formed when coal burns. This and other data can be used to predict combustion behavior and its impact on ash deposition, waterwall slagging, and other steam tube deposits.
Microanalysis is capable of helping operators to identify more efficient and cost effective corrective measures as well. Recognized control methods (i.e., soot-blowing or plant capacity reductions) are often expensive and ineffective. The same is true for trial and error operating changes. Logic dictates analyzing coal and ash deposits first and then modifying operating procedures accordingly; SEM/EMPA facilitates the process.
Brekke, DW
1994
Inorganic Phase Characterization of Coal Combustion Products Using Advanced SEM Techniques
Folkedahl, B.C.; Steadman, E.N.; Brekke, D.W. and Zygarlicke, C.J.
The Impact of Ash Deposition on Coal-Fired Plants, Taylor & Francis, Inc., 1994. Funded by US Department of Energy, Brigham Young University, Electric Power Research Institute, Dow, Texaco and Shell.
Scanning electron microscopy/electron microprobe analysis (SEM/EMPA) techniques can quantify the inorganic phases present in complex coal combustion materials, as well as provide information on the morphology of the sample. Recent advancements in SEM instrumentation, data manipulation, and automated image analysis techniques have made the routine analysis of a large number of samples and data points possible. The scanning electron microscopy point count (SEMPC) routine, developed at the Energy & Environmental Research Center (EERC), randomly selects a statistically valid number of points and analyzes them for chemistry. This routine also allows for the concurrent storage of digitized images and the measurement of sample porosity. A mineral classification of the chemical point data is determined using a new data manipulation program, MINCLASS©. This new program uses carbon and oxygen region of interest (ROI) x-ray counts to differentiate between oxides and metals as well as sulfates and sulfides. A user-friendly graphical user interface (GUI) to execute under Windows© has been implemented, which makes the application very easy to learn and use. The GUI allows the user to easily select data sets that may be used to define and classify the chemistries of raw data. Mineral definition data sets have been developed for several types of samples, including coal combustion and gasification. Users may also enter their own mineral definitions for the program to use in the classification of Materials into mineral phases. In conjunction with this new program. MINCLASS©, a viscosity calculation program, VISCALC©, can be used to determine viscosity of silicate materials. This viscosity model will produce visual displays of viscosity distributions. The viscosity calculation also associates a viscosity value with each analysis point in a file. The user can retrieve a stored image and inspect the morphology of the area surrounding each point and relate it to the calculated viscosity. The measurement of porosity, calculation of viscosity, and determination of mineral-phase distribution for a sample are great assets in the characterization and determination of strength development in coal combustion deposits and by-products. The association of chemistry, mineralogy, and morphology is realized, utilizing the SEMPC technique developed at the EERC.
New Analysis Techniques Help Control Boiler Fouling
Karner, F.R.; Zygarlicke, C.J.; Brekke, D.W.; Steadman, E.N. and Benson, S.A.
Power Engineering, 98:35-38, 1994. Funded by US Department of Energy, Brigham Young University and Electric Power Research Institute.
Severe boiler fouling can be controlled. But, it demands a thorough understanding of how minor changes in the chemical and physical properties of coal and ash and operating conditions can cause hardened deposits. Traditional analytical techniques have helped reveal some of these mechanisms in the past, but limitations inherent to the analysis left many questions unanswered.
Now, however, scanning electron microscopy and electron microprobe analysis (SEM/EMPA) provide researchers with the analytical tools necessary to truly understand deposit formation mechanisms. These new techniques are exposing the size, shape, and chemistry of the myriad individual ash particles formed when coal burns. This and other data can be used to predict combustion behavior and its impact on ash deposition, waterwall slagging, and other steam tube deposits.
Microanalysis is capable of helping operators to identify more efficient and cost effective corrective measures as well. Recognized control methods (i.e., soot-blowing or plant capacity reductions) are often expensive and ineffective. The same is true for trial and error operating changes. Logic dictates analyzing coal and ash deposits first and then modifying operating procedures accordingly; SEM/EMPA facilitates the process.