Rigby, JR
2000
Transformations of Coal-Derived Soot at Elevated Temperature
Rigby, J.R.; Ma, J.; Webb, B.W. and Fletcher, T.H.
Accepted for publication in Energy & Fuels (2000).
Contact: Webb
1998
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Prog. Energy Combust. Sci., 24:355-83 (1998).
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2-0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-colored temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NO2, O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most, but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and is described in detail in Section 3 of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Sprectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1997
Soot in Coal Combustion Systems
Fletcher, T.H.; Ma, J.; Rigby, J.R.; Brown, A.L. and Webb, B.W.
Prog. Energy Combust. Sci., 23:283-301(1997). Funded by ACERC.
Soot is generated from coal when volatile matter, tar in particular, undergoes secondary reactions at high temperatures. A description of soot in coal flames allows better calculations of radiative transfer and temperatures in near-burner regions, which in turn allows more accurate predictions of NOx formation in coal-fired furnaces. Experiments are reviewed that examine the formation, agglomeration and properties of coal-derived soot, including pyrolysis experiments and combustion experiments. This review includes the types of experiments performed, the soot yields obtained, the size of the soot particles and agglomerates, the optical properties of soot, the relationship between coal-derived soot and soot form simple hydrocarbons, and attempts to model soot in coal flames.
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Progress in Energy and Combustion Science, (in press), 1997. Funded by ACERC.
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2 -0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-cloud temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NOx O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and id described in detail in Section II of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Spectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1996
Measurements of the Optical Properties of Coal-Derived and Propane-Derived Soot in a Flat Flame Reactor
Rigby, J.R.; Webb, B.W. and Fletcher, T.H.
Proceedings of the Spring Meeting of the Western States Section of the Combustion Institute, Tempe, Arizona, March 11-12, 1996. Funded by ACERC.
All hydrocarbon-based fuels have the potential to form soot during combustion of devolatilization reactions. Soot resulting from incomplete combustion is the main contributor to luminosity in flames. Because of its high surface area and spectrally continuous radiation, sot is a very efficient thermal radiator. The optical properties of coal-derived soot have not received as much attention as soot derived from gaseous hydrocarbon fuels. The reason for this neglect may be the difficulty in separating the radiation effects of the coal-derived soot, char and fly ash. The radiative properties of coal-derived soot have not been characterized, nor have the influences of coal type, volume fraction and morphology been examined. The radiative properties of coal-derived soot char can be sued in combustion modeling and burner design. In the near-burner region, the stoichiometry is very fuel rich providing for the high soot volume fraction and for large radiative heat fluxes being transmitted to the burners and walls. In this region, neglecting soot can result in inaccurate radiant flux predictions, as well as inaccurate predictions of gas temperatures, species concentrations, pressure fields, and velocity profiles. Radiative properties of soot can also be used to determine soot volume fraction and soot temperature in-situ.
Based on preliminary results from this study, trends for C-lambda from coal-derived and propane-derived differ as a function of residence time in the post flame environment, even though the ranges of magnitudes of C-lambda overlap. All measurements indicate an increase in C-lambda at increasing wavelengths. Further work is needed to examine these trends for different coal-derived soots. Explanations of why the optical properties of soot change and parameters to characterize these changes are also needed. This work provides the basis for futures in-situ measurements that will measure soot volume fraction in a coal pyrolysis experiment.
Rigby, JR
2000
Transformations of Coal-Derived Soot at Elevated Temperature
Rigby, J.R.; Ma, J.; Webb, B.W. and Fletcher, T.H.
Accepted for publication in Energy & Fuels (2000).
Contact: Webb
1998
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Prog. Energy Combust. Sci., 24:355-83 (1998).
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2-0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-colored temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NO2, O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most, but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and is described in detail in Section 3 of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Sprectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1997
Soot in Coal Combustion Systems
Fletcher, T.H.; Ma, J.; Rigby, J.R.; Brown, A.L. and Webb, B.W.
Prog. Energy Combust. Sci., 23:283-301(1997). Funded by ACERC.
Soot is generated from coal when volatile matter, tar in particular, undergoes secondary reactions at high temperatures. A description of soot in coal flames allows better calculations of radiative transfer and temperatures in near-burner regions, which in turn allows more accurate predictions of NOx formation in coal-fired furnaces. Experiments are reviewed that examine the formation, agglomeration and properties of coal-derived soot, including pyrolysis experiments and combustion experiments. This review includes the types of experiments performed, the soot yields obtained, the size of the soot particles and agglomerates, the optical properties of soot, the relationship between coal-derived soot and soot form simple hydrocarbons, and attempts to model soot in coal flames.
Experimental Measurements in the Brigham Young University Controlled Profile Reactor
Tree, D.R.; Black, D.L.; Rigby, J.R.; McQuay, M.Q. and Webb, B.W.
Progress in Energy and Combustion Science, (in press), 1997. Funded by ACERC.
Energy conversion of fossil fuels or waste products to electricity and heat through clean and efficient combustion processes continues to be an issue of international importance. The Controlled Profile Reactor (CPR) is a small-scale (0.2 -0.4 MW) combustion facility that has been used to obtain data for model validation, the testing of new combustion concepts, and the development of new combustion instrumentation. The CPR has a cylindrical, down-fired combustion chamber, 240 cm long and 80 cm in diameter. This review of the past ten years of research completed in the CPR includes a description of the reactor and instrumentation used, a summary of three experimental data sets which have been obtained in the reactor, and a description of novel tests and instrumentation. Measurements obtained include gas species, gas temperature, particle velocity, particle size, particle number density, particle-cloud temperature profiles, radiation and total heat flux to the wall, and wall temperatures. Species data include the measurement of CO, CO2, NO, NOx O2, NH3 and HCN. The three combustion studies included one with natural gas combustion in a swirling flow, and two pulverized-coal combustion studies involving Utah Blind Canyon and Pittsburgh #8 coals. Most but not all of the above measurements were obtained in each study. The second coal study involving the Pittsburgh #8 coal contained the most complete set of data and id described in detail in Section II of the paper. Novel combustion instrumentation includes the use of Coherent Anti-Stokes Raman Spectroscopy (CARS) to measure gas temperature. Novel combustion experiments include the measurement of NOx and burnout with coal-char blends. The measurements have led to an improved understanding of the combustion process and an understanding of the strengths and weaknesses associated with different aspects of comprehensive combustion models.
1996
Measurements of the Optical Properties of Coal-Derived and Propane-Derived Soot in a Flat Flame Reactor
Rigby, J.R.; Webb, B.W. and Fletcher, T.H.
Proceedings of the Spring Meeting of the Western States Section of the Combustion Institute, Tempe, Arizona, March 11-12, 1996. Funded by ACERC.
All hydrocarbon-based fuels have the potential to form soot during combustion of devolatilization reactions. Soot resulting from incomplete combustion is the main contributor to luminosity in flames. Because of its high surface area and spectrally continuous radiation, sot is a very efficient thermal radiator. The optical properties of coal-derived soot have not received as much attention as soot derived from gaseous hydrocarbon fuels. The reason for this neglect may be the difficulty in separating the radiation effects of the coal-derived soot, char and fly ash. The radiative properties of coal-derived soot have not been characterized, nor have the influences of coal type, volume fraction and morphology been examined. The radiative properties of coal-derived soot char can be sued in combustion modeling and burner design. In the near-burner region, the stoichiometry is very fuel rich providing for the high soot volume fraction and for large radiative heat fluxes being transmitted to the burners and walls. In this region, neglecting soot can result in inaccurate radiant flux predictions, as well as inaccurate predictions of gas temperatures, species concentrations, pressure fields, and velocity profiles. Radiative properties of soot can also be used to determine soot volume fraction and soot temperature in-situ.
Based on preliminary results from this study, trends for C-lambda from coal-derived and propane-derived differ as a function of residence time in the post flame environment, even though the ranges of magnitudes of C-lambda overlap. All measurements indicate an increase in C-lambda at increasing wavelengths. Further work is needed to examine these trends for different coal-derived soots. Explanations of why the optical properties of soot change and parameters to characterize these changes are also needed. This work provides the basis for futures in-situ measurements that will measure soot volume fraction in a coal pyrolysis experiment.