Leger, CB
1992
The Desorption of Toluene from a Montmorillonite Clay Adsorbent in a Rotary Kiln Environment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing, D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Journal of Air Waste Management Assoc., 42:681-690, 1992. Funded by US Environmental Protection Agency, Gas Research Institute and ACERC.
The vaporization of toluene from pre-dried, 6mm montmorillonite clay particles was studied in a 130 kW pilot-scale rotary kiln with inside dimensions of 0.61 by 0.61 meters. Vaporization rates were obtained with a toluene weight fraction of 0.25 percent as a function of kiln fill fractions from 3 to 8 percent, rotation rates from 0.1 to 0.9 rpm, and kiln wall temperatures from 189 to 793ºC. Toluene desorption rates were obtained from gas-phase measurements and interpreted using a desorption model that incorporates the slumping frequency of the solids. Fill fraction of the kiln, binary gas diffusion in the bed, and particle desorption using an Arrhenius-type expression that is a function of bed temperature and average bed concentration. The model included three adjustable desorption parameters which were obtained by fitting the experimental data with a least squares technique. Solid and kiln-wall temperatures were continuously recorded and used by the model to perform toluene desorption predictions. The model was successful at predicting the effects of fill fraction and rotation rate over a range of temperatures. It was shown that an increase in kiln temperature and rotation rate increased toluene desorption rates. A decrease in kiln fill fraction showed an increase n desorption rate. Desorption predictions were performed using both predicted and measured temperature profiles. In addition, the model was used to perform sensitivity tests examine the relative importance of bed diffusion and particle desorption resistances. A methodology for predicting full-scale performance was developed. A full-scale, rotary-kiln heat-transfer model was used to estimate the bed thermal profile. This profile was then utilized by the model tp predict toluene desorption at full-scale.
1991
Rotary Kiln Incineration: Comparison and Scaling of Field-Scale Contaminant Evolution Rates from Sorbent Beds
Lester, T.W.; Cundy, V.A.; Sterling, A.M.; Montestruc, A.N.; Jakway, A.J.; Lu, C.; Leger, C.B.; Pershing D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Environmental Science Technology, 25:1142-1152, 1991. Funded by Environmental Protection Agency, Louisiana State University/Hazardous Waste Research Center and ACERC.
A comparison is made, for the first time, between the evolution of hydrocarbons from clay sorbent beds in a field-scale rotary kiln incinerator and in a pilot-scale rotary kiln simulator. To relate the data from the different sized units, due allowance is made for bed dynamical similitude, bed geometrical factors, and bed heat-up. To minimize the effects of disturbances caused by foreign matter in the field scale bed and differences in loading techniques, the rate of evolution is characterized by an "evolution interval" defined as the time required for the middle 80% of the ultimate containment evolution to occur. A comparison of evolution intervals with reciprocal bed temperature reveals that the data are consistent with an analysis that assumes a uniform bed temperature (at any instant of time) and desorption controlled evolution rate. Furthermore, the evolution intervals scale inversely with a modified Froude Number, which characterizes bed dynamics. The success in comparing field and simulator results indicates that pilot scale rotary kilns may be used to simulate certain features of industrial-scale units if dynamical, geometrical and thermal parameters are matched appropriately.
Thermal Analysis of Rotary Kiln Incineration: Comparison of Theory and Experiment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Combustion and Flame, 86:101-114, 1991. Funded by Gas Research Institute, ACERC and Louisiana State University/Hazardous Waste Research Center.
A comprehensive heat-transfer model and associated simplified scaling laws are developed and verified using a pilot-scale, directly fired rotary kiln with a slumping bed of dry or wet, 6-mm clay sorbent particles. The kiln operating conditions examined include: rotation rate (0.1 to 0.9 rpm), percent fill fraction (3-8), feed moisture content (0-20 wt.%), and inner-wall temperature (190º to 790ºC). The model is used to determine the relative importance of several heat-transfer mechanisms including radiation, gas-to-solid convection, and wall-to-solid convection. Simple scaling laws are also developed for water vaporization. Generally good agreement is obtained between theory and experiment without adjusting any model parameters. Further, the simplified scaling laws provide a reasonable estimate of the pilot scale performance. The key conclusions of this study for kilns at the conditions examined are (1) water exerts a profound effect on the solids thermal profile, (2) simple geometrical scaling is not sufficient, (3) the assumption of a well mixed (radially isothermal) solids bed for the heat transfer analysis is appropriate, (4) a dimensionless group, which is a function of temperature, can be defined giving the relative importance of radiative and convective modes of heat transfer, and (5) moisture vaporization rates can be roughly approximated by assuming that the water vaporizes at the boiling point at a rate controlled by the rate of heat transfer to the bed. The implications of the scaling laws for scale-up and kiln design are also examined.
1990
Rotary Kiln Incineration: Comparison of Field and Pilot Scale Measurements of Contaminant Evolution Rates from Sorbent Beds
Lester, T.W.; Cundy, V.A.; Sterling, A.M.; Montestruc, A.N.; Jakway, A.J.; Leger, C.B.; Pershing D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Environmental Science Technology, 1990. Funded by Environmental Protection Agency and Louisiana State University Hazardous Waste Research Center.
A comparison is made, for the first time, between the evolution of hydrocarbons from sorbent beds in an industrial rotary kiln incinerator and in a laboratory scale rotary kiln simulator. To relate the data from the different sized units, due allowance is made for bed dynamical similitude, bed geometrical factors, and bed heat-up. To minimize the effects of disturbances caused by foreign matter in the full scale bed and differences in loading techniques, the rate of evolution is characterized by an "evolution interval," that is defined as the time required for total hydrocarbon evolution at the maximum evolution rate. A comparison of evolution intervals with reciprocal bed temperature reveals that the data are consistent with an analysis that assumes a uniform bed temperature (at any instant of time) and desorption control of the evolution rate. Furthermore, the evolution intervals scale inversely with modified Froude Number, which characterizes bed dynamics. The success in comparing field and simulator results indicates that pilot scale rotary kilns may be used to simulate certain features of industrial scale units if appropriate care is taken in matching dynamical, geometrical and thermal parameters.
Thermal Analysis of Rotary Kiln Incineration: Comparison of Theory and Experiment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Combustion and Flame, 1990. Funded by Gas Research Institute, ACERC and Louisiana State University Hazardous Waste Research Center.
A comprehensive heat-transfer model and associated simplified scaling laws are developed and verified using a pilot-scale, directly-fired rotary kiln with a slumping bed of dry or wet, 2 mm clay sorbent particles. The kiln operating conditions examined include: rotation rate (0.1 to 0.9 rpm), percent fill fraction (3 to 8), feed moisture content (0 to 20 wt. percent), and inner-wall temperature (190 to 790º). The model is used to determine the relative importance of several heat-transfer mechanisms including radiation, gas-to-solid convection, and wall-to-solid convection. Simple scaling laws are also developed for water vaporization. Generally good agreement is obtained between theory and experiment without adjusting any model parameters. Further, the simplified scaling laws provide a reasonable estimate of the pilot scale performance.
The key conclusions of this study for kilns at the conditions examined are: (1) water exerts a profound effect on the solids thermal profile, (2) simple geometrical scaling is not sufficient, (3) the assumption of a well mixed (radially isothermal) solids bed for the heat transfer analysis is appropriate, (4) a dimensionless group, which is a function of temperature, can be defined giving the relative importance of radiative and convective modes of heat transfer, and (5) moisture vaporization rates can be roughly approximated by assuming that the water vaporized at the boiling point at a rate controlled by the rate of heat transfer to the bed. The implications of the scaling laws for scale-up and kiln design are also examined.
1989
Rotary Kiln Incineration--Combustion Chamber Dynamics
Cundy, V.A.; Lester, T.W.; Leger, C.B.; Miller, G.; Montestruc, A.N.; Acharya, S.; Sterling, A.M.; Pershing, D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Journal of Hazardous Materials, 22, 195-219,1989. Funded by US Environmental Proctection Agency and ACERC (National Science Foundation and Associates and Affiliates).
A multifaceted experimental and theoretical program aimed at understanding rotary kiln performance is underway. The overall program involves university, industry, and government participation and is broken into distinct sub-programs. This paper discusses in some detail the research effort performed to date in two of the sub-programs: Full-scale in situ sampling and kiln-simulator experimentation. Full-scale in situ measurements are obtained from the Louisiana Division rotary kiln facility of Dow Chemical USA, located in Plaquemine, Louisiana. Summary results obtained from controlled experiments that were performed during continuous processing of carbon tetrachloride and preliminary results obtained during batch mode processing of toluene-laden sorbent packs are presented. Kiln-simulator data are obtained by using the facilities of the Chemical Engineering Department at the University of Utah. Recent kiln-simulator work, conducted in support of the full-scale measurements sub-program, has aided in providing an understanding of the results that have been obtained at the full-scale. Modeling efforts, conducted at Louisiana State University and the University of Utah, have concentrated on the development of realistic, fluid-flow and heat-transfer models, near-term chlorinated kinetic models and bed mass-transfer models to be incorporated into a global three-dimensional kiln-simulator model. The paper concludes with an overview of these modeling efforts.
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
1st International Congress on Toxic Combustion, 1989. Funded by Remediation Technologies, the Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (CG/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1 meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MSn (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for naphthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
An In-Depth Study of Incineration - Rotary Kiln Performance Characterization
Cundy, V.A.; Lester, T.W.; Conway, L.R.; Jakway, A.J.; Leger, C.B.; Montestruc, A.N.; Acharya, S.; Sterling, A.M.; Owens, W.D.; Lighty, J.S.; Pershing, D.W. and Silcox, G.D.
Louisiana State University/Hazardous Waste Research Center SAC Review Meeting, Baton Rouge, Louisiana, 1989. Funded by Louisiana State University/Hazardous Waste Research Center (Supported by US Environmental Protection Agency).
A comprehensive study aimed at understanding rotary kiln performance is underway. The program is led by personnel from Louisiana State University. Bench and pilot-scale facilities at the University of Utah are available for use in solids desorption studies. Full-scale in situ measurements are obtained from the Louisiana Division rotary kiln facility of Dow Chemical USA, located in Plaquemine, Louisiana. This paper presents a summary of the project providing some detail of the work that has been accomplished from 1 January through 31 August 1989.
1988
Rotary Kiln Incineration I: An In-Depth Study - Liquid Injection
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 39 pgs. Funded by Environmental Protection Agency.
A multifaceted experimental and theoretical program directed toward the understanding of rotary kiln performance is underway. Following a general overview of the program, we describe in more detail the program components including: In-situ measurements from an industrial-scale rotary kiln located at the Louisiana Division of Dow Chemical USA in Plaquemine, Louisiana; laboratory-scale desorption characterization and kiln-simulator studies; and incinerator modeling efforts. Using water-cooled probes, hot-zone samples have been obtained from both the full-scale rotary kiln and the afterburner and have been analyzed subsequently using GC and/or GC/MS techniques. We report on these preliminary measurements in some detail.
Rotary Kiln Incineration II: Laboratory Scale Desorption and Kiln Simulator Studies - Solids
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 28 pgs. Funded by Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), and National Science Foundation/Presidential Young Investigators.
With landfill costs increasing and regulations on landfilling becoming more stringent, alternatives to conventional hazardous waste treatment strategies are becoming more desirable. Incineration is presently a permanent, proven solution for the disposal of most organic contaminants, but also a costly one, especially in the case of solids that require some auxiliary fuel. The goal of this research is to develop an understanding of the phenomena associated with the evolution of contaminants from solids in the primary combustor of an incineration system. A four-fold approach is being used. First, a bench scale Particle Characterization Reactor was developed to study the transport phenomena on a particle basis, where the controlling processes are mainly intraparticle. Second, a Bed Characterization Reactor was built to examine the controlling transport phenomena within a bed of particles, where the processes are primarily interparticle. The results of these studies can be applied to any primary combustor. A pilot-scale rotary kiln was developed to study the evolution of contaminants from solids within a realistic temperature and rotation environment. Finally, in-situ measurements are being obtained from a full-scale rotary-kiln.
This paper describes results obtained in a study using a commercial sorbent contaminated with toluene. The data are from the Particle Characterization Reactor and the Rotary-Kiln Simulator. The results show that the method of contamination and charge size does not have a large effect on desorption, while temperature and contaminant concentration are important parameters in the evolution of contaminants in a rotary kiln.
Rotary Kiln Incineration III: An In-depth Study - Full-Scale Incineration of Carbon Tetrachloride
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 31 pgs. Funded by Environmental Protection Agency.
Temperature and stable species concentration data are presented from various locations within a full-scale rotary kiln firing natural gas/carbon tetrachloride/air. The data are being collected as part of a cooperative program involving university, industrial and government participation. The overall goal of the program is to develop a rudimentary understanding of and a predictive capability for rotary kiln and afterburner performance as influenced by basic design and operation parameters. The data clearly demonstrates that severe non-uniformities exist at the kiln exit under certain operating conditions. Even so, the data further indicate that high destruction efficiencies were achieved through adequate secondary combustion processing. The data further show that flow perturbations from within the kiln can persist well into the afterburner section and even into the stack.
Leger, CB
1992
The Desorption of Toluene from a Montmorillonite Clay Adsorbent in a Rotary Kiln Environment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing, D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Journal of Air Waste Management Assoc., 42:681-690, 1992. Funded by US Environmental Protection Agency, Gas Research Institute and ACERC.
The vaporization of toluene from pre-dried, 6mm montmorillonite clay particles was studied in a 130 kW pilot-scale rotary kiln with inside dimensions of 0.61 by 0.61 meters. Vaporization rates were obtained with a toluene weight fraction of 0.25 percent as a function of kiln fill fractions from 3 to 8 percent, rotation rates from 0.1 to 0.9 rpm, and kiln wall temperatures from 189 to 793ºC. Toluene desorption rates were obtained from gas-phase measurements and interpreted using a desorption model that incorporates the slumping frequency of the solids. Fill fraction of the kiln, binary gas diffusion in the bed, and particle desorption using an Arrhenius-type expression that is a function of bed temperature and average bed concentration. The model included three adjustable desorption parameters which were obtained by fitting the experimental data with a least squares technique. Solid and kiln-wall temperatures were continuously recorded and used by the model to perform toluene desorption predictions. The model was successful at predicting the effects of fill fraction and rotation rate over a range of temperatures. It was shown that an increase in kiln temperature and rotation rate increased toluene desorption rates. A decrease in kiln fill fraction showed an increase n desorption rate. Desorption predictions were performed using both predicted and measured temperature profiles. In addition, the model was used to perform sensitivity tests examine the relative importance of bed diffusion and particle desorption resistances. A methodology for predicting full-scale performance was developed. A full-scale, rotary-kiln heat-transfer model was used to estimate the bed thermal profile. This profile was then utilized by the model tp predict toluene desorption at full-scale.
1991
Rotary Kiln Incineration: Comparison and Scaling of Field-Scale Contaminant Evolution Rates from Sorbent Beds
Lester, T.W.; Cundy, V.A.; Sterling, A.M.; Montestruc, A.N.; Jakway, A.J.; Lu, C.; Leger, C.B.; Pershing D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Environmental Science Technology, 25:1142-1152, 1991. Funded by Environmental Protection Agency, Louisiana State University/Hazardous Waste Research Center and ACERC.
A comparison is made, for the first time, between the evolution of hydrocarbons from clay sorbent beds in a field-scale rotary kiln incinerator and in a pilot-scale rotary kiln simulator. To relate the data from the different sized units, due allowance is made for bed dynamical similitude, bed geometrical factors, and bed heat-up. To minimize the effects of disturbances caused by foreign matter in the field scale bed and differences in loading techniques, the rate of evolution is characterized by an "evolution interval" defined as the time required for the middle 80% of the ultimate containment evolution to occur. A comparison of evolution intervals with reciprocal bed temperature reveals that the data are consistent with an analysis that assumes a uniform bed temperature (at any instant of time) and desorption controlled evolution rate. Furthermore, the evolution intervals scale inversely with a modified Froude Number, which characterizes bed dynamics. The success in comparing field and simulator results indicates that pilot scale rotary kilns may be used to simulate certain features of industrial-scale units if dynamical, geometrical and thermal parameters are matched appropriately.
Thermal Analysis of Rotary Kiln Incineration: Comparison of Theory and Experiment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Combustion and Flame, 86:101-114, 1991. Funded by Gas Research Institute, ACERC and Louisiana State University/Hazardous Waste Research Center.
A comprehensive heat-transfer model and associated simplified scaling laws are developed and verified using a pilot-scale, directly fired rotary kiln with a slumping bed of dry or wet, 6-mm clay sorbent particles. The kiln operating conditions examined include: rotation rate (0.1 to 0.9 rpm), percent fill fraction (3-8), feed moisture content (0-20 wt.%), and inner-wall temperature (190º to 790ºC). The model is used to determine the relative importance of several heat-transfer mechanisms including radiation, gas-to-solid convection, and wall-to-solid convection. Simple scaling laws are also developed for water vaporization. Generally good agreement is obtained between theory and experiment without adjusting any model parameters. Further, the simplified scaling laws provide a reasonable estimate of the pilot scale performance. The key conclusions of this study for kilns at the conditions examined are (1) water exerts a profound effect on the solids thermal profile, (2) simple geometrical scaling is not sufficient, (3) the assumption of a well mixed (radially isothermal) solids bed for the heat transfer analysis is appropriate, (4) a dimensionless group, which is a function of temperature, can be defined giving the relative importance of radiative and convective modes of heat transfer, and (5) moisture vaporization rates can be roughly approximated by assuming that the water vaporizes at the boiling point at a rate controlled by the rate of heat transfer to the bed. The implications of the scaling laws for scale-up and kiln design are also examined.
1990
Rotary Kiln Incineration: Comparison of Field and Pilot Scale Measurements of Contaminant Evolution Rates from Sorbent Beds
Lester, T.W.; Cundy, V.A.; Sterling, A.M.; Montestruc, A.N.; Jakway, A.J.; Leger, C.B.; Pershing D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Environmental Science Technology, 1990. Funded by Environmental Protection Agency and Louisiana State University Hazardous Waste Research Center.
A comparison is made, for the first time, between the evolution of hydrocarbons from sorbent beds in an industrial rotary kiln incinerator and in a laboratory scale rotary kiln simulator. To relate the data from the different sized units, due allowance is made for bed dynamical similitude, bed geometrical factors, and bed heat-up. To minimize the effects of disturbances caused by foreign matter in the full scale bed and differences in loading techniques, the rate of evolution is characterized by an "evolution interval," that is defined as the time required for total hydrocarbon evolution at the maximum evolution rate. A comparison of evolution intervals with reciprocal bed temperature reveals that the data are consistent with an analysis that assumes a uniform bed temperature (at any instant of time) and desorption control of the evolution rate. Furthermore, the evolution intervals scale inversely with modified Froude Number, which characterizes bed dynamics. The success in comparing field and simulator results indicates that pilot scale rotary kilns may be used to simulate certain features of industrial scale units if appropriate care is taken in matching dynamical, geometrical and thermal parameters.
Thermal Analysis of Rotary Kiln Incineration: Comparison of Theory and Experiment
Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Deng, X.-X.; Pershing D.W.; Cundy, V.A.; Leger, C.B. and Jakway, A.J.
Combustion and Flame, 1990. Funded by Gas Research Institute, ACERC and Louisiana State University Hazardous Waste Research Center.
A comprehensive heat-transfer model and associated simplified scaling laws are developed and verified using a pilot-scale, directly-fired rotary kiln with a slumping bed of dry or wet, 2 mm clay sorbent particles. The kiln operating conditions examined include: rotation rate (0.1 to 0.9 rpm), percent fill fraction (3 to 8), feed moisture content (0 to 20 wt. percent), and inner-wall temperature (190 to 790º). The model is used to determine the relative importance of several heat-transfer mechanisms including radiation, gas-to-solid convection, and wall-to-solid convection. Simple scaling laws are also developed for water vaporization. Generally good agreement is obtained between theory and experiment without adjusting any model parameters. Further, the simplified scaling laws provide a reasonable estimate of the pilot scale performance.
The key conclusions of this study for kilns at the conditions examined are: (1) water exerts a profound effect on the solids thermal profile, (2) simple geometrical scaling is not sufficient, (3) the assumption of a well mixed (radially isothermal) solids bed for the heat transfer analysis is appropriate, (4) a dimensionless group, which is a function of temperature, can be defined giving the relative importance of radiative and convective modes of heat transfer, and (5) moisture vaporization rates can be roughly approximated by assuming that the water vaporized at the boiling point at a rate controlled by the rate of heat transfer to the bed. The implications of the scaling laws for scale-up and kiln design are also examined.
1989
Rotary Kiln Incineration--Combustion Chamber Dynamics
Cundy, V.A.; Lester, T.W.; Leger, C.B.; Miller, G.; Montestruc, A.N.; Acharya, S.; Sterling, A.M.; Pershing, D.W.; Lighty, J.S.; Silcox, G.D. and Owens, W.D.
Journal of Hazardous Materials, 22, 195-219,1989. Funded by US Environmental Proctection Agency and ACERC (National Science Foundation and Associates and Affiliates).
A multifaceted experimental and theoretical program aimed at understanding rotary kiln performance is underway. The overall program involves university, industry, and government participation and is broken into distinct sub-programs. This paper discusses in some detail the research effort performed to date in two of the sub-programs: Full-scale in situ sampling and kiln-simulator experimentation. Full-scale in situ measurements are obtained from the Louisiana Division rotary kiln facility of Dow Chemical USA, located in Plaquemine, Louisiana. Summary results obtained from controlled experiments that were performed during continuous processing of carbon tetrachloride and preliminary results obtained during batch mode processing of toluene-laden sorbent packs are presented. Kiln-simulator data are obtained by using the facilities of the Chemical Engineering Department at the University of Utah. Recent kiln-simulator work, conducted in support of the full-scale measurements sub-program, has aided in providing an understanding of the results that have been obtained at the full-scale. Modeling efforts, conducted at Louisiana State University and the University of Utah, have concentrated on the development of realistic, fluid-flow and heat-transfer models, near-term chlorinated kinetic models and bed mass-transfer models to be incorporated into a global three-dimensional kiln-simulator model. The paper concludes with an overview of these modeling efforts.
Fast, Repetitive GC/MS Analysis of Thermally Desorbed Polycyclic Aromatic Hydrocarbons (PAHs) from Contaminated Soils
McClennen, W.H.; Arnold, N.S.; Roberts, K.A.; Meuzelaar, H.L.C.; Lighty, J.S. and Lindgren, E.R.
1st International Congress on Toxic Combustion, 1989. Funded by Remediation Technologies, the Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A system for on-line analysis of organic vapors by short column gas chromatography/mass spectrometry (CG/MS) has been used to monitor products from a thermal soil desorption reactor. The system consists of a unique air-sampling inlet with a 1 meter long capillary column coupled directly to a modified Ion Trap Mass Spectrometer (Finnigan MAT) with demonstrated detection limits for alkylbenzenes in the low ppb range. In this work the mobile instrument is used for repetitive GC/MS and GC/MSn (tandem MS) analysis at 30 to 60 sec intervals of PAH products from coal tar contaminated soils in a bed characterization reactor.
Results for naphthalene through dibenzanthracenes are compared to conventional, more detailed GC/MS analyses of extracts from the soil before and after thermal treatment.
An In-Depth Study of Incineration - Rotary Kiln Performance Characterization
Cundy, V.A.; Lester, T.W.; Conway, L.R.; Jakway, A.J.; Leger, C.B.; Montestruc, A.N.; Acharya, S.; Sterling, A.M.; Owens, W.D.; Lighty, J.S.; Pershing, D.W. and Silcox, G.D.
Louisiana State University/Hazardous Waste Research Center SAC Review Meeting, Baton Rouge, Louisiana, 1989. Funded by Louisiana State University/Hazardous Waste Research Center (Supported by US Environmental Protection Agency).
A comprehensive study aimed at understanding rotary kiln performance is underway. The program is led by personnel from Louisiana State University. Bench and pilot-scale facilities at the University of Utah are available for use in solids desorption studies. Full-scale in situ measurements are obtained from the Louisiana Division rotary kiln facility of Dow Chemical USA, located in Plaquemine, Louisiana. This paper presents a summary of the project providing some detail of the work that has been accomplished from 1 January through 31 August 1989.
1988
Rotary Kiln Incineration I: An In-Depth Study - Liquid Injection
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 39 pgs. Funded by Environmental Protection Agency.
A multifaceted experimental and theoretical program directed toward the understanding of rotary kiln performance is underway. Following a general overview of the program, we describe in more detail the program components including: In-situ measurements from an industrial-scale rotary kiln located at the Louisiana Division of Dow Chemical USA in Plaquemine, Louisiana; laboratory-scale desorption characterization and kiln-simulator studies; and incinerator modeling efforts. Using water-cooled probes, hot-zone samples have been obtained from both the full-scale rotary kiln and the afterburner and have been analyzed subsequently using GC and/or GC/MS techniques. We report on these preliminary measurements in some detail.
Rotary Kiln Incineration II: Laboratory Scale Desorption and Kiln Simulator Studies - Solids
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 28 pgs. Funded by Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), and National Science Foundation/Presidential Young Investigators.
With landfill costs increasing and regulations on landfilling becoming more stringent, alternatives to conventional hazardous waste treatment strategies are becoming more desirable. Incineration is presently a permanent, proven solution for the disposal of most organic contaminants, but also a costly one, especially in the case of solids that require some auxiliary fuel. The goal of this research is to develop an understanding of the phenomena associated with the evolution of contaminants from solids in the primary combustor of an incineration system. A four-fold approach is being used. First, a bench scale Particle Characterization Reactor was developed to study the transport phenomena on a particle basis, where the controlling processes are mainly intraparticle. Second, a Bed Characterization Reactor was built to examine the controlling transport phenomena within a bed of particles, where the processes are primarily interparticle. The results of these studies can be applied to any primary combustor. A pilot-scale rotary kiln was developed to study the evolution of contaminants from solids within a realistic temperature and rotation environment. Finally, in-situ measurements are being obtained from a full-scale rotary-kiln.
This paper describes results obtained in a study using a commercial sorbent contaminated with toluene. The data are from the Particle Characterization Reactor and the Rotary-Kiln Simulator. The results show that the method of contamination and charge size does not have a large effect on desorption, while temperature and contaminant concentration are important parameters in the evolution of contaminants in a rotary kiln.
Rotary Kiln Incineration III: An In-depth Study - Full-Scale Incineration of Carbon Tetrachloride
Cundy, V.A.; Lester, T.W.; Morse, J.S.; Montestruc, A.N.; Leger, C.B.; Acharya, S.; Sterling, A.M. and Pershing, D.W.
Submitted to Journal of the Air Pollution Control Association, 1988. 31 pgs. Funded by Environmental Protection Agency.
Temperature and stable species concentration data are presented from various locations within a full-scale rotary kiln firing natural gas/carbon tetrachloride/air. The data are being collected as part of a cooperative program involving university, industrial and government participation. The overall goal of the program is to develop a rudimentary understanding of and a predictive capability for rotary kiln and afterburner performance as influenced by basic design and operation parameters. The data clearly demonstrates that severe non-uniformities exist at the kiln exit under certain operating conditions. Even so, the data further indicate that high destruction efficiencies were achieved through adequate secondary combustion processing. The data further show that flow perturbations from within the kiln can persist well into the afterburner section and even into the stack.