Linz, DG
1990
Fundamentals for the Thermal Remediation of Contaminated Soils - Particle and Bed Desorption Models
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Environmental Science & Technology, 24 (5), 750-757, 1990. Funded by the Gas Research Institute, Dave Linz, Project Manager, NSF - Presidential Young Investigator Program, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A major research effort has been initiated to characterize the rate-controlling processes associated with the evolution of hazardous materials from soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants. Phenomena occurring both inside particles (intraparticle) and with a bed of particles (interparticle) were studied.
The results obtained suggest that the most important process variable are local thermal environment and gas-phase contaminant concentration because the adsorption equilibrium characteristics of the contaminant/soil pair control the desorption of contaminant from a particle at a given temperature. A mass-transfer/desorption model, which assumes gas/solid equilibrium at all points and time, is proposed and the model was found to predict the measured temperature dependence.
1989
Fundamental Experiments on Thermal Desorption of Contaminants from Soils
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Environmental Progress, 8 (1), 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, National Science Foundation - Presidential Young Investigator Program, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
The goals of this research are to develop an understanding of the transport phenomena that occur during the desorption of contaminants from soil and to obtain rate information. This information can then be used to develop a model to predict the performance of full-scale thermal treatment systems for optimization and cost reduction.
Fundamentals for the Thermal Remediation of Contaminated Soils - Particle and Bed Desorption Models
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Accepted for publication in Environ. Science Tech., 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, National Science Foundation/Presidential Young Investigators, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A major research effort has been initiated to characterize the rate-controlling processes associated with the evolution of hazardous materials from soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants. Phenomena occurring both inside particles (intraparticle) and with a bed of particles (interparticle) were studied.
The results obtained suggest that the most important process variables are local thermal environment and gas-phase contaminant concentration because the adsorption equilibrium characteristics of the contaminant/soil pair control the desorption of contaminant from a particle at a given temperature. A mass-transfer/desorption model, which assumes gas/solid equilibrium at all points and time, is proposed and the model was found to predict the measured temperature dependence.
1988-1987
Transport Fundamentals for the Thermal Remediation of Contaminated Soils
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Submitted for Review to AIChE Journal, 1988. 23 pgs. Funded by Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), and National Science Foundation/Presidential Young Investigators.
A major research effort has been initiated to characterize the transport phenomena associated with the evolution of hazardous materials from contaminated soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants from soils under a variety of experimental conditions. First, a particle-characterization reactor (PCR) is being employed to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Secondly, a packed-bed reactor is being used to examine interparticle transport within a bed of particles. In the third portion of the work, a 73 kW pilot-scale rotary kiln is providing time-resolved measurements of the species evolution. The results from the PCR experiments and modeling are reported in this manuscript.
The PCR experimental results obtained suggest that the most important process variable is local thermal environment and that the absorption characteristics of the contaminant/soil pair are important in the desorption process. The adsorption characteristics are a function of local temperature, thus accounting for the steep dependence of the cleanup efficiency of a soil on temperature. In addition, the adsorption characteristics are influenced by soil type and moisture; it has been found that these parameters also effect desorption of contaminants. A mass-transfer model, which assumes gas/solid equilibrium at all points and times, is proposed and the model predictions were found to exhibit temperature dependence similar to the data.
Characterization of Thermal Desorption Phenomena for the Clean-Up of Contaminated Soil
Lighty, J.S.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Accepted for Nuclear & Chemical Waste Management, 1987. 32 pgs. Funded by ACERC (National Science Foundation and Associates and Affiliates).
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils. An understanding of the mass transfer and heat transfer limitations might lead to a more economical option, where the contaminants are desorbed from the soil at lower temperatures in a primary combustor and then a secondary, high temperature combustor (afterburner) decomposes the hazardous off-gases. This work is aimed at providing fundamental rate information which will be used to model thermal desorption of contaminants from soils under a variety of thermal conditions, soil properties and contaminants.
The experimental approach is threefold. First, a bench scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed-bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73 kW pilot-scale rotary kiln will be used to obtain time resolved measurements of trace species evolution. This paper reports recent PCR results that indicate that soil properties, type of contaminant, and temperature are important in desorption of contaminants from soil particles.
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils and it may render the soil inert. A more economical option is to desorb the contaminants from the soil at lower temperatures and then use high temperature incineration to decompose the hazardous off-gases. This work is aimed at providing fundamental rate information which may be used to model the thermal desorption of contaminants from soils under a wide variety of thermal conditions.
The experimental approach is three-fold. First, a bench-scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73,000 Watt pilot-scale rotary kiln will be used to reports recent PCR and kiln results; it does not address the packed bed reactor studies since they are just being initiated. The PCR results indicate that soil pore structure is important in desorption of contaminants from soil particles and that the desorption/diffusion step is probably a controlling mechanism.
The Clean Up of Contaminated Soil By Thermal Desorption
Lighty, J.S.; Pershing, D.W.; Cundy, V.A.; Groves, F.R. Jr. and Linz, D.G.
Proc. 2nd Int. Conf. on New Frontiers in Hazardous Waste Management, 1987, NUS, Pittsburgh, PA. 10 pgs. Funded by Gas Research Institute, National Science Foundation, and ACERC (National Science Foundation and Associates and Affiliates).
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular, contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils and it may render the soil inert. A more economical option is to desorb the contaminants from the soil at lower temperatures and then use high temperature incineration to decompose the hazardous off-gases. This work is aimed at providing fundamental rate information which may be used to model the thermal desorption of contaminants from soils under a wide variety of thermal conditions.
The experimental approach is threefold First, a bench-scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73,000 Watt pilot-scale rotary kiln will be used to obtain time resolved measurements of trace species evolution. This paper reports recent PCR and kiln results; it does not address the packed bed reactor studies since they are just being initiated. The PCR results indicate that soil pore structure is important in desorption of contaminants from soil particles and that the desorption/diffusion step is probably a controlling mechanism.
Linz, DG
1990
Fundamentals for the Thermal Remediation of Contaminated Soils - Particle and Bed Desorption Models
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Environmental Science & Technology, 24 (5), 750-757, 1990. Funded by the Gas Research Institute, Dave Linz, Project Manager, NSF - Presidential Young Investigator Program, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A major research effort has been initiated to characterize the rate-controlling processes associated with the evolution of hazardous materials from soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants. Phenomena occurring both inside particles (intraparticle) and with a bed of particles (interparticle) were studied.
The results obtained suggest that the most important process variable are local thermal environment and gas-phase contaminant concentration because the adsorption equilibrium characteristics of the contaminant/soil pair control the desorption of contaminant from a particle at a given temperature. A mass-transfer/desorption model, which assumes gas/solid equilibrium at all points and time, is proposed and the model was found to predict the measured temperature dependence.
1989
Fundamental Experiments on Thermal Desorption of Contaminants from Soils
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Environmental Progress, 8 (1), 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, National Science Foundation - Presidential Young Investigator Program, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
The goals of this research are to develop an understanding of the transport phenomena that occur during the desorption of contaminants from soil and to obtain rate information. This information can then be used to develop a model to predict the performance of full-scale thermal treatment systems for optimization and cost reduction.
Fundamentals for the Thermal Remediation of Contaminated Soils - Particle and Bed Desorption Models
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Accepted for publication in Environ. Science Tech., 1989. Funded by the Gas Research Institute, Dave Linz, Project Manager, National Science Foundation/Presidential Young Investigators, ACERC (National Science Foundation and Associates and Affiliates), the State of Utah, and US Department of Energy.
A major research effort has been initiated to characterize the rate-controlling processes associated with the evolution of hazardous materials from soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants. Phenomena occurring both inside particles (intraparticle) and with a bed of particles (interparticle) were studied.
The results obtained suggest that the most important process variables are local thermal environment and gas-phase contaminant concentration because the adsorption equilibrium characteristics of the contaminant/soil pair control the desorption of contaminant from a particle at a given temperature. A mass-transfer/desorption model, which assumes gas/solid equilibrium at all points and time, is proposed and the model was found to predict the measured temperature dependence.
1988-1987
Transport Fundamentals for the Thermal Remediation of Contaminated Soils
Lighty, J.S.; Silcox, G.D.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Submitted for Review to AIChE Journal, 1988. 23 pgs. Funded by Gas Research Institute, ACERC (National Science Foundation and Associates and Affiliates), and National Science Foundation/Presidential Young Investigators.
A major research effort has been initiated to characterize the transport phenomena associated with the evolution of hazardous materials from contaminated soils. A threefold experimental approach is being used in conjunction with computer modeling to analyze thermal desorption of contaminants from soils under a variety of experimental conditions. First, a particle-characterization reactor (PCR) is being employed to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Secondly, a packed-bed reactor is being used to examine interparticle transport within a bed of particles. In the third portion of the work, a 73 kW pilot-scale rotary kiln is providing time-resolved measurements of the species evolution. The results from the PCR experiments and modeling are reported in this manuscript.
The PCR experimental results obtained suggest that the most important process variable is local thermal environment and that the absorption characteristics of the contaminant/soil pair are important in the desorption process. The adsorption characteristics are a function of local temperature, thus accounting for the steep dependence of the cleanup efficiency of a soil on temperature. In addition, the adsorption characteristics are influenced by soil type and moisture; it has been found that these parameters also effect desorption of contaminants. A mass-transfer model, which assumes gas/solid equilibrium at all points and times, is proposed and the model predictions were found to exhibit temperature dependence similar to the data.
Characterization of Thermal Desorption Phenomena for the Clean-Up of Contaminated Soil
Lighty, J.S.; Pershing, D.W.; Cundy, V.A. and Linz, D.G.
Accepted for Nuclear & Chemical Waste Management, 1987. 32 pgs. Funded by ACERC (National Science Foundation and Associates and Affiliates).
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils. An understanding of the mass transfer and heat transfer limitations might lead to a more economical option, where the contaminants are desorbed from the soil at lower temperatures in a primary combustor and then a secondary, high temperature combustor (afterburner) decomposes the hazardous off-gases. This work is aimed at providing fundamental rate information which will be used to model thermal desorption of contaminants from soils under a variety of thermal conditions, soil properties and contaminants.
The experimental approach is threefold. First, a bench scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed-bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73 kW pilot-scale rotary kiln will be used to obtain time resolved measurements of trace species evolution. This paper reports recent PCR results that indicate that soil properties, type of contaminant, and temperature are important in desorption of contaminants from soil particles.
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils and it may render the soil inert. A more economical option is to desorb the contaminants from the soil at lower temperatures and then use high temperature incineration to decompose the hazardous off-gases. This work is aimed at providing fundamental rate information which may be used to model the thermal desorption of contaminants from soils under a wide variety of thermal conditions.
The experimental approach is three-fold. First, a bench-scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73,000 Watt pilot-scale rotary kiln will be used to reports recent PCR and kiln results; it does not address the packed bed reactor studies since they are just being initiated. The PCR results indicate that soil pore structure is important in desorption of contaminants from soil particles and that the desorption/diffusion step is probably a controlling mechanism.
The Clean Up of Contaminated Soil By Thermal Desorption
Lighty, J.S.; Pershing, D.W.; Cundy, V.A.; Groves, F.R. Jr. and Linz, D.G.
Proc. 2nd Int. Conf. on New Frontiers in Hazardous Waste Management, 1987, NUS, Pittsburgh, PA. 10 pgs. Funded by Gas Research Institute, National Science Foundation, and ACERC (National Science Foundation and Associates and Affiliates).
The overall goal of this research is to develop an understanding of the fundamental transport phenomena associated with the evolution of hazardous materials from solids, in particular, contaminated soils. At the present time, incineration is a relatively costly alternative for the clean up of contaminated soils and it may render the soil inert. A more economical option is to desorb the contaminants from the soil at lower temperatures and then use high temperature incineration to decompose the hazardous off-gases. This work is aimed at providing fundamental rate information which may be used to model the thermal desorption of contaminants from soils under a wide variety of thermal conditions.
The experimental approach is threefold First, a bench-scale particle characterization reactor (PCR) has been developed and is being used to characterize intraparticle transport under conditions where the bulk concentration and temperature at the particle surface are known. Following these studies, a packed bed reactor will be used to examine interparticle transport within a well-characterized bed of particles. In the third portion of the work, a 73,000 Watt pilot-scale rotary kiln will be used to obtain time resolved measurements of trace species evolution. This paper reports recent PCR and kiln results; it does not address the packed bed reactor studies since they are just being initiated. The PCR results indicate that soil pore structure is important in desorption of contaminants from soil particles and that the desorption/diffusion step is probably a controlling mechanism.