Keyes, BR
1994
Fundamental Study of the Thermal Desoprtion of Toluene from Montmorillonite Clay Particles
Keyes, B.R. and Silcox, G.D.
Environmental Science Technology, 28:840, 1994. Funded by ACERC and Gas Research Institute.
Nonisothermal desorption of toluene from individual montmorillonite clay particles was measured experimentally and modeled mathematically to elucidate details of the overall thermal desorption process. A single-particle reactor was used. It consisted of a porous, 2-6mm clay pellet formed around a 0.05-mm diameter thermocouple in a 6- or 9-mm o.d. glass tube. The tube was surrounded by a supplementary heater and placed in a GC oven. Desorption rates were obtained as a function of heating rate, clay type, particle size, and purge gas flow rate. In addition, the absorption isotherms for two toluene/clay systems and one n-dodecane/clay system were measured and correlated using the Freundlich isotherm. At the conditions examined, the rate-controlling mechanism is associated with intraparticle diffusion. Isothermal desorption experiments using clay pellets of different sizes demonstrate that local desorption kinetics are not rate controlling. Toluene shows a slower desorption rate than n-dodecane at low concentrations. This is attributed to the hindered removal of toluene from interlamellar regions of the clay. Comparisons of single-particle reactor and pilot-scale rotary kiln results show that mass transport resistances associated with a bed of particles dominate the desorption process at rotary kiln conditions.
1992
A Fundamental Study of the Thermal Desorption of Organic Wastes from Montmorillonite Clay Particles
Keyes, B.R.
A Fundamental Study of the Thermal Desorption of Organic Wastes from Montmorillonite Clay Particles, Ph.D./U of U, August 1992, Advisor: Silcox
Keyes, BR
1994
Fundamental Study of the Thermal Desoprtion of Toluene from Montmorillonite Clay Particles
Keyes, B.R. and Silcox, G.D.
Environmental Science Technology, 28:840, 1994. Funded by ACERC and Gas Research Institute.
Nonisothermal desorption of toluene from individual montmorillonite clay particles was measured experimentally and modeled mathematically to elucidate details of the overall thermal desorption process. A single-particle reactor was used. It consisted of a porous, 2-6mm clay pellet formed around a 0.05-mm diameter thermocouple in a 6- or 9-mm o.d. glass tube. The tube was surrounded by a supplementary heater and placed in a GC oven. Desorption rates were obtained as a function of heating rate, clay type, particle size, and purge gas flow rate. In addition, the absorption isotherms for two toluene/clay systems and one n-dodecane/clay system were measured and correlated using the Freundlich isotherm. At the conditions examined, the rate-controlling mechanism is associated with intraparticle diffusion. Isothermal desorption experiments using clay pellets of different sizes demonstrate that local desorption kinetics are not rate controlling. Toluene shows a slower desorption rate than n-dodecane at low concentrations. This is attributed to the hindered removal of toluene from interlamellar regions of the clay. Comparisons of single-particle reactor and pilot-scale rotary kiln results show that mass transport resistances associated with a bed of particles dominate the desorption process at rotary kiln conditions.
1992
A Fundamental Study of the Thermal Desorption of Organic Wastes from Montmorillonite Clay Particles
Keyes, B.R.
A Fundamental Study of the Thermal Desorption of Organic Wastes from Montmorillonite Clay Particles, Ph.D./U of U, August 1992, Advisor: Silcox