Fundamental study of the thermal desorption of toluene from montmorillonite clay particles
- Univ. of Utah, Salt Lake City, UT (United States)
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, 2-6-mm 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 adsorption 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. 39 refs., 9 figs., 4 tabs.
- OSTI ID:
- 6977043
- Journal Information:
- Environmental Science and Technology; (United States), Vol. 28:5; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DESORPTION
MATHEMATICAL MODELS
TEMPERATURE DEPENDENCE
DODECANE
ADSORPTION
DIFFUSION
LAND POLLUTION ABATEMENT
TOLUENE
ADSORPTION ISOTHERMS
CHEMICAL REACTORS
MASS TRANSFER
MONTMORILLONITE
ALKANES
ALKYLATED AROMATICS
AROMATICS
CLAYS
HYDROCARBONS
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
ISOTHERMS
MATERIALS
ORGANIC COMPOUNDS
POLLUTION ABATEMENT
SORPTION
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
400201 - Chemical & Physicochemical Properties