(Sorptive properties of coal fines). Tenth quarterly report, December 1, 1984-February 28, 1985
Tables 1 and 2 list the heats of adsorption and of desorption of phenol and of pyridine and of their t-butyl derivatives on anthracite and bituminous coal powders. Pyridine and phenol are seen to have higher initial heats of adsorption and lower heats of desorption, which is considered evidence for the well-known penetration of these molecules into the coal. In contrast, the t-butyl derivatives have heats of adsorption and desorption of equal magnitude, and the desorption is complete in a very short time (about two minutes); this is compelling experimental evidence for very limited penetration into the coal. Standard deviations for the heats of adsorption and desorption are about 10% for the t-butyl derivatives. For the coal powders which were not heat-treated, slight penetration seemed to occur even with the t-butyl derivatives, for the initial heats of adsorption were often somewhat greater in magnitude than the successive heats of desorption and adsorption. The effects of washing the powdered coal with acetone and then with methylene chloride (30 minutes each) are illustrated for 3,5-di-t-butylphenol. The heats of adsorption-desorption increased with such washing for the low-ash bituminous coal, but decreased for the low-ash anthracite. Comparisons of heats of adsorption of acidic and basic probes on the same coal powders indicate the balance of basicity and acidity. For the powders which were not heat-treated the heats of adsorption of the basic probes exceeded those for the acidic probes for both bituminous coals and for the high-ash anthracite; this showed that the surface sites of these coals are predominantly acidic. The low-ash anthracite was predominantly basic, but after heating in the vacuum-oven it became predominantly acidic. 3 refs., 1 fig., 9 tabs.
- Research Organization:
- Lehigh Univ., Bethlehem, PA (USA). Dept. of Chemistry
- DOE Contract Number:
- FG22-82PC50809
- OSTI ID:
- 5856710
- Report Number(s):
- DOE/PC/50809-T10; ON: DE85010461
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Methods for characterizing the acidic and basic surface sites of coal
(Determinating of the surface reactivity of coal powders). Final report. [4t-butylpyridine; 2,6-di-t-butylpyridine; 3,5-di-t-butylphenol; 2,6-di-t-butylphenol]
Related Subjects
COAL
SORPTIVE PROPERTIES
SURFACE PROPERTIES
ADSORPTION
ADSORPTION HEAT
DESORPTION
EXPERIMENTAL DATA
FOURIER TRANSFORMATION
INFRARED SPECTRA
PHENOL
PYRIDINE
SURFACE AREA
TIME DEPENDENCE
AROMATICS
AZINES
CARBONACEOUS MATERIALS
DATA
ENERGY SOURCES
ENTHALPY
FOSSIL FUELS
FUELS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
INFORMATION
INTEGRAL TRANSFORMATIONS
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHENOLS
PHYSICAL PROPERTIES
PYRIDINES
SORPTION
SPECTRA
THERMODYNAMIC PROPERTIES
TRANSFORMATIONS
010600* - Coal
Lignite
& Peat- Properties & Composition