Weathering effects on yield and composition of pyrolytic coal tars

Conference · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5507568

Jakab, E; McClennen, W H; Hoesterey, B; Meuzelaar, H L.C.; Hill, G R

Results are presented of a study on the effects of weathering on pyrolytic tars produced by a vacuum micropyrolysis technique (Curie-point pyrolysis mass spectrometry) which can be used as a model system for short contact time pyrolysis processes in bench scale, as well as pilot plant scale reactors. Conclusions are as follows: Weathering-induced decreases in relative yields of pyrolytic tars from Western coals of different rank (lignite to hvb) may range from 20 to 50%, depending on pyrolysis conditions. Pyrolytic coal tars of remarkably similar composition are obtained from a Wellman Galusha reactor and from a vacuum micropyrolysis experiment in spite of 8 to 9 orders of magnitude differences in sample size. Vacuum micropyrolysis experiments on three Western coals of different rank (lignite, subbituminous and hvb-A) which were oxidized (''weathered'') under controlled laboratory conditions show marked differences in the behavior of aromatic tar components but an overall similarity in the increase of polar, aliphatic compounds. In each coal the observed changes in the relative abundance of aromatic compounds appear to be explainable by a loss of mobile phase components through ''grafting'' reactions with the network phase during coal weathering. Small but characteristic changes which occur in the composition of a Wellman Galusha reactor coal tar during exposure to oxygen at 80/sup 0/C point to the occurrence of condensation reactions involving dihydroxybenzenes and other hydroxyaromatic compounds. 15 refs., 5 figs., 2 tabs.

• Research Organization: Utah Univ., Salt Lake City (USA). Biomaterials Profiling Center
• DOE Contract Number: FG22-84PC70798
• OSTI ID: 5507568
• Report Number(s): CONF-850942-16; ON: DE85013078
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010406* -- Coal & Coal Products-- Pyrolysis & Cracking-- (-1987)
010600 -- Coal
Lignite
& Peat-- Properties & Composition
AIR
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COAL
COAL TAR
DATA
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDS
FOSSIL FUELS
FUELS
GASES
INFORMATION
LIGNITE
MASS SPECTRA
MASS SPECTROSCOPY
MATERIALS
MEDIUM TEMPERATURE
NITROGEN
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDATION
PYROLYSIS
SPECTRA
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
SUBBITUMINOUS COAL
TAR
THERMOCHEMICAL PROCESSES
WEATHERING
YIELDS