Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction
During this quarterly period progress has been made in the following three subjects related to the effects of low-temperature thermal and catalytic pretreatments on coal structure and reactivity in liquefaction. First, the liquefaction behavior of three bituminous coals with a carbon content ranging from 77% to 85% was evaluated spectroscopically by [sup 13]C NMR and pyrolysis/gas chromatography/mass spectrometry to delineate the structural changes that occur in the coal during liquefaction. Complementary data includes ultimate and proximate analysis, along with optical microscopy for maceral determinations. Even though these are all bituminous coals they exhibit quite different physical and chemical characteristics. The coals vary in rank, ranging from HvC b to HvA b, in petrographic composition, different maceral percentages, and in chemical nature, percent of carbon and of volatiles. It is these variations that govern the products, their distribution, and conversion percentages. Some of the products formed can be traced to a specific maceral group. Second, pyrolysis-GC-MS and FTIR techniques were used to characterize Wyodak coal before and after drying in vacuum and in air and the residues from its thermal and catalytic liquefactions. The analysis of the air-dried coal shows a decrease in the phenolic type structures in the coal network and increase in the carbonyl structures as the oxidative drying proceeds. An enhanced decrease in the carbonyl structure is observed in the liquefaction residues from the raw coal as compared to that of the vacuum dried coal. The analyses of the liquefaction residues of the air-dried coal show an increase in the ether linkages which may have a negative impact on liquefaction. The extent of the solvent adduction also increases during liquefaction with the extent of oxidation of the coal. Finally, the effects of reaction conditions were investigated on conversion of low-rank coals using a Texas subbituminous coal.
- Research Organization:
- Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC22-91PC91042
- OSTI ID:
- 6688961
- Report Number(s):
- DOE/PC/91042-T3; ON: DE93011445
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction. Technical progress report, August 1992--July 1992
Effects of low-temperature catalytic pretreatments on coal structure and reactivity in liquefaction
Related Subjects
COAL
HEAT TREATMENTS
COAL LIQUEFACTION
CHEMICAL REACTION KINETICS
BITUMINOUS COAL
CARBON 13
CATALYSTS
GAS CHROMATOGRAPHY
MASS SPECTROSCOPY
MICROSTRUCTURE
NUCLEAR MAGNETIC RESONANCE
ORGANIC SOLVENTS
PROGRESS REPORT
PYROLYSIS
SUBBITUMINOUS COAL
BLACK COAL
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
CHROMATOGRAPHY
CRYSTAL STRUCTURE
DECOMPOSITION
DOCUMENT TYPES
ENERGY SOURCES
EVEN-ODD NUCLEI
FOSSIL FUELS
FUELS
ISOTOPES
KINETICS
LIGHT NUCLEI
LIQUEFACTION
MAGNETIC RESONANCE
MATERIALS
NUCLEI
REACTION KINETICS
RESONANCE
SEPARATION PROCESSES
SOLVENTS
SPECTROSCOPY
STABLE ISOTOPES
THERMOCHEMICAL PROCESSES
010405* - Coal
Lignite
& Peat- Hydrogenation & Liquefaction