Changes in asphaltenes and preasphaltenes with reaction conditions and effects on coal structure
Asphaltene and preasphaltene data are presented to demonstrate the effect of temperature, pressure, and reducing gas composition on their hydrogen and phenolic content. The previous paper by Baltisberger showed how the hydrogen and phenolic content of the A and PA defined whether or not a coal derived product will be classified as such. The influence of processing parameters as discussed in this paper indicates that reduction in the number of phenolic functional groups and cracking are required to further convert asphaltene and preasphaltene material to distillates. That alcohol groups are present in aromatic bridging structures is indicated in the data in this report by the decreased MW of SR when processed with CO present since after hydrogenation an aliphatic bridge would cleave easier. The increased aliphatic hydrogen content in the asphaltene fraction when reacted with CO may also indicate that some alcohol groups were initially in the aromatic bridges. The presence of alcohol groups in long chain aliphatics is indicated because increased yields of long chain alkanes were observed when CO was present. The previous data have shown how operating conditions such as pressure and temperature affects the hydrogen content, phenolic content, and molecular weight range of asphaltene and preasphaltene fractions. The effects are reflected similarly in individual MW fractions of both A and PA material. The presence of alcohol groups in original coal (both lignites and bituminous coals) is strongly suggested. The preferential reaction of these alcohol groups with CO gas (but not H/sub 2/) to increase the hydrogen content of the asphaltenes, to reduce the overall MW distribution of coal, and to increase yields of alkanes indicates the beneficial effects of CO as a reductant of these functional groups which are present in both lignites and bituminous coals. 20 references, 8 figures.
- Research Organization:
- North Dakota Univ., Grand Forks (USA). Energy Research Center
- DOE Contract Number:
- FC21-83FE60181
- OSTI ID:
- 6844776
- Report Number(s):
- DOE/FE/60181-81; CONF-840805-3; ON: DE84010164
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chemistry and structure of coal derived asphaltenes and preasphaltenes. Quarterly progress report, January-March 1981
Investigation of original preasphaltene and asphaltene in coal
Related Subjects
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
ASPHALTENES
ASPHALTS
BITUMENS
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISTRY
CHROMATOGRAPHY
COAL
COAL LIQUEFACTION
COMPARATIVE EVALUATIONS
DATA
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
GAS CHROMATOGRAPHY
HYDROGEN
INFORMATION
LIGNITE
LIQUEFACTION
LIQUID COLUMN CHROMATOGRAPHY
MATERIALS
MOLECULAR WEIGHT
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
PRESSURE DEPENDENCE
REDUCING AGENTS
REDUCTION
SEPARATION PROCESSES
STRUCTURAL CHEMICAL ANALYSIS
TAR
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
YIELDS