Coal liquefaction using donor solvents hydrogenated at low temperatures
Direct coal liquefaction proceeds initially through a complex series of bond breaking and hydrogen transfer reactions involving coal and a donor solvent. When the recycle solvent contains high amounts of donor solvent, the requirement for high hydrogen gas pressure in the initial stage of liquefaction is reduced and coal conversion is augmented. Effective tests for hydrogen donating ability of coal derived solvents often consist of GC/MS, proton NMR, catalytic dehydrogenation, as well as microautoclave coal liquefaction testing [1,2,3]. Microautoclave testing is an empirical measure of solvent quality for hydrogen donation using coal, a donor solvent and an inert gas instead of hydrogen. Previous studies [4] have investigated the hydrogen transfer cycle for direct liquefaction using Illinois [number sign]6 high volatile bituminous coal and a distillate (650[degrees]F-770[degrees]F) derived from a coal liquefaction process solvent. The objective of this work is to determine the effects of donor solvent on coal conversions in microautoclave liquefaction experiments performed at 400[degrees]C with Wyodak coal. These tests used a heavy distillate solvent that had been hydrogenated with a synthesis gas (50% carbon monoxide:50% hydrogen) mixture and steam at low temperatures (300[degrees]C-325[degrees]C). The in situ water-gas shift (WGS) reaction provides an alternate source of hydrogen and has the potential of eliminating the need for high purity high pressure hydrogen for solvent hydrogenation. Hydrogenation at low temperatures can lead to increased donor content since larger amounts of hydroaromatics are produced at equilibrium with any given hydrogen pressure. Distillate solvents were hydrogenated at various weight hourly space velocities, using two different catalysts and used in microautoclave coal liquefaction tests to evaluate solvent pretreatment effects on coal solubility.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- DOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 7054783
- Report Number(s):
- SAND-92-2582C; CONF-930304--3; ON: DE93006292
- Country of Publication:
- United States
- Language:
- English
Similar Records
The hydrogen transfer cycle for coal liquefaction: Process implications
Sandia liquefaction process requires no hydrogen
Related Subjects
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
AUTOCLAVES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSTS
CHALCOGENIDES
CHEMICAL BONDS
CHEMICAL REACTIONS
CHROMATOGRAPHY
CLEAVAGE
COAL LIQUEFACTION
CRYSTAL STRUCTURE
FLUIDS
GAS CHROMATOGRAPHY
GASES
HYDROGEN 1
HYDROGEN ISOTOPES
HYDROGENATION
ISOTOPES
LIGHT NUCLEI
LIQUEFACTION
MAGNETIC RESONANCE
MASS SPECTROSCOPY
MICROSTRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC SOLVENTS
OXIDES
OXYGEN COMPOUNDS
RECYCLING
RESONANCE
SEPARATION PROCESSES
SOLVENTS
SPECTROSCOPY
STABLE ISOTOPES
SYNTHESIS GAS
THERMOCHEMICAL PROCESSES