Coal/water slurry preparation: Final report for the period ending June 30, 1986. [Hot water drying]

Technical Report · Mon Sep 01 04:00:00 EDT 1986

OSTI ID:7081180

Willson, W G; Baker, G G; Maas, D J; Potas, T A

Raw low-rank coal/water slurries, primarily due to the high inherent moisture, have such low energy densities that they cannot be economically utilized. However, hot-water drying (HWD) permanently removes the inherent moisture and some oxygen, allowing dramatic improvements in the resulting slurry energy density. This process results in the coal essentially being slurried in its own moisture and produces a liquid fuel with approximately the same heating value as the parent coal. Elevated process temperatures cause the low-rank coals to undergo both chemical and physical changes, which include decarboxylation, mild pyrolysis, dehydration, and surface modification. Tars and waxes also form and flow to the coal surface where they solidify upon cooling and plug micropore entrances. As a result, lignite and subbituminous coals acquire surface characteristics and improved coal quality, which allow the preparation and utilization of concentrated low-rank coal/water fuels. Improvement of the energy density of HWD coal/water fuels versus those prepared with the raw coal are typically >30%. Conceptual economic studies have determined the cost to process Wyoming subbituminous coal into a 60 wt % CWS to be $1.40/MMBtu (Bechtel National Inc.), $2.20/MMBtu (UNDERC) and for processing Australian brown coal $2.00/MMBtu (Davy McKee Pacific). 18 refs., 21 figs., 8 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy and Mineral Research Center
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 7081180
• Report Number(s): DOE/FE/60181-2125; ON: DE87001013
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010300* -- Coal
Lignite
& Peat-- Preparation-- (1987-)
ADDITIVES
ASHES
AUTOCLAVES
BROWN COAL
CALORIFIC VALUE
CARBON 13
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COAL
COMBUSTION PROPERTIES
DATA
DECARBOXYLATION
DECOMPOSITION
DISPERSIONS
ECONOMICS
ENERGY SOURCES
EVEN-ODD NUCLEI
EXPERIMENTAL DATA
FOSSIL FUELS
FUEL SLURRIES
FUELS
FUNCTIONAL MODELS
HYDROGEN COMPOUNDS
INFORMATION
ISOTOPES
LIGHT NUCLEI
LIGNITE
MAGNETIC RESONANCE
MATERIALS
MIXTURES
NUCLEAR MAGNETIC RESONANCE
NUCLEI
NUMERICAL DATA
OXYGEN COMPOUNDS
PARTICLE SIZE
PROCESS DEVELOPMENT UNITS
PYROLYSIS
RECOMMENDATIONS
REMOVAL
RESIDUES
RESONANCE
RHEOLOGY
SIZE
SLURRIES
STABLE ISOTOPES
SUBBITUMINOUS COAL
SUSPENSIONS
SYNTHESIS
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES
VISCOSITY
WATER
WATER REMOVAL