Catalyzed steam gasification of low-rank coals to produce hydrogen

Conference · Tue Apr 01 04:00:00 EST 1986

OSTI ID:5674500

Sears, R E; Timpe, R C; Galegher, S J; Willson, W G

Advanced coal gasification technologies using low-rank coal is a promising alternative for meeting future demand for hydrogen. Steam gasification tests conducted at temperatures between 700/sup 0/ and 800/sup 0/C and atmospheric pressure resulted in product gas compositions matching those predicted by thermodynamic equilibrium calculations, 63-65 mol% hydrogen and less than 1 mol% methane. Steam gasification tests with four low-rank coals and a single bituminous coal were performed in a laboratory-scale thermogravimetric analyzer (TGA) at temperatures of 700/sup 0/, 750/sup 0/, and 800/sup 0/C to evaluate process kinetics with and without catalyst addition. Catalysts screened included K/sub 2/CO/sub 3/, Na/sub 2/CO/sub 3/, trona, nahcolite, sunflower hull ash, and recycled lignite ash. Uncatalyzed lignites and a subbituminous coal were found to be eight to ten times more reactive with steam at 700/sup 0/ to 800/sup 0/C than an Illinois bituminous coal. This relationship, within this narrow temperature range, is important as this is the range that thermodynamically favors the production of hydrogen from steam gasification at atmospheric pressure. The reactivity of the uncatalyzed coals increased 3 to 4 times with an increase in steam gasification temperature from 700/sup 0/ to 800/sup 0/C. For the catalyzed coals during steam gasification: Reactivity increased approximately 2 times over the 700/sup 0/ to 800/sup 0/C temperature range for low-rank coals catalyzed with potassium carbonate. Sodium carbonate was found to be as effective a catalyst as potassium carbonate for the steam gasification of low-rank coal chars on a mass loading basis; and naturally occurring mineral sources of sodium carbonates/bicarbonates, trona and nahcolite, are as effective in catalyzing low-rank coal steam gasification as the pure carbonates. 18 refs., 6 figs., 2 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy and Mineral Research Center
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 5674500
• Report Number(s): DOE/FE/60181-189; CONF-860911-3; ON: DE86008933
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
08 HYDROGEN
080107 -- Hydrogen-- Production-- Coal Gasification
AIR
ALKALI METAL COMPOUNDS
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE MINERALS
CARBONATES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL ANALYSIS
CHEMICAL REACTION KINETICS
COAL
COAL GASIFICATION
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
GASES
GASIFICATION
GRAVIMETRIC ANALYSIS
HYDROGEN PRODUCTION
KINETICS
LIGNITE
MATERIALS
MINERALS
NAHCOLITE
OXYGEN COMPOUNDS
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
REACTION KINETICS
SODIUM CARBONATES
SODIUM COMPOUNDS
STEAM
SUBBITUMINOUS COAL
TEMPERATURE EFFECTS
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
THERMOCHEMICAL PROCESSES
THERMODYNAMICS
TRONA