Kinetics of catalyzed steam gasification of low-rank coals to produce hydrogen. Final report

Technical Report · Sun Jun 01 04:00:00 EDT 1986

OSTI ID:5645567

Galegher, S J; Timpe, R C; Willson, W G; Farnum, S A

The principal goal of coal char-steam gasification research is to establish the feasibility of low-rank coal gasification for hydrogen production. The program has focused on determining reaction conditions for maximum product gas hydrogen content and on evaluating process kinetics with and without catalyst addition. The high inherent reactivity of lignites and subbituminous coals, compared to coals of higher rank, make them the probable choice for use in steam gasification. An extensive matrix of char-steam gasification tests was performed in a laboratory-scale thermogravimetric analyzer (TGA) at temperatures of 700/sup 0/, 750/sup 0/, and 800/sup 0/C. Reaction conditions for these tests were based on the results of earlier work at UNDERC in which product gases from fixed-bed, atmospheric pressure, steam gasification at temperatures of 700/sup 0/ to 750/sup 0/C were found to contain 63 to 65 mole % hydrogen, with the remainder being carbon dioxide, carbon monoxide, and less than 1 mole % methane. Four low-rank coals and one bituminous coal were included in the TGA test matrix. Catalysts screened in the study included K/sub 2/CO/sub 3/, Na/sub 2/CO/sub 3/, trona, nahcolite, sunflower hull ash, and lignite ash. Results of this study showed uncatalyzed North Dakota and Texas lignites to be slightly more reactive than a Wyoming subbituminous coal, and 8 to 10 times more reactive than an Illinois bituminous coal. Several catalysts that substantially improved low-rank coal steam gasification rates included pure and mineral (trona and nahcolite) alkali carbonates. The reactivity observed when using trona and nahcolite to catalyze the steam gasification was the highest, at nearly 3.5 times that without catalysts. The use of these inexpensive, naturally-occurring, alkalis as gasification catalysts may result in elimination of the need for catalyst recovery in the hydrogen-from-coal process. 11 refs., 23 figs., 9 tabs.

• Research Organization: North Dakota Univ., Grand Forks (USA). Energy and Mineral Research Center
• DOE Contract Number: FC21-83FE60181
• OSTI ID: 5645567
• Report Number(s): DOE/FE/60181-2034; ON: DE86012209
• 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
ALKALI METAL COMPOUNDS
ASHES
BENCH-SCALE EXPERIMENTS
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE MINERALS
CARBONATES
CATALYSTS
CATALYTIC EFFECTS
CHARS
CHEMICAL ANALYSIS
COAL
COAL GASIFICATION
COAL RANK
COMPARATIVE EVALUATIONS
DATA
ENERGY SOURCES
EXPERIMENTAL DATA
FOSSIL FUELS
FUELS
GASIFICATION
GRAVIMETRIC ANALYSIS
HIGH TEMPERATURE
HYDROGEN PRODUCTION
INFORMATION
LIGNITE
MATERIALS
MINERALS
NAHCOLITE
NMR SPECTRA
NUMERICAL DATA
OXYGEN COMPOUNDS
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
PYROLYSIS PRODUCTS
QUANTITATIVE CHEMICAL ANALYSIS
RAW MATERIALS
RESIDUES
SODIUM CARBONATES
SODIUM COMPOUNDS
SPECTRA
STEAM
SUBBITUMINOUS COAL
TEMPERATURE EFFECTS
THERMAL ANALYSIS
THERMAL GRAVIMETRIC ANALYSIS
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE
TRONA
VERY HIGH TEMPERATURE
YIELDS