Catalytic gasification of graphite and chars

Conference · Sun Jan 01 04:00:00 EST 1989 · Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States)

OSTI ID:5969639

Heinemann, H; Somorjai, G A; Pereira, P; Carrazza, J

In earlier papers the authors reported on the low temperature catalytic gasification of carbonaceous materials with steam. The use of catalysts is necessary if the process is to be carried out at temperatures below 1000 K. While alkaline or alkaline-earth hydroxides and carbonates have been studied by many investigators, they show catalytic activity only at temperatures above 1000 K. Transition metals, in particular nickel and iron, are able to catalyze the process at temperatures as low as 750 K but they deactivate very fast. These transition metal catalysts are active only if the reaction conditions permit their presence in the metallic state. In the earlier work they described catalysts which are mixtures of potassium hydroxide and nickel oxide and have demonstrated that they showed the highest activity of all the systems previously studied at below 1000K. They also showed that this catalyst mixture formed a relatively low melting eutectic that can wet the surface of the carbon substrates forming a liquid film which attacks the carbonaceous material by edge recession mode rather than by a channeling mode which prevails for potassium hydroxide alone and nickel alone. A disadvantage found with the potassium-nickel catalysts is that they have a tendency to deactivate over a period of time when used on chars due to an interference or poisoning by ash components in the char. The present paper presents information on the role of ash components on catalytic gasification and describes another type of catalyst, namely a mixture of alkali and earth alkali oxides such as K/sub 2/O-CaO, which is almost as active and is less sensitive to poisoning than the potassium-nickel composition.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 5969639
• Report Number(s): CONF-8904169-
• Conference Information: Journal Name: Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States) Journal Volume: 34:1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
ACTIVATION ENERGY
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ASHES
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CALCIUM COMPOUNDS
CALCIUM OXIDES
CARBON
CARBONACEOUS MATERIALS
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHARS
CHEMICAL COMPOSITION
CHEMICAL PROPERTIES
COAL
COAL GASIFICATION
DEACTIVATION
ELEMENTAL MINERALS
ELEMENTS
ENERGY
ENERGY SOURCES
FOSSIL FUELS
FUELS
GASIFICATION
GRAPHITE
HYDROGEN COMPOUNDS
HYDROXIDES
LIGNITE
MATERIALS
MINERALS
NICKEL COMPOUNDS
NICKEL OXIDES
NONMETALS
OXIDES
OXYGEN COMPOUNDS
POISONING
POTASSIUM COMPOUNDS
POTASSIUM HYDROXIDES
POTASSIUM OXIDES
PYROLYSIS PRODUCTS
RESIDUES
STEAM
SUBBITUMINOUS COAL
SURFACE AREA
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS