Hydrogen gasification of oxidized carbons

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

OSTI ID:5871298

Treptau, M H; Miller, D J

Over the past several years the authors have conducted experimental studies to better understand alkali carbonate catalyst behavior in hydrogen gasification and to determine the effect of oxygen on gasification rate. They observe that catalyst behavior in hydrogen gasification is similar to that in steam gasification, leading them to believe that catalyst-carbon interactions are of primary importance in gasification and that catalyst behavior is relatively unaffected by reactant gas. Thus hydrogen is a suitable model environment for studying catalyst behavior. One exception, however, is that higher rates of catalyst loss are observed in hydrogen than in steam. For uncatalyzed gasification, they have shown that partial combustion of carbon black prior to exposure to hydrogen enhances methane formation rate, while high temperature pretreatment (degassing) drastically reduces reaction rate. These results arise from the addition or removal of active surface oxygen groups and from thermal annealing of the carbon active sites. Via pH measurements, they have found that partial combustion at 400/degree/C fixes acidic groups on the carbon surface. Gasified and degassed carbons contain a predominance of basic groups. The paper presents further studies of the role of surface oxygen and thermal treatments in both catalyzed and uncatalyzed hydrogen gasification. In this work, a second carbon substrate and oxidation by HNO/sub 3/ are investigated. Nitric acid produces a variety of groups on carbon, but does not alter the carbon structure. Comparison of results for the different carbons and two methods of oxidation provides clarification of the role of oxygen. X-ray photoelectron spectroscopy (XPS) provides further information.

• Research Organization: Michigan State Univ., East Lansing (USA)
• OSTI ID: 5871298
• 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
ADSORBENTS
ALKALI METAL COMPOUNDS
CARBON
CARBON BLACK
CARBON COMPOUNDS
CARBONATES
CATALYSTS
CATALYTIC EFFECTS
CHARCOAL
CHEMICAL PROPERTIES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL GASIFICATION
COMBUSTION
COMPLEXES
DEGASSING
ELECTRON SPECTROSCOPY
ELEMENTS
GASIFICATION
HEAT TREATMENTS
HYDROGEN
HYDROGEN COMPOUNDS
INORGANIC ACIDS
KINETICS
NITRIC ACID
NONMETALS
OXIDATION
OXYGEN COMPLEXES
OXYGEN COMPOUNDS
PH VALUE
PHOTOELECTRON SPECTROSCOPY
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
REACTION KINETICS
SPECTROSCOPY
SURFACE AREA
SURFACE PROPERTIES
THERMOCHEMICAL PROCESSES
X-RAY SPECTROSCOPY