A fundamental study of K sub 2 CO sub 3 -catalysis of hydrogasification of carbon and the role of oxygen in the catalysis

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:5004526

Zoheidi, H

In this work fundamental experimental kinetic studies of K{sub 2}CO{sub 3}-catalyzed and non-catalyzed hydrogasification of carbon blacks at 700-865 C and 500 psi hydrogen pressure have been conducted to gain more insight into the role of K{sub 2}CO{sub 2} and oxygen complexes. In these studies, the effects of different catalyst loadings on hydrogasification rate, potassium loss at high temperature, the nature of oxygen complexes in carbon black, and effects of oxygen chemisorption at 400 and 800 C and/or degassing at 1000 C on non-catalyzed and the catalyzed hydrogasification have been investigated. From the effect of various oxygen surface groups on rate of hydrogasification, it is postulated that oxygen groups thermally desorb from the carbon surface and create nascent active sites which act as active sites for hydrogasification, hence enhancing the reactivity of the carbon. K{sub 2}CO{sub 3} catalytic activity and potassium losses are influenced by the nature of oxygen surface groups. The formation of stable and active potassium-containing species via interaction of K{sub 2}CO{sub 3} and oxygen complexes leads to reduced potassium losses and enhanced hydrogasification rates. The interaction of K{sub 2}CO{sub 3} with carbonyl groups forms both stable and active species. Interaction with basic oxygen complexes, which are relatively inactive in uncatalyzed hydrogasification, form active but unstable intermediate species. Interaction with acidic complexes is not well characterized from the experiments. Degassing removes non-basic groups and thermally anneals the nascent active sites, resulting in reduced gasification rate and increased potassium.

• Research Organization: Michigan State Univ., East Lansing, MI (USA)
• OSTI ID: 5004526
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
ALKALI METAL COMPOUNDS
ALKALI METALS
CARBON
CARBON BLACK
CARBON COMPOUNDS
CARBONATES
CATALYSIS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISORPTION
COAL GASIFICATION
COMPLEXES
ELEMENTS
GASIFICATION
HYDROGENATION
KINETICS
LOSSES
METALS
NONMETALS
OXYGEN
OXYGEN COMPLEXES
OXYGEN COMPOUNDS
POTASSIUM
POTASSIUM CARBONATES
POTASSIUM COMPOUNDS
REACTION KINETICS
SEPARATION PROCESSES
SORPTION
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES