Painter, MM
1989
The Effects of Rank and Preparation Method on Coal Char Oxidation Rates
Hyde, W.D.; Hecker, W.C.; Cope, R.F.; Painter, M.M.; McDonald, K.M. and Bartholomew, C.H.
Western States Section/The Combustion Institute, Livermore, California, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates).
Coal char reactivity has been found to vary greatly depending on the rank and type of the parent coal. Also, the conditions under which a given coal is devolatilized to produce char can significantly effect the reactivity of the resulting char. Preparation conditions such as gas environment, heating rate, peak temperature, residence time, and particle size are very important in determining the resulting char reactivity in that they effect its chemical and physical structure.
The general objectives of this work are to (1) understand the effect of the rank of the parent coal on the oxidation rate (reactivity) of its derived char, (2) understand the effect of devolatilization conditions on the char oxidation rate, and (3) determine any correlations which may exist between char oxidation rates and the chemical and physical properties of the chars. Specifically, oxidation rates for char from 5 coals of various ranks were measured and compared. The differences in char reactivity of chars produced in three different char preparation apparatus: a muffle furnace, a flat-flame methane burner, and a high temperature inert-atmosphere reactor, were studied. The effects of peak temperature, residence time, and particle size were also studied. Finally, correlations of oxidation rate with hydrogen content, cluster size, and surface area were attempted.
Samples of chars from Beulah Zap (Lignite), Dietz (Subbituminous A), Utah Blind Canyon (hvC Bituminous), Pittsburgh #8 (hvA Bituminous), and Pocahontas #3 (lv Bituminous) were prepared at different residence times in the Flat-Flame Char Preparation Apparatus; samples of Pittsburgh #8, Beulah Zap, and Dietz were also prepared in the muffle furnace and the high temperature inert-atmosphere reactor. The low temperature reactivity of all the coal char samples was determined in a TGA using Tcrit as the reactivity indicator. Tcrit is defined at the temperature at which the mass loss of the sample reaches 11 percent per minute.
Painter, MM
1989
The Effects of Rank and Preparation Method on Coal Char Oxidation Rates
Hyde, W.D.; Hecker, W.C.; Cope, R.F.; Painter, M.M.; McDonald, K.M. and Bartholomew, C.H.
Western States Section/The Combustion Institute, Livermore, California, 1989. Funded by ACERC (National Science Foundation and Associates and Affiliates).
Coal char reactivity has been found to vary greatly depending on the rank and type of the parent coal. Also, the conditions under which a given coal is devolatilized to produce char can significantly effect the reactivity of the resulting char. Preparation conditions such as gas environment, heating rate, peak temperature, residence time, and particle size are very important in determining the resulting char reactivity in that they effect its chemical and physical structure.
The general objectives of this work are to (1) understand the effect of the rank of the parent coal on the oxidation rate (reactivity) of its derived char, (2) understand the effect of devolatilization conditions on the char oxidation rate, and (3) determine any correlations which may exist between char oxidation rates and the chemical and physical properties of the chars. Specifically, oxidation rates for char from 5 coals of various ranks were measured and compared. The differences in char reactivity of chars produced in three different char preparation apparatus: a muffle furnace, a flat-flame methane burner, and a high temperature inert-atmosphere reactor, were studied. The effects of peak temperature, residence time, and particle size were also studied. Finally, correlations of oxidation rate with hydrogen content, cluster size, and surface area were attempted.
Samples of chars from Beulah Zap (Lignite), Dietz (Subbituminous A), Utah Blind Canyon (hvC Bituminous), Pittsburgh #8 (hvA Bituminous), and Pocahontas #3 (lv Bituminous) were prepared at different residence times in the Flat-Flame Char Preparation Apparatus; samples of Pittsburgh #8, Beulah Zap, and Dietz were also prepared in the muffle furnace and the high temperature inert-atmosphere reactor. The low temperature reactivity of all the coal char samples was determined in a TGA using Tcrit as the reactivity indicator. Tcrit is defined at the temperature at which the mass loss of the sample reaches 11 percent per minute.