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Full-Text Articles in Chemical Engineering
Investigation Of An Iron-Based Additive On Coal Pyrolysis And Char Oxidation At High Heating Rates, John M. Sowa, Thomas H. Fletcher
Investigation Of An Iron-Based Additive On Coal Pyrolysis And Char Oxidation At High Heating Rates, John M. Sowa, Thomas H. Fletcher
Faculty Publications
Iron-based catalysts have been shown to enhance coal pyrolysis and char oxidation at low to moderate temperatures and heating rates (b1250 K and 1–1000 K/s). Such catalytic activity has not been demonstrated at high heating rates and temperatures approaching pulverized coal combustion applications. The effect of an iron-based additive on coal pyrolysis and char combustion was studied in a flat-flame burner system at high particle heating rates using a Kentucky bituminous coal. Pyrolysis and char reactivity of two treated coals with different catalyst loadings were studied and compared with the untreated coal. The total volatiles yield for the treated coals …
Experimental Measurements During Combustion Of Moist Individual Foliage Samples, Brent M. Pickett, Carl Isackson, Rebecca Wunder, Thomas H. Fletcher, Bret Buitler, David R. Weise
Experimental Measurements During Combustion Of Moist Individual Foliage Samples, Brent M. Pickett, Carl Isackson, Rebecca Wunder, Thomas H. Fletcher, Bret Buitler, David R. Weise
Faculty Publications
Individual samples of high moisture fuels from the western and southern United States and humidified aspen excelsior were burned over a flat-flame burner at 987◦ ±12 C and 10±0.5 mol% O2. Time-dependent mass and temperature profiles of these samples were obtained and analysed. It was observed that significant amounts of moisture remained in the individual samples after ignition occurred. Temperature histories showed a plateau at 200◦–300 C at the leaf perimeter rather than at 100 C, with a plateau of 140 C for the leaf interior. Implications are that classical combustion models should be altered to reflect the behaviour of …
Flame Interactions And Burning Characteristics Of Two Live Leaf Samples, Brent M. Pickett, Carl Isackson, Rebecca Wunder, Thomas H. Fletcher, Bret W. Butler, David R. Weise
Flame Interactions And Burning Characteristics Of Two Live Leaf Samples, Brent M. Pickett, Carl Isackson, Rebecca Wunder, Thomas H. Fletcher, Bret W. Butler, David R. Weise
Faculty Publications
Combustion experiments were performed over a flat-flame burner that provided the heat source for multiple leaf samples. Interactions of the combustion behavior between two leaf samples were studied. Two leaves were placed in the path of the flat-flame burner, with the top leaf 2.5 cm above the bottom leaf. Local gas and particle temperatures, as well as local oxygen concentrations, were measured along with burning characteristics of both leaves. Results showed that the time to ignition of the upper leaf was not significantly affected by the presence of the lower leaf. The major difference observed was that the time of …
Biomass-Coal Co-Combustion: Opportunity For Affordable Renewable Energy, Larry Lin Baxter
Biomass-Coal Co-Combustion: Opportunity For Affordable Renewable Energy, Larry Lin Baxter
Faculty Publications
This investigation explores the reasons for and technical challenges associated with co-combustion of biomass and coal in boilers designed for coal (mainly pulverized coal) combustion. Biomass-coal co-combustion represents a near-term, low-risk, low-cost, sustainable, renewable energy option that promises reduction in net CO2 emissions, reduction in SOx and often NOx emissions, and several societal benefits. Technical issues associated with cofiring include fuel supply, handling and storage challenges, potential increases in corrosion, decreases in overall efficiency, ash deposition issues, pollutant emissions, carbon burnout, impacts on ash marketing, impacts on SCR performance, and overall economics. Each of these issues has been investigated and …
The Impact Of Coal Pyrolysis On Combustion, Peter R. Solomon, Thomas H. Fletcher
The Impact Of Coal Pyrolysis On Combustion, Peter R. Solomon, Thomas H. Fletcher
Faculty Publications
The pyrolysis process has impacts throughout coal combustion. The roles of pyrolysis in various aspectsof the coal combustion process are described, including the devolatilization yield, nitrogen release, softening and swelling, soot formation, and char reactivity. These processes can be understood and quantitatively predicted using recently developed network pyrolysis models that describe the transformation of the coal's chemical structure. The models are described and examples of their predictive ability for important coal combustion phenomena are presented.