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Effects of catalytic mineral matter on CO/CO[sub 2] ratio, temperature and burning time for char combustion [electronic resource]

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Bibliographic Details
Online Access:	Online Access
Corporate Authors:	Massachusetts Institute of Technology. Department of Chemical Engineering (Researcher), National Energy Technology Laboratory (U.S.) (Researcher)
Format:	Government Document Electronic eBook
Language:	English
Published:	Washington, D.C. : Oak Ridge, Tenn. : United States. Dept. of Defense ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 1990.
Subjects:	Catalysts. Kinetics. Combustion. Thermochemical Processes. Document Types. Carbon Monoxide. Reaction Heat. Chemical Reaction Kinetics. Catalytic Effects. Physical Properties. Oxygen Compounds. Carbon Compounds. Carbon Dioxide. Particles. Minerals. Oxygen Enrichment. Thermodynamic Properties. Enrichment. Temperature Effects. Progress Report. Particulates. Pyrolysis Products. Chars. Carbon Oxides. Chemical Reactions. Particle Size. Oxides. Size. Reaction Kinetics. Oxidation. Chalcogenides. Enthalpy. Coal, Lignite, And Peat.

Description
Abstract:	The importance of the CO[sub 2]/CO ratio of carbon oxidation products is illustrated by examination of the heats of reaction for formation of these two products. The heat released by formation of CO[sub 2] is a factor of 3.5 higher than for CO so the temperature of a particle will depend strongly on the CO[sub 2]/CO ratio produced. If gas diffusion through the boundary layer is fast, increased direct production Of CO[sub 2] produces a higher temperature and a higher burning rate. If the supply of oxygen to the surface is limited by diffusion through the boundary layer, production of CO[sub 2] consumes half as much carbon as production of CO so carbon consumption rate is reduced even though temperature may be somewhat higher. Models of these complex interactions have been developed; however the CO[sub 2]/CO ratio produced by the carbon-oxygen reaction must, at present be assumed or inferred from measurement of particle temperature. CO[sub 2]/CO ratios can be strongly influenced by catalytic material in the carbon and by the char temperature. In this program we are measuring the CO[sub 2]/CO ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates. Measurements of CO[sub 2]/CO ratio for an uncatalyzed char (spherocarb) were reported in the Oct-Dec 1989 progress report. This ratio varied from a maximum of 1.5 at 700 K and 100% oxygen to 0.06 at 1430 K and 5% oxygen.
Item Description:	Published through the Information Bridge: DOE Scientific and Technical Information. 01/01/1990. "doe/pc/89774-t7" "DE93008536" Sarofim, A.F.; Longwell, J.P.; Bar-Ziv, E.; Du, Z.; Lee, Chun-Hyuk.
Physical Description:	Pages: (9 p) : digital, PDF file.