Combustion behavior of char/carbon particles

Annamalai, K.; Durbetaki, P.

doi:10.1016/s0082-0784(79)80019-3

Cited by 3 publications

(2 citation statements)

References 18 publications

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“…The mass fraction of CO at the surface is greater than about three times the mass fraction of O2 at the surface for T, > lo00 K for r, = 500 pm, and for T, > 1800 K for r, = 50 pm. If CO oxidation takes place in the gas film surrounding the particles, then it was shown earlier (Annamalai and Durbetaki, 1978 ) that Yc0,, B Yo,,, and YCq,, as long as 1600 < I', < 2200 K.…”

Section: Resultsmentioning

confidence: 97%

Distinctive burning characteristics of carbon particles

Annamalaim

Caton

1987

Can J Chem Eng

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Several reaction mechanisms exist in the literature for the gasification of char/carbon particles. The general procedure for modelling particle gasification is to assume a mechanism of combustion, obtain the theoretical burning rate and particle temperature, and then validate the mechanism by comparing the results with experimental data. The present work shows that the burning rate and particle temperature are independent of heterogeneous and homogeneous reaction mechanisms and their rate kinetics as long as the oxygen (O2) and carbon dioxide (CO2) concentrations at the burning surface are low compared to carbon monoxide (CO) concentration. Experimental data are cited which are in agreement with the model's predictions for both particle temperatures and burning times. The relevance of the results to industrial combustors is discussed.

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Section: Resultsmentioning

confidence: 97%

Distinctive burning characteristics of carbon particles

Annamalaim

Caton

1987

Can J Chem Eng

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“…(1967) and Field (1969) employed simple heat and mass transfer coefficients and assumed shrinking core reaction. The analysis was later extended to include a detailed account of external heat and mass transfer while retaining shrinking core oxidation (Ubhayakar, 1976;Libby and Blake, 1979;Annamalai and Durbetaki, 1979). Further extensions invoked considerations of intra particle diffusion, reaction and pore growth.…”

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confidence: 99%

A Theoretical Study of Combustion of Nonspherical Particles

Choi

Gavalas

1993

Combustion Science and Technology

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A theoretical study is carried out of the combustion of nonspherical carbonaceous particles in the regime of shrinking core reaction. The first problem addressed is the calculation of the pseudosteady temperature and oxidation rate for a particle of given shape. This problem involves the solution of the external diffusion and heat conduction equations with the reaction entering as a boundary condition over the particle surface. Using the boundary integral method, the problem is reformulated as a system of two coupled integral equations which are solved numerically by suitable discretization. The complete transient problem addressing the evolution of particle shape and particle temperature during burnout is similarly formulated by the boundary integral method and solved numerically. Over a broad range of parameters, the pseudosteady particle temperature and rate of oxidation are very nearly equal to those of spherical particles of equal volume and surface area respectively. The transient solutions obtained for parameters typical of pulverized combustion show that during burnout the particle becomes increasingly nonspherical. As expected, nonspherical particles burn faster than spherical particles of the same initial volume, but the difference in burnout times is less than 20% for initial aspect ratios between one and three.

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Unstetigkeiten im Abbrandverhalten angeströmter Kohlenstoffoberflächen

Adomeit¹,

Hocks²,

Henriksen³

1983

Ber Bunsenges Phys Chem

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In the present work the ignition and quench phenomena of the combustion of a carbon surface in oxidizing cross flow is investigated theoretically. For certain values of moisture content and of heterogeneous reaction rates, multiple ignition and quench phenomena are observed together with non‐monotonous dependence of the burning rate upon the surface temperature. These phenomena occur in the region of transition from the reaction controlled to the transport controlled regime. In dependence upon reaction rates this regime extends from 1300 K to about 2000 K.

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Combustion behavior of char/carbon particles

Cited by 3 publications

References 18 publications

Distinctive burning characteristics of carbon particles

Distinctive burning characteristics of carbon particles

A Theoretical Study of Combustion of Nonspherical Particles

Unstetigkeiten im Abbrandverhalten angeströmter Kohlenstoffoberflächen

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