Bifurcation behavior in a homogeneous-heterogeneous reaction system with a constant power source

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Combustion and Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(94)90168-6· OSTI ID:5377640

Zhang, Dongke ^[1]

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1. Univ. of Adelaide (Australia). Dept. of Chemical Engineering

A bifurcation analysis of ignition/explosion and extinction is performed for a system that involves chemical self-heating for an exothermic gas-phase (homogeneous) reaction in a spherical zone with a particle-gas (heterogeneous) reaction at the center initiated by a constant power source. It is shown that the criticality is a feature of such a reaction system, with multiple steady-state solutions that characterize both homogeneous and heterogeneous ignition behavior. Ignition occurs either on the particle surface, or in the gas phase, when conditions for steady-state solutions are broken down accompanying changes in the power. Depending on the gas composition, the surface reactions, and the particle size, several different phenomena can occur as the particle heating is increased. For small particles there is either no ignition or pure surface burning, but the gas phase never ignites. For large particles there is either no combustion or the gas phase ignites, but there is no regime with surface combustion only. For a range of intermediate particle size one observes first a transition from no combustion'' to surface combustion and thus a transition to gas phase ignition as the particle heating rate increases. These results are qualitatively supported by experimental data published in literature. The relevance of this study to practical application is also discussed.

• OSTI ID: 5377640
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 96:1-2; ISSN 0010-2180; ISSN CBFMAO
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
ACTIVATION ENERGY
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COCOMBUSTION
COMBUSTION
COMBUSTION HEAT
COMBUSTION KINETICS
ENERGY
ENTHALPY
FUELS
GAS FUELS
HEAT
KINETICS
MATHEMATICAL MODELS
OXIDATION
PHYSICAL PROPERTIES
REACTION HEAT
REACTION KINETICS
SOLID FUELS
THERMOCHEMICAL PROCESSES
THERMODYNAMIC PROPERTIES