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Influence of preheating rate on kinetics of high‐temperature gas–solid reactions
Author(s) -
Thiers Laurent,
Leitenberger Bryan J.,
Mukasyan Alexander S.,
Varma Arvind
Publication year - 2000
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690461218
Subject(s) - kinetics , thermodynamics , activation energy , diffusion , chemistry , reactivity (psychology) , chemical kinetics , context (archaeology) , reaction rate , analytical chemistry (journal) , chromatography , organic chemistry , medicine , paleontology , physics , alternative medicine , pathology , quantum mechanics , biology , catalysis
Abstract The influence of preheating rate on kinetics of high‐temperature reactions in gas–solid systems was investigated by a computer‐assisted electrothermography technique. Two systems were investigated: Nb–N 2 and Ti–N 2 , in the temperature ranges 2,100–2,500 K and 1,350–1,600 K, respectively. The results showed that for both systems, reaction kinetics are enhanced by increasing the preheating rate to the desired reaction temperature. Analysis of the experimental data in the context of the sharp‐interface model showed that the activation energy of the diffusion coefficient does not depend on heating rate, while the preexponential factor is affected. Additional experiments suggest that nonisothermal preheating, even though of short duration, about 10 ms, influences chemical reactivity of the solid reactant by changing its specific surface area.