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A study of CrO vapor decomposition in approximated isothermal RF plasma reactors
Author(s) -
Meubus P.,
Huczko A.
Publication year - 1989
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450670118
Subject(s) - arrhenius equation , activation energy , thermodynamics , isothermal process , decomposition , order of reaction , reaction rate constant , reaction rate , materials science , thermal decomposition , chemical kinetics , argon , kinetics , analytical chemistry (journal) , chemistry , physics , organic chemistry , quantum mechanics , catalysis
A simplified RF plasma reaction model has been used for describing the thermal decomposition reaction of chromium oxide (CrO) , using an argon RF plasma operated at 2.7 kW. A set of 3 approximated isothermal reactors in series were defined for this purpose within the RF torch. The conversion rate curves were obtained for the respective average isothermal temperatures 4250 K, 3500 K and 2950 K. Reaction order and reaction rate constant were determined at each temperature. Based on the values obtained for the reaction orders, it appears that the kinetics process involved is similar at 2950 K and 3500 K, while a distinctly different process occurs at 4250 K. Assuming that the two former reactions show an Arrhenius type behavior, an activation energy value has been derived, valid between 2900 K and 3500 K. The activation energy for the CrO decomposition reaction has been calculated on the basis of an Eyring and Polanyi model. The calculated and experimental results differ by about 20%. The main point responsible for the large reaction rate constant increase observed at 4250 K is the drastic change of the pre‐exponential factor in the Arrhenius equation.