Heat and mass transfer and chemical transformation in a cerium nitrate droplet

    Authors

    B. Pathak; S. Basu;R. Kumar

    Comments

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    Abbreviated Journal Title

    Int. J. Heat Mass Transf.

    Keywords

    Acoustic levitation; Heat and mass transfer; Chemical reaction; Droplet; vaporization; Nanoceria; Droplet agglomeration; PRECURSOR DROPLETS; THERMAL-DECOMPOSITION; VARIABLE PROPERTIES; VAPORIZATION; PLASMA; EVAPORATION; FIELD; PRESSURE; MODEL; Thermodynamics; Engineering, Mechanical; Mechanics

    Abstract

    This paper deals with the thermo-physical changes that a droplet undergoes when it is radiatively heated in a levitated environment. The heat and mass transport model has been developed along with chemical kinetics within a cerium nitrate droplet. The chemical transformation of cerium nitrate to ceria during the process is predicted using Kramers' reaction mechanism which justifies the formation of ceria at a very low temperature as observed in experiments. The rate equation modeled by Kramers is modified suitably to be applicable within the framework of a droplet, and predicts experimental results well in both bulk form of cerium nitrate and in aqueous cerium nitrate droplet. The dependence of dissociation reaction rate on droplet size is determined and the transient mass concentration of unreacted cerium nitrate is reported. The model is validated with experiments both for liquid phase vaporization and chemical reaction. Vaporization and chemical conversion are simulated for different ambient conditions. The competitive effects of sensible heating rate and the rate of vaporization with diffusion of cerium nitrate is seen to play a key role in determining the mass fraction of ceria formed within the droplet. Spatially resolved modeling of the droplet enables the understanding of the conversion of chemical species in more detail. (c) 2013 Elsevier Ltd. All rights reserved.

    Journal Title

    International Journal of Heat and Mass Transfer

    Volume

    63

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    301

    Last Page

    312

    WOS Identifier

    WOS:000320289900031

    ISSN

    0017-9310

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