Amaresh R.' Talk

Jun 05, 2014 - 17:00

Jun 05, 2014 - 18:00

Creativity Hall (Room 118) Chemical Engineering

Seminars

Amaresh R. Ph.D. student Chemical Engineering IITB

Knowledge of kinetics of reaction among the particulate solids has many diverse applications including synthesis of ceramics cements catalysts ferrites etc. It has been argued in the recent literature that such reactions have to be analyzed taking into account the fact that contact between the reacting particles occurs in a finite number of discrete `contact’ points. Among the models based on such considerations the model of Dalvi & Suresh (2011) has the correct asymptotic limits. In present study single step reaction between intimately mixed solid powders of Ca12Al14O33 (C12A7) and CaO (C) in formation of Ca3Al2O4 (C3A) is studied as a candidate system. The two major purposes of this study are (i) To demonstrate the effect of number of contact points (between particles of C and those of C12A7) and hence examine the validity of the contact point models (ii) To evolve a methodology consistent with the contact point models for estimating the kinetic parameters from literature. The scope of work involves (i) Synthesis of C12A7 and C with desired sizes to design experiments with different NAB; (ii) establishment of a protocol based on quantitative XRD for analysis of reaction samples (iii) Performing reactions on intimately mixed and pelletized specimens with wide range of NAB (3 to 3487) and at different temperatures; (iv) establishment of a parameter estimation methodology to interpret the kinetic data and determination of the kinetic parameters. It is shown in this study that NAB significantly affects the kinetics and estimated kinetic parameters diffusion co-efficient (D) activations energy (Q) and Initial neck size ratio between reacting particles (x1) in C12A7-C system by interpretation of data with diffusion controlled models from literature (Dalvi & Suresh 2011; Ginstling & Brounshtein 1950).