▪ Abstract The kinetics of solid state reactions generally cannot be assumed to follow simple rate laws that are applicable to gas-phase reactions. Nevertheless, a widely practiced method for extracting Arrhenius parameters from thermal analysis experiments involves force fitting of experimental data to simple reaction-order kinetic models. This method can produce significant errors in predicted rates outside the experimental range of temperatures, and it is of limited utility for drawing mechanistic conclusions about reactions. In this review, we discuss how an alternative “model-free” approach to kinetic analysis, which is based on the isoconversional method, can overcome some of these limitations.

Kinetics in solids

In principle, the kinetic analysis of thermal effects has limitations when based on a single measurement. Using a simulated example and the dehydration of Ca(OH)2 , it will be shown that, through the simultaneous application of non-linear regression to several measurements run at different heating rates (multivariate non-linear regression), the difficult problem of determining the probable reaction type can be reliably solved.

Kinetic Analysis Using Multivariate Non-linear Regression. I. Basic concepts

Experimental study of stages in aluminum particle combustion in air

A nonlinear algorithm has been suggested to increase the accuracy of evaluating the activation energy by the integral isoconversional method. A minor modification of the algorithm has made it possible to adapt the isoconversional method for an arbitrary variation of the temperature. This advanced isoconversional method allows for trustworthy estimates of the activation energy when the thermal effect of a reaction makes the temperature of a sample deviate from a prescribed heating program.

Advanced isoconversional method

The thermal decomposition of oxalates. A review

Assessment is given of physical and thermodynamic properties of sodium. FORTRAN subroutine computes enthalphy and entropy of sodium in given state, and composition, molecular weight, volume, and compressibility factor of corresponding vapor. Tabular results for saturated liquid and vapor are presented for a 500-2500 degree F range.

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G. H. Golden

Papers

Thermophysical properties of sodium