Reply to remarks on “A new equation for modeling nonisothermal reactions”

Abstract

There are numerous ways to solve the temperature integral. Integral methods are perhaps one of the most accurate and popularly used methods to solve the temperature integral [1][2][3]. In a recent paper, Agrawal [4] showed how the integral methods such as Coats Redfern, Gorbachev and Li equations were related and proposed a better equation based on these equations. The topic of Agrawal's paper was limited to these integral approximations as they were obtained by integrating the temperature integral by parts. It was not the purpose to review and examine the accuracy of all temperature integral approximations available in the volumenous literature; as this would be a formidable mission. Besides, the accuracy of various integrals were seldom available in the form of a plot of percent error of the temperature integral as a function of the E/R T ratio to make the task attemptable.Further it is futile to make such an attempt as the exact solution can be obtained by numerical techniques. Zsak6 [5] in his criticism of my work makes incorrect remarks and quotes some of my statements out of context. Zsak6 simply quotes his own publications to claim that the physical significance of the Arrhenius equation is obscure. No proofs or justifications are available in his quoted papers [6,7]. As discussed by Agrawal [8] (replying to another of Zsak6's [9] questions), many authors merely question the physical significance of the Arrhenius equation, but use it anyways. If Arrhenius equation is so objectionable and incorrect, then why isn't there a better equation available to replace it? The misconception on the use of Arrhenius equation has been referred to in detail by Agrawal [8,10]. It is sufficient to mention here that Arrhenius equation is perhaps the most used equation and it serves it purpose in correlating the kinetic data satisfactorily. The lack of an alternate method to correlate the temperature dependence of the rate constant clearly implies that the Arrhenius equation is universally accepted.I do not see the reasoning behind Zsak6's objections to methods to approximateJohn Wiley & Sons, Limited, Chichester Akad~miai Kiad6, Budapest

Model Dependence of the Activation Energy Derived from Nonisothermal Kinetic Data

“…More often, the integral version of eq 1 is used to reduce the noise of the differential data: where g( x ) is termed the integral kinetic function that represents various reaction models (Table ). In nonisothermal studies, approximations have been applied to the integral in various forms − to linearize eq 2. For example, the Coats−Redfern 5 approximation has the following form: where q is the linear heating rate in degrees Celsius per minute.…”