New procedure for derivation of approximations for temperature integral

A new procedure for the derivation of the approximations for temperature integral from its derivatives is presented. This procedure can produce a series of the approximations, including some published and some new ones. By combining the different order derivatives of temperature integral, a new approximation is proposed. The corresponding equation for the evaluation of kinetic parameters can be put in the form$$\ln\left[{G(\alpha)\over T^2}\right]=\ln\left[{AR\over \beta E}{3(E/RT)^2+16(E/RT)+4\over 3(E/RT)^2+22(E/RT)+30}\right]-{E\over RT}$$The validity of the new approximation has been tested with the true value of temperature integral from numerical calculation. Compared with several published approximations, the new one has the highest accuracy and at the same time retains simplicity, which indicates it is a good approximation for the evaluation of kinetic parameters from nonisothermal kinetic analysis. © 2006 American Institute of Chemical Engineers AIChE J, 2006