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This paper investigates the effect of non-linear thermal profile on the numerical solution of the multi-reaction model. According to the practical perspective, the temperature distribution at a different section of pyrolysis reactor is not necessarily following the ideal thermal history; therefore, it is necessary to predict the behaviour of the system for the higher degree of freedom. TG thermogram is obtained by the thermal degradation of pine needles sample in the thermogravimetric analyser (TGA). The activation energy, frequency factor, reaction order and the scale, shape and location parameters of a stochastic function are estimated for the non-linear parabolic thermal profile. The conventional Laplace integral is used to approximate the multi-reaction model. Activation energy obtained for the non-thermal profile lies in the range of 57.5–60 kJ·mol−1, whereas the frequency factor varies from 103–105 min-1. The obtained value of reaction order (n) lies in the domain of (0.9, 1.6).

This paper deals with pyrolysis decomposition of Cedrus deodara leaves with the help of thermogravimetric analysis (TGA). Experiments are performed in the presence of inert atmosphere of nitrogen. Experiments are conducted at three different heating rates of 5 °C∙min-1, 10 °C∙min-1 and 15 °C∙min-1 within temperature range of 35 °C to 700 °C. Arrhenius parameters such as activation energy and frequency factor are estimated by Flynn Wall and Ozawa (FWO), Kissinger-Akahira-Sonuse (KAS) and Kissinger. The activation energy and frequency factor calculated by using Kissinger method are 67.63 kJ∙mol-1 and 15.06 . 104 min-1 respectively; whereas the averaged values of the same parameters through FWO and KAS methods are 89.59 kJ∙mol-1 and 84.748 kJ∙mol-1, 17.27 . 108 min-1 and 62.13 . 107 min-1 respectively. Results obtained through Kissinger method represent the actual values of kinetic parameters. Conversely, FWO and KAS methods reflect the apparent values of kinetic parameters, as they are highly influenced by the overlapping of competitive reactions occur during pyrolysis.

This paper deals with the influence of some parameters relevant to biomass pyrolysis on the numerical solutions of the nonisothermal n th order distributed activation energy model using the Rayleigh distribution. Investigated parameters are the integral upper limit, the frequency factor, the heating rate, the reaction order and the scale parameters of the Rayleigh distribution. The influence of these parameters has been considered for the determination of the kinetic parameters of the non-isothermal n th order Rayleigh distribution from the experimentally derived thermoanalytical data of biomass pyrolysis.