Estimation of activation energy by isoconversion methods

Ozawa, Taku

doi:10.1016/0040-6031(92)85192-x

Cited by 389 publications

(179 citation statements)

References 15 publications

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“…(The latter equation is essentially the Flynn-Wall-Ozawa method [14,15].) Taking the difference of the latter two equations provides:…”

Section: Discussionmentioning

confidence: 99%

“…For the above mentioned methods κ equals 0 (FWO method), 2 (KAS method) and 1.9 to 1.95 for the methods by Starink [10]. Whilst all of these works [9][10][11][12][13][14][15][16][17][18] (and a vast range of other works) imply that the approximation involved in neglecting I(T o ) is appropriate, it appears that the actual influence of this approximation on the analysed activation energy values has never been quantitatively determined. The aim of the present short paper is to investigate the accuracy of this approximation.…”

Section: Introductionmentioning

confidence: 99%

“…These methods include the Kissinger method [11], the Kissinger-Akahira-Sunose (KAS) method [12,13] (also termed the generalised Kissinger method), the Flynn-WallOzawa (FWO) method [14,15], a method described by Vyazovkin and co-workers [16,17] and 3 highly accurate methods developed by the present author [10,18,19]. All of these methods involve the plotting of 1/T f vs. a logarithmic function which depends on the heating rate and often the temperature and all of these methods neglect the last integral term in Eq.…”

Section: Introductionmentioning

confidence: 99%

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Activation energy determination for linear heating experiments: deviations due to neglecting the low temperature end of the temperature integral

Starink

2006

J Mater Sci

127

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Model-free isoconversion methods which use approximations of the temperature integral are generally reliable methods for the calculation of activation energies of thermally activated reactions studied during linear heating. These methods generally neglect the temperature integral at the start of the linear heating, I (T o ). An analytical equation is derived which describes the deviations introduced by this approximation.It is shown that for most reactions encountered this assumption does not have a significant influence on the accuracy of the method. However, in cases where T o is within about 50 to 70K of the reaction stage to be investigated and activation energies are relatively low, significant deviations are introduced. It is shown that some of the published thermal analysis work on activation energy analysis of reactions occurring at relatively low temperatures is affected by these deviations. Examples are specific cases of dehydration reactions, cure reactions and cluster formation in Al alloys.

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“…(The latter equation is essentially the Flynn-Wall-Ozawa method [14,15].) Taking the difference of the latter two equations provides:…”

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Activation energy determination for linear heating experiments: deviations due to neglecting the low temperature end of the temperature integral

Starink

2006

J Mater Sci

127

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“…Fan [4] used a new method for the derivation of activation energies is proposed by Starink [5]. It was shown [5] that this method is an order of magnitude more accurate than the Kissinger and Ozawa methods [6]. These methods all comply with the following…”

Section: Experimental Measurements Of Thermite Heat Reactionmentioning

confidence: 99%

Numerical simulation of a patent technology for sealing of deep-sea oil wells using nonlinear finite element method

Abdelal

Robotham

Carragher³

2015

Journal of Petroleum Science and Engineering

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“…The curves are constructed with 3 dynamics, 3.33 × 10 -2 K/s 1 , 8.33 × 10 -2 K/s 1 and 1.67 × 10 -1 K/s 1 using TGA data where the tests were performed in a nitrogen atmosphere. The method is a variation of the Ozawa, Flynn and Wall [7][8] (OFW finds a constant slope of -Ε/R by plotting ln(β) versus 1/T for each value of conversional coefficient, α) based on the previous work of Friedman [9]). …”

Section: Tg/dtg Data and Kinetic Parameterizationmentioning

confidence: 99%

Pyrolysis Characterization of a Lineal Low Density Polyethylene

Capote¹,

Alvear²,

Abreu³

et al. 2011

Fire Safety Science - Proceedings of the 10th International Sym

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A set of parameters for pyrolysis characterization of linear low density polyethylene (LLDPE) were chosen to measure its combustion behaviour. Two kinds of parameters were selected, material and reaction. The material parameters were: effective values of the mass density (ρ); specific heat capacity (c); thermal conductivity (k); absorption coefficient (қ) and emissivity (ε). The reaction parameters were the exponential factor (Z), the energy of activation (Ε) and the reaction mechanism f(α). In addition simultaneous thermal analysis (STA) tests were carried out at heating rates of 2, 5 and 10 K/min in N 2 atmosphere to obtain the kinetic triplet and cone calorimeter tests at irradiance levels of 25, 40, 50 and 75 kW/m 2 to compare the simulated mass loss rate against real mass loss rate. Finally the cone calorimeter tests were used as input values to optimize the parameter set to perform real mass loss rate.

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Estimation of activation energy by isoconversion methods

Cited by 389 publications

References 15 publications

Activation energy determination for linear heating experiments: deviations due to neglecting the low temperature end of the temperature integral

Activation energy determination for linear heating experiments: deviations due to neglecting the low temperature end of the temperature integral

Numerical simulation of a patent technology for sealing of deep-sea oil wells using nonlinear finite element method

Pyrolysis Characterization of a Lineal Low Density Polyethylene

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