## 3 Results and Discussion
### Determination of Kinetic Parameters  
The kinetic parameters of crude oil oxidation include activation energy and the pre-exponential factor [41]. In this study, the activation energy and pre-exponential factor were calculated based on the Flynn-Wall-Ozawa method and the Arrhenius equation by using the TGA experimental results. The activation energy and pre-exponential factor are determined using Equations (2) and (3) with characteristic temperatures at the same conversion rate under different heating rates [42; 43]. The equations are as follows:  
\[E=-2.190R\frac{\mathrm{d}\mathrm{lg}\beta}{\mathrm{d}(1/T\alpha)} \tag{2}\]  
Figure 8: The weight loss rates with different heating rates: (**a**) oil sample G; (**b**) oil sample M.  
Figure 9: The conversion rates with different heating rates: (**a**) oil sample G; (**b**) oil sample M.  
\[A=\beta E\frac{\exp(E/RT\alpha)}{P_{O2}RT\alpha^{2}} \tag{3}\]  
where \(E\) is the activation energy, kJ/mol; \(R\) is the general gas constant, and its value is 8.314, J/(mol\(\cdot\)K); \(\beta\) is the heating rate, K/min; \(T\alpha\) is the temperature at a specific conversion, K; \(A\) is the pre-exponential factor, (kPa\(\cdot\)s)\({}^{-1}\); and \(P_{O2}\) is the partial pressure of oxygen, Pa.  
For the TGA experiments on the two different oil samples, a median heating rate of \(\beta\) = 5.0 K/min was determined. The characteristic temperatures for oil sample G were obtained from the TGA curve at the rate of 5.0 K/min as \(T\alpha_{1}\) = 765.75 K, and for oil sample M, it was \(T\alpha_{2}\) = 737.95 K. Subsequently, the specified conversion rates corresponding to these temperatures were determined based on the conversion rate and temperature data as \(\alpha_{1}\) = 0.965 for oil sample G and \(\alpha_{2}\) = 0.940 for oil sample M.  
According to the characteristic conversion rates, Table 6 presents the comparison of oxidation kinetic parameters with equal conversion. As shown in Figure 10, the linear fit equation for lg\(\beta\) against \(1/T\alpha\) for oil sample G is y = \(-\)7.2078x + 10.108, with a correlation coefficient R\({}^{2}\) = 0.9997. For oil sample M, the linear fit equation is y = \(-\)7.0261x + 10.224, with a correlation coefficient R\({}^{2}\) = 0.9997. By using Equation (2) to calculate the activation energy and Equation (3) to calculate the pre-exponential factor, the results for oil sample G were an activation energy \(E\) = 131.2 kJ/mol and a pre-exponential factor \(A\) = 9.46 \(\times\) 10\({}^{4}\) (kPa\(\cdot\)s)\({}^{-1}\). Similarly, for oil sample M, the activation energy was \(E\) = 127.9 kJ/mol, and the pre-exponential factor was \(A\) = 1.26 \(\times\) 10\({}^{5}\) (kPa\(\cdot\)s)\({}^{-1}\). Compared to the activation energy of 147 kJ/mol for coke combustion, the activation energies for the HTO stage of both oil samples were similar, indicating that high-temperature combustion could continue. This suggests that the oxidation kinetics of the two different heavy oil samples in terms of their viscosity, density, and composition met the requirements for ISC. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Sample**} & \multirow{2}{*}{\begin{tabular}{c} **Heating Rate \(\beta\)** \\ **(K/min)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **lg\(\beta\)** \\ **kg** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Specified Conversion** \\ **Rate \(\alpha\) (\%)** \\ \end{tabular} } & \multirow{2}{*}{\
\begin{tabular}{c} **Corresponding** \\ **Temperature \(T\alpha\) (K)** \\ \end{tabular} } & \multirow{2}{*}{
\begin{tabular}{c} **1/\(T\alpha\)** \\ **(10\({}^{3}\) K\({}^{-1}\))** \\ \end{tabular} } \\ \hline G & 3.0 & 0.477 & 0.965 & 748.55 & 0.001336 & 1.3359 \\  & 5.0 & 0.699 & 0.965 & 765.75 & 0.001306 & 1.3059 \\  & 7.0 & 0.845 & 0.965 & 778.35 & 0.001285 & 1.2848 \\ \hline M & 3.0 & 0.477 & 0.940 & 720.75 & 0.001387 & 1.3874 \\  & 5.0 & 0.699 & 0.940 & 737.95 & 0.001355 & 1.3551 \\  & 7.0 & 0.845 & 0.940 & 748.95 & 0.001335 & 1.3352 \\ \hline \hline \end{tabular}
\end{table}