## 3 Results and Discussion
### Effect of Heating Source Temperature  
The conducted theoretical research provided the ignition delay times of a double gas hydrate particle when varying the heating source temperature and using different schemes of heat supply (radiant, convective, and conductive) to the sample (Figure 2a-c). The comparison of the ignition delay times of the gas hydrates obtained in this research showed a positive correlation between the experimental and previous theoretical data [31; 36]. The lowest ignition delay times corresponded to the radiant heating conditions (up to 0.018 s (Figure 2a)) and decreased by 93% with an increase in the temperature in the muffle furnace in the range of 973-1273 K. Minimum delays during radiant heating can be explained by the fact that heat is evenly supplied to the gas hydrate from all sides. Under the conditions of convective and conductive heating, the essential heat flux is supplied from one side of the particle. The internal layers are heated more slowly as it takes more time for the gas hydrate pores to open for the gas release and subsequent ignition of the gas-vapor mixture compared with the radiant heating scheme. The highest ignition delay times were established when using convective heating, they did not exceed 0.1 s at 973 K (Figure 2b). With a rise in temperature, the ignition delay times also decreased to 0.004 s (by 96%). For conductive heating, the ignition delay times decreased from 0.045 s to 0.0005 s with  
Figure 2: The ignition delay times of the gas hydrate (\(R_{\text{g}}\) = 0.005 m) when varying the heating source temperature for three heat exchange schemes: (**a**) radiant [36], (**b**) convective [36], (**c**) conductive [31]. an increase in the metal heater temperature (Figure 2c). The Arrhenius law was found to be crucial for the reaction rates in all three heating schemes. As seen in Figure 2a-c, the heating source temperatures exponentially affected the ignition delay times. Table 2 presents the ignition delay times established for a methane-propane hydrate particle exposed to radiant heating at a variable furnace temperature. There were also ignition delay times of methane, propane, and ethane with the kinetics corresponding to the reactions of these gases in the air in the form of a gas-vapor mixture. These gases were chosen for comparison as the most common components in the composition of natural and artificial hydrates. The chemical reaction constants for the theoretical calculation of the ignition delay times under the conditions of radiant heating (\(E_{\text{a}}\)--activation energy, \(k_{0}\)--pre-exponential factor) for methane, propane, and ethane, adopted for the temperature range of 1000-3000 K [41] (Table 2), were taken from [42; 43; 44]. Considerable differences in the ignition delay times of the gas hydrate particles and gases (methane, propane) were attributed to the significantly different macrokinetics (Table 2). These differences arise from the fact that these kinetics are conventionally defined for different heating conditions. In the case of gas hydrates, the heating conditions have a major role to play. Therefore, it is important to adjust the kinetic scheme to the process conditions. The gas hydrate is not pure methane and propane. It consists of gases with certain impurities. Thus, the macrokinetics of the oxidation reactions needs to be adjusted relative to the reference values when scaling to the actual conditions of the sample ignition. A substantial volume in the composition of granules belongs to water in the form of ice, which turns to vapor when heated. The vapor, in turn, has a significant effect on the physical and chemical processes during the ignition and combustion of gas hydrate. As a result, the ignition delay times increase several-fold compared to the ignition of methane and propane as gas mixtures in the air medium (Table 2).