Experimental and kinetic investigation of the explosive behavior and free radical spectroscopic characteristics of hydrogen/propane mixed gas

Abstract

A detailed investigation of the explosion mechanism of hydrogen (H2) - propane (C3H8) mixture gas is the prerequisite for effective prevention of its explosion. This study delved into the explosion pressure and the spectral intensity of free radicals within the H2-C3H8 mixture, conducting a comprehensive investigation of reaction kinetics to elucidate reaction rates, elementary reaction sensitivity, and reaction path. Our findings unveiled a relationship between hydrogen augmentation and heightened explosion pressure, particularly when the hydrogen mixing ratio exceeded 80.0%, and the explosion index reached to St3 level, thereby indicating an exceeding safety risk. Moreover, a discernible augmentation was observed in the spectral intensities of H•, OH•, and O• radicals in tandem with an increased hydrogen mixing ratio. Notably, a linear correlation emerged between the explosion pressure and the spectral intensities of these free radicals. R1: H•+O2 =O•+OH• was the most important reaction step. As the ignition starts, H2 burns prior to C3H8, giving rise to the generation of H• radicals. These H• radicals, in turn, actively participate in the dehydrogenation of C3H8, effectively catalyzing the overall chemical reaction. These results can provide potent scientific support and guidance for the prevention and management of H2-C3H8 explosions.