Application of Argon Plasma Jet for Methane Hydrate Decomposition by Radio Frequency Irradiation

In this study, decomposition of methane hydrate using argon plasma jet investigated in the pressure range of 0.1MPa to 2.0MPa. The plasma generated under the high-pressure condition, which is difficult to achieve when using radio frequency (RF) plasma in the liquid method. By using emission spectrometer analysis, the excitation temperature is found to increase as the gas pressure increases, whereas, it decreases as the argon flow rate increases. During the process of plasma irradiation, the required essential reactions for methane hydrate decomposition, such as methane hydrate dissociation (MHD), steam methane reforming (SMR), and methane cracking reaction (MCR) were not completely satisfied due to an insignificant amount of methane. The gas chromatography analysis confirmed that the methane cracking reaction (MCR) was only occurred to generate hydrogen and the C(s), due to the absence of C2H2 and C2H4 as the byproducts. In comparison with the other primary reactions of methane hydrate decomposition, steam methane reforming reaction became dominant in converting methane into hydrogen. Although the hydrogen production efficiency is less than that of radio frequency plasma in liquid, the reduction of CO2 by the thermal decomposition of Teflon from CO making it possible is considered as an advanced promising technique in the future