Methane conversion to Hydrogen and Higher Hydrocarbons by Kilohertz pulsed plasma

The production of hydrocarbons directly from methane requires high temperatures, which makes the process expensive and non-selective. One of the new approaches to activate reactants is the electric gas discharge. A series of plasma and chemical processes such as ionization, dissociation and excitation of molecules and atoms are initiated that make the ionized fluid far from thermodynamic equilibrium. In such non-equilibrium medium the temperature of electrons can reach several eV while the temperature of the reactants remains relatively low, near room temperature. Hence, the electron collisions are responsible for the dissociation of the molecules. There are various works demonstrating the possibility of methane conversion by non-thermal plasmas [۱,۲]. The main drawback of non-thermal plasmas is their low chemical energy efficiency, reaching ۱۰% at most, which is far from the industrial demand that require high conversions at chemical efficiencies above ۳۰%. The pulsed plasmas, however, demonstrated far better results [۳-۷]. The main advantage of the pulsed plasmas, relative to the continues ones, is due to its ability of rendering temporal non equilibrium of population distribution among the molecular vibrational levels, through which the dissociation of the molecule take places more easily [۸].In this study we will examine the influence of electrode gap distance in the transformation of pure methane to produce hydrocarbons using short pulsed plasma reactor.

کلیدواژه ها:

Pulsed plasma ، Methane conversion ، Hydrogen ، Hydrocarbons