Non-thermal Arc Plasma for Ethanol Reforming and Hydrogen Production

Non-thermal plasma, also called non equilibrium arc plasma, is a kind of low temperature plasma. Thermal arc plasma is usually driven by a high power supply and characterized by a high current (several amperes to tens of amperes) and a small low voltage (tens of voltage). It is a kind of strongly self-sustaining high-temperature discharge. Unlike thermal plasma, non-thermal arc plasma is usually driven by a low AC or DC power supply and characterized by a high voltage (several thousand voltages) and a small low current (tens to hundreds amperes). Non-thermal plasma can generally be divided into non-thermal fixed arc plasma and non-thermal free arc plasma, and non-thermal free arc plasma can be divided into knife-shaped electrodes non-thermal plasma, semi-free rotated arc discharge and free rotated arc discharge. In the last section, various non-thermal arc ethanol reforming systems are introduced. Non-thermal fixed plasma can be generated by a pair of opposite tip electrodes or rod-shaped electrodes [1, 2]. For the reforming of liquid fuel, the most used reforming process and oxidation-steam reforming with this kind of discharge. There are two ways to feed the materials: (1) the pair of electrodes are immersed in the liquid phase, and two flows of air are input along the axis of the pair of electrodes and then a stable countercurrent gas passage can be generated in the electrode gaps; (2) an air flow is introduced to the discharge zone from the center bore of an electrode [1, 2]. Due to the fact that the direction of the air flow and that of the arc are the same, the position and the length is relatively fixed. This kind of discharge is also called non-thermal fixed arc discharge. Knife-shaped gliding arc plasma is one of the simplest non-thermal free arc discharges, with the characteristics of high power and high non equilibrium. Hence, this kind of discharge is widely used in the preparation of materials [3], treatment of pollutants [4, 5], disinfection [6, 7] and fuel reforming [8]. A pair of this kind of discharge reactors is made up of a pair of coplanar opposite knife-shaped metal