Hydrogen Production By Ethanol Reforming With Dielectric Barrier Discharge Plasma

Generating hydrogen from renewable liquid fuels with non-thermal plasma has become a hotspot in recent years.The optimization of reaction conditions is very important for the future applications of this process.This research aims to explore a simple and convenient method for hydrogen generation by ethanol reforming at low temperatures.In this work,dielectric barrier discharge was used to produce hydrogen at low temperatures by ethanol reforming.A mixture of water and ethanol was injected into the reactor without vaporization while plasma was generated by dielectric barrier discharge.Firstly,the changes of temperature and discharge parameters during plasma operation are studied.It is found that the reactor reaches thermal equilibrium in about40 minutes,and the equilibrium temperature increases with the increase of power,up to about 108℃.After reaching thermal equilibrium,the effect of hydrogen production is better.When the voltage applied at the reactor is constant,the current first increases and then decreases with the increase of frequency.When the voltage is between 30 and40 kV,the best discharge frequency for hydrogen production is about 9.7 kHz.The discharge characteristics of the reactor are studied by Q-V Lissajous graph.It is found that reducing the discharge gap can significantly enhance the discharge effect and reduce the generated heat.A small amount of solid produced in the process of hydrogen production from ethanol reforming has little impact on the discharge and hydrogen production,and the discharge device can operate stably for at least 4 hours.Then,the effects of discharge power,feed ethanol concentration and feed flow rate on hydrogen production by dielectric barrier discharge plasma were studied.Peak content of H₂ in the product was as high as 75.2%according to gas chromatography analysis,and the maximum ethanol conversion rate was 46%.Moreover,a higher energy yield was obtained by optimizing the feed composition and discharge conditions.The highest achieved energy yield was 4.8 mol（H₂）/kWh.