辉光放电低温等离子体分解乙醇水溶液制氢

Hydrogen Production from the Decomposition of Ethanol Aqueous Solution Using Glow Discharge Plasma Electrolysis

在辉光放电分解乙醇制氢过程中,高能电子在反应中起到了最为关键的作用,非法拉第效应使得电流效率获得大幅度提升,产物产量远远高于理论产量.本文研究了乙醇水溶液辉光放电等离子体电解制氢的过程.实验研究发现,辉光放电分解乙醇水溶液的产物主要以H2和CO为主,还有少量的C2H4、CH4、O2和C2H6.H2体积分数能达到59%以上,CO为20%左右.通过对影响辉光放电的因素进行实验后发现:乙醇体积分数的大小不会影响辉光放电的伏安特性参数;电导率的提高会使‘Kellogg区’收窄,同时使放电尽快进入辉光放电.此外,乙醇体积分数越高H2体积分数越低,产气速率在乙醇体积分数为30%和80%附近时达到极大值;提高放电电压和电导率对辉光放电的影响规律是相类似的,其实质都是增大了辉光放电加载在等离子鞘层两端的电压,H2体积分数基本不随二者的变化而变化,但提高溶液的电导率更有利于减少辉光放电引起的焦耳热.

High-energy electrons play the most important role in the decomposition of ethanol aqueous solutions under glow discharge plasma electrolysis （GDE）. The non-Faradaic currents greatly improve, resulting in the actual gas production yield exceeding the theoretical yield. In this paper, we investigated a novel process of hydrogen generation from ethanol decomposition by GDE. The main gaseous products were H2 and CO; in addition to small amounts of C2H,, CH4, O2, and O2H6. The H2 volume fraction was above 59% and CO was 20%. We conclude that voltages of points C and D （Vc and VD） do not change with the electrolyte concentration, but the ＇Kellogg area＇ becomes narrower with increasing electrolyte conductivity and the glow discharge is easier to attain. In addition, with increasing ethanol volume fraction, the H2 volume fraction decreases. The maximum gas production rate occurred for ethanol volume fractions of 30% and 80%. Improving the discharge voltage and raising the electrolyte conductivity had the same effect on glow discharge plasma electrolysis as the voltage load at both ends of the plasma steam sheath increases. The H2 volume fraction remains the same upon varying the discharge voltage or electrolyte conductivity, but increasing the electrolyte conductivity is advantageous to reduce Joule heating effects caused by GDE.