Hydrogen Generation From Glow Discharge Plasma Electrolysis Of Ethanol And Its Kinetic Simulation

Hydrogen is a kind of clean energy source, which has been widely used. Anew hydrogenproduction technique, hydrogen generation from glow discharge plasma electrolysis ofethanol conversion was introduced in this paper. Glow discharge electrolysis (GDPE) isregarded as an unconventional electrolysis where electrochemical processes occur in glowdischarges and at the interface between plasma and electrolyte. The remarkable feature ofGDPE is that its chemical yields produced by the glow discharge electrode are much higherthan the Faraday law value and the products are novel for conventional electrolysis. Becausechemical reactions in plasma are complex and unpredictable, it's a good way to research thispaper bymeans of experimental analysis, spectral diagnostics and dynamic simulation.Electrons were proved to be the most important radicals to trigger the plasma chemicalreactions on ethanol during GDPE. Molecules of ethanol were bombed and excited in glowdischarge plasmas and at the interface between plasmas and solutions, producing a lot ofactive radicals. Hydrogen, carbon monoxide, methane, ethane, propane, butane, formaldehyde,acetaldehyde, formic acid and acetic acid were the main products of GDPE on ethanolsolutions. The yields of hydrogen and energy consumption were affected by dischargedpolarity, discharged voltage and conductivity. Under the same reaction conditions, the amountof hydrogen yield in cathode was higher than that in anode, while the energy consumptionwas lower than that in anode. In the same polarity, the higher the voltage, the greater theyields of hydrogen becomes, and the energyconsumption.Optical emission speetroseopy (OES) is a powerful diagnostie tool—a simple methodwithout disturbing thereactions. In the paper, the distributions of different radicals such as H,CH+, C2, OH, C2, Na, K, O+ which were detected in the spectra range of 300 nm to 900 nmwere studied. After calculating, the electron temperature in plasma center ranger from 7700 Kto 11600 K, and the electron densityis 8.2×1015cm-3.Based on the combination of the experimental analysis and spectral diagnostics, amathematical model was proposed subsequently to describe the behavior of radicals in theglow discharges center and at the interface between plasma and electrolyte. The result ofsimulation was in good agreement with that of the experiment. The kinetic analysis indicatedthat in the region of glow discharges center, the products were small molecules and in theregion of the interface between plasmas and solutions, the products were relatively largemolecules. The increasing of H, CH2, HCO radical content, the reducing of CH3 and CHradical content, which is advantageous to the hydrogen production.