Possible role of nanobubbles in the pulsed plasma production of hydrogen

Abstract

Submerged dc plasma generated by nanosecond pulses in ethanol and methanol mixtures with water confirmed efficient production of the hydrogen synthesis gas H₂ + CO. The comparison of ethanol and methanol was made for their 35% contents in water. The methanol electrolyte exhibited about 25% more efficient production of synthesis gas compared with ethanol. Tests with 9 ns 9 kV negative dc pulses at the average power of 10 W confirmed production of up to 0.5 l/min of the synthesis gas with over 65% content of H₂. In both electrolytes the experiments indicated important role of small gas bubbles in the process. The bubbles were evidently generated by very short streamers formed during the dc pulses. The extraordinary properties of small bubbles, particularly those with submicron sizes, could explain the efficient production of the hydrogen rich gas.