Cold plasma assisted deoxygenation of liquid phase glycerol at atmospheric pressure

Abstract

The reaction mechanisms for liquid glycerol decomposition in the presence of cold plasma were studied experimentally and mathematically. Glycerol decomposition primarily proceeds via two routes: dehydration to acetol and cracking to methanol cation radicals and glycolaldehyde. In a N2 environment, dehydration route is dominant, leading to high proportions of hydrocarbons and alcohols. The unique properties of the two-phase gas-liquid cold plasma system generates intermediates such as methanol and methyl methanoate alongside acetol. Conversion was up to 5 times higher in N2 environment than in H2 environment. A full model of the glycerol decomposition process was developed and validated using experimental data. The predicted trends in product yields agreed well with experimental data, confirming that the mechanism of deoxygenation of liquid phase glycerol in the presence of highly energetic electrons at atmospheric conditions is based on an excited gas phase with radicals diffusing into the liquid phase.