Cold plasma assisted decomposition of alcohols

Abstract

The feasibility of oxygen removal from alcohols using cold plasma technologies at atmospheric pressure and low temperatures was studied experimentally and numerically. Methanol was used as a model compound to understand the effect of highly energetic electrons and the carrier gas on deoxygenation and to establish the reaction pathways. The results will provide insight into upgrading bio-oil derived from lignocellulosic pyrolysis, waste glycerol from biodiesel production processes and waste cooking oils.Under cold plasma at atmospheric conditions, the reaction mechanism is via radicals while the protective effects of the liquid-gas interface allows accumulation of products not otherwise feasible without specialised catalysts. The product distribution can be extensively tuned by changing the carrier gas and/or plasma power. Hydrogen favours longer chain hydrocarbons and helium generates liquid phase products including propanal, methyl methanoate and formic acid while nitrogen produces more carbon dioxide and water. Process yields and tunability could potentially be improved further by using simple catalysts or dielectric packing materials.