Microwave-Stimulated Conversion of a Tar/Lignin Blend into Hydrocarbons in a Plasma-Catalytic Mode

The study is devoted to the conversion of tar and iron-modified lignin under the action of microwave radiation. Lignin containing 0.5 wt % Fe absorbs about 80% of the supplied microwave radiation (2.45 GHz), which leads to a rapid increase in temperature in the reaction zone with the formation of plasma. During the conversion of a lignin (0.5 wt % Fe)/tar blend a wide range of gaseous and liquid hydrocarbons was produced, therewith the amount of light hydrocarbons was 75%. The solid carbon residue containing iron(III) oxide clusters is also characterized by the ability to absorb microwave radiation; it was employed as a catalyst and as a plasma generator in the 2nd cycle of the converting only tar under the influence of microwave radiation. The structure of nanosized iron-containing components was studied by transmission electron microscopy, X-ray diffraction, and Mössbauer spectroscopy, which made it possible to describe their genesis.