polymers Review Microwave Discharges in Liquid Hydrocarbons: Physical and Chemical Characterization Yuri A. Lebedev A.V. Topchiev Institute of Petrochemical Synthesis of the Russian Academy of Sciences (TIPS RAS), Leninsky Ave. 29, 119991 Moscow, Russia;
[email protected] Abstract: Microwave discharges in dielectric liquids are a relatively new area of plasma physics and plasma application. This review cumulates results on microwave discharges in wide classes of liquid hydrocarbons (alkanes, cyclic and aromatic hydrocarbons). Methods of microwave plasma generation, composition of gas products and characteristics of solid carbonaceous products are described. Physical and chemical characteristics of discharge are analyzed on the basis of plasma diagnostics and 0D, 1D and 2D simulation. Keywords: microwave discharge; discharges in liquids; microwave discharge in liquid hydrocar- bons; methods of generation; plasma properties; gas products; solid products; plasma diagnostics; plasma modeling 1. Introduction Recently, electrical discharges in liquids [1–10] and, in particular, microwave dis- charges [11–13] have been intensively studied. Microwave discharges in liquids are less Citation: Lebedev, Y.A. Microwave studied. These discharges exhibit properties that distinguish them from widely used Discharges in Liquid Hydrocarbons: DC, HF and high-voltage discharges. They can be used to produce hydrogen, coatings, Physical and Chemical nanoparticles and nanotubes, for water purification, etc. [13]. Several papers on modeling Characterization. Polymers 2021, 13, of electrodynamics and plasma processes in such discharges have been published [14–26]. 1678. https://doi.org/10.3390/ Microwave plasma in liquids is an extremely interesting object for investigation, since it is polym13111678 often non-equilibrium, heterogeneous, with large spatial gradients of parameters.