A study was conducted to investigate the synthesis of ethylene and acetylene from heavy residue of high-viscosity and high-sulfur crude, using low temperature plasma. The study involved conducting pyrolysis in a plasma unit, consisting of a plasmotron, plasma-chemical reactor, and quencher. Plasma-forming gas was heated to 3000-4000 K in an electric-arc plasmotron, which consists of a cathode, anode, and discharge chamber. The feedstock was introduced in the reaction zone, perpendicular to the direction of the plasma jet through a nozzle fed with a spraying gas. The gaseous products of pyrolysis were quenched in a heat exchanger.