NOVELTY - A reactor (10) for dissociating hydrogen sulfide, comprises fluid inlet comprised of hydrogen sulfide; a swirl generator that causes a rotational flow of fluids within a reaction chamber (12); first outlet together with the fluid inlet configured to cause a vortex flow in the chamber, and is comprised of non-disassociated hydrogen sulfide and hydrogen; a first electrode; and a second electrode connected to a power source. The electrodes have surfaces exposed within the chamber to provide generation of a gliding arc discharge within the chamber.    USE - For dissociating hydrogen sulfide useful for producing hydrogen and sulfur, for producing hydrogen-rich gas and collecting the hydrogen-rich gas exiting from the first outlet, for producing sulfur-rich liquid and collecting the sulfur-rich liquid exiting from the second outlet (claimed) for reducing greenhouse gas emissions emitted from chemical processes, such as oil refining industry.    ADVANTAGE - The reverse-vortex flow pattern provides extraction of sulfur clusters due to centrifugal effect of the spinning fluid, thus possibly increasing the efficiency of the reactor. The reverse vortex flow in reaction chamber causes the contents of reactor in reaction chamber to rotate around plasma region, while output stream travels in a direction upwards from the bottom of reactor to opening. The rotation can provide necessary time for the heating of the contents flowing to and in the relatively hot plasma region as the contents move downwardly around central core region. The rotation can be that the reverse vortex flow can increase the residence time of reactants and products, for example, sulfur clusters, inside reaction chamber. Increased residence time can help to improve sulfur separation. As residence time increases, the molar percentage of hydrogen in output stream can increase as well as the molar percentage of sulfur in sulfur output stream.    DETAILED DESCRIPTION - A reactor (10) for dissociating hydrogen sulfide, comprises a cylindrical reaction chamber (12); at least one fluid inlet configured to introduce an input fluid into the reaction chamber, where the input fluid is comprised of hydrogen sulfide; a swirl generator that is configured to cause a rotational flow of fluids within the reaction chamber; at least one first outlet configured for outputting a first outlet fluid, where first outlet and the fluid inlet are further configured to cause a vortex flow in the reaction chamber, and the first outlet fluid is comprised of non-disassociated hydrogen sulfide and hydrogen; a first electrode; and a second electrode connected to a power source. The first electrode and the second electrode have surfaces exposed within the reaction chamber to provide generation of a gliding arc discharge within the reaction chamber. The fluid input further comprises a nozzle configured as the swirl generator, where the nozzle is configured to introduce the input fluid into the reaction chamber in a tangential direction generally perpendicular to an axis of the reaction chamber. The nozzle is the swirl generator. The reactor further comprises at least one second outlet configured for outputting a second outlet fluid, where the second outlet fluid is comprised of sulfur. The input fluid is a gas. The first outlet fluid is a gas. The second outlet fluid is a liquid. The first electrode is positioned proximate to a second outlet configured for outputting a second outlet fluid, where the second outlet fluid is comprised of sulfur. The second electrode is positioned proximate to the first outlet. The vortex flow is a reverse-vortex flow. The vortex flow causes a plasma zone (40) to be located near an axis of the reaction chamber. The plasma zone is at a higher temperature than a location proximate to an inner surface of the reaction chamber thereby establishing a temperature differential across the reaction chamber. The plasma zone causes at least a portion of the hydrogen sulfide to dissociate into gaseous sulfur and gaseous hydrogen. The gaseous sulfur migrates from the plasma outward radially in a direction towards an inner surface of the reaction chamber. The gaseous sulfur releases heat and condenses to form sulfur clusters as the gaseous sulfur migrates toward the inner surface of the reaction chamber. At least a portion of the heat released during condensation is transferred to the input fluid as the input fluid migrates to the plasma zone. The input fluid is introduced into the reaction chamber at a speed of at least 90% of the speed of sound. An INDEPENDENT CLAIM is included for dissociating hydrogen sulfide into hydrogen and sulfur, involving providing the plasma reactor, exposing surfaces of the first electrode and the second electrode within the reaction chamber to provide for the generation of a gliding arc discharge within the reaction chamber; and introducing hydrogen sulfide into the reaction chamber through the fluid inlet.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the gliding arc discharge reactor using reverse-vortex flow.    Input fluid (2)    Reactor (10)    Reaction chamber (12)    Nozzles (14a, 14b)    Output stream (22, 24)    Plasma zone. (40)