A novel concept of remediation of polluted streams using High Energy Density Glow discharge (HEDGe)

Effluent gases containing SO₂, and/or NO_x, and/or particulate matter, volatile organic compounds and other hazardous substances, sometimes in an aerosol phase, are generated from many sources. Non-thermal plasmas including Pulsed nanosecond Corona (PC) was suggested for simultaneous removal of particulates and NO_x and SO₂ as well as for destruction of other toxic chemicals. PC demonstrated high removal efficiency, also in pilot-scale installations, but the cost of pulsed power supplies generating nanosecond pulses remains prohibitively high for most industrial, especially large-scale applications. With the purpose of reducing capital costs, DC coronas had been proposed in conjunction with a high velocity gas flow, typically in the range of 50-100 m/s. Such a flow stabilizes corona discharge allowing an order of magnitude higher specific power to be deposited in the treated media. These devices employ linear flow and thus the residence time is very short. They also require high-power gas compressors; we believe for the above reasons this king of discharge was not commercialized in cleaning applications. The main idea of a novel approach to creating a flow-stabilized discharge in large volumes required by industrial applications is providing a fast velocity gas flow in the vicinity of the ionizing electrodes that may be similar to those used in commercial ESPs, using rotational mechanism rather than longitudinal fast flow. Several designs are envisaged and discussed depending on the application, whereas either HV electrodes or grounded electrodes or both are rotated relative to each other in the same or opposite directions.