Scaling of surface-plasma reactors with a significantly increased energy density for NO conversion. J Hazard Mater 209-210:293-298

Frank Reidy Research Center for Bioelectrics, Old Dominion University, 4211 Monarch Way, Suite 300, Norfolk, VA 23508, USA.
Journal of hazardous materials (Impact Factor: 4.53). 03/2012; 209-210:293-8. DOI: 10.1016/j.jhazmat.2012.01.024
Source: PubMed


Comparative studies revealed that surface plasmas developing along a solid-gas interface are significantly more effective and energy efficient for remediation of toxic pollutants in air than conventional plasmas propagating in air. Scaling of the surface plasma reactors to large volumes by operating them in parallel suffers from a serious problem of adverse effects of the space charges generated at the dielectric surfaces of the neighboring discharge chambers. This study revealed that a conductive foil on the cathode potential placed between the dielectric plates as a shield not only decoupled the discharges, but also increased the electrical power deposited in the reactor by a factor of about forty over the electrical power level obtained without shielding and without loss of efficiency for NO removal. The shield had no negative effect on efficiency, which is verified by the fact that the energy costs for 50% NO removal were about 60 eV/molecule and the energy constant, k(E), was about 0.02 L/J in both the shielded and unshielded cases.

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    • "When multiple electrode assemblies were stacked and operated in parallel, the energy per pulse was found to be the product of the number of reactors times the energy of a single reactor. Obviously , the shielding due to the conducting layers between the reactors [16] or coupling of positive streamers with negative streamers on the same electrode assembly causes a complete decoupling of the reactors. This decoupling allows scaling of the reactors in a compact configuration with high throughput – an advantage in the use of such reactors for commercial applications. "
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    ABSTRACT: A coupled surface dielectric barrier discharge is reported and compared with a surface dielectric barrier discharge with respect to the spatial distribution of the plasma streamers, the energy dissipation in the discharge plasma, the scalability of the discharges, and their efficiency for ozone synthesis and nitric oxide conversion from air. Negative streamers were found to be more effective for the chemical reactions than positive streamers. Scaling of the discharges was achieved by: (i) employing multiple interconnected electrodes in the same space and (ii) operating stacked discharge chambers in parallel in a compact configuration. The increase in efficiency caused by the two scaling methods allowed us to obtain ozone concentrations of 1-9 g/N m(3) with an energy yield of 100-70 g/kWh and nitric oxide conversions of 10-95% with an energy cost of 20-80 eV/molecule from an initial concentration of similar to 330 ppm in air. The results are explained on the basis of the streamer development in the two barrier discharge configurations and the results are compared with those reported in the literature.
    Chemical Engineering Journal 11/2014; 256:222–229. DOI:10.1016/j.cej.2014.07.003 · 4.32 Impact Factor
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    • "A lot of studies have been carried out to investigate NO x removal by an electron-beam NTP-based process [8]. Masuda and Nakao first proposed the electrical NTP process for NO oxidation, and encouraging results have been obtained in both experimental and industrial investigations [9]–[13]. Furthermore, Byun et al. reported effective oxidation of Hg 0 with a dielectric barrier discharge and a pulsed corona discharge reactor [14]–[16]. "
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    ABSTRACT: The simultaneous removal of NOx, SO2, and Hg from simulated flue gas by a plasma-absorption hybrid system was investigated. In the nonthermal plasma reactor, NO could be effectively oxidized to NO2. However, Hg-0 oxidation was significantly restrained since NO concentration and its reactivity with O-3 are much higher than those of Hg-0. In the absorber, SO2 and NO2 were absorbed by (NH4)(2)SO3 solution, in which the S(IV) ions (SO32- and HSO3-) were found to be dominant for NO2 absorption. The S(IV) ions were significantly oxidized during the absorption, causing an increase in NO2 concentration with operating time. However, the addition of S2O32- inhibited the S(IV) oxidation and promoted the removal of NO2. With a followed electric mist eliminator, the NH3 slipped from the absorber can be captured, and Hg-0 was efficiently oxidized, which can be further removed by water absorption.
    IEEE Transactions on Plasma Science 02/2013; 41(2):312-318. DOI:10.1109/TPS.2012.2234483 · 1.10 Impact Factor
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    ABSTRACT: Bioelectrics is a new interdisciplinary field that investigates electric field effects on cell membranes and other cellular components. It incorporates four main technologies, including electroporation, nanosecond pulsed electric fields, picosecond pulsed electric fields and cold plasmas. The parent technology in Bioelectrics is electroporation, which uses milli- and/or micro-second electric pulses to permeabilize cells and tissues, for delivery of membrane impermeable molecules. It is now being used for electro-gene delivery, with vascular endothelial growth factor, for revascularization in wound healing and cardiovascular and peripheral vascular disease. Plasmids expressing IL-12 are being delivered for immune system activation in melanoma treatment, now in phase II clinical trials. DNA vaccine delivery by electroporation is also being investigated. More recently, electroporation has been extended to include nanosecond pulsed electric fields (nsPEFs), a pulse power technology that was originally designed for military applications. It stores intense levels of electric energy, and then unleashes nanosecond bursts of instantaneous power into cells and tissues, creating unique intracellular conditions of high power and low, non-thermal energy. It is presently being used for cancer ablation of skin and internal tumors, and for platelet activation for wound healing in injury and diabetes. An extension of nsPEFs is to make the pulses even shorter, using picosecond pulsed electric fields. This is being developed as an imaging system to detect cancer and other aberrant tissues, using an antenna. The fourth technology is cold plasmas or ionized gasses, a fourth state of matter. Applications of these ionized gases are being developed for decontaminating wounds, water, food and surfaces. Other possible applications that are of specific interest, but not yet fully investigated, and/or developed, are pain control, fat ablation and decontamination of indwelling catheters. This review will outline some applications of Bioelectrics, with greatest focus on nsPEF effects on cells in vitro and tumors in vivo.
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