Effect of reactor configuration on nitric oxide conversion in nitrogen plasma
ABSTRACT The configuration of a nonthermal plasma reactor strongly affects the rate of electron collision reactions. Experiments involving the decomposition of NO in N2 were performed in a reactor in which the number of parallel reactor tubes varied from 1 to 10 at a constant pressure of 147.6 kPa and ambient temperature. A previously developed lumped model of the reactions accurately predicted the effects of varying the initial concentrations of NO (from 240 ppm to 593 ppm) and gas residence time (from 1.93 to 7.42 s). With an increasing number of parallel reactor tubes, the rate of electron collision reactions decreases because the energy input per unit reactor volume at unit time decreases, while the energy consumption per molecule of NO converted to N2 and O2 decreases due to electrical and geometric effects associated with the decreasing peak width of the discharge voltage pulses and increasing reactor capacitance. Therefore, increasing the number of parallel reactor tubes provides a viable scale-up method for constructing more efficient pulsed corona discharge reactors. © 2005 American Institute of Chemical Engineers AIChE J, 2005
- Journal of Molecular and Cellular Cardiology - J MOL CELL CARDIOL. 01/2007; 42(6).
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ABSTRACT: Direct ozone (O3) injection is a promising flue-gas treatment technology based on oxidation of NO and Hg into soluble species like NO2, NO3, N2O5, oxidized mercury, etc. These product gases are then effectively removed from the flue gases with the wet flue gas desulfurization system for SO2. The kinetics and mixing behaviors of the oxidation process are important phenomena in development of practical applications. In this work, planar laser-induced fluorescence (PLIF) of NO and NO2 was utilized to investigate the reaction structures between a turbulent O3 jet (dry air with 2000 ppm O3) and a laminar co-flow of simulated flue gas (containing 200 ppm NO), prepared in co-axial tubes. The shape of the reaction zone and the NO conversion rate along with the downstream length were determined from the NO-PLIF measurements. About 62% of NO was oxidized at 15d (d, jet orifice diameter) by a 30 m/s O3 jet with an influence width of about 6d in radius. The NO2 PLIF results support the conclusions deduced from the NO-PLIF measurements.Fuel. 09/2010; 89(9):2346-2352.
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ABSTRACT: Hydrogen sulfide (H2S) dissociation into hydrogen and sulfur has been studied in a pulsed corona discharge reactor (PCDR). Due to the high dielectric strength of pure H2S (∼2.9 times higher than air), a nonthermal plasma could not be sustained in pure H2S at discharge voltages up to 30kV with our reactor geometry. Therefore, H2S was diluted with another gas with lower dielectric strength to reduce the breakdown voltage. Breakdown voltages of H2S in four balance gases (Ar, He, N2, and H2) have been measured at different H2S concentrations and pressures. Breakdown voltages are proportional to the partial pressure of H2S and the balance gas. With increasing H2S concentrations, H2S conversion initially increases, reaches a maximum, and then decreases. H2S conversion and the reaction energy efficiency depend on the balance gas and H2S inlet concentrations. H2S conversion in atomic balance gases, such as Ar and He, is more efficient than that in diatomic balance gases, such as N2 and H2. These observations can be explained by proposed reaction mechanisms of H2S dissociation in different balance gases. The results show that nonthermal plasmas are effective for dissociating H2S into hydrogen and sulfur.Chemical Engineering Science - CHEM ENG SCI. 01/2007; 62(8):2216-2227.