Non-thermal plasma

Penetrante B M, Bardsley J N and Hsiao M C 1997 Kinetic analysis of non-thermal plasmas used for pollution control Japan. J. Appl. Phys. 36 5007-17... 

Non-thermal plasmas can be produced in a number of ways, including a variety of electrical corona discharges, radio frequency discharges, microwave discharges and electron beams. The most common NTP technologies for emission reduction in engine exhaust streams are the following. 

Szanyi et al., using again in situ IR-TPD coupled skills, studied the effect of acid sites on the catalytic activities of a series of H+-modified Na-Y zeolites in the non-thermal plasma assisted NO reduction reaction using a simulated diesel engine exhaust gas mixture. The acid sites were formed by NH ion exchange and subsequent heat treatment of a NaY zeolite. The catalytic activities of these H+- modified NaY zeolites... 

Kwak, J.H., Peden, C.H.F. and Szanyi, J. (2006) Non-thermal plasma-assisted NO reduction over Na-Y zeolites The promotional effect of acid sites, Catal. Lett., 109, 1. 

Figure 5.4. Catalytic device for DeNOx reaction coupled with non-thermal plasma.

By coupling a non-thermal plasma reactor to a catalytic reactor containing alumina alone, Baudin [32] have observed the DeNO function of alumina at low temperature,... 

NON-THERMAL PLASMA-ASSISTED CATALYTIC NO REMEDIATION, FOR SUBSTITUTING FUNCTIONS 1 AND 2 OF THE MODEL. ACTIVATION OF THE LOW-TEMPERATURE DeNO -FUNCTION 3 OF ALUMINA [32-38]... 

Effect of a dielectric barrier discharge (DBD) type non-thermal plasma on a synthetic gaseous reaction mixture... 

Figure 5.14. Detection of organic products oxygenates and organic nitrogen-containing compounds at the outlet of non-thermal plasma reactor without catalyst. Feed NO (500 ppm) - C3H6 (2000ppm Cj) - 02 (8 vol.%) - N2 [32],...

Figure 5.15. Non-thermal plasma-assisted DeNO reaction over alumina alone, according to Baudin [32], (a) NO, N02, NO and N20 TPD plots, (b) NO conversion vs. T without plasma.

The preceding results suggest an advantageous plasma-catalyst coupling effect on the NO remediation, in full accordance with the proposed mechanism [38], The C H Oz and RNO compounds, produced by the non-thermal plasma before the catalytic reactor... 

The removal of a wide variety of pollutants by means of non-thermal plasma has been reported aliphatic hydrocarbons [1-3], aromatics [4-7], chlorinated hydrocarbons [4,8-10], as well as inorganic contaminants such as S02, H2S [11,12] and NOx, which will be discussed in detail in this chapter. 

REACTION MECHANISMS RESPONSIBLE FOR NO REMOVAL IN NON-THERMAL PLASMA... 

When hydrocarbons are present in the gas mixture, NO removal by oxidation to NOz occurs at much lower input energy and the reaction paths change significantly as compared to the case without hydrocarbons. Numerous works analyze the reaction mechanism of NO. conversion in non-thermal plasma with addition of hydrocarbons, especially ethylene [33,37,77,79,81-83], propylene [35,76,81,83-87], and propane [76,81,85,87],... 

Typical reaction products of NO removal in non-thermal plasma in the presence of propylene, predicted by the model in Martin et al. and Dorai and Kushner [86,88], include formaldehyde (HCHO), acetaldehyde (CH3CHO) methyl oxirane (C3H60), gly-coxal (CHO-CHO), methyl nitrite (CH3ONO), methyl nitrate (CH30N02), and 2-nitroso ethanal (ONCH2CHO). 

The influence of soot on NO removal in non-thermal plasma has been investigated by Dorai and Kushner and Dorai et al. [88,89] in the presence of propylene and propane. Soot particles were assumed to contain only C and H atoms, and were denoted (C Hy). Soot may undergo oxidation when reacting with O and OH radicals generated in the... 

The oxidation of NO to N02 can be considered an advantage when combining plasma with selective catalytic reduction, as it is well-known that at low temperature the efficiency of NO reduction by SCR strongly depends on the N02 concentration in the gas. An oxidation pre-treatment of the gas by non-thermal plasma, prior to the SCR reactor greatly enhances the performance of SCR at temperatures below 500 K. Therefore, the PE-SCR technique is very promising for efficient NO reduction. 

Holzer, F., Roland, U. and Kopinke, F.-D. (2002) Combination of non-thermal plasma and heterogeneous catalysis for oxidation of volatile organic compounds Part 1. Accessibility of the intra-particle volume, Appl. Cat. B Env. 38, 163-81. 

Ma, H., Chen, P., Zhang, M., et al. Study of S02 removal using non-thermal plasma induced by dielectric barrier discharge (DBD), Plasma Chem. Plasma Process 21, 239-54. 

Khacef, A., Cormier, J.M. and Pouvesle, J.M. (2002) NOx remediation in oxygen-rich exhaust gas using atmospheric pressure non-thermal plasma generated by a pulsed nanosecond dielectric barrier discharge, J. Phys. D Appl. Phys. 35, 1491-8. 

Ighigeanu, D., Martin, D., Zissulescu, E. et al. (2005) S02 and NOx removal by electron beam and electrical discharge induced non-thermal plasmas, Vacuum 77, 493-500. 

Shin, H.-H. and Yoon, W.-S. (2003) Hydrocarbon effects on the promotion of non-thermal plasma NO-N02 conversion, Plasma Chem. Plasma Process. 23, 681-704. 

Hammer, T. (2002) Non-thermal plasma application to the abatement of noxious emissions in automotive exhaust gases, Plasma Sources Sci. Technol. 11, A196-A201. 

Martin, A.R., Shawcross, J.T. and Whitehead, J.C. (2004) Modelling of non-thermal plasma after treatment of exhaust gas streams, J. Phys. D Appl. Phys. 37, 42-9. 

Broer, S. and Hammer, T. (2000) Selective catalytic reduction of nitrogen oxides by combining a non-thermal plasma and a V205-W03/Ti02 catalyst, Appl. Catal. B Env. 28, 101-11. 

Chae, J.-O. (2003) Non-thermal plasma for diesel exhaust treatment, J. Electrostatics 57, 251-62. 

Holzer, F., Kopinke, F.D. and Roland, U. (2005) Influence of ferroelectric materials and catalysts on the performance of non-thermal plasma (NTP) for the removal of air pollutants, Plasma Chem. Plasma Processing 25, 595-611. 

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