Thermal plasmas

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... 

Direct-current arcs into which no material is introduced have many appHcations as heat sources. Industrial processing of metals using plasma torches has been carried out in the former USSR (126). Thermal plasmas also are used in surface and heat treatment of materials (127,128). Metals can be... 

M. I. Boulos, P. Fauchais, and E. Pfender, Thermal Plasmas Fundamentals and Applications, Vol. 1, Plenum PubUshing Corp., New York, 1994. 

M. E. Zhukov and O. P. Solonenko, Thermal Plasma and New Materials Technology, Vols. 1 and 2, State Mutual Book and Periodical Service, Limited, New York, 1994. 

S. Sivaram, Principles of Chemical Vapor Deposition Thermal Plasma Deposition of Electronic Materials, Van Nostrand Reinhold, New York, 1995. 

Matsumoto, S., Deposition ofDiamond from Thermal Plasma, Proc. of the Mat. Res. Soc., Spring Meeting, Reno, NV, Extended Abstract, pp. 119-122 (April 1988)... 

Department of Chemical Engineering and Regional Research Center for Environmental Technology of Thermal Plasma, Inha University, 253 Yonghyun-dong, Nam-gu, Incheon 402-751, Korea... 

A thermal plasma system has been developed for the decomposition of methane. A schematic diagram of the experimental apparatus is shown in Fig. 1. The system consists primarily of D.C. plasma torch, plasma reactor and filter assembly. Plasma was discharged between a tungsten cathode and a copper anode using N2 gas. All the experiments were carried out at atmospheric pressure at 6 kW input electric power and N2 flow rate of 10 to 12 1/min. The feed gas (CH4) flow rates were varied from 3 to 15 1/min depending on the operating conditions, shown in Table. 1. 

Direct thermal decomposition of methane was carried out, using a thermal plasma system which is an environmentally favorable process. For comparison, thermodynamic equilibrium compositions were calculated by software program for the steam reforming and thermal decomposition. In case of thermal decomposition, high purity of the hydrogen and solidified carbon can be achieved without any contaminant. 

The methane conversion and hydrogen yield were investigated as a function of with respect to methane flow rate and both of the two were very high more than 90%. Particle size and sinface area of synthesized carbon were strongly dependent on methane flow rate. Hydrogen produced finm thermal plasma can be applied to fuel cell due to its high purity and carbon black can be applied for the synthesis of rubber industry. 

It could be concluded that thermal plasma process for methane decomposition is very effective for the production of high purity of the hydrogen as well as synthesis of the carbon black. 

Expanding Thermal Plasma Chemical Vapor Deposition. 163... 

In further sections extensions or adaptations of the PECVD method will be presented, such as VHF PECVD [16], the chemical annealing or layer-by-layer technique [17], and modulation of the RF excitation frequency [18]. The HWCVD method [19] (the plasmaless method) will be described and compared with the PECVD methods. The last deposition method that is treated is expanding thermal plasma CVD (ETP CVD) [20, 21]. Other methods of deposition, such as remote-plasma CVD, and in particular electron cyclotron resonance CVD (ECR CVD), are not treated here, as to date these methods are difficult to scale up for industrial purposes. Details of these methods can be found in, e.g., Luft and Tsuo [6]. 

The expanding thermal plasma chemical vapor deposition (ETP CVD) technique has been developed in the group of Schram [20, 556] and has been used for the... 

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... 

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