Decomposition of Mixed Malodorants in a Wire-Plate Pulse Corona Reactor

Abstract

Decomposition characteristics of two groups of representative mixed malodorants (1, ethanethiol + hydrogen sulfide; 2, ethanethiol + ammonia) in air were investigated employing a wire-plate pulse corona reactor. A new type of high-voltage pulse generator with a thyratron switch and a Blumlein pulse-forming network (BPFN) was used in our experiments. The experiments were conducted at a gas-flow rate of 13 m3/h. Important parameters, including peak voltage, chemical structures of malodorants, pulse frequency, and initial concentration, which influenced the removal efficiency, were investigated. The results showed that the mixed malodorants could be treated effectively by pulse corona. The removal efficiencies of 200 mg/m3 C2H5SH and 200 mg/m3 H2S for group 1 were 95.6% and 100%, respectively, which were almost equal to those of the two pollutants separately. The energy cost was about 65.1-81.4 J/L, which was 31.5-45.2% lower than for treating pollutants alone. The removal efficiencies of 105 mg/m3 C2HsSH and 40 mg/m3 NH3 for group 2 were 93.1% and almost 100%, and the energy cost was 65.1 J/L, 55.6% lower than that which was treated separately. In the case of two groups of mixed malodorants removal, NOx, 03, SO2, CO2, and CO were all observed. Moreover, some sulfur and white crystal ammonium nitrates were discovered adhering to the corona wires in the removal of groups 1 and 2, respectively. A dynamics model was developed to describe the relation of the removal efficiency with specific energy density and initial concentration. In the case of group 1 removal,the decomposition rate constants decreased as compared to the single treating. As for group 2 removal, the decomposition rate constants increased, especially for NH3. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned.

Combination of Nonthermal Plasma and Low Temperature-C3H8-Selective Catalytic Reduction over Co-In/H-beta Catalyst for Nitric Oxide Abatement

“…The feeding gas was prepared by a gas-mixing system, which contained four mass-flow controllers for N 2 , oxygen (O 2 ), NO, and C 3 H 8 . A newly developed Blumlein pulse-forming network (BPFN) type of narrow pulse generator, which has been introduced in our previous paper (Shi et al, 2005), was used to generate the pulse voltage. A DBD reactor was adopted in our experiments at atmospheric pressure and ambient temperature, which consisted of a film conductor; an embedded ceramic tube as a ground electrode, and an Ni-Cr line that was 0.5 mm in diameter was used as a high voltage electrode.…”

Plasma Flame Sustained by Microwaves and Burning Hydrocarbon Fuel: Its Applications

“…15, the energy is approximately 300 J/L. Even though the initial concentrations are different for H 2 S elimination, this work reveals that the kerosene microwave plasma burner may be more effective than the pulse corona reactor (Shi et al, 2005) and the gliding arc discharge (Czernichowski, 1994) in a standpoint of energy consumption. From the simple description for atomic oxygen produced in the microwave plasma burner , the atomic oxygen density n o was calculated to be n o = 5.7 × 10 13 /cm 3 , which effectively combusts hydrocarbon fuels.…”

Abatement of malodorants from pesticide factory in dielectric barrier discharges

“…They can react with the byproducts such as SO 2 , CO 2 , and NO x from DMS decomposition process to generate ammonium nitrates ((NH 4 ) 2 SO 4 , (NH 4 ) 2 CO 3 , NH 4 NO 3 , etc. ), which promotes the decomposition of DML [10]. Also, the conversion of DMS is higher than that treated separately under large range of peak voltages when it was mixed with DML.…”

“…It can be concluded from above that the removal efficiencies of malodorants are mostly related to their chemical structures [22], chemical properties, discharge power, reactivity with electrons, active species and decomposition products generated in a DBD discharge, gas composition [10].…”

“…Different types of reactors and power supplies have been developed for the production of NTP in the early researches. And the early researches mainly paid attention to the improvement of the conversion efficiencies, reduction of energy cost and product analysis in single odor treatment with dry air [4][5][6][7][8][9][10][11][12]. Whereas, it was mentioned above that the odors from pesticide factory had complicated composition with various humidity and oxygen contents.…”