PP11
Application
of Positive Pulsed Corona Discharge to Removal of SO2 and
NOX
Young-Sun Mok, In-Sik Nam and Rae-Woong Chang
Environment and Energy Research Division
Abstract
Removal of SO2 and NOx using positive
pulse corona discharge was investigated.
Chemical additives such as ammonia and olefins were used.
Compared to C2H4, C3H6
gave much better performance in the conversion of NO.
We carried out X-ray diffraction and scanning, electron
microscope analyses of the products.
Relative importance of each of the active species such as O,
OH, HO2 and O3 was evaluated.
Of those species, O3 was found to play a crucial
role in the oxidation of NO. Removal
of NOx using ozone was also investigated without applying
high voltage to induce non-thermal plasma discharge.
The amount of NO converted was nearly equal to that of O3
added. Since O3
molecule can be generated with small electrical energy less than 10
eV/O3 molecule, NOx removal using ozone may be
more energy efficient. SO2
could easily be removed by the reaction with NH3 in the
presence of water vapor.
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PP12
2-D Numerical Simulation of NOX Chemical Reaction in the
Pulse
Corona Discharge Process
Youn Taeg Kim and Ki Woong
Whang
School of Electrical Engineering
Seoul National University
Abstract
By a 2-D numerical simulation of positive corona with extensive NOx
chemical reactions, two parameters such as E/Neff
(effective electric field for electrical energy transfer) and
G-factor are calculated. E/Neff
weakly depends
on the relative humidity but strongly depends on the applied
voltage. G-factors of
OH, O radicals reach their mexima at E/N ~ 150 Td and G-factor of N
radical follows the change of E/Neff
. As the
applied voltage increases, the corona formation and propagation time
decrease, but the other parameters show very weak dependence.
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PP13
SO2 and CO Removal Characteristics of Nonthermal Plasma Reactor in a
Crossed DC Magnetic Field
Jae-Duk Moon, Guen-Taek Lee and
Chin-Gon Kim
Department of Electrical Engineering
Abstract
SO2 and CO gas removal characteristics of a
wire-to-cylinder type nonthermal plasma reactor corona-discharged in
various applied voltage (-dc, ad, fast rising pulse and high
frequency pulse) and a crossed dc magnetic field were investigated.
The experiment has been emphasized on the oxidizing
characteristics of SO2 and CO gas by O3 and
the applying of a crossed magnetic field, which would induce the
cyclotronic and drift motions of electrons making the residual time
longer in the removal airgap space.
In addition, it also would enhance the4 energy of electrons
and the electrophysicochemical actions to remove the pollutant gases
effectively. It was
found that the corona onset voltage and the breakdown voltage
decreased with increasing the crossed magnetic field and decreasing
initial fed SO2 and CO gas removal rate of 20 – 30[%]
can be obtained with –dc, ac and fast rising pulse corona
discharges in the crossed dc current-induced magnetic field.
But the high frequency pulse power was not effective to the
gas removal for applying of a crossed magnetic field.
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PP14
Development of a New Dry Desulfurization Process using a TiO2
Catalyst And a Non-Thermal
Plasma Hybrid Reactor
Hee-Joon Kim and Akira Mizuno
Department of Ecological Engineering
Masayoshi Sadakata
Department of Chemical System Engineering
Abstract
In the present paper we report the results of our experimental
studies of an oxidation reaction of SO2 to SO3.
In order to find out a new dry-type desulfurization process
with high efficiency and cost performance, we have designed a
reaction process that combines the pulsed streamer corona plasma and
the TiO2 catalyst. Experiments
of both gas phase reaction and surface reaction were performed in
order to elucidate the mechanism of oxidation of SO2 into
SO3.
The main results show that the conversion
ration of SO2 to SO3 in the gas phase reaction
was only below 5% at low temperatures (under 400oC).
Similarly, the conversion ration using TiO2 as
catalyst was negligible under the same reaction conditions.
When the gas phase reaction and the surface reaction were
combined, the oxidation ration was almost fixed at about 10% at
temperatures below 400oC.
The conversion ration of SO2 into SO3
could be increased significantly, when H2O was added in
proportions equivalent to about 0.2% in volume.
When hydrogen peroxide was added, the conversion ratio was
remarkable increased as compared to the case where only H2O
was added. A conversion
ration of 60% and 90% were achieved respectively when the reaction
was not assisted by plasma and when it was.
Finally, these results confirmed our initial hypotheses that
the OH radical enhances the oxidation reaction of SO2 in
both the gas phase reaction and the surface reaction on TiO2.
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PP15
A New Type Nonthermal Plasma Generation Means Utilizing
Ferroelectric
Pellets
Jae-Duk Moon, Sang-Taek Geum and Yong-Soo Son
Department of Electrical Eng.
Kyungpook National University.
Abstract
A new type of nonthrmal plasma reactor utilizing ferroelectric
pellets is proposed to generate nonthrmal plasma efficiently, which
is used for simultaneous control of various pollutant gases.
Electric charges stored on ferroelectric pellets by corona
discharge between corona tip and mesh electrode provide partial
electrical discharges among ferroelectric pellets.
These partial electrical discharges can enhance partial
discharges around surface of ferroelectric pellets and partial
discharge. Positive and
negative dc voltages are applied between corona tip and mesh
electrode to generate partial discharge.
Corona
currents are estimated to investigate charge storage on
ferroelectric pellets as a function of applied time of voltages,
polarities of corona discharges.
As a result, it is found that ferroelectric pellets, polarity
of applied voltage, and applied time of dc voltage influence the
generation of the nonathermal plasma in the plasma reactor.
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