Sains Malaysiana
39(6)(2010): 981–987
Discharge
Based Processing Systems for Nitric Oxide Remediation
(Sistem Pemprosesan Berasaskan Nyahcas
untuk Pemulihan Nitrik Oksida)
S.A. Hashim & C.S.
Wong*
Plasma Research Laboratory,
Physics Department, Faculty of Science
University of Malaya, 50603
Kuala Lumpur, Malaysia
M.R. Abas
Department of Chemistry, Faculty
of Science
University of Malaya, 50603
Kuala Lumpur, Malaysia
K.Z. Hj. Dahlan
Malaysian Nuclear Agency, Bangi,
43000 Kajang, Selangor, Malaysia
Diserahkan: 21 Oktober
2009 / Diterima: 4 Mac 2010
ABSTRACT
An
electron beam (EB) flue gas test rig and a dielectric barrier discharge (DBD)
reactor were tested for the removal of nitric oxide (NO) from gas stream in separate experiments. In both systems, energised
electrons were used to produce radicals that reacted with the pollutants. The EB system
was a laboratory scale test rig used to treat emission from a diesel run
generator. At 1.0 MeV and 10 mA more than 90% NO removal from flue gases
flowing at 120 Nm3/h can be achieved. For higher removal percentage, higher beam
current was required. In a related effort, a table top, two tubes DBD reactor
was used to process bottled gases containing 106 ppm NO. Total removal (>99%) was achieved when the inlet gas
contained only NO and N2. Additional SO2 in the in let gas stream lowered the removal rate but was
overcame by scaling up the system to 10 DBD tubes. The system was
operated with input AC voltage of 35 kV peak to peak. In the EB treatment system, the amount
of NO2 increased
at high beam current, showing that the NO was also oxidised in the
process. Whereas in the DBD reactor, the amount of NO2 remained insignificant
throughout the process. This leads to the conclusion that the DBD reactor
is capable of producing total removal of NO. This is highly desirable as post treatment will not be
necessary.
Keywords:
Dielectric barrier discharge; electron beam; nitric oxide
ABSTRAK
Kajian
terhadap penghapusan nitrik oksida (NO) menggunakan teknik alur elektron (EB) dan nyahcas dielektrik berpenghadang telah dijalankan secara
berasingan. Kedua-dua sistem ini menghasilkan elektron bertenaga tinggi untuk
menghasilkan radikal yang bertindak balas dengan bahan pencemar. Sistem alur
electron tersebut adalah binaan skala makmal yang digunakan untuk merawat gas
tercemar yang terhasil daripada sebuah generator disel. Pada 1.0 MeV dan 10 mA,
lebih 90% NO berupaya dinyahkan dari gas tercemar yang mengalir dengan kadar
120 Nm3/j. Arus bim yang lebih tinggi diperlukan untuk mencapai tahap
penghapusan yang lebih tinggi. Dalam kajian lain yang berkaitan, sebuah reaktor
2 tiub DBD digunakan untuk memproses gas dari selinder yang mengandungi NO dengan
kepekatan 106 ppm. Penghapusan sepenuhnya (>99%) telah dicapai apabila gas
masukan mengandungi hanya NO dan N2. SO2 tambahan pada gas masukan
menyebabkan kadar pengenyahanan susut tetapi ini dapat diatasi dengan menambah
bilangan tiub kepada 10. Sistem ini beroperasi pada voltan AC 35
kV puncak ke puncak. Bagi sistem menggunakan EB, didapati kepekatan gas nitrik dioksida (NO2) meningkat pada arus bim tinggi, menandakan NO telah
teroksida semasa proses berlaku. Di dalam sistem DBD bagaimanapun, kepekatan NO2 tidak
menunjukkan peningkatan yang ketara sepanjang proses. Ini menunjukkan bahawa
sistem DBD tersebut mampu menyahkan NO secara menyeluruh tanpa
keperluan rawatan susulan.
Kata
kunci: Alur electron; nitrik oksida; nyahcas dielektrik berpenghadang
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*Pengarang untuk surat-menyurat; email: cswong@um.edu.my
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