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Combustion
Characteristics of Refuse Derived Fuel (RDF) in a Fluidized Bed Combustor
(Ciri Pembakaran Bahan Api
Janaan Sampah (RDF) di dalam
Pembakar Lapisan Terbendalir)
A. JOHARI*, R. MAT,
H.
ALIAS,
H.
HASHIM,
M.H.
HASSIM,
Z.Y.
ZAKARIA
& M. ROZAINEE Institute of
Hydrogen Economy, Faculty of Chemical Engineering, Universiti Teknologi
Malaysia
81310 Johor
Bahru, Johor, Malaysia
Diserahkan:
28 September 2012/Diterima: 9 April 2013
ABSTRACT
The combustion characteristics of
refuse derived fuel (RDF) in a fluidized bed have been
studied. The gross heating value (GHV) of the RDF was
14.43 MJ/kg with moisture content of 25% by weight. Parameters of interest for
sustainable bed combustion were the fluidization number and primary air factor.
The study was performed in a rectangular fluidized bed combustor with
dimensions of 0.3 m in width, 0.7 m in length and 2 m in height. Sand with mean
particle size of 0.34 mm was used as a fluidization medium. The sand bed height
was at 0.3 m above the standpipes air distributor. The range of fluidization
number under investigation was 5–7 Umf in
which 5 Umf was found to be the optimum. The study was continued
for the determination of the optimum primary air factor with the selected range
of primary air factors being 0.6, 0.8, 1.0 and 1.2 in experiments conducted at
5 Umf. The final results showed that the optimum primary air
factor was at 0.8. An energy balance was also performed to determine the
thermal efficiency of the combustion. It was concluded that the thermal
efficiency depended on the bed temperature and the primary air factor being
used.
Keywords: Air factor; fluidized bed
combustor; fluidization number; operating parameter; refuse derived fuel (RDF);
thermal efficiency
ABSTRAK
Ciri pembakaran bahan api janaan
sampah (RDF) di dalam pembakar lapisan terbendalir telah dikaji.
Nilai pemanasan kasar (GHV) bahan api tersebut adalah 14.43
MJ/kg dan mempunyai 25% berat kandungan air. Parameter yang dikaji untuk
pembakaran lestari di dalam pembakar lapisan terbendalir adalah nombor
pembendaliran dan faktor pengudaraan utama. Kajian dilakukan di dalam pembakar
lapisan terbendalir bersegi empat bersaiz 0.3 m lebar, 0.7 m panjang dan 2 m
tinggi. Pasir dengan saiz purata 0.34 mm telah digunakan sebagai medium
perbendaliran. Ketinggian lapisan pasir adalah 0.3 m dari pengagih udara. Julat
nombor pembendaliran yang dikaji adalah dari 5 – 7 Umf dan
keputusan menunjukkan 5 Umf adalah nilai optimum. Kajian
diteruskan bagi mendapatkan faktor pengudaraan utama optimum dengan nilai 0.6,
0.8, 1.0 dan 1.2 dan uji kaji dilakukan pada 5 Umf.
Keputusan menunjukkan faktor pengudaraan utama yang optimum adalah 0.8.
Kecekapan terma pembakaran tersebut diperoleh dengan pengiraan imbangan tenaga
dan didapati bahawa kecekapan terma adalah bergantung kepada suhu lapisan
pembakaran dan faktor pengudaraan utama yang digunakan.
Kata kunci: Bahan api janaan sampah (RDF);
faktor udara; kecekapan terma; nombor pembendaliran; parameter operasi;
pembakar lapisan terbendalir
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*Corresponding author; email: anwar@cheme.utm.my
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