Sains Malaysiana 42(9)(2013): 1289–1292

Evaluation of Particulate Emission from a Palm Oil Mill Boiler

(Penilaian Perlepasan Zarah daripada Dandang Kilang Minyak Sawit)

M. Rashid¹*, W.C. Chong¹, M. Ramli², Z.N. Zainura² & J. NorRuwaida¹

¹Air Resources Research Laboratory, Malaysia-Japan International Institute of Technology

UTM Kuala Lumpur, 54100 Kuala Lumpur, Malaysia

²Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor

Malaysia

Received: 14 August 2012 /Accepted: 25 January 2013

ABSTRACT

A study to investigate the particulate emission from a boiler of a palm oil mill plant equipped with a multi-cyclones particulate arrestor was performed and reported in this paper. The particulate emission concentration was measured at the outlet of an 8000 kg steam/h capacity water-tube typed boiler of a palm oil mill plant processing 27000 kg/h of fresh fruit bunch (FFB). The particulate sample was collected iso-kinetically using the USEPA method 5 sampling train through a sampling port made at the duct of the exiting flue gas between the boiler and a multi-cyclones unit. The results showed that the particulate emission rates exiting the boiler varied from 8.51 g/s to 126 g/s with an average of 44.3±31.6 g/s. In terms of concentration, the average particulate emission concentration exiting the boiler was 7.75±4.71 g/Nm³ (corrected to 7% oxygen concentration), ranging from 1.50 to 17.7 g/Nm³ (@7% O₂) of the flue gas during the measurement. Based on the 27000 kg/h FFB processed, 6000 kg/h fiber and shell (F&S) burned and the capacity of the boiler of 8000 kg steam/h, the calculated particulate emission factor was 5.91±4.21 g particulate/kg FFB processed, 26.6±18.9 g particulate/kg F&S burned and 19.9±14.2 g particulate/kg boiler capacity, respectively. Based on the finding, in order to comply with the emission limits of 0.4 g/Nm³, the required collection efficiency of any given particulate pollution control system to consider for the mill will be between 73% and 98%, which is not easily achievable with the existing multi-cyclones unit.

Keywords: Air pollution; carbon soot; emission factor; multi-cyclone; palm oil mill

ABSTRAK

Kajian terhadap pelepasan zarah dari dandang kilang minyak sawit yang dilengkapi dengan perangkap siklon berbilang telah dilakukan dan dilaporkan dalam kertas ini. Kepekatan perlepasan zarah diukur di aliran keluar dandang jenis tiub air yang berkapasiti 8000 kg stim/jam di kilang minyak sawit yang memproses 27000 kg/jam tandan buah segar (FFB). Sampel zarah telah dikumpulkan melalui pensampelan iso kinetik menggunakan kaedah USEPA 5 melalui lubang persampelan di antara dandang dan nit multi-siklon. Hasil kajian menunjukkan bahawa kadar pelepasan zarah adalah antara 8.51 g/s dan 126 g/s dengan purata 44.3 ± 31.6 g/s. Daripada segi kepekatan, purata kepekatan pelepasan zarah keluar dandang adalah 7.75 ± 4.71 g/Nm³ (dengan kepekatan oksigen 7%), berjulat antara 1.50 hingga 17.7 g/Nm³ (@ 7% O₂) dalam aliran gas semasa pengukuran. Berdasarkan 27000 kg/jam FFB yang diproses, 6000 kg/jam serabut dan tempurung (F&S) dibakar dan keupayaan dandang 8000 kg stim/jam, faktor pelepasan zarah yang dikira adalah 5.91 ± 4.21 g zarah/kg FFB yang diproses, 26.6 ± 18.9 g zarah/kg F&S yang dibakar dan 19.9 ± 14.2g zarah/kg kapasiti dandang. Kajian mendapati untuk mematuhi had pelepasan zarah sebanyak 0.4 g/Nm³, kecekapan koleksi yang diperlukan oleh sistem kawalan pencemaran bagi kilang tersebut adalah antara 73% dan 98%, yang tidak mudah dicapai dengan unit siklon berbilang yang sedia ada.

Kata kunci: Faktor pengeluaran; jelaga karbon; kilang kelapa sawit; multi-siklon; pencemaran udara

REFERENCES

Cao, G.L., Zhang, X.Y., Gong, S.L. & Zheng, F.C. 2008. Investigation on emission factors of particulate matter and gaseous pollutants from crop residue burning. Journal of Environmental Sciences 20(1): 50-55.

Janhӓll, S., Andreae, M.O. & Pӧschl, U. 2010. Biomass burning aerosol emissions from vegetation fires: Particle number and mass emission factors and size distributions. Atmos. Chem. Phys. 10: 1427-1439.

Linak, W.P., Miller, C.A. & Wendt, J.O.L. 2000. Fine particle emissions from residual fuel oil combustion: Characterization  and mechanisms of formation. Symposium (International) on Combustion 28(2): 2651-2658.

Malaysia Palm Oil Board (MPOB), http://econ.mpob.gov.my/ economy/EID_web.htm., 2010. Accessed: 15 Jan 2010.

Rashid, M., Ramli, M. & Rozainee, M. 1997. A field evaluation of particulate emission concentration in palm oil mill boilers. Jurnal Teknologi 1-6.

Rose, D., Nowak, A., Achtert, P., Wiedensohle, R.A., Hu, M. & Shao, M. 2008. Cloud condensation nuclei in polluted air and biomass burning smoke near the mega-city Guangzhou, China - Part 1: Size-resolved measurements and implications for the modeling of aerosol particle hygroscopicity and CCN activity. Atmospheric Chemistry and Physics Discussions 8(5):17343-17392.

Wark, K., Warner, C.F. & Davis, W.T. 1998. Air Pollution: Its Origin and Control. 3rd ed., Menlo Park, Calif.: Addison- Wesley.

*Corresponding author; email: drrashid@ic.utm.my