Now showing 1 - 3 of 3
  • Publication
    Effect of additives on the ash element from combustion of palm fiber and shell
    (IOP Publishing, 2020)
    J Nor Ruwaida
    ;
    M Dewika
    ;
    S Shahidana
    ;
    M Rashid
    ;
    Abd Halim Md Ali
    ;
    M P Khairunnisa
    ;
    M R Ammar
    ;
    Zahiruddin S.
    ;
    Palm fibre and shell (F&S) are commonly used in the combustion process to produce steam and electricity in palm oil mills in Malaysia. Unfortunately, the combustion process releases various types of elements that tends to react with each other contributing to operational and environmental issues. Thus, this motivated, a study to evaluate the concentration of the elements such as C, O, Si, K, and Al in the ash with the presence of two combustion additive which are Kaolin and PreKotTM. The study was performed by simulating the industrial combustion in a laboratory-scale fluidised-bed reactor with addition of the additives at 8% ratio from the 40 g total weight of each sample at 800°C with the supply of 50% excess air at 1.24 L/min air flow. The ash residue were investigated for elemental composition on the ash surface. Interestingly, the study showed that the concentration of the element on the ash surface increased with the addition of additives especially at a 50% ratio of Kaolin and PreKotTM. The higher concentration of the element on the ash surface indicates the reduction of fine particulate. Hence, the study revealed that addition of Kaolin & PrekotTM in combustion process has a promising future not only within palm oil industry but also other industry.
  • Publication
    Performance evaluation of a retrofitted multi-cyclone using computational fluid dynamic
    (IOP Publishing, 2020)
    M Dewika
    ;
    M Rashid
    ;
    C M Hasrizam
    ;
    M P Khairunnisa
    ;
    J Norruwaida
    ;
    Multi-cyclone is widely used in industries as air pollution control device due to several advantages over other available separation units such as its low capital, operating, and maintenance cost and as well as its usability under a wide range of operational conditions. However, it is merely a pre-cleaner as it is inefficient in collecting fine particulate especially, particulate matter with size less than 10 µm (PM₁₀) and below. Hence a simple, cost-effective retrofit on a Conventional Multi-cyclone (CMC) with the motivation of increasing its overall performance on fine particulate emission control was carried out. The retrofit was performed by creating higher negative pressure inside the dust hopper of the CMC by extracting 10% and 24% from the total volumetric airflow rate of the unit with the means of an external Induced Draft Fan. The Computational Fluid Dynamics (CFD) with Reynold Stress Model (RSM) turbulence model was performed and validated using experimental data to gain a better understanding in pressure distribution, velocity profile and particulate movement between the CMC and the Retrofitted Multi-cyclone (RMC). The CFD results show deviation between 0% to 8% for pressure at inlet and outlet of cyclone compared to the experimental results. In addition, CFD results depict that the RMC has higher pressure at the inlet and lower pressure inside dust hopper of CMC, which cause the finer particle to be pulled in through suction outlet. Also, the emission of fine particulate is reduced in RMC by 9% to 16%. compared to the CMC. Moreover, the phenomena at the suction duct can be clearly explained with the usage of CFD. The finding suggests that a simple, cost-effective retrofit at the multi-cyclone has increased the overall performance in the fine particulate collection, and the understanding of the phenomena could be enhanced by the CFD.
  • Publication
    Estimation of particulate emission generation in palm oil mill boiler
    (IOP Publishing, 2020)
    N R Jamian
    ;
    M Rashid
    ;
    S M M Muzi
    ;
    N Hussein
    ;
    D Munisamy
    ;
    K M Pa’ad
    ;
    A H M Ali
    ;
    The palm oil industries in Malaysia has been positively growth throughout the year, for it sustainable approach in terms of production and environmental protection. However, this industry also producing considerable amount of particulate emission from the process of burning its biomass waste of palm fibre and shell in the boiler. This study present a method to estimate the particulate emission that are being generated from the boiler. The method were done by analyzing the proximate analysis value of the ash content of palm fibre and shell found in this study. The particulate emission were physically collected from five palm oil mill boilers with boiler capacity ranging from 18-45 tonne/hour. The particulate stack fly ash was collected from the stack gas downstream of a multi-cyclones particulate arrestor according to the USEPA Method 17-Determination of particulate matter emissions from stationary sources. Meanwhile the sample of palm fibre and shell were collected to determine the proximate value. The estimation were then being further analyzed according to the particulate emission that were obtained by the real-stack sampling. In summary, the average moisture content, ash content, volatile matter and fixed carbon for palm shell found in this study are 19.3 ± 5.7%, 2.79 ± 2.2%, 74.3 ± 3.0, and 11.3 ± 4.3, respectively.). The average particulate concentration for these five mills is 2.2±0.9g/Nm3 and the air pollution control requirement are between 64 and 96% with reference to Clean Air Regulations 2014 of 0.15g/Nm3 which is very high to be achieve. It also can be estimated that 26% of the ash generated from the combustion of palm fibre and shell in palm oil mill boiler are being released at the stack.