Papers by Hwai Chyuan Ong
Biodiesel is a recognized replacement for diesel fuel in compressed ignition engines due to its s... more Biodiesel is a recognized replacement for diesel fuel in compressed ignition engines due to its significant environmental benefits. The purpose of this study is to investigate the engine performance and emissions produced from Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in compressed ignition engine. The biodiesel production process and properties are discussed and a comparison of the three biodiesels as well as diesel fuel is undertaken. After that, engine performance and emissions testing was conducted using biodiesel blends 10%, 20%, 30% and 50% in a diesel engine at full throttle load. The engine performance shows that those biodiesel blends are suitable for use in diesel engines. A 10% biodiesel blend shows the best engine performance in terms of engine torque, engine power, fuel consumption and brake thermal efficiency among the all blending ratios for the three biodiesel blends. Biodiesel blends have also shown a significant reduction in CO 2 , CO and smoke opacity with a slight increase in NO x emissions.
International Communications in Heat and Mass Transfer, 2014
ABSTRACT The selection of flow passage's cross section shape is important in thermal syst... more ABSTRACT The selection of flow passage's cross section shape is important in thermal system design such as compact heat exchanger. A variety of duct's shapes can be used to enhance the thermal performance. However, it must be noted that different thermal and friction characteristics can be initiated due to this approach. Therefore this paper investigates the entropy generation characteristics of three types of duct's cross section subjected to constant heat flux. The considered shapes are circular, square and triangle (equilateral). Al2O3 and MWCNT based nanofluids are used as working fluids in the analysis. The study found that the total entropy generation of Al2O3 based nanofluids decreases with the increase of particle volume fractions. However, this parameter increases when working fluid's mass flow rate and heat flux applied to the duct increase. On the aspect of cross section's shape, circular duct exhibits lowest total entropy generation compared to other considered shapes. Moreover, it was also found that MWCNT based water nanofluids exhibit lower total entropy generation compared to Al2O3 based nanofluids due to its high thermal conductivity value.
The Scientific World Journal, 2014
This study projects electricity savings, cost-benefit analysis and emission reduction of lighting... more This study projects electricity savings, cost-benefit analysis and emission reduction of lighting retrofits in Malaysia residential sector. The cost-benefit is determined as a function of energy savings due to retrofit of more efficient lighting system. The energy savings were calculated based on 25, 50 and 75% of potential retrofits of inefficient lighting in residential sector. The study found that, this strategy save a significant amount of energy and consumers money. However, an effort to create energy efficiency awareness among consumers and subsidies efficient lighting should be identified, because this efficient lighting is quite expensive in Malaysia. #
Renewable and Sustainable Energy Reviews, 2014
ABSTRACT One-dimensional titanium dioxide (TiO2)-based nanotubes have attracted great interest to... more ABSTRACT One-dimensional titanium dioxide (TiO2)-based nanotubes have attracted great interest to be used as photocatalysts in the field of environmental applications. Three main approaches via template-assisted, electrochemical anodic oxidation and alkaline hydrothermal treatment used to prepare the nanostructured TiO2-based nanotubes are reviewed. The parameters that affect the formation of TiO2-based nanotubes via hydrothermal method such as phases and particle sizes of starting materials, types and concentrations of alkaline solution, temperature and duration of hydrothermal treatment, ultrasonication-and microwave-assisted hydrothermal synthesis, acid washing and calcination have been reviewed in details. This paper also discussed the possible crystal structure and formation mechanism of TiO2-based nanotubes via alkaline hydrothermal treatment. In addition, the recent research progress on the structural modification of TiO2-based nanotubes to be used as photocatalysts is summarized in this review. Modification strategies investigated include metal nanoparticles deposition, single- and co-doping of metal ions/non-metal ions, coupled with other semiconductors to form binary composites and hybrid with carbon nanomaterials.
Energy Conversion and Management, 2014
In the present study, crude Calophyllum inophyllum oil (CCIO) has been evaluated as a potential f... more In the present study, crude Calophyllum inophyllum oil (CCIO) has been evaluated as a potential feedstock for biodiesel production. C. inophyllum oil has high acid value which is 59.30 mg KOH/g. Therefore, the degumming, esterification, neutralization and transesterification process are carried out to reduce the acid value to 0.34 mg KOH/g. The optimum yield was obtained at 9:1 methanol to oil ratio with 1 wt.%. NaOH catalyst at 50°C for 2 h. On the other hand, the C. inophyllum biodiesel properties fulfilled the specification of ASTM D6751 and EN 14214 biodiesel standards. After that, the C. inophyllum biodiesel diesel blends were tested to evaluate the engine performance and emission characteristic. The performance and emission of 10% C. inophyllum biodiesel blends (CIB10) give a satisfactory result in diesel engines as the brake thermal increase 2.30% and fuel consumption decrease 3.06% compared to diesel. Besides, CIB10 reduces CO and smoke opacity compared to diesel. In short, C. inophyllum biodiesel can become an alternative fuel in the future.
Energy, 2014
Biodiesel is a recognized replacement for diesel fuel in compressed ignition engines due to its s... more Biodiesel is a recognized replacement for diesel fuel in compressed ignition engines due to its significant environmental benefits. The purpose of this study is to investigate the engine performance and emissions produced from Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in compressed ignition engine. The biodiesel production process and properties are discussed and a comparison of the three biodiesels as well as diesel fuel is undertaken. After that, engine performance and emissions testing was conducted using biodiesel blends 10%, 20%, 30% and 50% in a diesel engine at full throttle load. The engine performance shows that those biodiesel blends are suitable for use in diesel engines. A 10% biodiesel blend shows the best engine performance in terms of engine torque, engine power, fuel consumption and brake thermal efficiency among the all blending ratios for the three biodiesel blends. Biodiesel blends have also shown a significant reduction in CO 2 , CO and smoke opacity with a slight increase in NO x emissions.
The non-edible oil from Schleichera oleosa possesses the potential as a feedstock for biodiesel p... more The non-edible oil from Schleichera oleosa possesses the potential as a feedstock for biodiesel production.
In this study, the biodiesel production was performed using two-step transesterification process on a lab-
oratory scale. The parameters studied were reaction temperature, molar ratio of methanol to oil, catalyst
concentration, reaction time and catalysts type. An analysis of variance (ANOVA) was used to determine
the methyl ester yield. The optimum conditions were obtained as follows: reaction temperature at 55 C,
methanol to oil molar ratio of 8:1, 1 wt.% of hydroxide catalyst (KOH and NaOH) and 1 wt.% methoxide
catalyst (CH3OK and CH3ONa) for reaction time 90 min. Based from these optimum conditions, the
observed ester yields from different catalysts were average 96%, 93%, 91% and 88% for KOH, NaOH,
CH3OK and CH3ONa respectively as the catalyst. S. oleosa methyl ester (SOME) exhibited a satisfying
oxidative stability of 7.23 h and high cetane number (50.6) compared to petrol diesel (49.7). Besides,
SOME has good pour and cloud point of 3.0 C and 1.0 C respectively due to high unsaturated fatty
chain. As a conclusion, this study reveals that biodiesel production from SOME, as one of non-edible feed-
stock, is able to be an alternative for petrol diesel. Moreover, the produced biodiesel from SOME could be
used in diesel engine without major modification due to its properties and can be used in cold regions.
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Papers by Hwai Chyuan Ong
In this study, the biodiesel production was performed using two-step transesterification process on a lab-
oratory scale. The parameters studied were reaction temperature, molar ratio of methanol to oil, catalyst
concentration, reaction time and catalysts type. An analysis of variance (ANOVA) was used to determine
the methyl ester yield. The optimum conditions were obtained as follows: reaction temperature at 55 C,
methanol to oil molar ratio of 8:1, 1 wt.% of hydroxide catalyst (KOH and NaOH) and 1 wt.% methoxide
catalyst (CH3OK and CH3ONa) for reaction time 90 min. Based from these optimum conditions, the
observed ester yields from different catalysts were average 96%, 93%, 91% and 88% for KOH, NaOH,
CH3OK and CH3ONa respectively as the catalyst. S. oleosa methyl ester (SOME) exhibited a satisfying
oxidative stability of 7.23 h and high cetane number (50.6) compared to petrol diesel (49.7). Besides,
SOME has good pour and cloud point of 3.0 C and 1.0 C respectively due to high unsaturated fatty
chain. As a conclusion, this study reveals that biodiesel production from SOME, as one of non-edible feed-
stock, is able to be an alternative for petrol diesel. Moreover, the produced biodiesel from SOME could be
used in diesel engine without major modification due to its properties and can be used in cold regions.
In this study, the biodiesel production was performed using two-step transesterification process on a lab-
oratory scale. The parameters studied were reaction temperature, molar ratio of methanol to oil, catalyst
concentration, reaction time and catalysts type. An analysis of variance (ANOVA) was used to determine
the methyl ester yield. The optimum conditions were obtained as follows: reaction temperature at 55 C,
methanol to oil molar ratio of 8:1, 1 wt.% of hydroxide catalyst (KOH and NaOH) and 1 wt.% methoxide
catalyst (CH3OK and CH3ONa) for reaction time 90 min. Based from these optimum conditions, the
observed ester yields from different catalysts were average 96%, 93%, 91% and 88% for KOH, NaOH,
CH3OK and CH3ONa respectively as the catalyst. S. oleosa methyl ester (SOME) exhibited a satisfying
oxidative stability of 7.23 h and high cetane number (50.6) compared to petrol diesel (49.7). Besides,
SOME has good pour and cloud point of 3.0 C and 1.0 C respectively due to high unsaturated fatty
chain. As a conclusion, this study reveals that biodiesel production from SOME, as one of non-edible feed-
stock, is able to be an alternative for petrol diesel. Moreover, the produced biodiesel from SOME could be
used in diesel engine without major modification due to its properties and can be used in cold regions.