Can supervise: YES
Lin, BJ, Chen, WH, Lin, YY, Chang, JS, Farooq, A, Singh, Y, Ong, HC & Show, PL 2020, 'An evaluation of thermal characteristics of bacterium Actinobacillus succinogenes for energy use and circular bioeconomy', Bioresource Technology, vol. 301.View/Download from: Publisher's site
© 2020 Elsevier Ltd The thermal characteristics of Actinobacillus succinogenes (AS) from pyrolysis, torrefaction, and combustion are analyzed to evaluate the potential of this biomass as a renewable fuel. AS pyrolysis can be classified into four stages, and its main decomposition zone is at 200–500 °C. The solid yield of AS after 60 min torrefaction is over 60 wt%, and the torrefaction severity index map indicates that a high torrefaction temperature with a short duration has a more profound influence on its decomposition. The Py-GC/MS analysis of AS suggests that the volatile products from 500 °C pyrolysis are similar to microalgae-derived pyrolysis bio-oils. The combustibility index (S) of AS is 4.07 × 10−7 which is much higher than that of lignite coal (0.39 × 10−7) and bituminous coal (0.18 × 10−7), and close to those of biochar and bio-oil. The obtained results are conducive to the development of microorganisms as fuel to achieve a circular bioeconomy.
Yu, KL, Chen, WH, Sheen, HK, Chang, JS, Lin, CS, Ong, HC, Show, PL, Ng, EP & Ling, TC 2020, 'Production of microalgal biochar and reducing sugar using wet torrefaction with microwave-assisted heating and acid hydrolysis pretreatment', Renewable Energy, vol. 156, pp. 349-360.View/Download from: Publisher's site
© 2020 Elsevier Ltd This study employed the microwave-assisted acid hydrolysis pretreatment using wet torrefaction on two indigenous microalgae, Chlorella vulgaris ESP-31 and Chlorella sp. GD with different biomass composition to investigate the yields of solid biochar and total reducing sugar in the liquid hydrolysate. Operating conditions at low temperatures (160, 170 °C) with short holding time (5, 10 min) under several concentrations of diluted acid medium (0, 0.1 and 0.2 M) were carried out to investigate the torrefaction severity effects towards the properties of the solid and liquid products. The highest biochar yields of 54.5% and 74.6% are obtained from C. vulgaris ESP-31 and Chlorella sp. GD, respectively under the wet torrefaction conditions with an improvement in the properties for fuel and value-added environmental application. The highest total reducing sugar concentration of 98.11 g/L and 12.08 g/L are obtained in C. vulgaris ESP-31 and Chlorella sp. GD liquid hydrolysates, respectively after acid hydrolysis pretreatment. With the co-production of high total reducing sugar in the liquid hydrolysate that can be utilized for bioethanol production and solid biochar as another value-added product, the acid hydrolysis pretreatment using wet torrefaction can be one of the conversion technologies towards the application of renewable energy production.
Huang, Y, Mok, WC, Yam, YS, Zhou, JL, Surawski, NC, Organ, B, Chan, EFC, Mofijur, M, Mahlia, TMI & Ong, HC 2020, 'Evaluating in-use vehicle emissions using air quality monitoring stations and on-road remote sensing systems', Science of the Total Environment, vol. 740.View/Download from: Publisher's site
© 2020 Elsevier B.V. This study investigated real world in-use vehicle emissions using two regulatory techniques simultaneously, namely on-road remote sensing (RS) systems and air quality (AQ) monitoring stations, aiming to provide a full pollution profile from tailpipe to roadside and atmosphere. Two large AQ and RS datasets collected during 2012–2018 were analyzed. The effects of various emission control programmes on the trends of tailpipe emissions and air quality were evaluated. Correlations between tailpipe emissions and roadside and ambient air quality were also explored. The results showed a decreasing trend of NO2 at both roadside and ambient AQ stations from 2013 to 2016, which was attributed to the intensive implementation of a series of vehicle emissions control programmes. Although NO2 was decreasing, O3 was generally increasing for all AQ stations. AQ data showed that O3 had little correlation with either NO2 or NOx, but was mainly determined by NO2/NOx ratio. Roadside NO2/NOx ratio increased first and then decreased or stabilized after 2014, while ambient NO2/NOx ratio increased steadily. RS data showed that the overall NO decreased quickly during 2012–2015 and then decreased moderately after 2015. The decrease was mainly attributed to the effective NO reduction from LPG vehicles. However, diesel NO remained high and reduced relatively slowly during the study period. Gasoline vehicles were relatively clean compared with LPG and diesel vehicles. Finally, good correlations were demonstrated between NO measured by RS sites and NOx measured by roadside AQ stations, indicating that vehicle emissions were the major contributor to roadside NOx pollution. Ambient NOx emissions could be affected by various sources, leading to different correlation levels between RS and ambient AQ results.
Mahlia, TMI, Syazmi, ZAHS, Mofijur, M, Abas, AEP, Bilad, MR, Ong, HC & Silitonga, AS 2020, 'Patent landscape review on biodiesel production: Technology updates', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 118.View/Download from: Publisher's site
Ong, HC, Mofijur, M, Silitonga, AS, Gumilang, D, Kusumo, F & Mahlia, TMI 2020, 'Physicochemical Properties of Biodiesel Synthesised from Grape Seed, Philippine Tung, Kesambi, and Palm Oils', ENERGIES, vol. 13, no. 6.View/Download from: Publisher's site
Rizwanul Fattah, IM, Ong, HC, Mahlia, TMI, Mofijur, M, Silitonga, AS, Rahman, SMA & Ahmad, A 2020, 'State of the Art of Catalysts for Biodiesel Production', FRONTIERS IN ENERGY RESEARCH, vol. 8.View/Download from: Publisher's site
Deepanraj, B, Senthilkumar, N, Ranjitha, J, Jayaraj, S & Ong, HC 2020, 'Biogas from food waste through anaerobic digestion: optimization with response surface methodology', BIOMASS CONVERSION AND BIOREFINERY.View/Download from: Publisher's site
Gan, YY, Ong, HC, Chen, W-H, Sheen, H-K, Chang, J-S, Chong, CT & Ling, TC 2020, 'Microwave-assisted wet torrefaction of microalgae under various acids for coproduction of biochar and sugar', JOURNAL OF CLEANER PRODUCTION, vol. 253.View/Download from: Publisher's site
Goh, BHH, Ong, HC, Chong, CT, Chen, W-H, Leong, KY, Tan, SX & Lee, XJ 2020, 'Ultrasonic assisted oil extraction and biodiesel synthesis of Spent Coffee Ground', FUEL, vol. 261.View/Download from: Publisher's site
Hoang, CN, Wang, F-M, Kim, KD, Thanh, TP, Juan, H-Y, Nguyen, PN, Hwai, CO & Su, C-H 2020, 'Microwave-Assisted Noncatalytic Esterification of Fatty Acid for Biodiesel Production: A Kinetic Study', ENERGIES, vol. 13, no. 9.View/Download from: Publisher's site
Lee, XJ, Ong, HC, Gan, YY, Chen, W-H & Mahlia, TMI 2020, 'State of art review on conventional and advanced pyrolysis of macroalgae and microalgae for biochar, bio-oil and bio-syngas production', ENERGY CONVERSION AND MANAGEMENT, vol. 210.View/Download from: Publisher's site
Mazaheri, H, Ong, HC, Masjuki, HH, Arslan, A, Chong, WT & Amini, Z 2020, 'Friction and wear characteristics of rice bran oil based biodiesel using calcium oxide catalyst derived from Chicoreus Brunneus shell', Energy Sources, Part A: Recovery, Utilization and Environmental Effects.View/Download from: Publisher's site
© 2019, © 2019 Taylor & Francis Group, LLC. In this study, an investigation has been carried out to examine the tribological features of Rice bran oil (RBO) based biodiesel as an agent to improve lubricity. RBOB was successfully generated by the means of transesterification and the studied fuels were pure biodiesel (RBOB100), 10% (RBOB10), 30% (RBOB30), and 50% (RBOB50) of biodiesel combined with diesel and pure diesel (RBOB0). Examination in agreement with the ASTM D 4172 method was carried out under following conditions for all examined fuels: a constant load of 40 kg, a steady sliding speed of 1200 rpm, a constant temperature of 75°C and a reaction time of 3600 s. Frictional torque was recorded on line in the course of wear examination. Optical microscopy was implemented to investigate the wear scars of tested balls. Result showed that friction diminished with the decrease of biodiesel concentration. Moreover, formation of wear scars increased with increasing the biodiesel concentration. It could be concluded that lubricity decreases due to increasing the biodiesel concentration. Surface morphology analysis showed that pure biodiesel and diesel formed adhesive wears. However, all the wears formed by biodiesel-diesel blends were fallen into the abrasive wear group.
Mujtaba, MA, Muk Cho, H, Masjuki, HH, Kalam, MA, Ong, HC, Gul, M, Harith, MH & Yusoff, MNAM 2020, 'Critical review on sesame seed oil and its methyl ester on cold flow and oxidation stability', Energy Reports, vol. 6, pp. 40-54.View/Download from: Publisher's site
© 2019 The demand for renewable energy is steadily increasing due to rapid population growth and economic development worldwide. An additional reason is that fossil fuel reserves are limited, and this situation results in their non-uniform availability globally. Furthermore, the attitudes of the society, energy policies and technology choices are constantly changing. Thus, renewable energy resources are now considered good alternatives to fossil fuels. In the meantime, liquid energy, such as methyl ester from locally produced vegetable oils, is well accepted by many countries, even though it is currently being blended up to 20% with petroleum fuels. Recently, the industrialisation of biodiesel is a major problem because of its poor cold flow properties and oxidative stability. Vegetable oils are also being blended in an appropriate proportion before transesterification to obtain the desired properties in biodiesel. Similarly, poor cold flow properties and oxidative stability can be improved by choosing suitable vegetable oils for making blends. Amongst all available vegetable oils, sesame seed oil (SSO) has unique cold flow properties and oxidation stability, particularly because of naturally occurring antioxidants and preservatives, which enhance the stability of oil towards rancidity. Therefore, SSO can be used as a potential feedstock for blending with other vegetable oils to enhance the overall cold flow and oxidation stability properties. This overview summarises sesame cultivation, SSO production, the physicochemical properties of SSO and its potential as an alternative renewable fuel source. In this review, the physicochemical properties of sesame biodiesel are compared with those of biodiesel derived from other vegetable oils. Results show that blending SSO with palm oil before transesterification will successfully improve the cold flow properties and oxidation stability of palm methyl ester (biodiesel).
Ong, HC, Chen, W-H, Singh, Y, Gan, YY, Chen, C-Y & Show, PL 2020, 'A state-of-the-art review on thermochemical conversion of biomass for biofuel production: A TG-FTIR approach', ENERGY CONVERSION AND MANAGEMENT, vol. 209.View/Download from: Publisher's site
Silitonga, AS, Shamsuddin, AH, Mahlia, TM, Milano, J, Kusumo, F, Siswantoro, J, Dharma, S, Sebayang, AH, Masjuki, HH & Ong, HC 2020, 'Biodiesel synthesis from Ceiba pentandra oil by microwave irradiation-assisted transesterification: ELM modeling and optimization', RENEWABLE ENERGY, vol. 146, pp. 1278-1291.View/Download from: Publisher's site
Tang, RCO, Jang, JH, Lan, TH, Wu, JC, Yan, WM, Sangeetha, T, Wang, CT, Ong, HC & Ong, ZC 2020, 'Review on design factors of microbial fuel cells using Buckingham's Pi Theorem', Renewable and Sustainable Energy Reviews, vol. 130.View/Download from: Publisher's site
© 2020 Elsevier Ltd Microbial fuel cells (MFCs) have become a promising approach to generate cleaner and more sustainable electrical energy. Involvement of various disciplines had been contributing to enhance the performance of the MFCs. Factors affecting the performance such as chemical components, bacteria species, electrodes materials, flow interaction and electrical parts are being widely reviewed, however most of the research are highly field-specific without considering other important variables from different disciplines. In this study, Buckingham's Pi Theorem has been utilized to be implemented in the design pattern of MFCs. Several dominated variables of interest have also been pointed out including the design limitation. Modelling and application of Buckingham's Pi Theorem has been discussed as well which is useful for performance enhancement of MFCs and their application in wastewater treatment in the future.
Ubando, AT, Chen, W-H, Show, P-L & Ong, HC 2020, 'Kinetic and thermodynamic analysis of iron oxide reduction by graphite for CO2 mitigation in chemical-looping combustion', INTERNATIONAL JOURNAL OF ENERGY RESEARCH, vol. 44, no. 5, pp. 3865-3882.View/Download from: Publisher's site
Damanik, N, Ong, HC, Rahman, MM, Tong, CW, Silitonga, AS, Shamsuddin, AH, Sebayang, AH, Mahlia, TMI, Wang, CT & Jang, JH 2019, 'The performance and exhaust emissions of a diesel engine fuelled with Calophyllum inophyllum- palm biodiesel', Processes, vol. 7, no. 9.View/Download from: Publisher's site
© 2019 by the authors. Nowadays, increased interest among the scientific community to explore the Calophyllum inophyllum as alternative fuels for diesel engines is observed. This research is about using mixed Calophyllum inophyllum-palm oil biodiesel production and evaluation that biodiesel in a diesel engine. The Calophyllum inophyllum-palm oil methyl ester (CPME) is processed using the following procedure: (1) the crude Calophyllum inophyllum and palm oils are mixed at the same ratio of 50:50 volume %, (2) degumming, (3) acid-catalysed esterification, (4) purification, and (5) alkalinecatalysed transesterification. The results are indeed encouraging which satisfy the international standards, CPME shows the high heating value (37.9 MJ/kg) but lower kinematic viscosity (4.50 mm2/s) due to change the fatty acid methyl ester (FAME) composition compared to Calophyllum inophyllum methyl ester (CIME). The average results show that the blended fuels have higher Brake Specific Fuel Consumption (BSFC) and NOx emissions, lower Brake Thermal Efficiency (BTE), along with CO and HC emissions than diesel fuel over the entire range of speeds. Among the blends, CPME5 offered better performance compared to other fuels. It can be recommended that the CPME blend has great potential as an alternative fuel because of its excellent characteristics, better performance, and less harmful emission than CIME blends.
Jamaluddin, NAM, Riayatsyah, TMI, Silitonga, AS, Rahman, MM, Shamsuddin, AH, Ong, HC, Mahlia, TMI & Rahman, SMA 2019, 'Techno-economic analysis and physicochemical properties of Ceiba pentandra as second-generation biodiesel based on ASTM D6751 and EN 14214', Processes, vol. 7, no. 9.View/Download from: Publisher's site
© 2019 by the authors. Processing biodiesel from non-edible sources of feedstock seems to be thriving in recent years. It also has also gathered more attention than in the past, mainly because the biodiesel product is renewable and emits lower pollution compared to fossil fuels. Researchers have started their work on various kinds of biodiesel product, especially from a non-edible feedstock. Non-edible feedstocks such as Ceiba pentandra show great potential in the production of biodiesel, especially in the Southeast Asia region because the plants seem to be abundant in that region. Ceiba pentandra, also known as the Kapok tree, produces hundreds of pods with a length of 15 cm (5.9 in) and diameter 2-5 cm (1-2 in). The pods consist of seeds and fluffin the surrounding areas inside the pod, which itself contains yellowish fibre, a mixture of cellulose and lignin. The seeds of Ceiba pentandra can be used as feedstock for biodiesel production. The study for Ceiba pentandra will involve techno-economic, as well as a sensitivity analysis. Moreover, the study also shows that the techno-economic analysis of a biodiesel processing plant for 50 ktons Ceiba pentandra with a life span of 20 years is around $701 million with 3.7 years of the payback period. Besides that, this study also shows the differences in operating cost and oil conversion yield, which has the least impact on running cost. By improving the conversion processes continuously and by increasing the operational effciency, the cost of production will decrease. In addition, the study also explains the differences of final price biodiesel and diesel fossil fuel, both showing dissimilar scenarios subsidy and taxation. Biodiesel has a subsidy of $0.10/L and $0.18/L with a total tax exemption of 15%. The value was obtained from the latest subsidy cost and diesel in Malaysia. Finally, further research is needed in order to fully utilize the use of Ceiba pentandra as one of the non-edible sources of biodiesel.
Mofijur, M, Hasan, MM, Mahlia, TMI, Rahman, SMA, Silitonga, AS & Ong, HC 2019, 'Performance and Emission Parameters of Homogeneous Charge Compression Ignition (HCCI) Engine: A Review', Energies, vol. 12, no. 18.View/Download from: Publisher's site
Nurfahmi, Mofijur, M, Ong, HC, Jan, BM, Kusumo, F, Sebayang, AH, Husin, H, Silitonga, AS, Mahlia, TMI & Rahman, SMA 2019, 'Production Process and Optimization of Solid Bioethanol from Empty Fruit Bunches of Palm Oil Using Response Surface Methodology', PROCESSES, vol. 7, no. 10.View/Download from: Publisher's site
Rahman, MM, Mahlia, TMI, Silitonga, AS, Ong, HC, Silakhori, M, Hasan, MH, Putra, N & Ashrafur Rahman, SM 2019, 'Phase change materials (PCM) for solar energy usages and storage: An overview', Energies, vol. 12, no. 16.View/Download from: Publisher's site
© 2019 by the authors. Solar energy is a renewable energy source that can be utilized for different applications in today's world. The effective use of solar energy requires a storage medium that can facilitate the storage of excess energy, and then supply this stored energy when it is needed. An effective method of storing thermal energy from solar is through the use of phase change materials (PCMs). PCMs are isothermal in nature, and thus offer higher density energy storage and the ability to operate in a variable range of temperature conditions. This article provides a comprehensive review of the application of PCMs for solar energy use and storage such as for solar power generation, water heating systems, solar cookers, and solar dryers. This paper will benefit the researcher in conducting further research on solar power generation, water heating system, solar cookers, and solar dryers using PCMs for commercial development.
Silitonga, AS, Mahlia, TMI, Shamsuddin, AH, Ong, HC, Milano, J, Kusumo, F, Sebayang, AH, Dharma, S, Ibrahim, H, Husin, H, Mofijur, M & Rahman, SMA 2019, 'Optimization of Cerbera manghas Biodiesel Production Using Artificial Neural Networks Integrated with Ant Colony Optimization', ENERGIES, vol. 12, no. 20.View/Download from: Publisher's site
Optimizing the process parameters of biodiesel production is the key to maximizing biodiesel yields. In this study, artificial neural network models integrated with ant colony optimization were developed to optimize the parameters of the two-step Cerbera manghas biodiesel production process: (1) esterification and (2) transesterification. The parameters of esterification and transesterification processes were optimized to minimize the acid value and maximize the C. manghas biodiesel yield, respectively. There was excellent agreement between the average experimental values and those predicted by the artificial neural network models, indicating their reliability. These models will be useful to predict the optimum process parameters, reducing the trial and error of conventional experimentation. The kinetic study was conducted to understand the mechanism of the transesterification process and, lastly, the model could measure the physicochemical properties of the C. manghas biodiesel.
Ashok, B, Nanthagopal, K, Darla, S, Chyuan, OH, Ramesh, A, Jacob, A, Sahil, G, Thiyagarajan, S & Geo, VE 2019, 'Comparative assessment of hexanol and decanol as oxygenated additives with calophyllum inophyllum biodiesel', Energy, vol. 173, pp. 494-510.View/Download from: Publisher's site
© 2019 Elsevier Ltd In this research work, the four ternary blends were prepared with 30% and 40% by volume of higher alcohol (decanol and hexanol) with biodiesel while maintain 50% of diesel concentration. All ternary blends of diesel-biodiesel-higher alcohols were used in single cylinder engine and the results were compared with binary blend of 50%–50% biodiesel, pure diesel and biodiesel. It was revealed that thermal efficiency of ternary blends was higher than biodiesel and in some cases it is closer to pure diesel. In contrary, specific fuel consumption is found to lower with increase in alcohol fractions in ternary blends. Moreover, hydrocarbon, smoke, carbon monoxide emissions from alcohol-infused fuel blends were observed to be lower than both biodiesel and pure diesel. Significant reduction in oxides of nitrogen (NOx) emissions was also observed by the addition of higher alcohols to the fuel blend when compared to biodiesel fuel. It is to be noted that decanol 40% addition with diesel and biodiesel blend has shown better results in emission characteristics. Furthermore, the heat release rate and in-cylinder pressure for biodiesel were significantly lower compared to pure diesel fuels. However, addition of 40% decanol with fuel blend improved the heat release rate and in-cylinder pressure.
Cheah, MY, Ong, HC, Zulkifli, NWM, Masjuki, HH & Salleh, A 2019, 'Physicochemical and tribological properties of microalgae oil as biolubricant for hydrogen-powered engine', International Journal of Hydrogen Energy.View/Download from: Publisher's site
© 2019 Hydrogen Energy Publications LLC Hydrogen fuel offers a cleaner fuel alternative to fossil fuel due to more efficient burning as well as reduces the environmental and health issues brought by fossil fuel usage. In engine application, regardless of either pure hydrogen or in combination with air or/and other biofuel, all the moving parts are exposed to friction and wear, and lubricant is used to minimize friction and wear for optimum operation. Thus, in this study, the use of microalgae oil as an alternative biolubricant is evaluated from the physicochemical and tribological aspects. It is found that modified microalgae oil (MMO) has demonstrated great anti-friction and anti-wear potential, particularly the 10% modified microalgae oil blend (MMO-10). The coefficient of friction is reduced (up to 10.1%) and significant reductions of wear loss and surface roughness are obtained in comparison to pure poly-alpha-olefin. Lubricant's heat dissipation is also enhanced with MMO addition, demonstrating great prospect for MMO for hydrogen-powered engine utilization.
Chen, WH, Lin, YY, Liu, HC, Chen, TC, Hung, CH, Chen, CH & Ong, HC 2019, 'A comprehensive analysis of food waste derived liquefaction bio-oil properties for industrial application', Applied Energy, vol. 237, pp. 283-291.View/Download from: Publisher's site
© 2019 Elsevier Ltd Hydrothermal liquefaction is a promising technology to convert wet biomass into bio-oil with high calorific value and without drying process. To evaluate the potential application of liquefaction bio-oil in industry, the present study aims to provide a comprehensive analysis on the properties of liquefaction bio-oil derived from food waste. The food waste is pretreated with K2CO3 at 100 °C for 1 h, followed by liquefaction in a semi-pilot reactor at 320 °C for 30 min. The higher heating value of produced bio-oil is 34.79 MJ kg−1, accounting for 53% increase when compared to the feedstock (22.74 MJ kg−1). The ignition and burnout temperatures of the bio-oil are lower than other liquefaction bio-oils, reflecting its higher reactivity and combustibility. Meanwhile, the bio-oil has a higher oxidation onset temperature than pyrolysis bio-oils, showing its higher thermal stability. The independent parallel reaction model in association with the particle swarm optimization indicates that the pyrolysis kinetics of the bio-oil can be approximated by four groups. The component analysis further reveals two important groups of fatty acids and amides in the bio-oil, stemming from the conversion of carbohydrate and protein in the food waste. The comprehensive analysis shows that the liquefaction bio-oil from food waste, characterized by higher energy density and better combustibility, is a potential substitute to the fossil fuels.
Chen, W-H, Wang, C-W, Ong, HC, Show, PL & Hsieh, T-H 2019, 'Torrefaction, pyrolysis and two-stage thermodegradation of hemicellulose, cellulose and lignin', FUEL, vol. 258.View/Download from: Publisher's site
Chong, CT, Mong, GR, Ng, J-H, Chong, WWF, Ani, FN, Lam, SS & Ong, HC 2019, 'Pyrolysis characteristics and kinetic studies of horse manure using thermogravimetric analysis', ENERGY CONVERSION AND MANAGEMENT, vol. 180, pp. 1260-1267.View/Download from: Publisher's site
Chong, W-T, Muzammil, WK, Ong, H-C, Sopian, K, Gwani, M, Fazlizan, A & Poh, S-C 2019, 'Performance analysis of the deflector integrated cross axis wind turbine', RENEWABLE ENERGY, vol. 138, pp. 675-690.View/Download from: Publisher's site
Gan, YY, Ong, HC, Ling, TC, Chen, W-H & Chong, CT 2019, 'Torrefaction of de-oiled Jatropha seed kernel biomass for solid fuel production', ENERGY, vol. 170, pp. 367-374.View/Download from: Publisher's site
Goh, BHH, Ong, HC, Cheah, MY, Chen, WH, Yu, KL & Mahlia, TMI 2019, 'Sustainability of direct biodiesel synthesis from microalgae biomass: A critical review', Renewable and Sustainable Energy Reviews, vol. 107, pp. 59-74.View/Download from: Publisher's site
© 2019 Elsevier Ltd Microalgae has been identified as a potential feedstock for biodiesel production since its cultivation requires less cropland compared to conventional oil crops and the high growth rate of microalgae. Research on microalgae oils often are focused on microalgae oil extraction and biomass harvesting techniques. However, energy intensive and costly lipid extraction methods are the major obstacles hampering microalgae biodiesel commercialisation. Direct biodiesel synthesis avoids such problems as it combines lipid extraction techniques and transesterification into a single step. In this review, the potential of direct biodiesel synthesis from microalgae biomass was comprehensively analysed. The various species of microalgae commonly used as biodiesel feedstock was critically assessed, particularly on high lipid content species. The production of microalgae biodiesel via direct conversion from biomass was systematically discussed, covering major enhancements such as heterogeneous catalysts, the use of ultrasonic and microwave- techniques and supercritical alcohols that focus on the overall improvement of biodiesel production. In addition, this review illustrates the cultivation conditions for biomass growth and lipid productivity improvement, the available harvesting and lipid extraction technologies, as well as the key challenges and future prospect of microalgae biodiesel production. This review serves as a basis for future research on direct biodiesel synthesis from modified microalgae biomass to improve profitability of microalgae biodiesel.
Hoang, CN, Hwai, CO, Thi, TTP, Thi, KKD & Su, C-H 2019, 'Microwave-mediated noncatalytic synthesis of ethyl levulinate: A green process for fuel additive production', INTERNATIONAL JOURNAL OF ENERGY RESEARCH, vol. 44, no. 3, pp. 1698-1708.View/Download from: Publisher's site
Hossain, N, Razali, AN, Mahlia, TMI, Chowdhury, A, Chowdhury, H, Ong, HC, Shamsuddin, AH & Silitonga, AS 2019, 'Experimental Investigation, Techno-Economic Analysis and Environmental Impact of Bioethanol Production from Banana Stem', ENERGIES, vol. 12, no. 20.View/Download from: Publisher's site
Banana stem is being considered as the second largest waste biomass in Malaysia. Therefore, the environmental challenge of managing this huge amount of biomass as well as converting the feedstock into value-added products has spurred the demand for diversified applications to be implemented as a realistic approach. In this study, banana stem waste was experimented for bioethanol generation via hydrolysis and fermentation methods with the presence of Saccharomyces cerevisiae (yeast) subsequently. Along with the experimental analysis, a realistic pilot scale application of electricity generation from the bioethanol has been designed by HOMER software to demonstrate techno-economic and environmental impact. During sulfuric acid and enzymatic hydrolysis, the highest glucose yield was 5.614 and 40.61 g/L, respectively. During fermentation, the maximum and minimum glucose yield was 62.23 g/L at 12 h and 0.69 g/L at 72 h, respectively. Subsequently, 99.8% pure bioethanol was recovered by a distillation process. Plant modeling simulated operating costs 65,980 US$/y, net production cost 869347 US$ and electricity cost 0.392 US$/kWh. The CO2 emission from bioethanol was 97,161 kg/y and SO2 emission was 513 kg/y which is much lower than diesel emission. The overall bioethanol production from banana stem and application of electricity generation presented the approach economically favorable and environmentally benign
Jeevanantham, AK, Nanthagopal, K, Ashok, B, Al-Muhtaseb, AH, Thiyagarajan, S, Geo, VE, Ong, HC & Samuel, KJ 2019, 'Impact of addition of two ether additives with high speed diesel-Calophyllum Inophyllum biodiesel blends on NOx reduction in CI engine', ENERGY, vol. 185, pp. 39-54.View/Download from: Publisher's site
Karthickeyan, V, Thiyagarajan, S, Geo, VE, Ashok, B, Nanthagopal, K, Chyuan, OH & Vignesh, R 2019, 'Simultaneous reduction of NOx and smoke emissions with low viscous biofuel in low heat rejection engine using selective catalytic reduction technique', Fuel, vol. 255.View/Download from: Publisher's site
© 2019 Elsevier Ltd The present work offered a comprehensive investigation on engine characteristics of single cylinder Direct Injection (DI) diesel engine fuelled with Lemon oil (LO) biofuel. LO was obtained from the peels of lemon using steam distillation process. The physio-chemical properties of LO were analysed based ASTM biodiesel standard and compared with diesel. The chemical composition of LO was observed with Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography and Mass Spectrometry (GC–MS). In-order to enhance the properties of LO, a cetane enhancer namely Pyrogallol (PY) was added. The engine combustion chamber components namely piston head, cylinder head and intake and exhaust valves were thermally coated with Partially Stabilized Zirconia (PSZ) which converted the conventional engine into low heat rejection engine. In the PSZ coated engine, enhanced performance and combustion characteristics were observed with LO and PY blend. Declined carbon monoxide (CO), hydrocarbon (HC) and smoke emissions were observed with LO and PY blend in coated engine. Further, the work was extended with the application of Selective catalytic reduction (SCR) and Catalytic Converter (CC) as post treatment system for the reduction of NOx emission. With post treatment, LO and pyrogallol in PSZ coated engine showed lower NOx emission than diesel and LO. Consequently, LO and pyrogallol in PSZ coated engine with post treatment was considered as more advantageous than other fuel samples on account of its performance, combustion and emission characteristics.
Khoo, KS, Chew, KW, Ooi, CW, Ong, HC, Ling, TC & Show, PL 2019, 'Extraction of natural astaxanthin from Haematococcus pluvialis using liquid biphasic flotation system', BIORESOURCE TECHNOLOGY, vol. 290.View/Download from: Publisher's site
Kusumo, F, Mahlia, TMI, Shamsuddin, AH, Ong, HC, Ahmad, AR, Ismail, Z, Ong, ZC & Silitonga, AS 2019, 'The effect of multi-walled carbon nanotubes-additive in physicochemical property of rice brand methyl ester: Optimization analysis', Energies, vol. 12, no. 17.View/Download from: Publisher's site
© 2019 by the authors. Biodiesel as an alternative to diesel fuel produced from vegetable oils or animal fats has attracted more and more attention because it is renewable and environmentally friendly. Compared to conventional diesel fuel, biodiesel has slightly lower performance in engine combustion due to the lower calorific value that leads to lower power generated. This study investigates the effect of multi-walled carbon nanotubes (MWCNTs) as an additive to the rice bran methyl ester (RBME). Artificial neural network (ANN) and response surface methodology (RSM) was used for predicting the calorific value. The interaction effects of parameters such as dosage of MWCNTs, size of MWCNTs and reaction time on the calorific value of RBME were studied. Comparison of RSM and ANN performance was evaluated based on the correlation coefficient (R2), the root mean square error (RMSE), the mean absolute percentage error (MAPE), and the average absolute deviation (AAD) showed that the ANN model had better performance (R2 = 0.9808, RMSE = 0.0164, MAPE = 0.0017, AAD = 0.173) compare to RSM (R2 = 0.9746, RMSE = 0.0170, MAPE = 0.0028, AAD = 0.279). The optimum predicted of RBME calorific value that is generated using the cuckoo search (CS) via lévy flight optimization algorithm is 41.78 (MJ/kg). The optimum value was obtained using 64 ppm of < 7 nm MWCNTs blending for 60 min. The predicted calorific value was validated experimentally as 41.05 MJ/kg. Furthermore, the experimental results have shown that the addition of MWCNTs was significantly increased the calorific value from 36.87 MJ/kg to 41.05 MJ/kg (11.6%). Also, the addition of MWCNTs decreased flashpoint (−18.3%) and acid value (−0.52%). As a conclusion, adding MWCNTs as an additive had improved the physicochemical properties characteristics of RBME. To our best knowledge, no research has yet been performed on the effect of multi-walled carbon nanotubes-additive in physicochemical property of rice brand methyl ester app...
Leong, KY, Chew, SP, Gurunathan, BA, Ku Ahmad, KZ & Ong, HC 2019, 'An experimental approach to investigate thermal performance of paraffin wax and 1-hexadecanol based heat sinks for cooling of electronic system', International Communications in Heat and Mass Transfer, vol. 109.View/Download from: Publisher's site
© 2019 Elsevier Ltd The efficiency and life span of an electronic device or system depends on its operating temperature. Longer operation period in elevated temperatures leads to system failure. In addition, miniaturization of electronic device and generation of high energy density are the current trend in this field. Therefore, an efficient cooling system is vital for ensuring this system operates in optimum temperature. Integration of heat sinks together with phase change material (PCM) can be adapted to dissipate heat generation by electronic system. This study intends to investigate thermal performance of various configuration of cross-fin heat sinks with and without PCM. Two types of PCMs considered are paraffin wax and 1-hexadecanol. The study implies that addition of fins and PCM capable of augmented thermal performance of the heat sinks. Higher number of cross-fin and amount of PCM led to lower heat sinks base temperature. The base temperature of heat sinks with cross-fin (16 square cavities) fully added with paraffin wax is 46.9 °C compared to 51.6 °C observed for similar heat sinks without paraffin wax. Heat sinks filled with paraffin wax performed better than heat sinks filled with 1-hexadecanol. This translates to lower base heat sinks temperature especially at the mid-region of the test period.
Lin, B-J, Chen, W-H, Hsieh, T-H, Ong, HC, Show, PL & Naqvi, SR 2019, 'Oxidative reaction interaction and synergistic index of emulsified pyrolysis bio-oil/diesel fuels', RENEWABLE ENERGY, vol. 136, pp. 223-234.View/Download from: Publisher's site
Mahlia, TMI, Syaheed, H, Abas, AEP, Kusumo, F, Shamsuddin, AH, Ong, HC & Bilad, MR 2019, 'Organic Rankine Cycle (ORC) System Applications for Solar Energy: Recent Technological Advances', ENERGIES, vol. 12, no. 15.View/Download from: Publisher's site
Ong, HC, Chen, WH, Farooq, A, Gan, YY, Lee, KT & Ashokkumar, V 2019, 'Catalytic thermochemical conversion of biomass for biofuel production: A comprehensive review', Renewable and Sustainable Energy Reviews, vol. 113.View/Download from: Publisher's site
© 2019 Elsevier Ltd The increasing demand for energy and diminishing sources of fossil fuels have called for the discovery of new energy sources. The effective energy conversion process of biomass is able to fulfill energy needs. Among the advanced biomass conversion technologies, thermochemical processes hold considerable potential approaches and needed for optimization. Thus, this study presents a comprehensive review of the research and development on the effects of catalysts on the thermochemical conversion of biomass to determine the progress of catalytic thermochemical conversion processes. The effects of catalysts on torrefaction, pyrolysis, hydrothermal liquefaction, and gasification are highlighted. Aspects related to reaction conditions, reactor types, and products are discussed comprehensively with the reaction mechanisms involved in the catalytic effects. Hydrogenation and hydrodeoxygenation can occur in the presence of zeolite catalysts during fast pyrolysis while producing highly aromatic bio-oil. A heterogeneous catalyst in liquefaction increases the hydrocarbon content and decreases viscosity, acid value, and oxygenated compounds in the bio-oil. Thus, expanding and enhancing knowledge about catalyst utilization in the thermochemical conversion technologies of biomass will play an important role in the generation of renewable and carbon-neutral fuels.
Ong, HC, Milano, J, Silitonga, AS, Hassan, MH, Shamsuddin, AH, Wang, C-T, Mahlia, TMI, Siswantoro, J, Kusumo, F & Sutrisno, J 2019, 'Biodiesel production from Calophyllum inophyllum-Ceiba pentandra oil mixture: Optimization and characterization', JOURNAL OF CLEANER PRODUCTION, vol. 219, pp. 183-198.View/Download from: Publisher's site
Ooi, XY, Gao, W, Ong, HC, Lee, HV, Juan, JC, Chen, WH & Lee, KT 2019, 'Overview on catalytic deoxygenation for biofuel synthesis using metal oxide supported catalysts', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 112, pp. 834-852.View/Download from: Publisher's site
Ooi, XY, Oi, LE, Choo, MY, Ong, HC, Lee, HV, Show, PL, Lin, YC & Juan, JC 2019, 'Efficient deoxygenation of triglycerides to hydrocarbon-biofuel over mesoporous Al2O3-TiO2 catalyst', Fuel Processing Technology, vol. 194.View/Download from: Publisher's site
© 2019 Elsevier B.V. The renewable hydrocarbon-like biofuel from biomass is crucial to substitute fossil fuel. A series of mesoporous Al2O3-TiO2 mixed oxide catalysts with different TiO2 content (0.1Ti-0.9Al, 0.2Ti-0.8Al and 0.3Ti-0.7Al) have been synthesized. The physicochemical properties of the catalysts were characterized by XRD, FESEM-EDX, BET, FTIR, NH3-TPD, FTIR-Py, and TGA. The deoxygenation (DO) of triglyceride (i.e. triolein) was carried out in the absence of hydrogen and solvent. The mesoporous Al2O3-TiO2 catalysts showed high catalytic activity performance as compared to that of Al2O3 and TiO2. It was found that 0.2Ti-0.8Al catalyst exhibited the highest conversion (76.86%), and selectivity (27.26%) toward n-C15 + n-C17 at 380 °C after 4 h. The excellence performance of mesoporous Al2O3-TiO2 was attributed to its acidity, mesoporosity and larger surface area. The results reveal that the mesoporous Al2O3-TiO2 catalyst is a promising catalyst for the synthesis of hydrocarbon-like biofuel.
Phwan, CK, Chew, KW, Sebayang, AH, Ong, HC, Ling, TC, Malek, MA, Ho, Y-C & Show, PL 2019, 'Effects of acids pre-treatment on the microbial fermentation process for bioethanol production from microalgae.', Biotechnology for biofuels, vol. 12.View/Download from: Publisher's site
Background:Microalgae are one of the promising feedstock that consists of high carbohydrate content which can be converted into bioethanol. Pre-treatment is one of the critical steps required to release fermentable sugars to be used in the microbial fermentation process. In this study, the reducing sugar concentration of Chlorella species was investigated by pre-treating the biomass with dilute sulfuric acid and acetic acid at different concentrations 1%, 3%, 5%, 7%, and 9% (v/v). Results:3,5-Dinitrosalicylic acid (DNS) method, FTIR, and GC-FID were employed to evaluate the reducing sugar concentration, functional groups of alcohol bonds and concentration of bioethanol, respectively. The two-way ANOVA results (p < 0.05) indicated that there was a significant difference in the concentration and type of acids towards bioethanol production. The highest bioethanol yield obtained was 0.28 g ethanol/g microalgae which was found in microalgae sample pre-treated with 5% (v/v) sulfuric acid while 0.23 g ethanol/g microalgal biomass was presented in microalgae sample pre-treated with 5% (v/v) acetic acid. Conclusion:The application of acid pre-treatment on microalgae for bioethanol production will contribute to higher effectiveness and lower energy consumption compared to other pre-treatment methods. The findings from this study are essential for the commercial production of bioethanol from microalgae.
Samiran, NA, Chong, CT, Ng, J-H, Manh-Vu, T, Ong, HC, Valera-Medina, A, Chong, WWF & Jaafar, MNM 2019, 'Experimental and numerical studies on the premixed syngas swirl flames in a model combustor', INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 44, no. 44, pp. 24126-24139.View/Download from: Publisher's site
Tan, SX, Lim, S, Ong, HC & Pang, YL 2019, 'State of the art review on development of ultrasound-assisted catalytic transesterification process for biodiesel production', FUEL, vol. 235, pp. 886-907.View/Download from: Publisher's site
Tan, SX, Lim, S, Ong, HC, Pang, YL, Kusumo, F, Goh, BHH & Chong, CT 2019, 'Two-step catalytic reactive extraction and transesterification process via ultrasonic irradiation for biodiesel production from solid Jatropha oil seeds', CHEMICAL ENGINEERING AND PROCESSING-PROCESS INTENSIFICATION, vol. 146.View/Download from: Publisher's site
Tan, SX, Ong, HC, Lim, S, Pang, YL & Milano, J 2019, 'Process intensification of biodiesel synthesis via ultrasound-assisted in situ esterification of Jatropha oil seeds', JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, vol. 94, no. 5, pp. 1362-1373.View/Download from: Publisher's site
Ubando, AT, Chen, W-H & Ong, HC 2019, 'Iron oxide reduction by graphite and torrefied biomass analyzed by TG-FTIR for mitigating CO2 emissions', ENERGY, vol. 180, pp. 968-977.View/Download from: Publisher's site
Why, ESK, Ong, HC, Lee, HV, Gan, YY, Chen, W-H & Chong, CT 2019, 'Renewable aviation fuel by advanced hydroprocessing of biomass: Challenges and perspective', ENERGY CONVERSION AND MANAGEMENT, vol. 199.View/Download from: Publisher's site
Yap, HC, Pang, YL, Lim, S, Abdullah, AZ, Ong, HC & Wu, CH 2019, 'A comprehensive review on state-of-the-art photo-, sono-, and sonophotocatalytic treatments to degrade emerging contaminants', International Journal of Environmental Science and Technology, vol. 16, no. 1, pp. 601-628.View/Download from: Publisher's site
© 2018, Islamic Azad University (IAU). Emerging contaminants (ECs) are commonly originated from personal care products, cosmetics, pharmaceuticals, pesticides, dioxins, polycyclic aromatic hydrocarbons (PAHs), and alkylphenolic compounds. Due to the huge development of these industries, these ECs have been constantly detected in wastewater, groundwater, and surface water in hazardous quantity. The discharge of these ECs into the environment causes considerable non-esthetic pollution and could be a great threat to the entire ecosystem. The common wastewater treatment plants (WWTPs) which consist of biological, physical, and chemical treatments such as activated sludge, filtration, adsorption, and coagulation are found to be ineffective for desired removal of ECs. In turn, various emerging advanced oxidation processes (AOPs) such as ultrasonic and ultraviolet irradiation with or without the presence of catalyst have raised great attention due to their great potential in remediation of ECs. This paper presents a critical review on types, recent occurrence, sources, environmental impacts, and emerging treatment methods applicable to treat ECs. The current research and applications of ultrasonic, ultraviolet, and combination of both irradiations to treat ECs in wastewater are particularly reviewed. The effect of key parameters on photo-, sono- and, sonophotocatalytic degradation of ECs are commendably accessed such as ultrasonic power, ultrasonic frequency, light intensity, ultraviolet wavelength, solution pH, oxidizing agents, chemical additives, catalyst dosage, and modification of catalyst. The possible reaction mechanisms of ECs degradation process and kinetic model study are also elucidated in detail. Lastly, future research directions and conclusions are proposed to strengthen the understanding on their fate in water. All this information is vital to predict the negative impacts of ECs on the receiving environment effectively.
Sandu, S, Yang, M, Mahlia, TMI, Wongsapai, W, Ong, HC, Putra, N & Ashrafur Rahman, SM 2019, 'Energy-related CO2 emissions growth in ASEAN countries: Trends, drivers and policy implications', Energies, vol. 12, no. 24.View/Download from: Publisher's site
© 2019 by the authors. The primary objective of this paper is to analyse the growth of energy-related CO2 emissions in ASEAN (Association of Southeast Asian Nations), with specific emphasis on identifying its trends and underlying drivers. This objective is premised on the arguments that: (1) there is a general lack of analysis of energy-related CO2 emissions growth across ASEAN countries; and (2) such an analysis is critical, because it could enable an assessment to be made of the efficacy of existing energy policies for reducing emissions. Decomposition analysis is the main approach adopted in this paper. The findings of this paper suggest that the growth of energy-related CO2 emissions has slowed in some major emitters in the region, due to energy efficiency improvement, and, to a lesser extent, a gradual switch in energy fuel mix towards lower emission sources (gas and renewables). However, this improvement is unlikely to drive a major transformation in the energy sectors of the region to the extent considered adequate for redressing the challenge of rising emissions, as indicated by a steady emissions growth in most ASEAN countries over the entire study period (1971–2016). By implication, this suggests that a significant scale-up of existing policy effort is needed to rectify the situations.
Asikin-Mijan, N, Lee, HV, Juan, JC, Noorsaadah, AR, Ong, HC, Razali, SM & Taufiq-Yap, YH 2018, 'Promoting deoxygenation of triglycerides via Co-Ca loaded SiO2-Al2O3 catalyst', APPLIED CATALYSIS A-GENERAL, vol. 552, pp. 38-48.View/Download from: Publisher's site
Chia, SR, Chew, KW, Show, PL, Yap, YJ, Ong, HC, Ling, TC & Chang, J-S 2018, 'Analysis of Economic and Environmental Aspects of Microalgae Biorefinery for Biofuels Production: A Review', BIOTECHNOLOGY JOURNAL, vol. 13, no. 6.View/Download from: Publisher's site
Chia, SR, Ong, HC, Chew, KW, Show, PL, Phang, S-M, Ling, TC, Nagarajan, D, Lee, D-J & Chang, J-S 2018, 'Sustainable approaches for algae utilisation in bioenergy production', RENEWABLE ENERGY, vol. 129, pp. 838-852.View/Download from: Publisher's site
Chia, SR, Show, PL, Phang, S-M, Ling, TC & Ong, HC 2018, 'Sustainable approach in phlorotannin recovery from macroalgae', JOURNAL OF BIOSCIENCE AND BIOENGINEERING, vol. 126, no. 2, pp. 220-225.View/Download from: Publisher's site
Damanik, N, Ong, HC, Tong, CW, Mahlia, TMI & Silitonga, AS 2018, 'A review on the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends.', Environmental science and pollution research international, vol. 25, no. 16, pp. 15307-15325.View/Download from: Publisher's site
Biodiesels have gained much popularity because they are cleaner alternative fuels and they can be used directly in diesel engines without modifications. In this paper, a brief review of the key studies pertaining to the engine performance and exhaust emission characteristics of diesel engines fueled with biodiesel blends, exhaust aftertreatment systems, and low-temperature combustion technology is presented. In general, most biodiesel blends result in a significant decrease in carbon monoxide and total unburned hydrocarbon emissions. There is also a decrease in carbon monoxide, nitrogen oxide, and total unburned hydrocarbon emissions while the engine performance increases for diesel engines fueled with biodiesels blended with nano-additives. The development of automotive technologies, such as exhaust gas recirculation systems and low-temperature combustion technology, also improves the thermal efficiency of diesel engines and reduces nitrogen oxide and particulate matter emissions.
Gan, YY, Ong, HC, Ling, TC, Zulkifli, NWM, Wang, C-T & Yang, Y-C 2018, 'Thermal conductivity optimization and entropy generation analysis of titanium dioxide nanofluid in evacuated tube solar collector', APPLIED THERMAL ENGINEERING, vol. 145, pp. 155-164.View/Download from: Publisher's site
Gan, YY, Ong, HC, Show, PL, Ling, TC, Chen, W-H, Yu, KL & Abdullah, R 2018, 'Torrefaction of microalgal biochar as potential coal fuel and application as bio-adsorbent', ENERGY CONVERSION AND MANAGEMENT, vol. 165, pp. 152-162.View/Download from: Publisher's site
Husin, H, Solo, BB, Ibrahim, IM, Chyuan, OH & Roslan, A 2018, 'Weight loss effect and potentiodynamic polarization response of 1-butyl-3-methylimidazolium chloride ionic liquid in highly acidic medium', Journal of Engineering Science and Technology, vol. 13, no. 4, pp. 1005-1015.
© School of Engineering, Taylor's University. Ionic liquids are increasingly being used as corrosion inhibitors when oil and gas industries started to give focus on sustainability and green impact in their operations. In this study, 1-butyl-3-methylimidazolium chloride ionic liquid in 2M HCl medium has been investigated on mild steel, stainless steel and aluminium bars by using weight loss technique and potentiodynamic polarization measurement. Results showed that 1-butyl-3-methylimidazolium chloride is able to reduce the weight loss of aluminium metal under acidic corrosive surrounding up to 11% compared to that of without the presence of 1-butyl-3-methylimidazolium chloride. Based on potentiodynamic polarization response, percentage of corrosion inhibition efficiency is found to be up to 99.3%. In summary, 1-butyl-3-methylimidazolium chloride is highly potential to act as an anti-corrosion agent, even in a very low concentration.
Leong, KY, Razali, I, Ahmad, KZK, Ong, HC, Ghazali, MJ & Rahman, MRA 2018, 'Thermal conductivity of an ethylene glycol/water-based nanofluid with copper-titanium dioxide nanoparticles: An experimental approach', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, vol. 90, pp. 23-28.View/Download from: Publisher's site
Mazaheri, H, Ong, HC, Masjuki, HH, Amini, Z, Harrison, MD, Wang, C-T, Kusumo, F & Alwi, A 2018, 'Rice bran oil based biodiesel production using calcium oxide catalyst derived from Chicoreus brunneus shell', ENERGY, vol. 144, pp. 10-19.View/Download from: Publisher's site
Milano, J, Ong, HC, Masjuki, HH, Silitonga, AS, Chen, W-H, Kusumo, F, Dharma, S & Sebayang, AH 2018, 'Optimization of biodiesel production by microwave irradiation-assisted transesterification for waste cooking oil-Calophyllum inophyllum oil via response surface methodology', ENERGY CONVERSION AND MANAGEMENT, vol. 158, pp. 400-415.View/Download from: Publisher's site
Milano, J, Ong, HC, Masjuki, HH, Silitonga, AS, Kusumo, F, Dharma, S, Sebayang, AH, Cheah, MY & Wang, C-T 2018, 'Physicochemical property enhancement of biodiesel synthesis from hybrid feedstocks of waste cooking vegetable oil and Beauty leaf oil through optimized alkaline-catalysed transesterification', WASTE MANAGEMENT, vol. 80, pp. 435-449.View/Download from: Publisher's site
Pang, YL, Tee, SF, Lim, S, Abdullah, AZ, Ong, HC, Wu, C-H, Chong, WC, Mohammad, AW & Mahmoudi, E 2018, 'Enhancement of photocatalytic degradation of organic dyes using ZnO decorated on reduced graphene oxide (rGO)', DESALINATION AND WATER TREATMENT, vol. 108, pp. 311-321.View/Download from: Publisher's site
Phwan, CK, Ong, HC, Chen, W-H, Ling, TC, Ng, EP & Show, PL 2018, 'Overview: Comparison of pretreatment technologies and fermentation processes of bioethanol from microalgae', ENERGY CONVERSION AND MANAGEMENT, vol. 173, pp. 81-94.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Ong, HC, Sebayang, AH, Dharma, S, Kusumo, F, Siswantoro, J, Milano, J, Daud, K, Mahlia, TMI, Chen, WH & Sugiyanto, B 2018, 'Evaluation of the engine performance and exhaust emissions of biodiesel-bioethanol-diesel blends using kernel-based extreme learning machine', Energy, vol. 159, pp. 1075-1087.View/Download from: Publisher's site
© 2018 Elsevier Ltd It is known that biodiesel and bioethanol are viable alternative fuels to replace diesel for compression ignition engines. In this study, an experimental investigation is carried out to evaluate the performance and exhaust emissions of a single cylinder diesel engine fuelled with biodiesel-bioethanol-diesel blends. The engine performance parameters evaluated are the brake speciﬁc fuel consumption and brake thermal efﬁciency whereas the exhaust emission parameters evaluated are carbon monoxide, nitrogen oxide, and smoke opacity. Kernel-based extreme learning machine is used to predict the engine performance and exhaust emission parameters of the fuel blends at full throttle conditions. Based on the experimental results, the brake specific fuel consumption is lower while the brake thermal efficiency is higher for the biodiesel-bioethanol-diesel blends. The carbon monoxide emissions and smoke opacity are also lower for these fuel blends. The mean absolute percentage error of the brake specific fuel consumption, brake thermal efficiency, carbon monoxide, nitrogen oxide, and smoke opacity is 1.363, 1.482, 4.597, 2.224, and 2.090%, respectively. Thus, it can be concluded that K-ELM is a reliable method to estimate the engine performance and exhaust emission parameters of a single cylinder compression ignition engine fuelled with biodiesel-bioethanol-diesel blends to reduce fuel consumption and exhaust emissions.
Tan, SX, Ong, HC, Lim, S & Pang, YL 2018, 'In situ reactive extraction of Jatropha curcas L. seeds assisted by ultrasound: Preliminary studies', ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS, vol. 40, no. 14, pp. 1772-1779.View/Download from: Publisher's site
Tang, Z-E, Lim, S, Pang, Y-L, Ong, H-C & Lee, K-T 2018, 'Synthesis of biomass as heterogeneous catalyst for application in biodiesel production: State of the art and fundamental review', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 92, pp. 235-253.View/Download from: Publisher's site
Wang, C-T, Huang, Y-S, Sangeetha, T, Chen, Y-M, Chong, W-T, Ong, H-C, Zhao, F & Yan, W-M 2018, 'Novel bufferless photosynthetic microbial fuel cell (PMFCs) for enhanced electrochemical performance', BIORESOURCE TECHNOLOGY, vol. 255, pp. 83-87.View/Download from: Publisher's site
Yang, Y-C, Wang, P-H, Tsai, Y-T & Ong, H-C 2018, 'Influences of feedstock and plasma spraying parameters on the fabrication of tubular solid oxide fuel cell anodes', CERAMICS INTERNATIONAL, vol. 44, no. 7, pp. 7824-7830.View/Download from: Publisher's site
Yu, KL, Show, PL, Ong, HC, Ling, TC, Chen, W-H & Salleh, MAM 2018, 'Biochar production from microalgae cultivation through pyrolysis as a sustainable carbon sequestration and biorefinery approach', CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY, vol. 20, no. 9, pp. 2047-2055.View/Download from: Publisher's site
Zainal, BS, Zinatizadeh, AA, Chyuan, OH, Mohd, NS & Ibrahim, S 2018, 'Effects of process, operational and environmental variables on biohydrogen production using palm oil mill effluent (POME)', INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 43, no. 23, pp. 10637-10644.View/Download from: Publisher's site
Amini, Z, Ilham, Z, Ong, HC, Mazaheri, H & Chen, W-H 2017, 'State of the art and prospective of lipase-catalyzed transesterification reaction for biodiesel production', ENERGY CONVERSION AND MANAGEMENT, vol. 141, pp. 339-353.View/Download from: Publisher's site
Amini, Z, Ong, HC, Harrison, MD, Kusumo, F, Mazaheri, H & Ilham, Z 2017, 'Biodiesel production by lipase-catalyzed transesterification of Ocimum basilicum L. (sweet basil) seed oil', ENERGY CONVERSION AND MANAGEMENT, vol. 132, pp. 82-90.View/Download from: Publisher's site
Asikin-Mijan, N, Lee, HV, Taufiq-Yap, YH, Abdulkrem-Alsultan, G, Mastuli, MS & Ong, HC 2017, 'Optimization study of SiO2-Al2O3 supported bifunctional acid-base NiO-CaO for renewable fuel production using response surface methodology', ENERGY CONVERSION AND MANAGEMENT, vol. 141, pp. 325-338.View/Download from: Publisher's site
Chen, W-H, Hsu, H-J, Kumar, G, Budzianowski, WM & Ong, HC 2017, 'Predictions of biochar production and torrefaction performance from sugarcane bagasse using interpolation and regression analysis', BIORESOURCE TECHNOLOGY, vol. 246, pp. 12-19.View/Download from: Publisher's site
Damanik, N, Ong, HC, Chong, WT & Silitonga, AS 2017, 'Biodiesel production from Calophyllum inophyllum-palm mixed oil', ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS, vol. 39, no. 12, pp. 1283-1289.View/Download from: Publisher's site
Dharma, S, Hassan, MH, Ong, HC, Sebayang, AH, Silitonga, AS & Kusumo, F 2017, 'Optimization of biodiesel production from mixed jatropha curcas-ceiba pentandra using artificial neural network- genetic algorithm: Evaluation of reaction kinetic models', Chemical Engineering Transactions, vol. 56, pp. 547-552.View/Download from: Publisher's site
Copyright © 2017, AIDIC Servizi S.r.l.. Biodiesel production from non-edible vegetable oil is one effective way to anticipate the problems associated with fuel crisis and environmental issues. In this study, artificial neural network and genetic algorithm based Box Behnken experimental design used to optimize the parameters of the biodiesel production for mixed of Jatropha curcas?Ceiba pentandra oil such as methanol to oil ratio, agitation speed and catalyst concentration. Based on the results, the optimum operating parameters for the transesterification of the oil mixture J50C50 are as follows: methanol-To-oil ratio: 40 %v/v, agitation speed: 1,794 rpm and the catalyst concentration: 0.68 % wt. This process is carried out at constant temperature and time of 60 °C and 2 h. The theoretical yield predicted under this the highest yield for the J50C50 biodiesel with a value of 93.70 %. The model developed was validated by applying the optimum values to three independent experimental replicates with a 93.56 %. Comparison between the predicted values to the actual value with a small error percentage indicates that the regression model was reliable in predicting the conversion at any given conditions within the ranges studied. Moreover, the activation energy of 24.421 kJmol-1 and frequency factor of 1.88 x 102 min-1 was required for the transesterification process. The fuel properties of the biodiesel were measured according to ASTM D 6751 and EN14214 standards and found to be within the specifications.
Dharma, S, Hassan, MH, Ong, HC, Sebayang, AH, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Experimental study and prediction of the performance and exhaust emissions of mixed Jatropha curcas-Ceiba pentandra biodiesel blends in diesel engine using artificial neural networks', JOURNAL OF CLEANER PRODUCTION, vol. 164, pp. 618-633.View/Download from: Publisher's site
Iranmanesh, S, Ong, HC, Ang, BC, Sadeghinezhad, E, Esmaeilzadeh, A & Mehrali, M 2017, 'Thermal performance enhancement of an evacuated tube solar collector using graphene nanoplatelets nanofluid', JOURNAL OF CLEANER PRODUCTION, vol. 162, pp. 121-129.View/Download from: Publisher's site
Kusumo, F, Silitonga, AS, Masjuki, HH, Ong, HC, Siswantoro, J & Mahlia, TMI 2017, 'Optimization of transesterification process for Ceiba pentandra oil: A comparative study between kernel-based extreme learning machine and artificial neural networks', Energy, vol. 134, pp. 24-34.View/Download from: Publisher's site
© 2017 Elsevier Ltd In this study, kernel-based extreme learning machine (K-ELM) and artificial neural network (ANN) models were developed in order to predict the conditions of an alkaline-catalysed transesterification process. The reliability of these models was assessed and compared based on the coefficient of determination (R2), root mean squared error (RSME), mean average percent error (MAPE) and relative percent deviation (RPD). The K-ELM model had higher R2(0.991) and lower RSME, MAPE and RPD (0.688, 0.388 and 0.380) compared to the ANN model (0.984, 0.913, 0.640 and 0.634). Based on these results, the K-ELM model is a more reliable prediction model and it was integrated with ant colony optimization (ACO) in order to achieve the highest Ceiba pentandra methyl ester yield. The optimum molar ratio of methanol to oil, KOH catalyst weight, reaction temperature, reaction time and agitation speed predicted by the K-ELM model integrated with ACO was 10:1, 1 %wt, 60 °C, 108 min and 1100 rpm, respectively. The Ceiba pentandra methyl ester yield attained under these optimum conditions was 99.80%. This novel integrated model provides insight on the effect of parameters investigated on the methyl ester yield, which may be useful for industries involved in biodiesel production.
Kusumo, F, Silitonga, AS, Ong, HC, Masjuki, HH & Mahlia, TMI 2017, 'A comparative study of ultrasound and infrared transesterification of Sterculia foetida oil for biodiesel production', ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS, vol. 39, no. 13, pp. 1339-1346.View/Download from: Publisher's site
Lam, MK, Yusoff, MI, Uemura, Y, Lim, JW, Khoo, CG, Lee, KT & Ong, HC 2017, 'Cultivation of Chlorella vulgaris using nutrients source from domestic wastewater for biodiesel production: Growth condition and kinetic studies', RENEWABLE ENERGY, vol. 103, pp. 197-207.View/Download from: Publisher's site
Leong, KY, Ahmad, KZK, Ong, HC, Ghazali, MJ & Baharum, A 2017, 'Synthesis and thermal conductivity characteristic of hybrid nanofluids - A review', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 75, pp. 868-878.View/Download from: Publisher's site
Leong, KY, Najwa, ZA, Ahmad, KZK & Ong, HC 2017, 'Investigation on Stability and Optical Properties of Titanium Dioxide and Aluminum Oxide Water-Based Nanofluids', INTERNATIONAL JOURNAL OF THERMOPHYSICS, vol. 38, no. 5.View/Download from: Publisher's site
Mardhiah, HH, Ong, HC, Masjuki, HH, Lim, S & Lee, HV 2017, 'A review on latest developments and future prospects of heterogeneous catalyst in biodiesel production from non-edible oils', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 67, pp. 1225-1236.View/Download from: Publisher's site
Mardhiah, HH, Ong, HC, Masjuki, HH, Lim, S & Pang, YL 2017, 'Investigation of carbon-based solid acid catalyst from Jatropha curcas biomass in biodiesel production', ENERGY CONVERSION AND MANAGEMENT, vol. 144, pp. 10-17.View/Download from: Publisher's site
Mojumder, JC, Ong, HC, Chong, WT, Izadyar, N & Shamshirband, S 2017, 'The intelligent forecasting of the performances in PV/T collectors based on soft computing method', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 72, pp. 1366-1378.View/Download from: Publisher's site
Mojumder, JC, Ong, HC, Chong, WT, Leong, KY & Izadyar, N 2017, 'An empirical analysis on photovoltaic thermal system with fin design by forced air circulation', JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY, vol. 31, no. 5, pp. 2549-2557.View/Download from: Publisher's site
Norjannah, B, Ong, HC & Masjuki, HH 2017, 'Effects of methanol and enzyme pretreatment to Ceiba pentandra biodiesel production', ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS, vol. 39, no. 14, pp. 1548-1555.View/Download from: Publisher's site
Ong, ZC, Mishani, MBM, Chong, WT, Soon, RS, Ong, HC & Ismail, Z 2017, 'Identification of optimum Calophyllum inophyllum bio-fuel blend in diesel engine using advanced vibration analysis technique', RENEWABLE ENERGY, vol. 109, pp. 295-304.View/Download from: Publisher's site
Riayatsyah, TMI, Ong, HC, Chong, WT, Aditya, L, Hermansyah, H & Mahlia, TMI 2017, 'Life Cycle Cost and Sensitivity Analysis of Reutealis trisperma as Non-Edible Feedstock for Future Biodiesel Production', ENERGIES, vol. 10, no. 7.View/Download from: Publisher's site
Sebayang, AH, Hasan, MH, Chyuan, OH, Dharma, S, Bahar, AH, Silitonga, AS & Kusumo, F 2017, 'Enzymatic hydrolysis using ultrasound for bioethanol production from durian (durio zibethinus) seeds as potential bio fuel', Chemical Engineering Transactions, vol. 56, pp. 553-558.View/Download from: Publisher's site
Copyright © 2017, AIDIC Servizi S.r.l.. The appealing second generation bioethanol production brings a good promise to achieve a fuel production that is renewable and sustainable; this makes durian (Durio zibethinus) seed interesting to take advantage of, especially for a tropical country like Malaysia. This paper aims to produce bioethanol from durian seed by utilizing ultrasound technique in its enzymatic hydrolysis process. 9 % (w/v) pre-Treated durian seed was brought into the ultrasound-Assisted glass reactor to begin the liquefaction and saccharification processes. Bacillus licheniformis Type XII-A was employed, and ultrasound at 50% amplitude for 60 min was set for liquefaction process; while amyloglucosidase from Aspergillus niger was used, and ultrasound at 40% amplitude for 120 min was run for saccharification process. The sum of both processes in hydrolysis yielded 41.07 g/L of reducing sugar, which was immediately brought to fermentation stage. Saccharomyces cerevisiae was employed for fermentation and resulted 18.48 g/L (0.44 g ethanol/g glucose), which is equivalent to 86.27 % of theoretical ethanol yield (0.51 g ethanol/g glucose) after 84 h of fermentation at 37 °C with 150 rpm incubator shaker. The ethanol purity was improved in the next stage, distillation. Using zeolite as adsorbent, ethanol with purity of 95.7% (v/v) was produced. From the acquired results, durian seed shows a justifiably potential as a second generation bioethanol feedstock. To further improve its potential, studies of optimization using this feedstock is highly encouraged.
Sebayang, AH, Hassan, MH, Ong, HC, Dharma, S, Silitonga, AS, Kusumo, F, Mahlia, TMI & Bahar, AH 2017, 'Optimization of reducing sugar production from Manihot glaziovii starch using response surface methodology', Energies, vol. 10, no. 1, pp. 1167-1175.View/Download from: Publisher's site
Bioethanol is known as a viable alternative fuel to solve both energy and environmental crises. This study used response surface methodology based on the Box-Behnken experimental design to obtain the optimum conditions for and quality of bioethanol production. Enzymatic hydrolysis optimization was performed with selected hydrolysis parameters, including substrate loading, stroke speed, α-amylase concentration and amyloglucosidase concentration. From the experiment, the resulting optimum conditions are 23.88% (w/v) substrate loading, 109.43 U/g α-amylase concentration, 65.44 U/mL amyloglucosidase concentration and 74.87 rpm stroke speed, which yielded 196.23 g/L reducing sugar. The fermentation process was also carried out, with a production value of 0.45 g ethanol/g reducing sugar, which is equivalent to 88.61% of ethanol yield after fermentation by using Saccharomyces cerevisiae (S. cerevisiae). The physical and chemical properties of the produced ethanol are within the specifications of the ASTM D4806 standard. The good quality of ethanol produced from this study indicates that Manihot glaziovii (M. glaziovii) has great potential as bioethanol feedstock.
Sebayang, AH, Masjuki, HH, Ong, HC, Dharma, S, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Optimization of bioethanol production from sorghum grains using artificial neural networks integrated with ant colony', INDUSTRIAL CROPS AND PRODUCTS, vol. 97, pp. 146-155.View/Download from: Publisher's site
Sebayang, AH, Masjuki, HH, Ong, HC, Dharma, S, Silitonga, AS, Kusumo, F & Milano, J 2017, 'Prediction of engine performance and emissions with Manihot glaziovii bioethanol - Gasoline blended using extreme learning machine', FUEL, vol. 210, pp. 914-921.View/Download from: Publisher's site
Silitonga, AS, Hassan, MH, Ong, HC & Kusumo, F 2017, 'Analysis of the performance, emission and combustion characteristics of a turbocharged diesel engine fuelled with Jatropha curcas biodiesel-diesel blends using kernel-based extreme learning machine', ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH, vol. 24, no. 32, pp. 25383-25405.View/Download from: Publisher's site
Silitonga, AS, Mahlia, TMI, Ong, HC, Riayatsyah, TMI, Kusumo, F, Ibrahim, H, Dharma, S & Gumilang, D 2017, 'A comparative study of biodiesel production methods for Reutealis trisperma biodiesel', Energy Sources, Part A: Recovery, Utilization and Environmental Effects, vol. 39, no. 20, pp. 2006-2014.View/Download from: Publisher's site
© 2017 Taylor & Francis Group, LLC. In this study, three types of biodiesel production methods are compared in order to maximize Reutealis trisperma biodiesel yields and it is found that the best method is esterification-neutralization-transesterification. The optimum methanol to oil molar ratio, catalyst concentration, reaction temperature, and reaction time are also determined from laboratory experiments and modeling using response surface methodology. There is excellent agreement between the predicted and experimental Reutealis trisperma biodiesel yields under optimum process conditions, with a value of 99.23 and 98.72%, respectively. The physicochemical properties of the Reutealis trisperma biodiesel also fulfill the fuel specifications of the ASTM D6751 standard.
Silitonga, AS, Masjuki, HH, Ong, HC, Mahlia, TMI & Kusumo, F 2017, 'Optimization of extraction of lipid from Isochrysis galbana microalgae species for biodiesel synthesis', Energy Sources, Part A: Recovery, Utilization and Environmental Effects, vol. 39, no. 11, pp. 1167-1175.View/Download from: Publisher's site
© 2017 Taylor & Francis Group, LLC. Microalgae are promising alternative plant sources for biodiesel production because of the signiﬁcant increase in lipid yield through heterotrophic cultivation and genetic engineering approaches. This study aims to evaluate the extraction and conversion of lipids from Isochrysis galbana. Response surface methodology (RSM) was used to optimize lipid extraction and thereby obtain high yields from the four microalgae species. The optimal lipid yields for Isochrysis galbana is 8.41 wt%. Moreover, the dominant lipid composition found from Isochrysis galbana extractions was palmitic acid (C16:0) at 22.3%. The high saturated acid of Isochrysis galbana contributed to the improved biodiesel properties because biodiesel quality is influenced by the lipid composition of microalgae species. The study employed the two-step esteriﬁcation–transesteriﬁcation process to convert the microalgae oil into biodiesel, glycerol, and water. The FAME content is 99.7% under the methanol to oil molar mass of 12:1, 1 wt%, 65°C, and 800 rpm. Furthermore, the main biodiesel properties, such as viscosity, higher heating value, and iodine value, were measured according to ASTM D6751 and EN 14124. Results show that microalgae oil can potentially be used as biofuel in future applications.
Yang, Y-C, Chen, C-C, Huang, C-S, Wang, C-T & Ong, H-C 2017, 'Developments of metallic anodes with various compositions and surfaces for the microbial fuel cells', INTERNATIONAL JOURNAL OF HYDROGEN ENERGY, vol. 42, no. 34, pp. 22235-22242.View/Download from: Publisher's site
Yu, KL, Lau, BF, Show, PL, Ong, HC, Ling, TC, Chen, W-H, Ng, EP & Chang, J-S 2017, 'Recent developments on algal biochar production and characterization', BIORESOURCE TECHNOLOGY, vol. 246, pp. 2-11.View/Download from: Publisher's site
Yu, KL, Show, PL, Ong, HC, Ling, TC, Lan, JC-W, Chen, W-H & Chang, J-S 2017, 'Microalgae from wastewater treatment to biochar - Feedstock preparation and conversion technologies', ENERGY CONVERSION AND MANAGEMENT, vol. 150, pp. 1-13.View/Download from: Publisher's site
Chen, Y-C, Chen, W-H, Lin, B-J, Chang, J-S & Ong, HC 2016, 'Impact of torrefaction on the composition, structure and reactivity of a microalga residue', APPLIED ENERGY, vol. 181, pp. 110-119.View/Download from: Publisher's site
Dharma, S, Masjuki, HH, Ong, HC, Sebayang, AH, Silitonga, AS, Kusumo, F & Mahlia, TMI 2016, 'Optimization of biodiesel production process for mixed Jatropha curcas-Ceiba pentandra biodiesel using response surface methodology', ENERGY CONVERSION AND MANAGEMENT, vol. 115, pp. 178-190.View/Download from: Publisher's site
Dharma, S, Ong, HC, Sebayang, AH & Silitonga, AS 2016, 'An overview of engine durability and compatibility using biodiesel-bioethanol-diesel blends in compression-ignition engines', ENERGY CONVERSION AND MANAGEMENT, vol. 128, pp. 66-81.View/Download from: Publisher's site
Fauzi, H, Metselaar, HSC, Mahlia, TMI, Ong, HC, Nasruddin & Khanlou, HM 2016, 'Preparation and thermal characteristics of eutectic fatty acids/Shorea javanica composite for thermal energy storage', APPLIED THERMAL ENGINEERING, vol. 100, pp. 62-67.View/Download from: Publisher's site
Iranmanesh, S, Mehrali, M, Sadeghinezhad, E, Ang, BC, Ong, HC & Esmaeilzadeh, A 2016, 'Evaluation of viscosity and thermal conductivity of graphene nanoplatelets nanofluids through a combined experimental-statistical approach using respond surface methodology method', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, vol. 79, pp. 74-80.View/Download from: Publisher's site
Izadyar, N, Ong, HC, Chong, WT & Leong, KY 2016, 'Resource assessment of the renewable energy potential for a remote area: A review', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 62, pp. 908-923.View/Download from: Publisher's site
Izadyar, N, Ong, HC, Chong, WT, Mojumder, JC & Leong, KY 2016, 'Investigation of potential hybrid renewable energy at various rural areas in Malaysia', JOURNAL OF CLEANER PRODUCTION, vol. 139, pp. 61-73.View/Download from: Publisher's site
Khanahmadi, S, Yusof, F, Ong, HC, Amid, A & Shah, H 2016, 'Cocoa pod husk: A new source of CLEA-lipase for preparation of low-cost biodiesel: An optimized process', JOURNAL OF BIOTECHNOLOGY, vol. 231, pp. 95-105.View/Download from: Publisher's site
Lee, HV, Juan, JC, Hin, T-YY & Ong, HC 2016, 'Environment-Friendly Heterogeneous Alkaline-Based Mixed Metal Oxide Catalysts for Biodiesel Production', ENERGIES, vol. 9, no. 8.View/Download from: Publisher's site
Leong, KY, Ong, HC, Amer, NH, Norazrina, MJ, Risby, MS & Ahmad, KZK 2016, 'An overview on current application of nanofluids in solar thermal collector and its challenges', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 53, pp. 1092-1105.View/Download from: Publisher's site
Milano, J, Ong, HC, Masjuki, HH, Chong, WT, Lam, MK, Loh, PK & Vellayan, V 2016, 'Microalgae biofuels as an alternative to fossil fuel for power generation', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 58, pp. 180-197.View/Download from: Publisher's site
Mojumder, JC, Chong, WT, Ong, HC, Leong, KY & Abdullah-Al-Mamoon 2016, 'An experimental investigation on performance analysis of air type photovoltaic thermal collector system integrated with cooling fins design', ENERGY AND BUILDINGS, vol. 130, pp. 272-285.View/Download from: Publisher's site
Mojumder, JC, Ong, HC, Chong, WT, Shamshirband, S & Abdullah-Al-Mamoon 2016, 'Application of support vector machine for prediction of electrical and thermal performance in PV/T system', ENERGY AND BUILDINGS, vol. 111, pp. 267-277.View/Download from: Publisher's site
Norjannah, B, Ong, HC, Masjuki, HH, Juan, JC & Chong, WT 2016, 'Enzymatic transesterification for biodiesel production: a comprehensive review', RSC ADVANCES, vol. 6, no. 65, pp. 60034-60055.View/Download from: Publisher's site
Nurfahmi, Ong, HC, Jan, BM, Tong, CW, Fauzi, H & Chen, W-H 2016, 'Effects of organosolv pretreatment and acid hydrolysis on palm empty fruit bunch (PEFB) as bioethanol feedstock', BIOMASS & BIOENERGY, vol. 95, pp. 78-83.View/Download from: Publisher's site
Oi, LE, Choo, M-Y, Lee, HV, Ong, HC, Abd Hamid, SB & Juan, JC 2016, 'Recent advances of titanium dioxide (TiO2) for green organic synthesis', RSC ADVANCES, vol. 6, no. 110, pp. 108741-108754.View/Download from: Publisher's site
Pang, YL, Lim, S, Ong, HC & Chong, WT 2016, 'Research progress on iron oxide-based magnetic materials: Synthesis techniques and photocatalytic applications', CERAMICS INTERNATIONAL, vol. 42, no. 1, pp. 9-34.View/Download from: Publisher's site
Pang, YL, Lim, S, Ong, HC & Chong, WT 2016, 'Synthesis, characteristics and sonocatalytic activities of calcined gamma-Fe2O3 and TiO2 nanotubes/gamma-Fe2O3 magnetic catalysts in the degradation of Orange G', ULTRASONICS SONOCHEMISTRY, vol. 29, pp. 317-327.View/Download from: Publisher's site
Sebayang, AH, Masjuki, HH, Ong, HC, Dharma, S, Silitonga, AS, Mahlia, TMI & Aditiya, HB 2016, 'A perspective on bioethanol production from biomass as alternative fuel for spark ignition engine', RSC ADVANCES, vol. 6, no. 18, pp. 14964-14992.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Ong, HC, Kusumo, F, Mahlia, TMI & Bahar, AH 2016, 'Pilot-scale production and the physicochemical properties of palm and Calophyllum inophyllum biodiesels and their blends', JOURNAL OF CLEANER PRODUCTION, vol. 126, pp. 654-666.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Ong, HC, Yusaf, T, Kusumo, F & Mahlia, TMI 2016, 'Synthesis and optimization of Hevea brasiliensis and Ricinus communis as feedstock for biodiesel production: A comparative study', INDUSTRIAL CROPS AND PRODUCTS, vol. 85, pp. 274-286.View/Download from: Publisher's site
Fauzi, H, Metselaar, HSC, Mahlia, TMI, Silakhori, M & Ong, HC 2015, 'Thermal characteristic reliability of fatty acid binary mixtures as phase change materials (PCMs) for thermal energy storage applications', APPLIED THERMAL ENGINEERING, vol. 80, pp. 127-131.View/Download from: Publisher's site
Izadyar, N, Ghadamian, H, Ong, HC, Moghadam, Z, Tong, CW & Shamshirband, S 2015, 'Appraisal of the support vector machine to forecast residential heating demand for the District Heating system based on the monthly overall natural gas consumption', ENERGY, vol. 93, pp. 1558-1567.View/Download from: Publisher's site
Izadyar, N, Ong, HC, Shamshirband, S, Ghadamian, H & Tong, CW 2015, 'Intelligent forecasting of residential heating demand for the District Heating System based on the monthly overall natural gas consumption', ENERGY AND BUILDINGS, vol. 104, pp. 208-214.View/Download from: Publisher's site
Mirhassani, S, Ong, HC, Chong, WT & Leong, KY 2015, 'Advances and challenges in grid tied photovoltaic systems', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 49, pp. 121-131.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC, Kusumo, F, Aditiya, HB & Ghazali, NNN 2015, 'Schleichera oleosa L oil as feedstock for biodiesel production', FUEL, vol. 156, pp. 63-70.View/Download from: Publisher's site
Chong, WT, Hew, WP, Yip, SY, Fazlizan, A, Poh, SC, Tan, CJ & Ong, HC 2014, 'The experimental study on the wind turbine's guide-vanes and diffuser of an exhaust air energy recovery system integrated with the cooling tower', ENERGY CONVERSION AND MANAGEMENT, vol. 87, pp. 145-155.View/Download from: Publisher's site
Ganandran, GSB, Mahlia, TMI, Ong, HC, Rismanchi, B & Chong, WT 2014, 'Cost-Benefit Analysis and Emission Reduction of Energy Efficient Lighting at the Universiti Tenaga Nasional', SCIENTIFIC WORLD JOURNAL.View/Download from: Publisher's site
Lee, KT, Lim, S, Pang, YL, Ong, HC & Chong, WT 2014, 'Integration of reactive extraction with supercritical fluids for process intensification of biodiesel production: Prospects and recent advances', PROGRESS IN ENERGY AND COMBUSTION SCIENCE, vol. 45, pp. 54-78.View/Download from: Publisher's site
Leong, KY & Ong, HC 2014, 'Entropy generation analysis of nanofluids flow in various shapes of cross section ducts', INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER, vol. 57, pp. 72-78.View/Download from: Publisher's site
Noraini, MY, Ong, HC, Badrul, MJ & Chong, WT 2014, 'A review on potential enzymatic reaction for biofuel production from algae', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 39, pp. 24-34.View/Download from: Publisher's site
Ong, HC, Masjuki, HH, Mahlia, TMI, Silitonga, AS, Chong, WT & Leong, KY 2014, 'Optimization of biodiesel production and engine performance from high free fatty acid Calophyllum inophyllum oil in CI diesel engine', ENERGY CONVERSION AND MANAGEMENT, vol. 81, pp. 30-40.View/Download from: Publisher's site
Ong, HC, Masjuki, HH, Mahlia, TMI, Silitonga, AS, Chong, WT & Yusaf, T 2014, 'Engine performance and emissions using Jatropha curcas, Ceiba pentandra and Calophyllum inophyllum biodiesel in a CI diesel engine', ENERGY, vol. 69, pp. 427-445.View/Download from: Publisher's site
Pang, YL, Lim, S, Ong, HC & Chong, WT 2014, 'A critical review on the recent progress of synthesizing techniques and fabrication of TiO2-based nanotubes photocatalysts', APPLIED CATALYSIS A-GENERAL, vol. 481, pp. 127-142.View/Download from: Publisher's site
Atabani, AE, Silitonga, AS, Ong, HC, Mahlia, TMI, Masjuki, HH, Badruddin, IA & Fayaz, H 2013, 'Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 18, pp. 211-245.View/Download from: Publisher's site
Ong, HC, Silitonga, AS, Masjuki, HH, Mahlia, TMI, Chong, WT & Boosroh, MH 2013, 'Production and comparative fuel properties of biodiesel from non-edible oils: Jatropha curcas, Sterculia foetida and Ceiba pentandra', ENERGY CONVERSION AND MANAGEMENT, vol. 73, pp. 245-255.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC & Chong, WT 2013, 'Experimental study on performance and exhaust emissions of a diesel engine fuelled with Ceiba pentandra biodiesel blends', ENERGY CONVERSION AND MANAGEMENT, vol. 76, pp. 828-836.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC, Atabani, AE & Chong, WT 2013, 'A global comparative review of biodiesel production from jatropha curcas using different homogeneous acid and alkaline catalysts: Study of physical and chemical properties', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 24, pp. 514-533.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Mahlia, TMI, Ong, HC, Chong, WT & Boosroh, MH 2013, 'Overview properties of biodiesel diesel blends from edible and non-edible feedstock', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 22, pp. 346-360.View/Download from: Publisher's site
Silitonga, AS, Ong, HC, Mahlia, TMI, Masjuki, HH & Chong, WT 2013, 'Characterization and production of Ceiba pentandra biodiesel and its blends', FUEL, vol. 108, pp. 855-858.View/Download from: Publisher's site
Silitonga, AS, Ong, HC, Masjuki, HH, Mahlia, TMI, Chong, WT & Yusaf, TF 2013, 'Production of biodiesel from Sterculia foetida and its process optimization', FUEL, vol. 111, pp. 478-484.View/Download from: Publisher's site
Ong, HC, Mahlia, TMI & Masjuki, HH 2012, 'A review on energy pattern and policy for transportation sector in Malaysia', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 16, no. 1, pp. 532-542.View/Download from: Publisher's site
Ong, HC, Mahlia, TMI & Masjuki, HH 2011, 'A review on emissions and mitigation strategies for road transport in Malaysia', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 15, no. 8, pp. 3516-3522.View/Download from: Publisher's site
Ong, HC, Mahlia, TMI & Masjuki, HH 2011, 'A review on energy scenario and sustainable energy in Malaysia', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 15, no. 1, pp. 639-647.View/Download from: Publisher's site
Fauzi, H, Metselaar, HSC, Mahlia, TMI, Silakhori, M & Ong, HC 2018, 'Investigation of thermal characteristic of eutectic fatty acid/damar gum as a composite phase change material (CPCM)' in Exergy for a Better Environment amd Improved Sustainability 2: Applications (Green Energy and Technology), Springer, Switzerland, pp. 607-616.View/Download from: Publisher's site
© 2018, Springer International Publishing AG, part of Springer Nature. A composite phase change material (CPCM) of myristic acid/palmitic acid/sodium myristate (MA/PA/SM) has been proposed by impregnating a porous material of purified damar gum, also called Shorea javanica (SJ), to improve the thermal conductivity of CPCM. The thermal properties, thermal conductivity and thermal stability, of CPCM were measured using differential scanning calorimetry (DSC) thermal analysis, hot-disc thermal conductivity analyzer, and simultaneous thermal analyzer (STA). Moreover, a chemical reaction between fatty acid binary mixture and SJ in CPCM was evaluated by Fourier transform infra-red (FT-IR) spectrophotometer. The results of this study showed that the thermal conductivity of MA/PA/SM/SJ composite phase change material (CPCM) was improved by addition of 3 wt.% of Shorea javanica into MA/PA/SM eutectic mixture without showing a significant change in the thermophysical properties of CPCM. Moreover, the eutectic CPCM also does not show occurrence of chemical reaction between MA/PA/SM and SJ, and it has a good thermal performance and thermal stability. Therefore, the MA/PA/SM/SJ CPCM proposed in this study can be recommended as a new novelty material for thermal energy storage application.
Husin, H, Ahmad, N, Jamil, N, Chyuan, OH & Roslan, A 2017, 'Evaluation on the Presence of Nano Silver Particle in Improving a Conventional Water-based Drilling Fluid', 3RD INTERNATIONAL CONFERENCE ON GLOBAL SUSTAINABILITY AND CHEMICAL ENGINEERING (ICGSCE), 3rd International Conference on Global Sustainability and Chemical Engineering (ICGSCE), IOP PUBLISHING LTD, Putrajaya, MALAYSIA.View/Download from: Publisher's site
Husin, H, Aman, Z & Chyuan, OH 2017, 'Correlation between rate of deposition and temperature of asphaltene particles', MATERIALS TODAY-PROCEEDINGS, 3rd International Conference on Green Chemical Engineering and Technology (GCET) - Materials Science, ELSEVIER SCIENCE BV, MALAYSIA, pp. 22128-22136.View/Download from: Publisher's site
Tang, ZE, Lim, S, Pang, YL & Ong, HC 2018, 'Optimisation of corncob based heterogeneous acid catalysed biodiesel synthesis using response surface methodology', IOP Conference Series: Materials Science and Engineering.View/Download from: Publisher's site
© Published under licence by IOP Publishing Ltd. Biodiesel, which is also known as fatty acid methyl ester (FAME) can be produced through esterification reaction of vegetable oil or animal fats catalysed by heterogeneous acid catalyst. The objective of this study was to synthesise a corncob derived carbon based heterogeneous acid catalyst functionalised by the arylation of 4-benzenediazonium sulfonate (4-BDS) for biodiesel production by using palm fatty acid distillate (PFAD) as feedstock for the esterification reaction. Subsequently, the biodiesel production reaction was optimised by using response surface methodology (RSM). RSM was employed to study the interaction between the primary factors: reaction time (2.5-6.5 h), temperature (60 to 100 °C), oil to methanol molar ratio (1: 13 to 1: 29) and catalyst loading (5 to 11 wt.%) in esterification reaction. The five-level, four factors central composite design (CCD) consisted of 30 experiments was chosen in this investigation. The predicted optimum reaction conditions was 6.48 h reaction time, 89.21 °C reaction temperature, 1 to 21.94 molar ratio of PFAD to methanol and 11 wt.% catalyst loading with 85.94% of predicted biodiesel yield. The actual optimum biodiesel yield of 83.48% was successfully achieved at the corresponding optimum operating conditions which proved the validity of the statistical optimisation model.
Thaib, R, Fauzi, H, Ong, HC, Rizal, S, Mahlia, TMI & Riza, M 2017, 'Thermal characteristic investigation of eutectic composite fatty acid as heat storage material for solar heating and cooling application', IOP Conference Series: Materials Science and Engineering, International Conference on Chemical Engineering Sciences and Applications, Ulee Kareng, Indonesia.View/Download from: Publisher's site
© Published under licence by IOP Publishing Ltd. A composite phase change material (CPCM) of myristic acid/palmitic acid/sodium myristate (MA/PA/SM) and of myristic acid/palmitic acid/sodium laurate (MA/PA/SL) were impregnated with purified damar gum as called Shorea Javanica (SJ) to improve the thermal conductivity of CPCM. The thermal properties, thermal conductivity, and thermal stability of both CPCM have investigated by using a Differential Scanning Calorimetry (DSC) thermal analysis, hot disc thermal conductivity analyzer, and Simultaneous Thermal Analyzer (STA), simultaneously. However, a chemical compatibility between both fatty acid eutectic mixtures and SJ in composite mixtures measured by Fourier Transform Infra-Red (FT-IR) spectrophotometer. The results were obtained that the thermal conductivity of MA/PA/SM/SJ and MA/PA/SL/SJ eutectic composite phase change material (CPCM) were improved by addition 3 wt.% and 2 wt.% of Shorea javanica (SJ), respectively, without occur a significant change on thermal properties of CPCM. Moreover, the absorbance spectrum of FT-IR shows the good compatibility of SJ with both MA/PA/SM and MA/PA/SL eutectic mixtures, the composite PCM also present good thermal performance and good thermal stability. Therefore, it can be noted that the purified Shorea Javanica proposed, the as high conductive material in this study was able to improve the thermal conductivity of eutectic PCM without any significant reduction on its thermo-physical and chemical properties and can be recommended as novelty composite phase change material for thermal energy storage application.
Chen, Y-C, Chen, W-H, Lin, B-J, Chang, J-S & Ong, HC 2016, 'Fuel property variation of biomass undergoing torrefaction', 8TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY (ICAE2016), 8th International Conference on Applied Energy (ICAE), ELSEVIER SCIENCE BV, Beijing Inst Technol, Beijing, PEOPLES R CHINA, pp. 108-112.View/Download from: Publisher's site
Ee, TZ, Lim, S, Ling, PY, Huei, WK & Chyuan, OH 2017, 'Synthesis of Seaweed Based Carbon Acid Catalyst by Thermal Decomposition of Ammonium Sulfate for Biodiesel Production', GREEN AND SUSTAINABLE TECHNOLOGY, International Symposium on Green and Sustainable Technology (ISGST), AMER INST PHYSICS, MALAYSIA.View/Download from: Publisher's site
Silitonga, AS, Masjuki, HH, Ong, HC, How, HG, Kusumo, F, Teoh, YH & Mahlia, TMI 2015, 'Engine Performance, Emission and Combustion in Common Rail Turbocharged Diesel Engine from Jatropha Curcas Using Artificial Neural Network', SAE Technical Papers.
Copyright © 2015 SAE Japan and Copyright © 2015 SAE International. This paper investigates the performance, emission and combustion of a four cylinder common-rail turbocharged diesel engine using jatropha curcas biodiesel blends (JCB). The test was performed with various ratios of jatropha curcas methyl ester (JCME) in the blends (JCB10, JCB20, JCB30, and JCB50). An artificial neural networks (ANN) model based on standard back-propagation algorithm was used to predict combustion, performance and emissions characteristics of the engine using MATLAB. To acquire data for training and testing of the proposed ANN, the different engine speeds (1500-3500 rpm) was selected as the input parameter, whereas combustion, performance and emissions were chosen as the output parameters for ANN modeling of a common-rail turbocharged diesel engine. The performance, emissions and combustion of the ANN were validated by comparing the prediction dataset with the experimental results. The results show that the correlation coefficient was successfully controlled within the range 0.9798-0.9999 for the ANN model and test data. The value of MAPE (Mean Absolute Percentage Error) was within the range 1.2373-6.4217 and the Root Mean Square (RSME) value was below 0.05 by the model, which is acceptable. This study shows that modeling techniques as an approach in alternative energy can give improvement advantage of reliability in the prediction of performance and emission of internal combustion engines.
Ong, HC, Silitonga, AS, Mahlia, TMI, Masjuki, HH & Chong, WT 2014, 'Investigation of Biodiesel Production from Cerbera Manghas Biofuel Sources', INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014, 6th International Conference on Applied Energy (ICAE), ELSEVIER SCIENCE BV, Taipei, TAIWAN, pp. 436-439.View/Download from: Publisher's site
Silitonga, AS, Ong, HC, Mahlia, TMI, Masjuki, HH & Chong, WT 2014, 'Biodiesel conversion from high FFA crude jatropha curcas, calophyllum inophyllum and ceiba pentandra oil', INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014, 6th International Conference on Applied Energy (ICAE), ELSEVIER SCIENCE BV, Taipei, TAIWAN, pp. 480-483.View/Download from: Publisher's site