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We investigate the sooting propensity of an Alcohol-to-Jet-Synthetic Kerosene with Aromatics (ATJ-SKA) biojet fuel. The soot volume fraction and primary particle size in the pre-vaporised diffusion flames using ATJ-SKA biojet and blends with Jet A-1 at atmospheric conditions were measured experimentally and compared to numerical simulations. The measurements were conducted using extinction calibrated laser induced incandescence (LII). The soot volume fractions measured using the ATJ-SKA fuel do not show significant differences relative to measurements with Jet A-1. A comparison of the chemical composition of the fuels suggests that the Degree of Unsaturation (DoU) may not determine the sooting propensity of biojet fuels. The SEM analysis shows that diffusion flames using neat Jet A-1 produce finer soot particles and larger number density compared to the biojet and biojet surrogate. The soot model employs a semi-detailed chemical kinetic mechanism and a physical model which integrates the population balance equation governing the soot particle size distribution with an in-house reactive flow solver for multicomponent ideal gases. The model predicts the maximum soot volume fraction (SVFm) in the neat biojet case and the blended cases with Jet A-1 fuels within an error margin of 13% of the measured values. However, the predicted soot volume fraction distribution patterns differ from the measured one and the possible causes are discussed.
Bo Tian; Anxiong Liu; Cheng Tung Chong; Luming Fan; Shiyao Ni; Andrew Hull; Angelica Hull; Stelios Rigopoulos; Kai H. Luo; Simone Hochgreb. Measurement and simulation of sooting characteristics by an ATJ-SKA biojet fuel and blends with Jet A-1 fuel in laminar non-premixed flames. Combustion and Flame 2021, 233, 111582 .
AMA StyleBo Tian, Anxiong Liu, Cheng Tung Chong, Luming Fan, Shiyao Ni, Andrew Hull, Angelica Hull, Stelios Rigopoulos, Kai H. Luo, Simone Hochgreb. Measurement and simulation of sooting characteristics by an ATJ-SKA biojet fuel and blends with Jet A-1 fuel in laminar non-premixed flames. Combustion and Flame. 2021; 233 ():111582.
Chicago/Turabian StyleBo Tian; Anxiong Liu; Cheng Tung Chong; Luming Fan; Shiyao Ni; Andrew Hull; Angelica Hull; Stelios Rigopoulos; Kai H. Luo; Simone Hochgreb. 2021. "Measurement and simulation of sooting characteristics by an ATJ-SKA biojet fuel and blends with Jet A-1 fuel in laminar non-premixed flames." Combustion and Flame 233, no. : 111582.
Empty fruit bunch (EFB), which is one of the primary agricultural wastes generated from the palm oil plantation, is generally discharged into the open environment or ends up in landfills. The utilization of this EFB waste for other value-added applications such as activated carbon and biofuels remain low, despite extensive research efforts. One of the reasons is that the EFB is highly vulnerable to microbial and fungi degradation under natural environment owning to its inherent characteristic of high organic matter and moisture content. This can rapidly deteriorate its quality and results in poor performance when processed into other products. However, the lignocellulosic components in degraded EFB (DEFB) still largely remain intact. Consequently, it could become a promising feedstock for production of bio-products after suitable pretreatment with organic solvents. In this study, DEFB was subjected to five different types of organic solvents for the pretreatment, including ethanol, ethylene glycol, 2-propanol, acetic acid and acetone. The effects of temperature and residence time were also investigated during the pretreatment. Organosolv pretreatment in ethylene glycol (50 v/v%) with the addition of NaOH (3 v/v%) as an alkaline catalyst successfully detached 81.5 wt.% hemicellulose and 75.1 wt.% lignin. As high as 90.4 wt.% cellulose was also successfully retrieved at mild temperature (80 °C) and short duration (45 min), while the purity of cellulose in treated DEFB was recorded at 84.3%. High-purity lignin was successfully recovered from the pretreatment liquor by using sulfuric acid for precipitation. The amount of recovered lignin from alkaline ethylene glycol liquor was 74.6% at pH 2.0. The high recovery of cellulose and lignin in DEFB by using organosolv pretreatment rendered it as one of the suitable feedstocks to be applied in downstream biorefinery processes. This can be further investigated in more detailed studies in the future.
Danny Chin; Steven Lim; Yean Pang; Chun Lim; Siew Shuit; Kiat Lee; Cheng Chong. Effects of Organic Solvents on the Organosolv Pretreatment of Degraded Empty Fruit Bunch for Fractionation and Lignin Removal. Sustainability 2021, 13, 6757 .
AMA StyleDanny Chin, Steven Lim, Yean Pang, Chun Lim, Siew Shuit, Kiat Lee, Cheng Chong. Effects of Organic Solvents on the Organosolv Pretreatment of Degraded Empty Fruit Bunch for Fractionation and Lignin Removal. Sustainability. 2021; 13 (12):6757.
Chicago/Turabian StyleDanny Chin; Steven Lim; Yean Pang; Chun Lim; Siew Shuit; Kiat Lee; Cheng Chong. 2021. "Effects of Organic Solvents on the Organosolv Pretreatment of Degraded Empty Fruit Bunch for Fractionation and Lignin Removal." Sustainability 13, no. 12: 6757.
Modeling of heat and mass transfer in liquid fuel combustion requires several material properties in a wide temperature and pressure range. The unavailable data are commonly patched with various estimation methods. In this paper, group contribution methods (GCM) and law of corresponding states (LCS) were analyzed for estimating material properties of n-alkanes (up to C10H22 and C12H26), 1-alcohols (up to C10H22O), and methyl esters (up to C19H38O2 and C19H36O2). These were compared to reference data to evaluate their applicability. LCS suggested by Poling et al. provides proper estimation for the acentric factor. GCM of Joback accurately estimates normal boiling point, critical properties, and specific heat capacity of the vapor-phase, the latter was corrected for methanol, however, GCM of Constantinou is more accurate for critical pressure of methyl esters. GCM of Ruzicka is suitable for estimating liquid-phase specific heat capacity. This method was updated for methanol. GCM of Elbro gives a proper estimation for liquid-phase density, while LCS of Lucas estimates vapor-phase viscosity properly. LCS of Chung and the modified Eucken method for vapor-phase and GCM of Sastri for liquid-phase thermal conductivity are appropriate. Considering the gas-phase mutual diffusion coefficient, the method of Fuller provides the best estimation, while LCS methods of Riedel and Chen are suitable for the enthalpy of vaporization at the normal boiling point.
Dávid Csemány; István Gujás; Cheng Tung Chong; Viktor Józsa. Evaluation of material property estimating methods for n-alkanes, 1-alcohols, and methyl esters for droplet evaporation calculations. Heat and Mass Transfer 2021, 1 -15.
AMA StyleDávid Csemány, István Gujás, Cheng Tung Chong, Viktor Józsa. Evaluation of material property estimating methods for n-alkanes, 1-alcohols, and methyl esters for droplet evaporation calculations. Heat and Mass Transfer. 2021; ():1-15.
Chicago/Turabian StyleDávid Csemány; István Gujás; Cheng Tung Chong; Viktor Józsa. 2021. "Evaluation of material property estimating methods for n-alkanes, 1-alcohols, and methyl esters for droplet evaporation calculations." Heat and Mass Transfer , no. : 1-15.
Biodiesel is considered as a potential substitute for petroleum-based diesel fuel owing to its comparable properties to diesel. Biodiesel is generally produced from renewable sources such as agricultural products and microalgae in the presence of a suitable catalyst. Recently ionic liquid (IL) catalyzed synthesis of biodiesel has become a promising pathway to an eco-friendly production route for biodiesel. This review focuses on the use of ILs both as solvents as well as catalysts for sustainable biodiesel production from agricultural feedstocks and microalgae with high free fatty acid content. Reactions catalyzed by ILs are known to render high reactivity under the mild condition and high selectivity of ester product with simple separation steps. The article first discusses the state of the art of biodiesel production using ILs along with the physicochemical properties of the produced biodiesel. Then, current IL technologies were elucidated in terms of the categories such as acidic and basic ILs. The use of more advanced ILs such as supported ionic liquids and ionic liquid-enzyme catalysts on different biodiesel feedstocks were also discussed. Furthermore, the role of IL catalyst in intensified biodiesel production methods such as microwave and ultrasound technologies were also discussed. Finally, the prospects and challenges of IL catalyzed biodiesel production are discussed in this article. The review shows that ILs with brønsted acidity or basicity not only pose a low risk to the environment but also result in high biodiesel yields with mild reaction conditions in a short time. Brønsted acidic ILs can convert free fatty acids as well as triglycerides to biodiesel without the need for pretreatment, which facilitates in reducing the production cost of biodiesel. From the review, it can be concluded that ILs present great potential as catalysts for biodiesel production.
Hwai Chyuan Ong; Yong Wei Tiong; Brandon Han Hoe Goh; Yong Yang Gan; M. Mofijur; I.M. Rizwanul Fattah; Cheng Tung Chong; Asraful Alam; Hwei Voon Lee; A.S. Silitonga; T.M.I Mahlia. Recent advances in biodiesel production from agricultural products and microalgae using ionic liquids: Opportunities and challenges. Energy Conversion and Management 2020, 228, 113647 .
AMA StyleHwai Chyuan Ong, Yong Wei Tiong, Brandon Han Hoe Goh, Yong Yang Gan, M. Mofijur, I.M. Rizwanul Fattah, Cheng Tung Chong, Asraful Alam, Hwei Voon Lee, A.S. Silitonga, T.M.I Mahlia. Recent advances in biodiesel production from agricultural products and microalgae using ionic liquids: Opportunities and challenges. Energy Conversion and Management. 2020; 228 ():113647.
Chicago/Turabian StyleHwai Chyuan Ong; Yong Wei Tiong; Brandon Han Hoe Goh; Yong Yang Gan; M. Mofijur; I.M. Rizwanul Fattah; Cheng Tung Chong; Asraful Alam; Hwei Voon Lee; A.S. Silitonga; T.M.I Mahlia. 2020. "Recent advances in biodiesel production from agricultural products and microalgae using ionic liquids: Opportunities and challenges." Energy Conversion and Management 228, no. : 113647.
In a previous study we demonstrated a novel two-phase PIV technique based on the laser-induced incandescence (LII) signal from black submicron tungsten carbide particles (WC), which achieved velocity measurements for both dispersed-form (large water droplet) and continuous-form (gas). Submicron WC particles are intentionally seeded into a two-phase flow, and heated by a light sheet generated by a double-pulsed PIV laser running at high energy. The 200 nm diameter, light absorbing WC particles are heated to several thousand degrees to emit strong incandescence signals, whilst the temperature rise in liquid droplets or large particles remains negligible. The small particles follow the gas phase flow, unlike the droplets which may have a different velocity. Droplets are detected via the Mie scatter signal at the same incident wavelength, whereas the LII signal from small WC particles is detected at a suitably different wavelength within the LII emission spectrum, thus allowing discrimination of velocities between phases. The LII-PIV technique had been implemented with a low-speed CCD PIV camera in non-reacting flows. In flames, the strong flame luminosity saturated the second frame due to the long exposure time as the characteristics of the device. To solve this problem, in the present study, we synchronized two high-speed CMOS cameras to a low speed laser. One records the LII signal and the other records the Mie scatter signal from 36.6 µm water droplets. The scattering from WC particles appears only as a weak background signal in the Mie image, which can be easily removed by applying a high-pass filter. Simultaneous velocity measurements for both gas and liquid phase are demonstrated in an air jet, a cold impinging flow, and finally in a Bunsen flame. The last two cases are repeated using the traditional two-phase PIV technique based on image segmentation so as to conduct a fair comparison of both techniques. We show that LII-PIV can achieve the same level of accuracy as the segmentation method in non-reacting flows, and can be applied to measure in flames with two-phase flows with less stringent requirements regarding seeding quality.
Luming Fan; Cheng Tung Chong; Bo Tian; Yutao Zheng; Dante McGrath; Simone Hochgreb. Simultaneous two-phase flame velocity measurement using laser-induced incandescence particle image velocimetry (LII-PIV). Proceedings of the Combustion Institute 2020, 38, 1589 -1597.
AMA StyleLuming Fan, Cheng Tung Chong, Bo Tian, Yutao Zheng, Dante McGrath, Simone Hochgreb. Simultaneous two-phase flame velocity measurement using laser-induced incandescence particle image velocimetry (LII-PIV). Proceedings of the Combustion Institute. 2020; 38 (1):1589-1597.
Chicago/Turabian StyleLuming Fan; Cheng Tung Chong; Bo Tian; Yutao Zheng; Dante McGrath; Simone Hochgreb. 2020. "Simultaneous two-phase flame velocity measurement using laser-induced incandescence particle image velocimetry (LII-PIV)." Proceedings of the Combustion Institute 38, no. 1: 1589-1597.
The effect of water droplets on strained methane-air laminar flames is investigated using particle image velocimetry of both gas and liquid phases. We use the impinging flame configuration to measure the laminar flame speed (gas) as well as the motion of the liquid phase, simultaneously. Water droplets of mean diameter 36.6 µm are produced by an ultrasonic atomizer and dispersed in a methane/air flow, for a constant molar ratio (12–36%) to the fuel (methane). This corresponds to a water mass fraction of 0.8–2.2% at stoichiometry. The slip motion between gas phase and droplets is quantified by seeding 1.7 µm mean diameter oil droplets into the reactant flow, and using an image segmentation method to determine the velocity of the gaseous flow and water droplets separately. The result reveals a clear slip velocity between the two phases: the inertia of relatively large droplets results in a drift into the flame front at a higher speed than the gaseous flow, by a factor of 10–30% in most cases. Measurements of the gas-phase flow show that the addition of water droplets significantly reduces the reference flame speed, especially at high strain rates. However, numerical simulations on water vapor addition at the same conditions predict only a slight drop in the reference flame speed, suggesting water droplets are more effective in flame suppression than vapor. This is the first time that the two-phase PIV technique has been applied to solve a problem in combustion investigations. We validate this technique under a non-reacting impinging flow prior to the flame experiment, and report the strategies adopted for better image quality and subsequently easier segmentation between oil and water droplets. The technique can be next applied to measure the slip velocity for volatile fuel sprays, where the slip motion plays an important role in determining both their evaporation rate and residence time in a flame.
Luming Fan; Cheng Tung Chong; Kenji Tanno; Dante McGrath; Yutao Zheng; Simone Hochgreb. Measurement of the effect of water droplets on strained laminar flames using two-phase PIV. Proceedings of the Combustion Institute 2020, 38, 3183 -3192.
AMA StyleLuming Fan, Cheng Tung Chong, Kenji Tanno, Dante McGrath, Yutao Zheng, Simone Hochgreb. Measurement of the effect of water droplets on strained laminar flames using two-phase PIV. Proceedings of the Combustion Institute. 2020; 38 (2):3183-3192.
Chicago/Turabian StyleLuming Fan; Cheng Tung Chong; Kenji Tanno; Dante McGrath; Yutao Zheng; Simone Hochgreb. 2020. "Measurement of the effect of water droplets on strained laminar flames using two-phase PIV." Proceedings of the Combustion Institute 38, no. 2: 3183-3192.
The increase in human consumption of plant and animal oils has led to the rise in waste cooking oil (WCO) production. Instead of disposing the used cooking oil as waste, recent technological advance has enabled the use of WCO as a sustainable feedstock for biofuels production, thereby maximising the value of biowastes via energy recovery while concomitantly solving the disposal issue. The current regulatory frameworks for WCO collection and recycling practices imposed by major WCO producing countries are reviewed, followed by the overview of the progress in biodiesel conversion techniques, along with novel methods to improve the feasibility for upscaling. The factors which influence the efficiency of the reactions such as properties of feedstock, heterogenous catalytic processes, cost effectiveness and selectivity of reaction product are discussed. Ultrasonic-assisted transesterification is found to be the least energy intensive method for producing biodiesel. The production of bio-jet fuels from WCO, while scarce, provide diversity in waste utilisation if problems such as carbon chain length, requirements of bio-jet fuel properties, extreme reaction conditions and effectiveness of selected catalyst-support system can be solved. Technoeconomic studies revealed that WCO biofuels is financially viable with benefit of mitigating carbon emissions, provided that the price gap between the produced fuel and commercial fuels, sufficient supply of WCO and variation in the oil properties are addressed. This review shows that WCO is a biowaste with high potential for advanced transportation fuel production for ground and aviation industries. The advancement in fuel production technology and relevant policies would accelerate the application of sustainable WCO biofuels.
Brandon Han Hoe Goh; Cheng Tung Chong; Yuqi Ge; Hwai Chyuan Ong; Jo-Han Ng; Bo Tian; Veeramuthu Ashokkumar; Steven Lim; Tine Seljak; Viktor Józsa. Progress in utilisation of waste cooking oil for sustainable biodiesel and biojet fuel production. Energy Conversion and Management 2020, 223, 113296 .
AMA StyleBrandon Han Hoe Goh, Cheng Tung Chong, Yuqi Ge, Hwai Chyuan Ong, Jo-Han Ng, Bo Tian, Veeramuthu Ashokkumar, Steven Lim, Tine Seljak, Viktor Józsa. Progress in utilisation of waste cooking oil for sustainable biodiesel and biojet fuel production. Energy Conversion and Management. 2020; 223 ():113296.
Chicago/Turabian StyleBrandon Han Hoe Goh; Cheng Tung Chong; Yuqi Ge; Hwai Chyuan Ong; Jo-Han Ng; Bo Tian; Veeramuthu Ashokkumar; Steven Lim; Tine Seljak; Viktor Józsa. 2020. "Progress in utilisation of waste cooking oil for sustainable biodiesel and biojet fuel production." Energy Conversion and Management 223, no. : 113296.
Biodiesel and blends with petroleum diesel are promising renewable alternative fuels for engines. In the present study, the soot concentration generated from four biodiesels, two pure methyl esters, and their blends with petroleum diesel are measured in a series of fully pre-vapourised co-flow diffusion flames. The experimental measurements are conducted using planar laser induced-incandescence (LII) and laser extinction optical methods. The results show that the maximum local soot volume fractions of neat biodiesels are 24.4% - 41.2% of pure diesel, whereas the mean soot volume fraction of neat biodiesel cases was measured as 11.3% - 21.3% of pure diesel. The addition of biodiesel to diesel not only reduces the number of inception particles, but also inhibits their surface growth. The discretised population balance modelling of a complete set of soot processes is employed to compute the 2D soot volume fraction and size distribution across the tested flames. The results show that the model also demonstrates a reduction of both soot volume fraction and primary particle size by adding biodiesel fuels. However, it is not possible to clearly determine which factors are responsible for the reduction from the comparison alone. Moreover, analysis of the discrepancies between numerical and experimental results for diesel and low-blending cases offers an insight for the refinement of soot formation modelling of combustion with large-molecule fuels.
B. Tian; A.X. Liu; C.T. Chong; L. Fan; S. Ni; J.-H. Ng; S. Rigopoulos; K.H. Luo; S. Hochgreb. Experimental and numerical study on soot formation in laminar diffusion flames of biodiesels and methyl esters. Proceedings of the Combustion Institute 2020, 38, 1335 -1344.
AMA StyleB. Tian, A.X. Liu, C.T. Chong, L. Fan, S. Ni, J.-H. Ng, S. Rigopoulos, K.H. Luo, S. Hochgreb. Experimental and numerical study on soot formation in laminar diffusion flames of biodiesels and methyl esters. Proceedings of the Combustion Institute. 2020; 38 (1):1335-1344.
Chicago/Turabian StyleB. Tian; A.X. Liu; C.T. Chong; L. Fan; S. Ni; J.-H. Ng; S. Rigopoulos; K.H. Luo; S. Hochgreb. 2020. "Experimental and numerical study on soot formation in laminar diffusion flames of biodiesels and methyl esters." Proceedings of the Combustion Institute 38, no. 1: 1335-1344.
Biomass-based feedstock is an attractive alternative to fossil fuel due to its sustainability and potential as a clean energy source. The present work focuses on the valorisation of horse manure biowaste to produce bioenergy via microwave-assisted pyrolysis technique. The thermal decomposition process is conducted by considering the effects of pyrolysis temperature, catalyst loading and carrier gas flow rate on the yield and quality of end products. The pyrolysed gaseous product contains up to 73.1 vol% of syngas components. The solid biochar obtained contains a heating value of 35.5 MJ/kg with high surface to pore volume ratio. The relatively high specific energy contents of gaseous products and biochar indicate their potential as biofuels. The liquid product is found to contain oxygenated phenolic compound of up to 79.4 wt%. In spite of an overall energy deficit achieved when comparing the total energy of end products with the feedstock, the energy balance analysis indicates the optimum production parameters. The least energy deficit is achieved at the reactive conditions of 350–450 °C and manure-to-catalyst ratio of 1:1. A reaction mechanism pathway for the pyrolysis of horse manure is presented to show the production route for bioenergy and valuable chemicals.
Guo Ren Mong; Cheng Tung Chong; Jo-Han Ng; William Woei Fong Chong; Su Shiung Lam; Hwai Chyuan Ong; Farid Nasir Ani. Microwave pyrolysis for valorisation of horse manure biowaste. Energy Conversion and Management 2020, 220, 113074 .
AMA StyleGuo Ren Mong, Cheng Tung Chong, Jo-Han Ng, William Woei Fong Chong, Su Shiung Lam, Hwai Chyuan Ong, Farid Nasir Ani. Microwave pyrolysis for valorisation of horse manure biowaste. Energy Conversion and Management. 2020; 220 ():113074.
Chicago/Turabian StyleGuo Ren Mong; Cheng Tung Chong; Jo-Han Ng; William Woei Fong Chong; Su Shiung Lam; Hwai Chyuan Ong; Farid Nasir Ani. 2020. "Microwave pyrolysis for valorisation of horse manure biowaste." Energy Conversion and Management 220, no. : 113074.
Combustion characteristics of palm biodiesel/methyl esters (PME) and natural gas (NG) blend were examined using a model gas turbine swirl burner at vane angle (θ) 30°, 45° and 60°. A twin fluid air blast atomiser was utilised for atomising liquid fuel at air-to-liquid ratio (ALR) 2.50. Swirling flow was initiated by using an axial swirler as main air passed through it. Combustible mixture was formed as swirling air flow mixed up with liquid fuel spray at burner outlet. Flame colour for PME/NG was mainly bluish, resembling that of neat PME despite subtle liftoff was observed in PME/NG swirl flames. Flame spectroscopic analysis showed that PME/NG swirl flames were more intense than baseline PME. Furthermore, θ = 60° operation led to significantly lower reaction intensity. Meanwhile, PME/NG combustion with 20%-30% NG input power fraction was observed to lower nitric oxide (NO) emission by a factor of 2.7 when compared with diesel and neat PME in θ = 60° combustion. Novel empirical models for emissions were also proposed, enabling the estimation of NO emission from PME/NG combustion at different NG input power proportions and vane angle. This research shows that PME/NG combustion is a promising way of reducing NO emission against neat PME and diesel in gas turbine operation. Moreover, flame instability provoked by liftoff in dual fuel operation is not aggravated, mainly due to nullification by intensified global reaction when NG is added. Such attributes feature PME/NG as a viable alternative fuel for use in land-based power generation gas turbines.
Meng-Choung Chiong; Agustin Valera-Medina; William Woei Fong Chong; Cheng Tung Chong; Guo Ren Mong; Mohammad Nazri Mohd Jaafar. Effects of swirler vane angle on palm biodiesel/natural gas combustion in swirl-stabilised gas turbine combustor. Fuel 2020, 277, 118213 .
AMA StyleMeng-Choung Chiong, Agustin Valera-Medina, William Woei Fong Chong, Cheng Tung Chong, Guo Ren Mong, Mohammad Nazri Mohd Jaafar. Effects of swirler vane angle on palm biodiesel/natural gas combustion in swirl-stabilised gas turbine combustor. Fuel. 2020; 277 ():118213.
Chicago/Turabian StyleMeng-Choung Chiong; Agustin Valera-Medina; William Woei Fong Chong; Cheng Tung Chong; Guo Ren Mong; Mohammad Nazri Mohd Jaafar. 2020. "Effects of swirler vane angle on palm biodiesel/natural gas combustion in swirl-stabilised gas turbine combustor." Fuel 277, no. : 118213.
While dual fuel firing of power generation combustion systems can improve the fuel flexibility of such systems, several studies on compression ignition engines have also shown a positive impact on NOX and PM emissions. Previous multiphase fuel combustion studies for combustion turbines are limited, thus the present study addresses that gap by fuelling a model swirl stabilised gas turbine combustor with a blend of waste cooking oil-derived biodiesel and methane. Methane was increasingly injected into swirling combustion air flow while simultaneously reducing the biodiesel spray flowrate across a pressure atomiser, thus maintaining an overall equivalence ratio of 0.7 while delivering a thermal power output of 15 kW in all cases, except for flame stability range trials. Direct flame imaging, CH* and C2* chemiluminescence imaging, post combustion emissions as well as stability performance of the flames were evaluated. NOX emissions were found to decrease by 29% and unburnt hydrocarbons increased by 10% as the fraction of methane in fuel mix increased to 30%. Further, flame images suggest increased wrinkling and perturbing of the flame front as gas fraction of the biodiesel/methane flame increases. However, the temporal variation of integral intensity of CH* and C2* species chemiluminescence point to at least an 8% improvement in flame stability when 30% of flame heat output is supplied by methane compared to neat biodiesel burn. Also, it was found that flame stability limits reduce as methane partly replaces biodiesel in the flame.
Ogbonnaya Agwu; Jon Runyon; Burak Goktepe; Cheng Tung Chong; Jo-Han Ng; Anthony Giles; Agustin Valera-Medina. Visualisation and performance evaluation of biodiesel/methane co-combustion in a swirl-stabilised gas turbine combustor. Fuel 2020, 277, 118172 .
AMA StyleOgbonnaya Agwu, Jon Runyon, Burak Goktepe, Cheng Tung Chong, Jo-Han Ng, Anthony Giles, Agustin Valera-Medina. Visualisation and performance evaluation of biodiesel/methane co-combustion in a swirl-stabilised gas turbine combustor. Fuel. 2020; 277 ():118172.
Chicago/Turabian StyleOgbonnaya Agwu; Jon Runyon; Burak Goktepe; Cheng Tung Chong; Jo-Han Ng; Anthony Giles; Agustin Valera-Medina. 2020. "Visualisation and performance evaluation of biodiesel/methane co-combustion in a swirl-stabilised gas turbine combustor." Fuel 277, no. : 118172.
Liquid fuels are likely to remain the main energy source in long-range transportation and aviation for several decades. To reduce our dependence on fossil fuels, liquid biofuels can be blended to fossil fuels – or used purely. In this paper, coconut methyl ester, standard diesel fuel (EN590:2017), and their blends were investigated in 25 V/V% steps. A novel turbulent combustion chamber was developed to facilitate combustion in a large volume that leads to ultra-low emissions. The combustion power of the swirl burner was 13.3 kW, and the air-to-fuel equivalence ratio was 1.25. Two parameters, combustion air preheating temperature and atomizing air pressure were adjusted in the range of 150–350 °C and 0.3–0.9 bar, respectively. Both straight and lifted flames were observed. The closed, atmospheric combustion chamber resulted in CO emission below 10 ppm in the majority of the cases. NO emission varied between 60 and 183 ppm at straight flame cases and decreased below 20 ppm when the flame was lifted since the combustion occurred in a large volume. This operation mode fulfills the 2015/2193/EU directive for gas combustion by 25%, which is twice as strict as liquid fuel combustion regulations. The 90% NO emission reduction was also concluded when compared to a lean premixed prevaporized burner under similar conditions. This favorable operation mode was named as Mixture Temperature-Controlled (MTC) Combustion. The chemiluminescent emission of lifted flames was also low, however, the OH* emission of straight flames was clearly observable and followed the trends of NO emission. The MTC mode may lead to significantly decreased pollutant emission of steady-operating devices like boilers, furnaces, and both aviation and industrial gas turbines, meaning an outstanding contribution to more environmentally friendly technologies.
Viktor Józsa; Gyöngyvér Hidegh; Attila Kun-Balog; Jo-Han Ng; Cheng Tung Chong. Ultra-low emission combustion of diesel-coconut biodiesel fuels by a mixture temperature-controlled combustion mode. Energy Conversion and Management 2020, 214, 112908 .
AMA StyleViktor Józsa, Gyöngyvér Hidegh, Attila Kun-Balog, Jo-Han Ng, Cheng Tung Chong. Ultra-low emission combustion of diesel-coconut biodiesel fuels by a mixture temperature-controlled combustion mode. Energy Conversion and Management. 2020; 214 ():112908.
Chicago/Turabian StyleViktor Józsa; Gyöngyvér Hidegh; Attila Kun-Balog; Jo-Han Ng; Cheng Tung Chong. 2020. "Ultra-low emission combustion of diesel-coconut biodiesel fuels by a mixture temperature-controlled combustion mode." Energy Conversion and Management 214, no. : 112908.
The dual-fuel combustion characteristics of palm biodiesel/methyl esters (PME) and natural gas (NG) in a model gas turbine swirl flame burner is investigated at 9.3 kW thermal power. The PME is atomised into a spray, while the gaseous NG is premixed with the main bulk swirling air before entering the combustion chamber. The dual-fuel PME/NG flame structure is similar to the single fuel PME, where the sooty flame brush is noticeably absent. The PME and PME/NG flames emit higher peak intensity of OH* and CH* radicals as compared to diesel at the same equivalence ratio. Dual fuel operation results in lower NO but higher CO at = 0.9 as compared to pure diesel and PME spray flames. The higher CO emission level for dual-fuel is attributed to poor mixing and incomplete combustion as a result of reduced air flow. At leaner operation of = 0.65, enhanced turbulence due to higher bulk air flow results in improved mixing, lowering the overall CO but increasing the NO emissions due to the more intense flame core. The study shows that optimisation of the multiphase dual-fuel injection system is needed to achieve low emissions in a gas turbine combustor.
Cheng Tung Chong; Meng-Choung Chiong; Jo-Han Ng; Manh-Vu Tran; Agustin Valera-Medina; Viktor Józsa; Bo Tian. Dual-Fuel Operation of Biodiesel and Natural Gas in a Model Gas Turbine Combustor. Energy & Fuels 2020, 34, 3788 -3796.
AMA StyleCheng Tung Chong, Meng-Choung Chiong, Jo-Han Ng, Manh-Vu Tran, Agustin Valera-Medina, Viktor Józsa, Bo Tian. Dual-Fuel Operation of Biodiesel and Natural Gas in a Model Gas Turbine Combustor. Energy & Fuels. 2020; 34 (3):3788-3796.
Chicago/Turabian StyleCheng Tung Chong; Meng-Choung Chiong; Jo-Han Ng; Manh-Vu Tran; Agustin Valera-Medina; Viktor Józsa; Bo Tian. 2020. "Dual-Fuel Operation of Biodiesel and Natural Gas in a Model Gas Turbine Combustor." Energy & Fuels 34, no. 3: 3788-3796.
Brandon Han Hoe Goh; Hwai Chyuan Ong; Cheng Tung Chong; Wei-Hsin Chen; Kin Yuen Leong; Shiou Xuan Tan; Xin Jiat Lee. Ultrasonic assisted oil extraction and biodiesel synthesis of Spent Coffee Ground. Fuel 2020, 261, 1 .
AMA StyleBrandon Han Hoe Goh, Hwai Chyuan Ong, Cheng Tung Chong, Wei-Hsin Chen, Kin Yuen Leong, Shiou Xuan Tan, Xin Jiat Lee. Ultrasonic assisted oil extraction and biodiesel synthesis of Spent Coffee Ground. Fuel. 2020; 261 ():1.
Chicago/Turabian StyleBrandon Han Hoe Goh; Hwai Chyuan Ong; Cheng Tung Chong; Wei-Hsin Chen; Kin Yuen Leong; Shiou Xuan Tan; Xin Jiat Lee. 2020. "Ultrasonic assisted oil extraction and biodiesel synthesis of Spent Coffee Ground." Fuel 261, no. : 1.
Present-day, commercial airlines are getting into the use of bio-jet fuel, by blending vegetable oil derived bio-jet fuel with fossil jet fuel in maximum up to 50%, which is ASTM-certified. In order to reduce the dependency on fossil jet fuel, recent research trend shows that most of the renewable aviation fuel or bio-jet fuel were derived from the complex liquid biomass via hydroprocessing technology. Hence there is a necessity to have an insight into the production technology, typically the hydroprocessing technology. Generally, hydroprocessing technology for the liquid biomass conversion into bio-jet fuel involved multi intermediate steps, such as deoxygenation, cracking and isomerization. This conventional process is further upgraded and simplified into single step reaction, which minimizes the post-treatment effort to be done in every reaction step, and thus reduces the production cost. Moreover, other economic factors such as catalyst price, hydrogen production cost and plant size will also consider as major impacts towards biofuel production scale and cost. Therefore, this paper aims to review the bio-jet fuel conversion technologies in a different perspective, by comparing the hydroprocessing technology of bio-jet fuel (i.e. three-step process, two-step process, single step process), and the effect of reaction variables (i.e. feedstock, catalyst, and reacting gas). The details of outputs for different hydroprocessing technology are also discussed herein. In summary, most research works have achieved positive findings in single step process, by adapting hydrodeoxygenation process in majority. However, there are some limitation and challenges that can be further improved in the single step process, such as exploration on potential feedstock, development of catalyst and optimization of reacting parameters. The energy, environmental and economic analysis on the advanced hydroprocessing of bio-jet fuel are yet to be conducted, in order to compare their merits.
Elaine Siew Kuan Why; Hwai Chyuan Ong; Hwei Voon Lee; Yong Yang Gan; Wei-Hsin Chen; Cheng Tung Chong. Renewable aviation fuel by advanced hydroprocessing of biomass: Challenges and perspective. Energy Conversion and Management 2019, 199, 112015 .
AMA StyleElaine Siew Kuan Why, Hwai Chyuan Ong, Hwei Voon Lee, Yong Yang Gan, Wei-Hsin Chen, Cheng Tung Chong. Renewable aviation fuel by advanced hydroprocessing of biomass: Challenges and perspective. Energy Conversion and Management. 2019; 199 ():112015.
Chicago/Turabian StyleElaine Siew Kuan Why; Hwai Chyuan Ong; Hwei Voon Lee; Yong Yang Gan; Wei-Hsin Chen; Cheng Tung Chong. 2019. "Renewable aviation fuel by advanced hydroprocessing of biomass: Challenges and perspective." Energy Conversion and Management 199, no. : 112015.
Nor Afzanizam Samiran; Cheng Tung Chong; Jo-Han Ng; Manh-Vu Tran; Hwai Chyuan Ong; Agustin Valera-Medina; William Woei Fong Chong; Mohammad Nazri Mohd Jaafar. Experimental and numerical studies on the premixed syngas swirl flames in a model combustor. International Journal of Hydrogen Energy 2019, 44, 24126 -24139.
AMA StyleNor Afzanizam Samiran, Cheng Tung Chong, Jo-Han Ng, Manh-Vu Tran, Hwai Chyuan Ong, Agustin Valera-Medina, William Woei Fong Chong, Mohammad Nazri Mohd Jaafar. Experimental and numerical studies on the premixed syngas swirl flames in a model combustor. International Journal of Hydrogen Energy. 2019; 44 (44):24126-24139.
Chicago/Turabian StyleNor Afzanizam Samiran; Cheng Tung Chong; Jo-Han Ng; Manh-Vu Tran; Hwai Chyuan Ong; Agustin Valera-Medina; William Woei Fong Chong; Mohammad Nazri Mohd Jaafar. 2019. "Experimental and numerical studies on the premixed syngas swirl flames in a model combustor." International Journal of Hydrogen Energy 44, no. 44: 24126-24139.
Cheng Tung Chong; Meng-Choung Chiong; Jo-Han Ng; MookTzeng Lim; Manh-Vu Tran; Agustin Valera-Medina; William Woei Fong Chong. Oxygenated sunflower biodiesel: Spectroscopic and emissions quantification under reacting swirl spray conditions. Energy 2019, 178, 804 -813.
AMA StyleCheng Tung Chong, Meng-Choung Chiong, Jo-Han Ng, MookTzeng Lim, Manh-Vu Tran, Agustin Valera-Medina, William Woei Fong Chong. Oxygenated sunflower biodiesel: Spectroscopic and emissions quantification under reacting swirl spray conditions. Energy. 2019; 178 ():804-813.
Chicago/Turabian StyleCheng Tung Chong; Meng-Choung Chiong; Jo-Han Ng; MookTzeng Lim; Manh-Vu Tran; Agustin Valera-Medina; William Woei Fong Chong. 2019. "Oxygenated sunflower biodiesel: Spectroscopic and emissions quantification under reacting swirl spray conditions." Energy 178, no. : 804-813.
This paper starts with a review on challenges and need of improved supercapacitor application, which is then followed by advantages of biomass compared with other materials for use in supercapacitor application. The conversion of biomass into carbon nanofiber using different techniques was extensively reviewed for its advantages and limitations. It was revealed that the materials currently used are yet to be fully sustainable or feasible for energy storage application. In contrast, biomass represents a widely available and sustainable material to be converted into carbon nanofiber for energy storage application. Different techniques were employed for carbon nanofiber production to achieve different objectives, comprising high product yield, feasible diameter adjustment, low electric consumption, and shorter production time. Nevertheless, it was revealed that many key properties of the biomass-derived carbon nanofiber have yet to be fully investigated, as there are still knowledge gaps to be filled for each technique. Thus, more studies are needed to broaden the existing understanding in the key parameters of different techniques in order to develop a highly desirable carbon nanofiber from biomass for sustainable energy storage application.
Elfina Azwar; Wan Adibah Wan Mahari; Joon Huang Chuah; Dai-Viet N. Vo; Nyuk Ling Ma; Wei-Haur Lam; Su Shiung Lam. Transformation of biomass into carbon nanofiber for supercapacitor application – A review. International Journal of Hydrogen Energy 2018, 43, 20811 -20821.
AMA StyleElfina Azwar, Wan Adibah Wan Mahari, Joon Huang Chuah, Dai-Viet N. Vo, Nyuk Ling Ma, Wei-Haur Lam, Su Shiung Lam. Transformation of biomass into carbon nanofiber for supercapacitor application – A review. International Journal of Hydrogen Energy. 2018; 43 (45):20811-20821.
Chicago/Turabian StyleElfina Azwar; Wan Adibah Wan Mahari; Joon Huang Chuah; Dai-Viet N. Vo; Nyuk Ling Ma; Wei-Haur Lam; Su Shiung Lam. 2018. "Transformation of biomass into carbon nanofiber for supercapacitor application – A review." International Journal of Hydrogen Energy 43, no. 45: 20811-20821.
We demonstrate the use of laser-induced incandescence (LII) of submicron tungsten carbide (WC) particles as a method for particle image velocimetry (PIV). The technique allows a single laser to be used for separate measurements of velocity of two phases in a droplet-laden flow. Submicron WC particles are intentionally seeded into a two-phase flow, and heated by a light sheet generated by a double-pulsed PIV laser operating at sufficiently high pulse energy. The small size and large absorption cross section allows particles to be heated up to several thousand degrees Kelvin to emit strong incandescence signals, whilst the laser-induced temperature increase in liquid droplets/large particles is negligible. The incandescence signal from WC and Mie scattering from droplets/large particles are separately captured by deploying different filters to a PIV camera. The consecutive images of the laser-induced incandescence (LII) are used to determine the velocity field of the gas-phase flow, and those of Mie scatter are used to extract the velocity of droplets/large particles. The proposed technique is demonstrated in an air jet first and compared with the result given by a normal PIV test, which shows that submicron WC particles can accurately follow the gas flow, and that the LII images can be used to perform cross-correlations. We then apply this technique on an ethanol droplet/air jet (non-reacting), demonstrating the resulting slip velocity between two phases. The proposed technique combining PIV and LII with a single laser requires little additional equipment, and is applicable to a much higher droplet/particle density than previously feasible. Finally, the possibility of applying this technique to a flame is demonstrated and discussed.
Luming Fan; Dante McGrath; Cheng Tung Chong; Mohammad Nazri Mohd Jaafar; Hongtao Zhong; Simone Hochgreb. Laser-induced incandescence particle image velocimetry (LII-PIV) for two-phase flow velocity measurement. Experiments in Fluids 2018, 59, 156 .
AMA StyleLuming Fan, Dante McGrath, Cheng Tung Chong, Mohammad Nazri Mohd Jaafar, Hongtao Zhong, Simone Hochgreb. Laser-induced incandescence particle image velocimetry (LII-PIV) for two-phase flow velocity measurement. Experiments in Fluids. 2018; 59 (10):156.
Chicago/Turabian StyleLuming Fan; Dante McGrath; Cheng Tung Chong; Mohammad Nazri Mohd Jaafar; Hongtao Zhong; Simone Hochgreb. 2018. "Laser-induced incandescence particle image velocimetry (LII-PIV) for two-phase flow velocity measurement." Experiments in Fluids 59, no. 10: 156.
Microwave co-pyrolysis (MCP) of waste cooking oil (WCO) and waste polyolefins (WP) was examined for its potential to convert these wastes into liquid fuel. The influence of performing the pyrolysis process under N2 atmosphere and vacuum environment was investigated with emphasis on the temperature profile, heating rate, and the yield and properties of the liquid oil obtained. Different ratios of WP to WCO (1:2, 1:1.5, 1:1, 1.5:1, and 2:1) were also investigated. MCP performed under vacuum environment recorded higher heating rates (20–24 °C/min) and higher yield of liquid oil (up to 62 wt.%) compared to that performed under N2 atmosphere (18–22 °C/min of heating rate and 24–50 wt.% of liquid oil). The high heating rate resulted in shorter reaction time and lower power consumption, leading to lower energy consumption by the pyrolysis process. The liquid oil comprised C13–C24 hydrocarbons (aliphatics, aromatics) within the hydrocarbon range of diesel fuel. It also showed promising green properties comprising low nitrogen and oxygen content, and free of sulphur. Combined with the detection of high energy content (42–49 MJ/kg) and low moisture content (<1 wt.%), the liquid oil shows great potential to be used as a fuel. Our results show that MCP performed under vacuum environment shows potential as a promising pyrolysis approach with improved heating performance and production of hydrocarbon fuel with desirable fuel properties.
Wan Adibah Wan Mahari; Cheng Tung Chong; Wei-Haur Lam; Tuan Nurul Sabiqah Tuan Anuar; Nyuk Ling Ma; Mohd Danial Ibrahim; Su Shiung Lam. Microwave co-pyrolysis of waste polyolefins and waste cooking oil: Influence of N2 atmosphere versus vacuum environment. Energy Conversion and Management 2018, 171, 1292 -1301.
AMA StyleWan Adibah Wan Mahari, Cheng Tung Chong, Wei-Haur Lam, Tuan Nurul Sabiqah Tuan Anuar, Nyuk Ling Ma, Mohd Danial Ibrahim, Su Shiung Lam. Microwave co-pyrolysis of waste polyolefins and waste cooking oil: Influence of N2 atmosphere versus vacuum environment. Energy Conversion and Management. 2018; 171 ():1292-1301.
Chicago/Turabian StyleWan Adibah Wan Mahari; Cheng Tung Chong; Wei-Haur Lam; Tuan Nurul Sabiqah Tuan Anuar; Nyuk Ling Ma; Mohd Danial Ibrahim; Su Shiung Lam. 2018. "Microwave co-pyrolysis of waste polyolefins and waste cooking oil: Influence of N2 atmosphere versus vacuum environment." Energy Conversion and Management 171, no. : 1292-1301.