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Highlights • SOI and dwell angle on engine's out-responses of biodiesel blends was studied. • Lower NOx around 110 ppm with late SOI for B20 and B50 fuels. • B50 gives simultaneous NOx and smoke reductions with late SOI and longer dwell angle. • Two-stage injection is a practical strategy to reduce NOx and smoke simultaneously. Abstract Diesel engine is widely used as prime mover due to its high thermal efficiency. Usage of renewable biodiesel in diesel engine is also widely studied due to its potential in reducing emission and as a replacement of conventional diesel. Biodiesel performance could be improved by blending it with petroleum diesel besides introducing appropriate injection strategies. In this experiment, the effect of percentage of biodiesel blends and injection strategies such as variations in start of injection (SOI) timing and dwell angle on diesel engine performance were investigated. The test engine used is four-stroke turbocharged direct injection diesel engine. Results show that exhaust emissions, engine performance and combustion characteristics are substantially affected by biodiesel blending ratio and SOI timing but slightly influenced by two-stage injection dwell angle. Biodiesel blends percentage could be raised to improve NOx and smoke emissions. Even though SOI performed at a later timing could reduce NOx emission, smoke emission increased. Dwell angle between two successive injections could be prolonged to lower the effect of the increase in smoke emission. It could also be inferred that by setting a proper SOI timing and dwell angle under two-stage injection scheme when suitable biodiesel blend is used, the engine performance could be optimized. [ABSTRACT FROM AUTHOR]

The smoke point of several fuel mixtures was measured using a smoke meter defined by American Society for Testing Material D1322. The threshold soot index (TSI) was calculated to compare the sooting tendency of fuels. Two aviation biofuels produced by hydroprocessing of coconut oil, four jet range normal paraffins (n-paraffins), iso-octane, and propylbenzene were used to investigate the effects of chain length of n-paraffins, iso-paraffins, and aromatics on the sooting tendency. The results show that the effect of propylbenzene on the smoke point of the mixtures is dominant compared to that of the chain length of n-paraffins and the fraction of iso-paraffins. The differences in the sooting tendency among these n-paraffins are insignificant. In addition, blending aviation biofuels with Jet A1 leads to a decrease in the sooting tendency. Aromatics in Jet A1 play an important role on the sooting tendency of the mixtures of aviation biofuels and Jet A1. [ABSTRACT FROM AUTHOR]

Biodiesel is an alternative and renewable diesel fuel, can be produced from diverse kinds of vegetable oils. The biodiesel effects on engine performance and emissions vary as the source of oil changes. In this study, castor oil biodiesel (CAB), coconut oil biodiesel (COB) and waste cooking oil biodiesel (WCB) were produced by transesterfication approach and blended with conventional diesel fuel (CDF). The volumetric blending ratios of biodiesels with CDF were set at 5, 10, 20, and 30. Tests were carried out under different loads and speeds which simultaneously change. Change in engine performance and emission characteristics against speed or load were investigated on a turbocharged DI compression ignition engine. Viscosity, oxygen amount in fuel, length of hydrocarbon chain, cetane number, biodiesel amount in fuel, engine speed, load have been considered separately, for better consideration of the effects of each parameters, in this study they were considered and compared in similar laboratorial condition. Based on the main effects of load and engine speed on emissions and engine performance, it this study both of them were considered simultaneously. Totally, the experimental results indicated that the best performance and emission characteristics belong to WCB and COB blends respectively fueled in the diesel engine. [ABSTRACT FROM AUTHOR]

Straight vegetable oils attracted attention several times as alternative fuel for mobile machinery. Certain efforts have already been undertaken to enable the usage of the high viscous oils in compression ignition engines. While physical properties are well specified for different kind of oils, only few information is available on the ignition behavior of vegetable oils under modern engine like conditions. Therefore, the ignition behavior of nine different vegetable oils and two oil mixtures was investigated using the Advanced Fuel Ignition Delay Analyser (AFIDA). The AFIDA is a modern constant volume combustion chamber apparatus equipped with a high pressure injection system. Analysis was performed at combustion chamber temperatures ranging from 796 K to 967 K and at air density levels of 4.7 kg/m 3 , 9.3 kg/m 3 and 17.7 kg/m 3 . Ignition behavior was correlated to the structure indices average number of carbon atoms and average number of double bonds. Both were calculated using the fatty acid composition of the oils. Ignition delay decreased with rising temperature and air density. Coconut oil ignited first at every temperature except for the lowest air density level. Start of combustion was always last for linseed oil, followed by camelina and soybean oil. Ignition delay increased linearly with rising average number of double bonds and decreasing average number of carbon atoms. The effect of the average number of double bonds on ignition delay was more pronounced than that of carbon chain length. Fatty acids with two or more carbon-carbon double bonds led mostly to a stronger increase in ignition delay compared to those with only one double bond. [ABSTRACT FROM AUTHOR]

Providing more and more energy is an essential task of the today's energetic industry. In the last few years, in addition to the traditional methods of energy production, alternative energy sources have been developing fast. One of the devices that can make use of these sources is a fuel cell. The fuel cells can be a power source of future mainly due to their high efficiency, low influence on environment and the possibility of powering with different fuels. Most often, fuel cells are powered by hydrogen. However, the problems with its cheap production and storage are the reason for the search for alternative fuels for fuel cells. It is important that the new fuel will be characterized by zero or low emission level. One of these fuels can be vegetable oil. The paper presents the measurements pertaining to electrooxidation of coconut oil emulsion on a smooth platinum electrode in an aqueous solution of KOH. The electrochemical measurements were performed in a glass cell with AMEL System 5000 potentiostat. The obtained maximum current density is equal to 25 mA/cm2. Therefore the coconut oil can be used as fuel for fuel cell provided that the temperature of process is kept above 303K. [ABSTRACT FROM AUTHOR]

Fluctuating petroleum prices, environmental concerns and the understanding that petroleum is a finite resource have encouraged investigation into alternative fuels. Coconut oil can be potentially be used as the triglyceride feedstock for biodiesel production. The objective of this study was to complete energy performance analyses of four (4) coconut oil biodiesels. The energy performance metrics investigated were net energy ratio (NER), net energy balance (NEB), net renewable energy value (NREV) and fossil energy ratio (FER). NER values ranged from 0.51 to 0.77, NEB from -12.00 MJ/L to -46.21 MJ/L, NREV from 9.00 to 21.31 MJ/L and FER from 1.52 to 2.88. The energy metrics implied that the small-scale transesterification process is neither energy-efficient nor sustainable in Trinidad and Tobago. At the atom efficient 3:1 methanol to oil ratio, the NREV and FER values are improved, however, compared to the 6:1 methanol to oil ratio process. Additionally, since most of their physical properties are already within specification for use in the local vehicular market, all biodiesels are a prospective component of environmentally friendly blends with petrodiesel. [ABSTRACT FROM AUTHOR]

This research article mainly discusses the impact of emissions and fuel economy rules as well as the range of design options and technological advances, required to reduce emissions, improving engine efficiency, and developing fuel economy. Today's energy needs are meeting all the way through fossil fuel and natural gas. As an outcome the amount of natural fuels, such as coal or gas from the remains of living organisms, is on receding for many years. This research confirms the concept of coconut oil as a renewable and substitute fuel for marine engines. Since, a diesel engine has flexible uses including small power generation and transportation sectors. In this article principally the focus is on the performance and emission level even a biofuel used as an alternative for marine engine. Experimentation shows a variety of studies based on the performance of a low speed diesel engine use of variant blends of biofuel obtained with a mixing coconut oil and diesel. While using biofuel blends as a fuel in test engine, it was running in a fine manner. Various blends of biofuel (i.e. B25, B50, and B 75 etc.) have been used to keep away from difficult alteration of the engine. As the outset compares the engine performance for biodiesel blends it was accepted to conclude the most excellent feasible blend for various working condition. As concerns this research work diesel fuel-coconut oil blends performed in lower smoke density and oxides of nitrogen emissions. Finally, this research work shows a pollution free environment with the support of biofuel concentrations. [ABSTRACT FROM AUTHOR]

The effects of cycloparaffin and aromatic hydrocarbons when blended with soap-derived biokerosene (SBK) and normal paraffins (n-paraffins) on the sooting tendency and the freezing point are quantified to determine a method for improving the properties of SBK and n-paraffin fuels. In this study, SBK was derived from the saponification and dercarboxylation of coconut oil, and consists predominantly of n-paraffins with carbon chain lengths from C7 to C17. Dodecane, butylcyclohexane and butylbenzene were chosen as surrogate components for n-paraffins in SBK, cycloparaffins and aromatics, respectively. The total soot volume was measured from the light extinction at ambient conditions in a wick-fed laminar diffusion flame. The measured smoke point of the fuel was correlated with the required sooting tendency according to the jet fuel standard. The freezing point was measured using the JIS K2276 test method. The results show that butylcyclohexane affects the sooting tendency much lesser than butylbenzene when blended with SBK or dodecane. In contrast, butylcyclohexane decreases the freezing point more, as compared to butylbenzene, when blended with dodecane. Butylcyclohexane and butylbenzene have a similar trend of effect on the freezing point when blended with SBK or dodecane. Blending SBK or dodecane with butylcyclohexane matches the requirements of both smoke point and freezing point for jet fuel specified by ASTM D1655. Conversely, blending SBK or dodecane with butylbenzene does not meet these requirements. Therefore, given the tradeoff between sooting tendency and freezing point, cycloparaffins are considered more promising than aromatics for blending with SBK or n-paraffin fuels. [ABSTRACT FROM AUTHOR]

The properties, performance, and exhaust emissions of a four-cylinder indirect injection diesel engine fueled by FAME from waste coconut oil was evaluated in this study. Polymerization and carbon deposits on fuel-injector nozzles were also monitored. Ordinary diesel (OD) oil was used as a benchmark for comparison purposes. Tests included measuring high heating value, kinematic viscosity, specific density, cetane index, pour point, flash point, and Conradson carbon residue. Results showed that, the high calorific value decreased with increased coconut oil in coconut-oil blends. On average, the calorific value of all coconut-oil blends were about 6% lower than that of OD fuel. Density increased with increased coconut oil in coconut-oil blends because of the higher amount of carbon atoms in coconut-oil molecules. As a result, viscosity also increased with increased coconut oil in blends. Other properties of blended fuels varied according to their physicochemical properties. Results also showed that the brake power output of engine increased by about 5% when fueled by 30% coconut-oil-blended fuel. The average specific fuel consumption of coconut-oil-blended fuels increased by 7–10% compared with OD oil. The exhaust emissions of blended fuel were found to be much cleaner, containing less CO, HC, NO x, and smoke and benzene concentration. The coconut-oil-blended fuel also produced low particulate emission and carbon deposit on injector nozzles. For each coconut-oil-blended fuel, the engine did not have any starting difficulty and combustion noise at >25 °C. The coconut-oil-based fuel also did not pose a severe environmental threat because of its low sulfur content. [ABSTRACT FROM AUTHOR]

Four novel Brønsted acidic ionic liquids were synthesized and characterized by FT-IR, 1 H NMR and 13 C NMR for the first time. Their catalytic activities for the synthesis of biodiesel via the transesterification of coconut oil and methanol were investigated. Among all the tested ionic liquids, [CyN 1,1 PrSO 3 H][Tos] performed best, and its catalytic performance was systematically explored by orthogonal experiment based on the single factor experiment. The results show that the order of factors on the yield of biodiesel is reaction temperature, molar ratio of methanol/oil, catalyst dosage and reaction time. The maximum biodiesel yield of 98.7% was obtained under the optimal reaction conditions. There was no significant decrease of its catalytic activity after being reused for five successive cycles. The refined biodiesel meets the European biodiesel standard (EN 14214). [ABSTRACT FROM AUTHOR]

The effect of biodiesel and its blends synthesized from coconut oil (CNO) via alkali catalyzed transeterification on the key fuel properties and corrosion characteristics of copper were investigated. The transesterification of the CNO via ethanol in the presence of potassium hydroxide was performed and the resulting coconut oil ethyl ester (COEE) was blended with fossil diesel (B0). The fuel properties such as density, kinematic viscosity (KV), pour and cloud points (PP and CP, respectively) and American Petroleum Institute of Gravity (API) of B0, COEE-diesel blend (B50) and COEE (B100) were characterized and compared with that of ASTM D6751 and EN14214 standards. Static immersion tests were conducted by exposing copper coupons toB0, B50 and B100 at different temperatures (50, 65 and 80 °C) for 5 days. Corrosion rates of copper in these fuels were determined by weight loss method. Also, during the period of investigation, these fuels were analyzed by measuring total acid number (TAN). The results showed that the density, KV, PP and CPincreased while the API gravity decreased as the percentage of the biodiesel in the blend increased. The highest corrosion rates for copper at the end of the investigation were 0.054, 0.0954 and 0.139 mpy in B0, B50 and B100, respectively. The minimum TAN (0.17 mg KOH/g) and maximum TAN (0.62 mg KOH/g) were observed in B0 and B100 containing copper, respectively. [ABSTRACT FROM AUTHOR]

The conventional biodiesel production method requires oil extraction followed by transesterification with methanol. The solubility of vegetable oils in methanol is low which decreases the overall rate of reaction. To eliminate the oil extraction step and improve the overall reaction rate, simultaneous extraction, esterification and transesterification were conducted by directly mixing methanol and tetrahydrofuran (THF) co-solvent and sulfuric acid catalyst with ground, desiccated coconut meat (copra) in a batch process and continuing the reaction until the system reached steady state. After separation of the mixture, yield was obtained by measuring the content of triglycerides, diglycerides and monoglycerides in the biodiesel phase. The yield increases with THF:methanol ratio, methanokoil molar ratio and temperature. Within the range of conditions tested, the highest yield achieved was 96.7% at 60 °C, THF:methanol volume ratio of 0.4 and methanokoil molar ratio of 60:1. The methanokoil molar ratio is necessarily high in order to completely wet the copra mass, but is still lower than in previous studies by other researchers on in situ transesterification. Product assays show that the resulting biodiesel product is similar to conventionally produced coconut biodiesel. The results indicate that the in situ transesterification of copra using methanol/THF mixtures merits further study. [ABSTRACT FROM AUTHOR]