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This paper reviews and discusses the potential of papaya seed and stone fruit kernel biodiesels — the two sources of 2nd generation transport biodiesels in Australia. The challenges associated with biodiesel production and their possible solutions, particularly on feedstock selection, oil extraction, conversion of oil into biodiesel, biodiesel storage and transport, costs of production and the information needs for commercialising these sources of biodiesels are discussed, along with the eco-friendly attributes of these biodiesels to Australian transport sector. Some researchers report that the use of papaya seed and stone fruit kernel biodiesels reduce engine power only 2 to 5%), however significantly reduce harmful engine emission such as HC reductions of 9 to 19%, PM reductions of 19.5 to 35% and CO reductions of 11 to 29%. Keywords: Papaya seed, Stone fruit kernel, Apricot, RSM, Biodiesel, Renewable energy, Australia, Optimisation, Challenges, Engine performance, Emission, Second generation

This study investigated the impact of the addition of a novel series of biodiesels on diesel engine performance, emissions and combustion characteristics. Two non-edible biodiesels, namely waste cooking oil and macadamia oil (Macadamia integrifolia) biodiesels were experimentally tested in this study. The fuel blends were prepared in such a way that the fuel oxygen remains at 3.35 wt% in the blend. A 4-stroke, 4-cylinder, naturally aspirated diesel engine was used for all experiments. The engine was coupled and loaded with an eddy current dynamometer. The experimental results indicated that compared to diesel, all diesel-biodiesel blends show no significant changes in engine performance, but higher combustion efficiency and significant reductions in all major diesel emissions with a little penalty of NOx emission. Fuel energy and exergys were almost unchanged or slightly lower than diesel.

This investigation explored engine performance, combustion and exhaust emissions with a new series of fuels for compression ignition engine. Three blends were formulated using diesel, tea tree oil and diethylene glycol dimethyl ether (DGM). Low grade tea tree oil is considered as waste, which was used as fuel in this investigation. DGM was blended with tea tree oil and diesel as an additive for its high oxygen content and cetane number. Diesel was chosen for comparison purposes. The three blends examined in this study were, 70-30-0, 70-20-10 and 70-10-20 in ratios of diesel-tea tree oil-DGM. A six-cylinder, four-stroke, turbocharged diesel engine was used in this experiment. Four different loads of 25%, 50%, 75%, 100% and 1500 revolutions per minute (rpm) were selected for the experiments. Engine performance parameters like efficiency, power, mean effective pressure and specific fuel consumption were considered. In-cylinder pressure, the rate of heat release, peak and boost pressure were considered for combustion parameters. Carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM) and particulate number (PN) were considered for emission parameters. A maximum of 70% PM, 54% PN and 33% CO reductions were observed with three blends. However, 16% higher NOx emissions were observed with the blends.

A one-dimensional (1-D) thermodynamic model for engine performance, combustion and emissions using a regular diesel and two paraffin fuels (decane and dodecane) were developed using a GT-Suite simulation software. The engine performance, combustion and emission parameters for two paraffin fuels were analysed and compared with that of regular diesel. Thermal efficiency and specific fuel consumption were considered for engine performance analysis. Amongst the combustion parameters, in-cylinder pressure, rate of heat release, maximum temperature, start of combustion, ignition delay, 50% burned crank angle, 50% burned duration, and volumetric efficiency and excess air ratio were taken into consideration for analysis. Finally, specific oxides of nitrogen (NOx), and specific soot emissions were considered for emission analysis. Based on the engine performance, combustion and emissions analysis of all three fuels, it was found that decane and dodecane can be used as alternative fuels for diesel engine.

Increasing global energy demand at a rate faster than the population growth has led the researcher to look for alternative fuel. Amongst the options, biodiesel is an environmentally sustainable substitute of diesel fuel being renewable, biodegradable and have similar properties of fossil diesel. Among the biodiesel sources, microalgae is a potential third generation biodiesel feedstock which can be produced throughout the year and its oil yield is higher than any other crops. This paper reviews recent development in microalgae biodiesel in terms of its oil extraction technics, challenges of oil extraction, production of biodiesel from microalgae oil and its fuel properties. Finally, the paper discusses the performance and combustion analysis of diesel engine fuelled with microalgae biodiesel. This paper provides a clear understanding of the potential use of microalgae biodiesel as an alternative source to fossil diesel for diesel engines.

The present study compares diesel engine performance, emissions, energy and exergy parameters of three non-edible biodiesels blends and a reference diesel. The three biodiesel blends were prepared so as to keep the blend oxygen percentage at around 3.3 wt%. Considering the economy and availability, waste cooking and macadamia (Macadamia integrifolia) biodiesels were chosen for all the engine experiments. A commercial diesel was used as a reference fuel to compare the performance and emissions with those of the biodiesel blends. To keep the oxygen percentage of the blends approximately the same as for the reference diesel, around 30% waste cooking biodiesel was added to 70% reference diesel to make the first blend. Similarly, around 30% macadamia biodiesel was mixed with 70% reference diesel to make the second blend. In addition, 10% macadamia biodiesel and 20% waste cooking biodiesel were mixed with the 70% reference diesel to make the third blend with similar oxygen content. The macadamia blend is designated as MaD, the waste cooking blend is termed WcD, and the blend with macadamia and waste cooking biodiesel is abbreviated as MaWcD. This study aimed to investigate the influence of the fuel-oxygen on engine performance, emissions, energy and exergy parameters. A well-instrumented, 4-cylinder, 4-stroke, naturally aspirated direct injection (DI) diesel engine was used for the experiments. The engine was loaded and coupled with an eddy current dynamometer. Performance, emissions, energy and exergy parameters for the three biodiesel blends were compared with those of the reference diesel. Without significant reduction in engine performance, a significant reduction in total unburnt hydrocarbon (THC), carbon monoxide (CO), and particulate matter (PM) emissions with a penalty of increased nitrogen oxides (NOx) emissions were realised with all three biodiesel blends.

Waste management cost for Australia is increasing every year, and thus, it is important to find alternative ways to use the waste. For example, essential oil has a significant waste stream that can be utilized in vehicles of their producers. However, some of the essential oils contain oxygen which considerably affects engine performance, emission, and combustion characteristics of diesel engines. Thus, this research paper will try to evaluate the essential oils as a replacement of diesel fuel to operate a multicylider diesel engine. For this study, two essential oils are selected which contain different oxygenated functional groups, tea tree oil (5.4% oxygen) and eucalyptus oil (8.4% oxygen), with an aim to evaluate the effect of these functional groups on engine performance and emission parameters. These oils were blended with neat diesel (0% oxygen) to obtain a blend cotaining 2.2% oxygen by weight. The blends produced similar brake power; however, brake-specific fuel consumption (BSFC) increased for eucalyptus oil blends (2.4–3.7%) and tea tree oil blends (3.9–5.3%). Essential oil–diesel blends resulted in less CO and increased NOX emission, produced similar peak pressure, and indicated mean effective pressure. The results then lead to the conclusion that oxygenated essential oils can have a role to reduce dependency of agricultural sector on diesel in the near future.

Essential oils are obtained from the non-fatty parts of a plant, such as the roots, bark, leaves, stems and flowers. These oils are mainly used in the natural medicine sector due to claimed health benefits, as well as the flavouring and fragrance sector, and the market has experienced rapid growth in recent years. The high quality required of the products leads to a very significant low-value waste stream, which is available for use in the transport and agricultural sectors. The use of essential oils in the compression ignition (CI) engine is a concept that has not yet been explored thoroughly. This paper analyses the available literature on the effect of essential oils and their blends on the performance, combustion characteristics and emission parameters of the CI engine. Regarding their properties, essential oils have similar properties to neat diesel. Engine performance using several essential oils and their blends improve brake thermal efficiency (BTE) and reduce brake-specific fuel consumption. A significant reduction in particulate matter (PM) emissions along with reduced hydrocarbon and carbon monoxide emissions has been reported in the literature. Furthermore, essential oils and their blends increase peak cylinder pressure and heat release rate (HRR) compared to neat diesel and biodiesel. However, most of the literature reported increased emissions of nitrogen oxides attributed to the lower cetane number and higher oxygen content. Due to having a low cetane number, essential oils can be used in CI engines by blending with either diesel or biodiesel. The rapid growth of the essential oil sector increases the likelihood of their utilization in CI engines in the future.

Essential oils are derived from not-fatty parts of plants and are mostly used in aromatherapy, as well as cosmetics and perfume production. The essential oils market is growing rapidly due to their claimed health benefits. However, because only therapeutic grade oil is required in the medicinal sector, there is a substantial low-value waste stream of essential oils that can be used in the transportation and agricultural sectors. This study investigated the influence of orange, eucalyptus, and tea tree oil on engine performance and combustion characteristics of a multi-cylinder compression ignition engine. Orange, eucalyptus, and tea tree oil were blended with diesel at 10% by volume. For benchmarking, neat diesel and 10% waste cooking biodiesel-diesel blend were also tested. The selected fuels were used to conduct engine test runs with a constant engine speed (1500 RPM (revolutions per minute)) at four loads. As the load increased, frictional power losses decreased for all of the fuel samples and thus mechanical efficiency increased. At higher loads (75% and 100%), only orange oil-diesel blends produced comparable power to diesel and waste cooking biodiesel-diesel blends. Fuel consumption (brake and indicated) for the essential oil-diesel blends was higher when compared to base diesel and waste cooking biodiesel-diesel blends. Thermal efficiency for the essential oil-diesel blends was comparable to base diesel and waste cooking biodiesel-diesel blends. At higher loads, blow-by was lower for essential oil blends as compared to base diesel and waste cooking biodiesel-diesel blends. At 50% and 100% load, peak pressure was lower for all of the essential oil-diesel blends when compared to base diesel and waste cooking biodiesel-diesel blends. From the heat release rate curve, the essential oil-diesel blends ignition delay times were longer because the oils have lower cetane values. Overall, the low-value streams of these essential oils were found to be suitable for use in diesel engines at 10% blends by agricultural producers of these oils.

In this study, the biodiesel properties and effects of blends of oil methyl ester petroleum diesel on a CI direct injection diesel engine is investigated. Blends were obtained from the marine dinoflagellate Crypthecodinium cohnii and waste cooking oil. The experiment was conducted using a four-cylinder, turbo-charged common rail direct injection diesel engine at four loads (25%, 50%, 75% and 100%). Three blends (10%, 20% and 50%) of microalgae oil methyl ester and a 20% blend of waste cooking oil methyl ester were compared to petroleum diesel. To establish suitability of the fuels for a CI engine, the effects of the three microalgae fuel blends at different engine loads were assessed by measuring engine performance, i.e. mean effective pressure (IMEP), brake mean effective pressure (BMEP), in cylinder pressure, maximum pressure rise rate, brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), heat release rate and gaseous emissions (NO, NOx,and unburned hydrocarbons (UHC)). Results were then compared to engine performance characteristics for operation with a 20% waste cooking oil/petroleum diesel blend and petroleum diesel. In addition, physical and chemical properties of the fuels were measured. Use of microalgae methyl ester reduced the instantaneous cylinder pressure and engine output torque, when compared to that of petroleum diesel, by a maximum of 4.5% at 50% blend at full throttle. The lower calorific value of the microalgae oil methyl ester blends increased the BSFC, which ultimately reduced the BTE by up to 4% at higher loads. Minor reductions of IMEP and BMEP were recorded for both the microalgae and the waste cooking oil methyl ester blends at low loads, with a maximum of 7% reduction at 75% load compared to petroleum diesel. Furthermore, compared to petroleum diesel, gaseous emissions of NO and NOx, increased for operations with biodiesel blends. At full load, NO and NOx emissions increased by 22% when 50% microalgae blends were used. Petroleum diesel and a 20% blend of waste cooking oil methyl ester had emissions of UHC that were similar, but those of microalgae oil methyl ester/petroleum diesel blends were reduced by at least 50% for all blends and engine conditions. The tested microalgae methyl esters contain some long-chain, polyunsaturated fatty acid methyl esters (FAMEs) (C22:5 and C22:6) not commonly found in terrestrial-crop-derived biodiesels yet all fuel properties were satisfied or were very close to the ASTM 6751-12 and EN14214 standards. Therefore, Crypthecodinium cohnii- derived microalgae biodiesel/petroleum blends of up to 50% are projected to meet all fuel property standards and, engine performance and emission results from this study clearly show its suitability for regular use in diesel engines.

The main objective of this study was to develop a model for performance analysis of a spark ignition engine fueled with propane and octane. GT-Suite software was used to develop the model for a single cylinder 4-stroke gasoline engine having a bore of 85 mm and a stroke of 85 mm with a capacity of 0.48 litres. A one-dimensional gas dynamics was considered for heat transfer model development for different engine components. Different sub models including flow in the intake and exhaust system, port fuel injection, throttle, combustion, heat and energy transfer were combined to produce different engine performance parameters. The model was run for 12 different rotational speeds ranging from 500 rpm to 6000 rpm at a wide open throttle position. The influence of compression ratio of 8 to 10 for the port fuel injection on different engine performance parameters was also investigated in this study. It was found that propane has a considerable potential to be an alternative fuel for a gasoline engine.

This study uses the first and second laws of thermodynamics to investigate the effect of 18 oxygenated fuels on the quality and quantity of energy in a turbo-charged, common-rail six19 cylinder diesel engine. This work was performed using a range of fuel oxygen content based 20 on diesel, waste cooking biodiesel, and a triacetin. The experimental engine performance and 21 emission data was collected at 12 engine operating modes. Energy and exergy parameters were 22 calculated, and results showed that the use of oxygenated fuels can improve the thermal 23 efficiency leading to lower exhaust energy loss. Waste cooking biodiesel (B100) exhibited the 24 lowest exhaust loss fraction and highest thermal efficiency (up to 6% higher than diesel). 25 Considering the exergy analysis, lower exhaust temperatures obtained with oxygenated fuels 26 resulted in lower exhaust exergy loss (down to 80%) and higher exergetic efficiency (up to 27 10%). Since the investigated fuels were oxygenated, this study used the oxygen ratio (OR) 28 instead of the equivalence ratio to provide a better understanding of the concept. The OR has 29 increased with decreasing engine load and increasing engine speed. Increasing the OR 30 decreased the fuel exergy, exhaust exergy and destruction efficiency. With the use of B100, 31 there was a very high exergy destruction (up to 55%), which was seen to decrease with the 32 addition of triacetin (down to 29%).

This paper reports on the influence of jatropha biodiesel (JBD) addition to Fischer−Tropsch (FT) fuel on diesel engine performance and exhaust emissions. JBD was produced from Jatropha Carcus oil a...

This paper presents production of biodiesel (BD) from non-edible renewable karanja (Pongamia Pinnata) oil, determination of BD properties and influence of BD on engine performance and emissions. Bangladesh imports 2.4 million metric ton (MT) DF each year [M.N. Nabi, M.S. Akhter, K.M.F. Islam, Prospect of biodiesel production from jatropha curcas, a promising non edible oil seed in Bangladesh. International Conference on Mechanical Engineering (ICME, Dhaka, Bangladesh) Proceedings 2007, paper no. ICME07-TH-06. [1]]. It has 0.32 million hectare of unused land [M.N. Nabi, S.M.N. Hoque, M.S. Uddin, Prospect of Jatropha curcas and pithraj cultivation in Bangladesh. Journal of Engineering and Technology. IUT Dhaka, Bangladesh, 7 (1) (2009) 41-54.[2]]. It has been found that cultivating of karanja plant in such unused land; Bangladesh can reduce DF import by 28%. Karanja methyl ester (KME), which is termed as BD, has been produced by well-known transesterification process. The properties of B100 (B100) and its blends were determined mainly according to ASTM standard and some of them were as per EN14214 standard. The Fourier transform infrared (FTIR) analysis showed that the DF fuel contained mainly alkanes and alkens, while the B100 contained mainly esters. The gas chromatography (GC) of B100 revealed that a maximum of 97% methyl ester was produced from karanja oil. Engine experiment result showed that all BD blends reduced engine emissions including carbon monoxide (CO), smoke and engine noise, but increased oxides of nitrogen (NOx). Compared to DR B100 reduced CO. and smoke emissions by 50 and 43%, while a 15% increase in NOx emission was observed with the B100. Compared to DF, engine noise with B100 was reduced by 2.5 dB. (C) 2009 Elsevier B.V. All rights reserved.

The use of biodiesel is rapidly expanding around the world, making it imperative to fully understand the impacts of biodiesel on the diesel engine combustion process and pollutant formation. Biodiesel is known as the mono-alkyl-esters of long chain fatty acids derived from renewable feedstocks, such as, vegetable oils or animal fats, for use in compression ignition engines. Different parameters for the optimization of biodiesel production were investigated in the first phase of this study, while in the next phase of the study performance test of a diesel engine with neat diesel fuel and biodiesel mixtures were carried out. Biodiesel was made by the well known transesterification process. Cottonseed oil (CSO) was selected for biodiesel production. Cottonseed is non-edible oil, thus food versus fuel conflict will not arise if this is used for biodiesel production. The transesterification results showed that with the variation of catalyst, methanol or ethanol, variation of biodiesel production was realized. However, the optimum conditions for biodiesel production are suggested in this paper. A maximum of 77% biodiesel was produced with 20% methanol in presence of 0.5% sodium hydroxide. The engine experimental results showed that exhaust emissions including carbon monoxide (CO) particulate matter (PM) and smoke emissions were reduced for all biodiesel mixtures. However, a slight increase in oxides of nitrogen (NOx) emission was experienced for biodiesel mixtures.

This paper investigates diesel engine performance and exhaust emissions with marine gas oil (MGO) and a blend of MGO and synthetic diesel fuel. Ten per cent by volume of Fischer-Tropsch (FT), a synthetic diesel fuel, was added to MGO to investigate its influence on the diesel engine performance and emissions. The blended fuel was termed as FT10 fuel, while the neat (100 vol%) MGO was termed as MGO fuel. The experiments were conducted with a fourstroke, six-cylinder, turbocharged, direct injection, Scania DC 1102 diesel engine. It is interesting to note that all emissions including smoke (filter smoke number), total particulate matter (TPM), carbon monoxide (CO), total unburned hydrocarbon (THC), oxides of nitrogen (NOx) and engine noise were reduced with FT10 fuel compared with the MGO fuel. Diesel fine particle number and mass emissions were measured with an electrical low pressure impactor. Like other exhaust emissions, significant reductions in fine particles and mass emissions were observed with the FT10 fuel. The reduction was due to absence of sulphur and aromatic compounds in the FT fuel. In-cylinder gas pressure and engine thermal efficiency were identical for both FT10 and MGO fuels.