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Over the years, oxygenated fuels such as biodiesel and alcohol fuels have been useful in reducing particulate matter (PM) emissions of diesel engines. The presence of oxygen in the fuel impacts the soot oxidation process and thus the morphology and nanostructural characteristics of soot particles change. The nanostructure characteristics of soot particles hold an importance for their oxidation reactivity and toxicity. Higher reactivity and exposure of soot particles to oxygen will affect the regeneration and filtration efficiency of diesel particulate filters. In this study, we investigate the impact of oxygen functional groups on morphology and nanostructure of soot particles by blending different types of essential oil in diesel. The test fuels were prepared by mixing orange oil, tea tree oil, eucalyptus oil and coconut biodiesel to keep an overall oxygen content of 0 and 2.2%. Transmission electron microscopy was used to investigate the physical changes in the nanostructure of soot particles. The primary particle diameter decreases, and fractal dimension of soot aggregates increases for oxygenated fuels. Microscopy reveals that the arrangement of carbon lamellae within the soot particles changes significantly with use of oxygenated as observed by the changes in fringe length, fringe tortuosity and fringe separation distance. Lower fringe length, higher fringe tortuosity and fringe separation distance shows disordered arrangement of carbon layers with more possibility of oxygen attack. The different structural characteristics for oils having same oxygen content shows that formation and structure of soot particles strongly depend upon chemical structure and composition of the fuel.

Metallic composition of diesel particulate matter, even though a relatively small proportion of total mass, can reveal important information regarding engine conditions, fuel/lubricating oil characteristics and for health impacts. In this study, a detailed investigation into the metallic elemental composition at different particle diameter sizes has been undertaken. A bivariate statistical analysis was performed in order to investigate the correlation between the metallic element, measured engine performance and engine emission variables. Major sources of metallic elements in the emitted particles are considered in this study, including the fuel and lubricating oil compositions, engine wear emissions and metal-containing dust in the ambient air. Metallic solid ultrafine-particles (Dp < 100 nm) are strongly associated with metallic compounds derived from lubricating oil (Ca, Zn, Mg and K), while the fuel related metallic compounds and engine wear emissions are represented in the accumulation mode particle fraction (> 100 nm). Calculated correlation matrices show a clear effect of engine load conditions and fuel S contents on particle number and mass emissions.

Laser micro texturing technique has shown its potential in reducing friction and wear at various mechanical interfaces such as automotive and cutting tools etc.. Automotive parts are coated with Diamond-like Carbon (DLC) coatings to enhance their performance. Due to stringent condition at the automotive contacts and demand for performance enhancement, increase in performance of DLC coatings is required. In this study laser micro texturing is being combined with tungsten doped DLC coating. In order to analyze the benefits of laser micro texturing on tungsten doped DLC coating. Tribological testing was conducted on a reciprocating test rig at various loading conditions. The results indicated that laser textured tungsten doped DLC coating showed the lower coefficient of friction compared to un-textured tungsten doped DLC coating at a load of 15 N, 25 N and 35 N. Higher graphitization was observed in the case of un-textured coating at 35 N load.

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 like lihood of their utilization in CI engines in the future.

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.

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.

Physico-chemical properties of microalgae biodiesel depend on the microalgae species and oil extraction method. Dioctyl phthalate (DOP) is a clear, colourless and viscous liquid as a plasticizer. It is used in the processing of polyvinyl chloride (PVC) resin and polymers. A new potential biofuel, hydrothermally liquefied microalgae bio-oil can contain nearly 11% (by mass) of DOP. This study investigated the feasibility of using up to 20% DOP blended in 80% diesel fuel (v/v) in an existing diesel engine, and assessed the performance and exhaust emissions. Despite reasonable differences in density, viscosity, surface tension, and boiling point, blends of DOP and diesel fuel were found to be entirely miscible and no separation was observed at any stage during prolonged miscibility tests. The engine test study found a slight decrease in peak cylinder pressure, brake, and indicated mean effective pressure, indicated power, brake power, and indicated and brake thermal efficiency with DOP blended fuels, where the specific fuel consumption increased. This is due to the presence of 16.4% oxygen in neat DOP, responsible for the relatively lower heating value, compared to that of diesel. The emission tests revealed a slight increase in nitrogen oxides (NOx) and carbon monoxide (CO) emissions from DOP blended fuels. However, particulate matter (PM) emissions were lower from DOP blended fuels, although some inconsistency in particle number (PN) was present among different engine loads.

As a potential means of offsetting diesel fuel usage and reducing the environmental impact of used tyres, this study investigates the NOx emissions of a modern commercial passenger vehicle run on a blend of diesel and tyre pyrolysis oil (TPO). The test vehicle was driven on a route representative of the driving expected by a courier. Vehicle drivability with the TPO/diesel blend, compared to neat diesel, was not reported to be perceived differently by the automotive industry experienced driver. Additionally, the NOx emissions were comparable between the neat diesel trip and those run on the blend of TPO/diesel. Interestingly, the results showed that short transients had a substantive impact on aggregate NOx emissions—making conclusive on-road comparisons between fuels difficult. Despite this, the data collected for this study indicate that there is no substantive NOx emissions degradation when running the TPO/diesel blend.

This study reports on a turbo-charged diesel engine performance, combustion and exhaust emissions when fuelled with three non-edible biodiesel blends, a neat waste cooking biodiesel (WBD100) and a neat reference diesel (D100). Waste cooking biodiesel was chosen as the non-edible biodiesel for its availability and low cost. Diethylene glycol dimethyl ether (DGM) was introduced as an additive owing to its superior ignitability and high oxygen content. The three blends tested in this investigation were 70/30/0, 70/20/10 and 70/10/20 in proportions of diesel/waste cooking biodiesel/DGM. In all cases, a commercial diesel was taken as the reference fuel for comparative discussion about parameters of the engine performance, combustion and exhaust emissions. A fully-instrumented, 4-stroke, 6-cylinder, turbocharged diesel engine was utilised for the experiments. Without significantly deteriorating engine performance, the three biodiesel blends and WBD100 reduced both particulate matter (PM) and particulate number (PN) emissions remarkably with the expected increase of nitrogen oxides (NOx) emissions.

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 i

Particle emission characteristics and engine performance were investigated from an auxiliary, heavy duty, six-cylinder, turbocharged and after-cooled diesel engine with a common rail injection system using spiked fuels with different combinations of sulphur (S) and vanadium (V) spiking. The effect of fuel S content on both particle number (PN) and mass (PM) was clearly observed in this study. Higher PN and PM were observed for fuels with higher S contents at all engine load conditions. This study also found a correlation between fuel S content and nucleation mode particle number concentration which have more harmful impact on human health than larger particles. The highest PN and PM were observed at partial load conditions. In addition, S in fuel resulted in higher viscosity of spiked fuels, which led to lower engine blow-by. Fuel V content was observed in this study, evidencing that it had no clear effect on engine performance and emissions. Increased engine load also resulted in higher engine blow-by. The lower peak of in-cylinder pressure observed at both pre-mixed and diffusion combustion phases with the spiked fuels may be associated with the lower energy content in the fuel blends compared to diesel fuel.

Biomass is a promising sustainable and renewable energy source, due to its high diversity of sources, and as it is profusely obtainable everywhere in the world. It is the third most important fuel source used to generate electricity and for thermal applications, as 50% of the global population depends on biomass. The increase in availability and technological developments of recent years allow the use of biomass as a renewable energy source with low levels of emissions and environmental impacts. Biomass energy can be in the forms of biogas, bio-liquid, and bio-solid fuels. It can be used to replace fossil fuels in the power and transportation sectors. This paper critically reviews the facts and prospects of biomass, the pyrolysis process to obtain bio-oil, the impact of different pyrolysis technology (for example, temperature and speed of pyrolysis process), and the impact of various reactors. The paper also discusses different pyrolysis products, their yields, and factors affecting biomass products, including the present status of the pyrolysis process and future challenges. This study concluded that the characteristics of pyrolysis products depend on the biomass used, and what the pyrolysis product, such as bio-oil, can contribute to the local economy. Finally, more research, along with government subsidies and technology transfer, is needed to tackle the future challenges of the development of pyrolysis technology.

The potential use of waste stream essential oils were evaluated as fuel supplements for diesel vehicle/machinery used by producers of these oils. Orange, eucalyptus and tea tree oils were selected; which are native to and/or extensively cultivated throughout Australia. These essential oils are mainly used in the medical and natural therapy sector as well as fragrance and flavouring industry. The high quality of the final product leads to a significant very low value waste stream. Engine performance and emissions evaluation showed that essential oils are comparable to diesel fuel. Their use will help to reduce diesel dependency and fuel costs.

In 2014, global demand for essential oils was 165 kt and it is expected to grow 8.5% per annum up to 2022. Every year Australia produces approximately 1.5k tonnes of essential oils such as tea tree, orange, lavender, eucalyptus oil, etc. Usually essential oils come from non-fatty areas of plants such as the bark, roots, heartwood, leaves and the aromatic portions (flowers, fruits) of the plant. For example, orange oil is derived from orange peel using various extraction methods. Having similar properties to diesel, essential oils have become promising alternate fuels for diesel engines. The present study explores the opportunity of using sweet orange oil in a compression ignition engine. Blends of sweet orange oil-diesel (10% sweet orange oil, 90% diesel) along with neat diesel fuel were used to operate a six-cylinder diesel engine (5.9 litres, common rail, Euro-III, compression ratio 17.3:1). Some key fuel properties such as: viscosity, density, heating value, and surface tension are presented. Engine performance (brake specific fuel consumption) and emission parameters (CO, NOX, and Particulate Matter) were measured to evaluate running with the blends. The engine was operated at 1500 rpm (maximum torque condition) with different loads. The results from the property analysis showed that sweet orange oil-diesel blend exhibits lower density, viscosity and surface tension and slightly higher calorific value compared to neat diesel fuel. Also, from the engine test, the sweet orange oil-diesel blend exhibited slightly higher brake specific fuel consumption, particulate mass and particulate number; however, the blend reduced the brake specific CO emission slightly and brake specific NOX emission significantly compared to that of neat diesel.

This paper builds on previous work using surrogate fuel to investigate advanced internal combustion engine fuels. To date, a surrogate fuel of this nature has not been used for microalgae hydrothermal liquefaction (HTL) biocrude. This research used five different chemical groups found in microalgae HTL biocrude to design a surrogate fuel. Those five chemical groups constitute around 65% (by weight) of a microalgae biocrude produced by HTL. Weight percentage of the microalgae HTL biocrude chemical compounds were used to design the surrogate fuel, which was miscible with diesel at all percentages. The engine experiments were conducted on a EURO IIIA turbocharged common-rail direct-injection six-cylinder diesel engine to test engine performance and emissions. Exhaust emissions, including particulate matter and other gaseous emissions, were measured with the surrogate fuel and a reference diesel fuel. Experimental results showed that without significantly deteriorating engine performance, lower particulate mass, particulate number and CO emissions were observed with a penalty in NOx emissions for all surrogate blends compared to those of the reference diesel.

Liquefied natural gas (LNG) projects are regulated by host countries, but policy and regulation should depend on geography and meteorology. Without considering the role of geography and meteorology, sub-optimal design choices can result, leading to energy conversion efficiency and capital investment decisions that are less than ideal. A key step in LNG is regasification, which transforms LNG back from liquid to the gaseous state and requires substantial heat input. This study investigated different LNG regasification technologies used around the world and benchmarked location and meteorology-related factors, such as seawater temperatures, ambient air temperatures, wind speeds and relative humidity. Seawater vaporizers are used for more than 95% of locations subject to water quality. Ambient air conditions are relatively better for South America, India, Spain and other Asian countries (Singapore, Taiwan, Indonesia, and Thailand) and provide a much cleaner regasification technology option for natural and forced draft systems and air-based intermediate fluid vaporizers. On a global basis, cold energy utilization currently represents <1% of the total potential, but this approach could deliver nearly 12 Gigawatt (GW) per annum. Overall, climate change is expected to have a positive financial impact on the LNG regasification industry, but the improvement could be unevenly distributed.

This investigation deals with the production of Alexandrian laurel (Calophyllum inophyllum) biodiesel (ALB) and study of the effects of its fatty acid methyl ester (FAME) compositions and physicochemical properties on the engine performance, combustion, and emissions. The experiment had been conducted in a four cylinder turbocharged diesel engine under varying speeds and full loading condition. 10% (ALB10) and 20% (ALB20) blends of Alexandrian laurel biodiesel along with the Diesel and B5 fuel (95% diesel and 5% palm biodiesel) were used for this experiment. ALB consisted of 31.6% saturated and 68.4% unsaturated FAME. Longer chain fatty acids and 10.9% oxygen content of ALB greatly influenced the engine combustion and emission characteristics. Brake specific fuel consumption (bsfc) was found on average 6%-20% higher for B5, ALB10, and ALB20 blends compared to diesel fuel. It was observed that ALB operation shortened the ignition delay period, increased the mass fraction burnt (MFB), and reduced the pick cylinder pressure, heat release rate (HRR) and combustion duration. CO and HC emissions were decreased significantly while operating on B5, ALB10, and ALB20 blends compared to diesel fuel. ALB blends produced on average, 2.5%-3% higher NOx emissions with respect to diesel fuel.

The present research is aimed to investigate the feasibility of using palm (PB), mustard (MB) and Calophyllum biodiesel (CB) as renewable and alternative fuels. Biodiesels were produced from the respective crude vegetable oils and physicochemical properties of the biodiesel-diesel blends were graphically compared for all possible biodiesel blends at every 10% composition interval. By applying the curve-fitting method, equations were developed for predicting important properties, which show very close fit to the experimental data. This will help future research such as the optimization of blending percentage, engine combustion and performance and emission analysis. As up to 20% blends of biodiesels showed similar properties to diesel fuel, the engine performance and emission of the 10% and 20% biodiesel-diesel blends were studied for all three feedstocks, as well as diesel fuel, to perform a comparative study. An average of 7-12% BSFC increment was observed for biodiesel blends compared to diesel fuel. The brake power was decreased on average of 4.1-7.7% while operating on the biodiesel blends. Nitric oxide (NO) emission increased 9-17% and hydrocarbon and carbon monoxide (CO) emission showed improved results for the biodiesel blends. An average of 23-43% lower HC and 45-68% lower CO emission resulted from the biodiesel blends compared to those from diesel fuel.

The transportation, agricultural, and power sector of Bangladesh is largely dependent on fossil fuels that decrease day by day. The government has to import large volumes of fuel from foreign sources to meet the fuel demand for power production, causing a negative impact on the country's economy. Finding an alternative to fossil fuels is becoming the most urgent issue. Biodiesel can thus be a destined source to future energy demands. Increasing the usage of biodiesel will also decrease the global problem of environmental pollution, as fossil fuels are considered to be the major source of harmful emissions. Biodiesel is renewable, bio-degradable, non-toxic, technologically feasible, and can be used as a bio-lubricant In this study, the current energy scenario of Bangladesh, available potential biodiesel feedstocks, production process and engine fuel property, environmental impact, performance and emission characteristics on diesel engines, comparison of cost analysis, and future direction are discussed. Various research related to these feedstocks are performed in Bangladesh, which include an overview of biodiesel properties, engine performance, and emission parameters used in diesel engines. All types of biodiesel have similar functional properties compared with diesel fuel and can be successfully used in compression ignition engines. Biodiesel can thus serve as a subsequent replacement of non-renewable fossil fuels. Compared with diesel fuel, CO and HC emission were also low, but a slight increase in NOx was observed in some cases. One of the major advantages is that Bangladesh is a country with plenty of biodiesel feedstock sources, such as mustered, Jatropha curcas, rapeseed, sesame, castor, cottonseed, neem, algae, coconut, and groundnut In conclusion, producing biodiesel from different feedstocks is greatly possible and can thus assist in future energy needs. (C) 2015 Elsevier Ltd. All rights reserved.

This study focuses on the physicochemical fuel characteristics and engine performance-emission features of three prospective alternative transportation fuels: Alexandrian laurel biodiesel (ALBD), jatropha biodiesel (JBD) and GTL fuel at high idling conditions. The blends of GTL fuel (G10, G20), JBD (J10, J20) and ALBD (AL10, AL20) with diesel had been investigated in a multi-cylinder diesel engine at different load-speed conditions. Analysis of the fuel properties showed a linear variation of the major fuel properties with an increase of alternative fuel quantity in the blends. Engine performance test results revealed an average decrease of brake specific fuel consumption (BSFC) (ca. 8.65–12.26%) and brake specific energy consumption (BSEC) (ca. 8.27–11.51%), but a higher brake thermal efficiency (BTE) (ca. 8.56–12.58%) by GTL blends, whereas, the biodiesel blends showed higher BSFC (ca. 5.01–12.18%) and BSEC (ca. 3.41–9.67%) and lower BTE (ca. 3.68–9.93%), respectively, than those of diesel. Referring to the emission analysis, the results revealed that GTL blends showed a slight reduction in NOx (ca. 3.89–6.85%), but a significant reduction in CO (ca. 48.25–51.38%), HC (ca. 44.81–51.43%) and smoke (ca. 15.21–18.78%), respectively, when compared to diesel. The biodiesel blends demonstrated reduced CO (on average ca. 29.12–33.71%), HC (ca. 29.67–35.46%) and smoke (ca. 2.49–6.87%), but increased NOx (on average ca. 2.83–9.81%), respectively, than those of diesel.

Present energy situation of the world is unsustainable due to unequal geographical distribution of natural wealth as well as environmental, geopolitical and economical concerns. Ever increasing drift of energy consumption due to growth of population, transportation and luxurious lifestyle has motivated researchers to carry out research on biofuel as a sustainable alternative fuel for diesel engine. Biofuel such as biodiesel and ethanol, produced from renewable feedstock's, are the most appropriate alternative of petroleum fuels. Government of many countries has set a target to use biofuel in transportation and industrial sectors to reduce the fossil fuel demand in their countries. This report compiled the findings on global energy scenario, potential of biofuel as a renewable energy source, biofuel policy and target of some selected countries and the effect of mixed blends of biofuel and diesel on engine performance and emission parameters of a diesel engine. The study concluded that the energy consumption and CO2 emissions in ASEAN countries increasing day by day. To reduce the energy consumption and harmful gasses emission to the environment, government of ASEAN countries have set target to use biofuel in diesel engines as biofuel-diesel blend have potential to reduce dependency on fossil fuel as well as the exhaust emissions of the engine.

Diesel engine emissions produced during burning of fossil fuel are extremely accountable for numerous serious problems. In order to lessen these emissions, performance of diesel engine needs to be improved. Fuel injection pressure is one of the operating parameters that affects the performance and emissions of a diesel engine which has been reported in this review paper. Decrease in injection pressure results in inferior combustion which leads to increase in BSFC and decrease in BTE. Injection pressure increase results in better mixing of air and fuel. As a result, combustion improves which leads to reduced BSFC and increased BTE. Due to superior air–fuel mixture resulting from increase in injection pressure, CO and HC emission decreases. Also, exhaust gas temperature decreases too. Increase in injection pressure results in increased heat release rate which leads increase in NOx emission. Literatures reports that, increasing the injection pressure results in up to 18% and 9% reduction of BSFC and EGT. Furthermore, it is possible to achieve more than 50% CO and HC and 28% NOx emission reduction by increasing the fuel injection pressure.