• Energy Research

Abstract Combustion of fossil fuels has a significant share in producing harmful emissions in the global emission context. With a threat of fossil fuel crisis and the necessity of reducing emission from diesel engine combustion system, biodiesel is considered as one of the key environmentally-friendly diesel fuel alternatives. In this study, sunflower biodiesel has been considered as a key ingredient to infuse waste plastic (polystyrene, PS) as another cleaner source of hydrocarbon fuel in the diesel engines. Polystyrene was infused (5% w/v) into sunflower biodiesel to produce a blend of diesel-biodiesel-polymer (DBP) fuel. The emission characteristics of the diesel, diesel–biodiesel (binary blend) and diesel-biodiesel-polymer (ternary blend) were compared in an unmodified diesel engine. The results showed that the emission compositions of the DBP were comparable to those of diesel which effectively reduced the NOx emission, as compared to diesel-biodiesel blend. In addition, the brake specific fuel consumption (BSFC) and CO emission were reduced in DBP, as compared to biodiesel and diesel fuels. Based on these results, it can be concluded that the polymer blended fuels could be potentially used as another emission reducing fuel source in an unmodified diesel engine. The utilisation of waste polymers in biodiesel production could help find an alternative use for non-recyclable plastics, while also contributing to cleaner emission.

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.

Abstract In this study, three potential wind sites such as Hamilton Island, Proserpine, and South Johnstone wind speed data has been analyzed using Weibull distribution. The half-hourly time series wind speed data used in this analysis were obtained from Bureau of Meteorology, Australia wind monitoring stations. With the aim assessing the wind energy potential, method of moments (MOM), empirical method (EM), and power density method (PDM) were employed for determining the Weibull factors of the available data. The accuracy of the results was analyzed using a statistical test tool named chi-square error (χ2). The EM method was found to be the best method among the three studied methods for calculating Weibull parameters. Based on the analyzed data, a horizontal axis wind turbine specification was proposed. Finally, wind power profile of Hamilton Island site was evaluated for the proposed turbine specification.

Abstract 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.

Utilising pyrolysis as a waste tyre processing technology has various economic and social advantages, along with the fact that it is an effective conversion method. Despite extensive research and a notable likelihood of success, this technology has not yet seen implementation in industrial and commercial settings. In this review, over 100 recent publications are reviewed and summarised to give attention to the current state of global tyre waste management, pyrolysis technology, and plastic waste conversion into liquid fuel. The study also investigated the suitability of pyrolysis oil for use in diesel engines and provided the results on diesel engine performance and emission characteristics. Most studies show that discarded tyres can yield 40–60% liquid oil with a calorific value of more than 40 MJ/kg, indicating that they are appropriate for direct use as boiler and furnace fuel. It has a low cetane index, as well as high viscosity, density, and aromatic content. According to diesel engine performance and emission studies, the power output and combustion efficiency of tyre pyrolysis oil are equivalent to diesel fuel, but engine emissions (NOX, CO, CO, SOX, and HC) are significantly greater in most circumstances. These findings indicate that tyre pyrolysis oil is not suitable for direct use in commercial automobile engines, but it can be utilised as a fuel additive or combined with other fuels.

AbstractEver 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 feedstocks, are the most appropriate alternative of petroleum fuels. However, direct using of ethanol in diesel fuel face some technical problem especially in cold weather, due to low cetane number, lower flash point and poor solubility. Biodiesel can be blended with both ethanol and diesel fuel and biodiesel–alcohol–diesel blends can be used in diesel engines. The aim of this review paper is to discuss the effect of mixed blends of biodiesel alcohol and diesel on engine performance and emission parameters of a diesel engine. Most of the researchers reported that adding ethanol into biodiesel-diesel blend in diesel engines significantly reduce HC, PM, NOx and smoke emissions but slightly increase fuel consumption. The study concluded that biodiesel-diesel-ethanol blend can be used as a substitute of petro-diesel fuel to reduce dependency on fossil fuel as well as the exhaust emissions of the engine.

Abstract The prospect of biofuels as a transport alternative fuel in Australia is reviewed and discussed in this paper. The Australian transport sector is the second largest energy consuming sector which consumes about 24% of total energy consumption. A part of this energy demand can be met by ecofriendly biofuels. A wide array of different biofuels feedstocks including Australian native species, their distributions, oil content, traditional uses are reviewed and listed in the descending order of their oil content. The world biofuel scenario as well as the 20 largest biofuel production countries and their mandates on biofuels blending with petroleum diesel are presented. Australia’s biofuel production, consumption, production facilities and future investment projects are also reviewed and discussed. The study developed a biofuel supply chain for Australia and found that the second generation biofuels have better prospects as a future alternative transport fuel in Australia. These biofuel feedstocks are readily available and can overcome the shortcomings of the first generation biofuels, such as socio-economic, environmental and food versus land use challenges. Although some research is in progress, further study is needed on the process development of second generation biofuel production at commercial scale in Australia and abroad.