Bio: K. Anand is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Diesel fuel & Biodiesel. The author has an hindex of 15, co-authored 25 publications receiving 863 citations. Previous affiliations of K. Anand include University of Wisconsin-Madison & Indian Institutes of Technology.
TL;DR: In this paper, a turbocharged, direct injection, multi-cylinder truck diesel engine fitted with a mechanical distributor type fuel injection pump using biodiesel-methanol blend and neat karanji oil derived biodiesel under constant speed and varying load conditions without altering injection timings.
Abstract: The increased focus on alternative fuels research in the recent years are mainly driven by escalating crude oil prices, stringent emission norms and the concern on clean environment. The processed form of vegetable oil (biodiesel) has emerged as a potential substitute for diesel fuel on account of its renewable source and lesser emissions. The experimental work reported here has been carried out on a turbocharged, direct injection, multi-cylinder truck diesel engine fitted with mechanical distributor type fuel injection pump using biodiesel-methanol blend and neat karanji oil derived biodiesel under constant speed and varying load conditions without altering injection timings. The results of the experimental investigation indicate that the ignition delay for biodiesel-methanol blend is slightly higher as compared to neat biodiesel and the maximum increase is limited to 1 deg. CA. The maximum rate of pressure rise follow a trend of the ignition delay variations at these operating conditions. However, the peak cylinder pressure and peak energy release rate decreases for biodiesel-methanol blend. In general, a delayed start of combustion and lower combustion duration are observed for biodiesel-methanol blend compared to neat biodiesel fuel. A maximum thermal efficiency increase of 4.2% due to 10% methanol addition in the biodiesel is seen at 80% load and 16.67 s−1 engine speed. The unburnt hydrocarbon and carbon monoxide emissions are slightly higher for the methanol blend compared to neat biodiesel at low load conditions whereas at higher load conditions unburnt hydrocarbon emissions are comparable for the two fuels and carbon monoxide emissions decrease significantly for the methanol blend. A significant reduction in nitric oxide and smoke emissions are observed with the biodiesel-methanol blend investigated.
TL;DR: In this article, the authors proposed surrogate models for the nine fuels for advanced combustion engines (FACE) that have been developed for studying low-emission, high-efficiency advanced diesel engine concepts.
Abstract: The fuels used in internal-combustion engines are complex mixtures of a multitude of different types of hydrocarbon species. Attempting numerical simulations of combustion of real fuels with all of the hydrocarbon species included is highly unrealistic. Thus, a surrogate model approach is generally adopted, which involves choosing a few representative hydrocarbon species whose overall behavior mimics the characteristics of the target fuel. The present study proposes surrogate models for the nine fuels for advanced combustion engines (FACE) that have been developed for studying low-emission, high-efficiency advanced diesel engine concepts. The surrogate compositions for the fuels are arrived at by simulating their distillation profiles to within a maximum absolute error of ∼4% using a discrete multi-component (DMC) fuel model that has been incorporated in the multi-dimensional computational fluid dynamics (CFD) code, KIVA-ERC-CHEMKIN. The simulated surrogate compositions cover the range and measured concen...
TL;DR: In this article, a convenient method of estimating the heating values of straight and processed vegetable oils based on the bond energies of their fatty acid/methyl ester constituents is proposed, and the accuracy of estimations when compared with the available experimental data is observed to be within 3%.
Abstract: Due to concerns regarding energy security, fuel cost, and the environment, straight and processed vegetable oils are being considered as part or full replacement of diesel fuel in compression ignition engines. The lower heating value of a candidate fuel is an important characteristic used in energy release estimation. In this work, a convenient method of estimating the heating values of straight and processed vegetable oils based on the bond energies of their fatty acid/methyl ester constituents is proposed. The estimated lower heating values of 17 different straight vegetable oils are on the order of 37 MJ/kg and for 15 different processed fuels on the order of 38 MJ/kg. The accuracy of estimations when compared with the available experimental data is observed to be within 3%.
TL;DR: In this paper, the effect of biodiesel fuel composition and properties on NOx emissions emanating from biodiesel fueled engines and describes fuel modifications and engine tuning measures for their mitigation, and the best possible ways for achieving biodiesel-NOx neutrality are outlined.
Abstract: Biodiesel fuels comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats serve as a potential alternative to fossil diesel. The biodiesel fueled engine does not require any major hardware modifications in the existing configuration. Also, the uses of biodiesel in compression ignition engines are found to significantly lower soot emissions. Thus, the conventional nitric oxide-soot trade-off problem narrows down to a unidirectional control of nitric oxide emissions which are generally known to increase with several candidate biodiesel fuels. The formation of oxides of nitrogen (NOx) from biodiesel fuel is dependent on both fuel and engine characteristics. The present work reviews the effect of biodiesel fuel composition and properties on NOx emissions emanating from biodiesel fueled engines and describes fuel modifications and engine tuning measures for their mitigation. The other outcomes of biodiesel NOx control measures in terms of engine performance and emission changes are also highlighted and the best possible ways for achieving biodiesel-NOx neutrality are outlined.
TL;DR: In this article, a comprehensive methodology for estimating the properties of biodiesel fuels based on their composition and chemical structure is proposed, which is used for compression ignition engine performance and emission analysis.
Abstract: Among the various alternative fuels, biodiesel is emerging as a promising choice for compression ignition engines due to its renewable nature and superior emission characteristics. The experimental investigations conducted by various researchers on variety of biodiesel fuels show a wide variation in engine performance and emission characteristics. The lack of correlations predicting various physical properties of biodiesel fuels derived from different feed stocks is posing a serious limitation to the combustion modelers. The present study attempts to evolve a comprehensive methodology for estimating the properties of biodiesel fuels based on their composition and chemical structure.
TL;DR: In this paper, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized, and it was shown that several fuel properties, including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics are highly correlated with the average unsaturation of the FA profiles.
Abstract: Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.
TL;DR: In this article, a detailed review has been conducted to highlight different related aspects to the biodiesel industry, including, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodies, the economical viability and finally the future of the future biodiesel.
Abstract: As the fossil fuels are depleting day by day, there is a need to find out an alternative fuel to fulfill the energy demand of the world. Biodiesel is one of the best available resources that have come to the forefront recently. In this paper, a detailed review has been conducted to highlight different related aspects to biodiesel industry. These aspects include, biodiesel feedstocks, extraction and production methods, properties and qualities of biodiesel, problems and potential solutions of using vegetable oil, advantages and disadvantages of biodiesel, the economical viability and finally the future of biodiesel. The literature reviewed was selective and critical. Highly rated journals in scientific indexes were the preferred choice, although other non-indexed publications, such as Scientific Research and Essays or some internal reports from highly reputed organizations such as International Energy Agency (IEA), Energy Information Administration (EIA) and British Petroleum (BP) have also been cited. Based on the overview presented, it is clear that the search for beneficial biodiesel sources should focus on feedstocks that do not compete with food crops, do not lead to land-clearing and provide greenhouse-gas reductions. These feedstocks include non-edible oils such as Jatropha curcas and Calophyllum inophyllum , and more recently microalgae and genetically engineered plants such as poplar and switchgrass have emerged to be very promising feedstocks for biodiesel production. It has been found that feedstock alone represents more than 75% of the overall biodiesel production cost. Therefore, selecting the best feedstock is vital to ensure low production cost. It has also been found that the continuity in transesterification process is another choice to minimize the production cost. Biodiesel is currently not economically feasible, and more research and technological development are needed. Thus supporting policies are important to promote biodiesel research and make their prices competitive with other conventional sources of energy. Currently, biodiesel can be more effective if used as a complement to other energy sources.
TL;DR: The use of non-edible plant oils is very significant because of the tremendous demand for edible oils as food source as mentioned in this paper, however, edible oils’ feedstock costs are far expensive to be used as fuel.
Abstract: World energy demand is expected to increase due to the expanding urbanization, better living standards and increasing population. At a time when society is becoming increasingly aware of the declining reserves of fossil fuels beside the environmental concerns, it has become apparent that biodiesel is destined to make a substantial contribution to the future energy demands of the domestic and industrial economies. There are different potential feedstocks for biodiesel production. Non-edible vegetable oils which are known as the second generation feedstocks can be considered as promising substitutions for traditional edible food crops for the production of biodiesel. The use of non-edible plant oils is very significant because of the tremendous demand for edible oils as food source. Moreover, edible oils’ feedstock costs are far expensive to be used as fuel. Therefore, production of biodiesel from non-edible oils is an effective way to overcome all the associated problems with edible oils. However, the potential of converting non-edible oil into biodiesel must be well examined. This is because physical and chemical properties of biodiesel produced from any feedstock must comply with the limits of ASTM and DIN EN specifications for biodiesel fuels. This paper introduces non-edible vegetable oils to be used as biodiesel feedstocks. Several aspects related to these feedstocks have been reviewed from various recent publications. These aspects include overview of non-edible oil resources, advantages of non-edible oils, problems in exploitation of non-edible oils, fatty acid composition profiles (FAC) of various non-edible oils, oil extraction techniques, technologies of biodiesel production from non-edible oils, biodiesel standards and characterization, properties and characteristic of non-edible biodiesel and engine performance and emission production. As a conclusion, it has been found that there is a huge chance to produce biodiesel from non-edible oil sources and therefore it can boost the future production of biodiesel.
TL;DR: This work reviews the recent status of methodologies and techniques related to the construction of digital twins mostly from a modeling perspective to provide a detailed coverage of the current challenges and enabling technologies along with recommendations and reflections for various stakeholders.
Abstract: Digital twin can be defined as a virtual representation of a physical asset enabled through data and simulators for real-time prediction, optimization, monitoring, controlling, and improved decision making. Recent advances in computational pipelines, multiphysics solvers, artificial intelligence, big data cybernetics, data processing and management tools bring the promise of digital twins and their impact on society closer to reality. Digital twinning is now an important and emerging trend in many applications. Also referred to as a computational megamodel, device shadow, mirrored system, avatar or a synchronized virtual prototype, there can be no doubt that a digital twin plays a transformative role not only in how we design and operate cyber-physical intelligent systems, but also in how we advance the modularity of multi-disciplinary systems to tackle fundamental barriers not addressed by the current, evolutionary modeling practices. In this work, we review the recent status of methodologies and techniques related to the construction of digital twins mostly from a modeling perspective. Our aim is to provide a detailed coverage of the current challenges and enabling technologies along with recommendations and reflections for various stakeholders.
TL;DR: In this paper, the authors introduced some species of non-edible vegetables whose oils are potential sources of biodiesel, such as Pongamia pinnata (karanja), Calophyllum inophyllus (Polanga), Maduca indica (mahua), Hevea brasiliensis (rubber seed), Cotton seed, Simmondsia chinesnsis (Jojoba), Nicotianna tabacum (tobacco), Azadirachta indica, Linum usitatissimum (Linseed)
Abstract: Energy demand is increasing dramatically because of the fast industrial development, rising population, expanding urbanization, and economic growth in the world. To fulfill this energy demand, a large amount of fuel is widely used from different fossil resources. Burning of fossil fuels has caused serious detrimental environmental consequences. The application of biodiesel has shown a positive impact in resolving these issues. Edible vegetable oils are one of the potential feedstocks for biodiesel production. However, as the use of edible oils will jeopardize food supplies and biodiversity, non-edible vegetable oils, also known as second-generation feedstocks, are considered potential substitutes of edible food crops for biodiesel production. This paper introduces some species of non-edible vegetables whose oils are potential sources of biodiesel. These species are Pongamia pinnata (karanja), Calophyllum inophyllum (Polanga), Maduca indica (mahua), Hevea brasiliensis (rubber seed), Cotton seed, Simmondsia chinesnsis (Jojoba), Nicotianna tabacum (tobacco), Azadirachta indica (Neem), Linum usitatissimum (Linseed) and Jatropha curcas (Jatropha). Various aspects of non-edible feedstocks, such as biology, distribution, and chemistry, the biodiesel’s physicochemical properties, and its effect on engine performance and emission, are reviewed based on published articles. From the review, fuel properties are found to considerably vary depending on feedstocks. Analysis of the performance results revealed that most of the biodiesel generally give higher brake thermal efficiency and lower brake-specific fuel consumption. Emission results showed that in most cases, NOx emission is increased, and HC, CO, and PM emissions are decreases. It was reported that a diesel engine could be successfully run and could give excellent performance and the study revealed the most effective regulated emissions on the application of karanja, mahua, rubber seed, and tobacco biodiesel and their blends as fuel in a CI engine.