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.

A comprehensive review on biodiesel as an alternative energy resource and its characteristics

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.

Non-edible vegetable oils: A critical evaluation of oil extraction, fatty acid compositions, biodiesel production, characteristics, engine performance and emissions production

From a Novel

Annual Energy Outlook 2008 With Projections to 2030

The rapid depletion of conventional fossil fuels and day-by-day growth of environmental pollution due to use of extensive use of fossil fuels have raised concerns over the use of the fossil fuels; and thus search for alternate renewable and sustainable sources for fuels has started in the last few decades. In this context biomass derived fuels seems to be the promising path; and various routes are available for the biomass processing such as pyrolysis, transesterification, hydrothermal liquefaction, steam reforming, etc.; and the hydrothermal liquefaction (HTL) of wet biomass seems to be the promising route. Therefore, this article briefly enlightened a few concepts of HTL such as the elemental composition of bio-crude obtained by HTL, different types of feedstock adopted for HTL, mechanism of HTL processes, possible process flow diagrams for HTL of both wet and dry biomass and energy efficiency of the process. In addition, this article also enlisted possible future research scope for concerned researchers and a few of them are setting up HTL plant suitable for both wet and dry biomass feedstock; analysing influence of parameters such as temperature, pressure, residence time, catalytic effects, etc.; deriving optimized pathways for better conversion; and development of theoretical models representing the process to the best possible accuracy depending on nature of feedstock.

A review on hydrothermal liquefaction of biomass

Scheduling problems in an FMS have been considered as complex optimization problems whose solution by conventional techniques requires a great deal of efforts and time. In this paper, a simultaneous loading and scheduling of part and tool has been proposed for a flexible manufacturing system which has identical machines and a common tool magazine. All the tools are stored in the common tool magazine, and shared among the different machines through a material handling system. Each tool type is single in number. A modified genetic algorithm (MGA) with three parent crossover and a mutation operator is used to find the optimal solution of the loading and scheduling problem. The MGA uses an algorithm which is based on Giffler and Thompson procedure with a heuristic approach to resolve the job conflict and generate an active feasible schedule. The performance of the proposed algorithm is analyzed by comparing the makespan results with the results existing in literature. It is observed that the MGA yields better results than the algorithms reported so far. Furthermore, efficiency of MGA improves as the problem size increases.

Integrated scheduling of part and tool in a flexible manufacturing system using modified genetic algorithm

An Experimental Analysis of Biodiesel Production from Mixture of Neem (Azadirachta indica) Oil and Sesame (Sesamum indicum L.) Oil and its Performance and Emission Testing on a Diesel Engine

India is one of the fastest-growing economies in the world and requires a vast amount of energy which is mainly met by fossil fuels. India, however, spends a huge amount of foreign exchange for importing crude petroleum due to limited indigenous production. The diesel consumption in India is nearly four times higher than gasoline. It is widely used in locomotives, city transport buses, heavy trucks, electric generators, agricultural equipment, and underground mining equipment due to its versatility and higher efficiency. Diesel engines have the main environmental disadvantage of producing more soot particles and nitrogen oxides. They must also meet the stringent Euro VI emission standards, which are difficult to attain just by modifying the engine design. In this situation, higher alcohols such as butanol, pentanol, hexanol, and octanol have vast potential. Previous work on the use of lower alcohols as a blend with diesel in compression-ignition engines has suggested a reduction in emissions. However, problems such as phase separation and increased fuel consumption have also been encountered during the use of lower alcohols, e.g., ethanol in diesel engines. Higher alcohols have the potential to be used along with diesel to make a homogenous blend without any phase separation. They also have molecular oxygen present which improves the combustion and reduces emissions. Higher alcohols are sustainable and have the potential to address the issues of climate change and energy security. However, the use of these fuels in India is still in the early stage and large-scale production and adaptation will take its own time.

Higher Alcohols as Diesel Engine Fuel

Energy is an essential and vital input for social and economic development of any country. Increased consumption of fossil fuels and concern due to environmental pollution caused by fossil fuels are some of the major issues which led investigators all over the world to look for alternative renewable fuels and biodiesel produced from vegetable oils has been recognized world over as one of the strong contenders for reduction in exhaust emissions and to maintain energy equilibrium. In this experimental study an effort was made to find out the optimum combination of feasibility of four factors namely low percentage thumba biodiesel diesel blends, compression ratio, injection pressure and injection angle on single cylinder variable compression ratio diesel engine using Taguchi method and grey relational analysis. An L 9 orthogonal array was used to collect data for various engine performance and emission related responses at zero, intermediate and full engine loading conditions. In this study, since the process is multiple-response performance characteristics, therefore, the grey relational analysis that uses grey relational grade as performance index is specially adopted to determine the optimal combination of engine performance parameters. The results of the study revealed that combination of factors and their level comprising of a blend consisting of 30% thumba biodiesel (B30), a compression ratio of 14, an injection pressure of 250 bar and an injection angle of 20o produced maximum multiple-performance of a diesel engine together with minimum multiple-emissions from the engine.

Paper ID : 20100142 Optimization of Diesel Engine Performance Parameters by Applying Taguchi Method and Grey Relational Analysis

Biodiesel production via supercritical technology has been reported as a novel technology for transesterification of different vegetable oils. However, foods waste materials containing oil and other lingo-cellulosic materials such as waste orange peels have not been widely reported. In this experimental research, direct in-situ supercritical transesterification of waste orange peels into biodiesel was conducted. The reaction conditions for optimal biodiesel yield were determined using response surface Methodology (RSM). Finding from the results revealed that the optimal conversion obtained was 58.95% against 60.77% predicted obtained under the following reaction conditions-reactant molar ratio of 5/70, reaction time was 15 minutes while reaction temperature was 260°C. Temperature was the most significant factor. Predominant fatty acids identified include oleic and stearic acids with highly unsaturated acids identified as well. Fuels properties were within the standard limits except in few cases. It was concluded that supercritical transesterification of fresh Citrus Peel Waste CPW was viable for the production of biodiesel under the conditions stated.

Non-Catalytic In-Situ transesterification of Citrus Peel Waste into Biodiesel via Supercritical Technology: Optimisation by Response Surface Methodology

Naveen Kumar

Papers

Integrated scheduling of part and tool in a flexible manufacturing system using modified genetic algorithm

An Experimental Analysis of Biodiesel Production from Mixture of Neem (Azadirachta indica) Oil and Sesame (Sesamum indicum L.) Oil and its Performance and Emission Testing on a Diesel Engine

Higher Alcohols as Diesel Engine Fuel

Paper ID : 20100142 Optimization of Diesel Engine Performance Parameters by Applying Taguchi Method and Grey Relational Analysis

Non-Catalytic In-Situ transesterification of Citrus Peel Waste into Biodiesel via Supercritical Technology: Optimisation by Response Surface Methodology