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

Flow Simulation and Theoretical Investigation on Aerodynamics of NACA-2415 Aerofoil at Low Reynolds Number

The quest of moving from conventional diesel fuels to alternate fuels is never‐ending. Renewable diesel stands out as it has a similar molecular structure to that of diesel. Renewable diesel from hydroprocessing of Jatropha oil in presence of ruthenium catalyst is not much researched and the same has been worked upon in this paper. The objective of this paper is to analyze physiochemical properties of renewable diesel (R100), biodiesel (B100), and blends of diesel (D100) and renewable diesel and to check the operational feasibility. Renewable diesel was mixed in 10%, 20%, 30%, 40%, and 50%, by volume in diesel. It was observed that renewable diesel had better cold flow properties than diesel. Calorific value (CV) of renewable diesel and biodiesel was 1.84% and 3.92% less than diesel respectively. Present study shows up to 30% renewable diesel in diesel is a substitute fuel, as their viscosities (2.55, 2.60, 2.64cSt), densities (834.4 kg/m3, 831.87 kg/m3, 830.6 kg/m3) and CVs (42.42 MJ/kg, 42.30 MJ/kg, 42.09 MJ/kg) are close to diesel (2.42cSt, 837 kg/m3 and 42.57 MJ/kg). This is also confirmed by a storage stability test conducted for 24 weeks. Cetane number of blends of R100 greater than 30% are found to be high; this can interfere with engine power output hence requiring amendments in current engines, which is not possible, therefore it is feasible to use blends only up to 30% of R100. GC–MS and Fourier transform infrared radiation showed a higher number of hydrocarbon atoms with diminutive oxygen percentage in R100, vis‐a‐vis, higher levels of unsaturation with more oxygen in B100.

Comparative analysis of renewable diesel and biodiesel produced from Jatropha oil

Many biofuels extracted from the trees can be directly used as a fuel without any major treatment processes. Among these biofuels the pine and eucalyptus oil have low viscosity and other properties...

Naveen Kumar

Papers

Flow Simulation and Theoretical Investigation on Aerodynamics of NACA-2415 Aerofoil at Low Reynolds Number

Comparative analysis of renewable diesel and biodiesel produced from Jatropha oil

Synergistic Effect of Pine Oil and Eucalyptus Oil on the Performance of a Compression Ignition Engine

Synthesis of Linseed oil Biodiesel using a Non-Catalytic Supercritical Transesterification Process

Utilization of Blends of Biodiesel and Higher Alcohols in a Small Capacity Diesel Engine