Biodiesel production from non-edible plant oils

Because of biodegradability and nontoxicity biodiesel has become more attractive as alternative fuel. Biodiesel is produced mainly from vegetable oils by transesterification of triacylglycerols. From economic and social reasons, edible oils should be replaced by lower-cost and reliable feedstocks for biodiesel production such as non-edible plant oils. This paper reviews various methods for biodiesel production from common non-edible oils employing alcoholysis reactions. The aim of this paper is to present the possibilities of the use of non-edible oils into biodiesel production, to consider the various methods for treatment of non-edible oils and to emphasize the influence of the operating and reaction conditions on the process rate and the ester yield. The special attention is paid to the possibilities of optimization, kinetics and improvement of biodiesel production from non-edible oils.     

Performance and emission evaluation of a diesel engine fueled with methyl esters of rubber seed oil

Recent concerns over the environment, increasing fuel prices and scarcity of its supply have promoted the interest in development of the alternative sources for petroleum fuels. At present, biodiesel is commercially produced from the refined edible vegetable oils such as sunflower oil, palm oil and soybean oil, etc. by alkaline-catalyzed esterification process. This process is not suitable for production of biodiesel from many unrefined non-edible vegetable oils because of their high acid value. Hence, a two-step esterification method is developed to produce biodiesel from high FFA vegetable oils. The biodiesel production method consists of acid-catalyzed pretreatment followed by an alkaline-catalyzed transesterification. The important properties of methyl esters of rubber seed oil are compared with other esters and diesel. Pure rubber seed oil, diesel and biodiesel are used as fuels in the compression ignition engine and the performance and emission characteristics of the engine are analyzed. The lower blends of biodiesel increase the brake thermal efficiency and reduce the fuel consumption. The exhaust gas emissions are reduced with increase in biodiesel concentration. The experimental results proved that the use of biodiesel (produced from unrefined rubber seed oil) in compression ignition engines is a viable alternative to diesel.     

Economic feasibility of algal biodiesel under alternative public policies

The motivation for this research was to determine the influence of public policies on economic feasibility of producing algal biodiesel in a system that produced all its energy needs internally. To achieve this, a steady-state mass balance/unit operation system was modeled first. Open raceway technology was assumed for the production of algal feedstock, and the residual biomass after oil extraction was assumed fermented to produce ethanol for the transesterification process. The project assumed the production of 50 million gallons of biodiesel per year and using about 14% of the diesel output to supplement internal energy requirements. It sold the remainder biodiesel and ethanol as pure biofuels to maximize the rents from the renewable fuel standards quota system. Assuming a peak daily yield of 500 kg algal biomass (dry basis)/ha, the results show that production of algal biodiesel under the foregoing constraints is only economically feasible with direct and indirect public policy intervention. For example, the renewable fuel standards' tracking RIN (Renewable fuel Identification Number) system provides a treasury-neutral value for biofuel producers as does the reinstatement of the renewable fuel tax credit. Additionally, the capital costs of an integrated system are such that some form of capital cost grant from the government would support the economic feasibility of the algal biodiesel production.     

Biodiesel production from renewable feedstocks: Status and opportunities

The increased demand for energy, climate change, and energy security concerns has driven the research interest for the development of alternative fuel from plant origin. Biodiesel derived from plant oils, which include edible and non-edible oil have gained interest for the last two decades as alternative for diesel around the world. Among these plant origin oils more than 95% of biodiesel production feedstocks come from edible oils, because they are readily available in many regions. The major advantage of these feedstocks is the properties of biodiesel produced from them are suitable to be used as diesel fuel substitute. But the consequence is the increase demand of the feedstock for food as well as fuel. A sustainable alternative fuel should be derived from renewable non-food biomass sources. The main objective of this review is to give an overview on the synthesis of biodiesel through esterification and transesterification using non-edible oil resources which are available in India, and available processes for synthesis of biodiesel (acid-, base-catalyzed transesterification reactions (homogeneous and heterogeneous), their importance, and which is the commercial process also discussed here.     

Production characterization and efficiency of biodiesel: a review

Vegetable oil is one of the main first generation liquid biofuels. The fuel characteristics of vegetable oil such as viscosity and atomization cannot be accommodated by existing diesel engines. An alternate process has been developed to improve the fuel characteristics of vegetable oils through the process of alcoholysis to produce a fuel called biodiesel. It can be used in engines as substitute for fossil fuel. This paper reviews the characteristics of different oils available for biodiesel production and the production technologies, engine performance using vegetable oil and biodiesel, and emission studies. Copyright © 2014 John Wiley & Sons, Ltd.     

Biodiesel resources and production technologies – A review

The environmental concern and availability of fuels are greatly affecting the trends of fuels for transportation vehicles. Biodiesel is one of the options as alternative transport fuel. This can be produced from straight vegetable oils (SVOs), oils extracted from various plant species and animal fats. Amongst many resources, availability and cost economy are the major factors affecting the large scale production of the biodiesels. The transesterification is one of the production processes for biodiesel, but incomplete esterification of all fatty acids in the starting material, lengthy purification methods such as water washing, relatively long reaction times, contamination and separation difficulties associated with co-production of glycerol and saponification of the starting material under certain reaction conditions are still being major challenges in the biodiesel production. Technological advancement and enhanced production methods are the demand of present time for large scale and sustainable production of biodiesel. In the present paper, comprehensive review on its production process, feed stock and its applications have been made. From many case studies it was concluded that engine performance with B20 biodiesel blends, and mineral diesel were found comparable.     

A review on microwave-assisted production of biodiesel

Energy is the most important necessity for human existence on the earth. Limited crude petroleum resources and increasing awareness regarding the environmental impacts of fossil fuels are driving the search for new energy sources and alternative fuels. Biodiesel is a fuel which is renewable, biodegradable, environmentally friendly, and non-toxic in nature and has attracted considerable attention during the past decades. The costs of feedstock and the production process are two major hurdles to large-scale biodiesel production in particular. Various technologies have been developed to reduce the production cost. This paper attempts to extensively review microwave-assisted technology for biodiesel production. Additionally, different types of feedstocks for biodiesel production have been summarized in this paper. It is concluded that the microwave-assisted technique reduces the reaction time significantly in comparison with conventional methods. In addition, a high quality biodiesel can be obtained from microwave-assisted transesterification of different kinds of oils. Finally, the energy payback for 1kg biodiesel produced by microwave-assisted technology is calculated in this paper and it indicated that the system is sustainable. Therefore it can be a suitable method of decreasing the cost of biodiesel and can also help the commercialization of this fuel.     

Quality analysis studies on biodiesel production of neochloris oleoabundans algae

The petroleum fuels play a major role in industry, agriculture, and transport besides meeting out many other basic human needs. However, fossil fuels are limited in quantity and are depleting day by day as the consumption is increasing very rapidly. Biodiesel is one such fuel in which there is a lot of hope. In the recent past, biodiesel received considerable attention as a renewable fuel. In India, it has not been possible to produce biodiesel from edible oils since the same is very scarce. Hence, the scope of opting to non-edible oils from plants as raw material for biodiesel production recently gained momentum. This paper presents the production of biodiesel from nonedible, Neochloris oleoabundans oil and its characterization. The studies were carried out on transesterification of oil with methanol, sodium hydroxide, and Sodium methoxide as catalyst for the production of biodiesel. The process parameters such as catalyst concentration, reaction time, and reaction temperature were optimized for the production of Neochloris oleoabundans oil biodiesel. The biodiesel yield of 95.15% was noticed at optimal process parameters.     

Necessity of biodiesel utilization as a source of renewable energy in Malaysia

In recent decades, the energy crisis and environmental issues have become a crucial problem. The rapid industrialization has lead humankind to deplete the fossil fuels and consequently the pollutant emissions have increased in the world. Many investigations have been done to find an alternative fuel to fulfill increasing energy demand. Recently, biodiesel has been introduced as an economical renewable and sustainable fuel which is cited as an environment-friendly resource. Around 350 oil-bearing crops were analyzed and some of them were capable to be considered as potential alternative fuels for diesel engines. These include virgin vegetable oils and waste vegetable oils. Rapeseed, jatropha, soybean, and palm oil are mentioned as the most common sources of biodiesel. Many countries have invested in biodiesel as an acceptable source of energy not only in research area but also in production and export. It has been proven that the biodiesel combustion characteristics are similar as petroleum. Higher ignition pressure and temperature, shorter ignition delay and higher peak release were reported in experimental combustion of biodiesel blends. Also, the efficiency of biodiesel base catalysts is more than enzymes and acid catalysts. This article is a literature review on necessity of biodiesel production as alternative fuel recourse in Malaysia and tries to illustrate the combustion characteristics and pollutant formation in biodiesel application.     

Comparison of performance characteristics of agricultural tractor diesel engine operating on home and industrially produced biodiesel

Owing to unstable diesel fuel prices in the world market, many farmers have been looking for alternative fuels. Vegetable oils are one of the alternatives, which can be used as fuel in diesel engines either in the form of straight vegetable oil or in the form of biodiesel. This study aims to present experimental data by utilization of home and industrial biodiesel as fuel in an agricultural tractor diesel engine. The home biodiesel production was made from different vegetable oils (crude rapeseed, edible sunflower and waste oil) with the process of one‐stage‐based catalyzed transesterification. A commercially available agricultural tractor ZETOR 7745 was employed. Measurements were taken on the power take‐off shaft by electrical dynamometer FROMENT XT200. According to the results, agricultural tractor diesel engine operating on home biodiesel fuels had better performance characteristics related to industrially produced biodiesel and similar to conventional diesel fuel. Copyright © 2009 John Wiley & Sons, Ltd.     

Analysis and evaluation of operating variables for the yield of Karanja and neem oil-based biodiesel production

The aim of this research is to present the possibilities of the use of non-edible oils in biodiesel production, to consider the various methods for treatment of non-edible oils and to emphasise the influence of the operating and reaction conditions on the process rate and the ester yield. Because of biodegradability and non-toxicity biodiesel has become more attractive as alternative fuel. Biodiesel is produced mainly from vegetable oils by transesterification. For economic and social reasons, edible oils should be replaced by lower-cost and reliable feedstock for biodiesel production, such as non-edible plant oils. In this work biodiesel is produced from neem and Karanja by using butanol, propanol, ethanol and methanol as alcohols and KOH and NaOH as alkali catalysts by the transesterification process. The aim of this research is to analyse the different reaction parameters such as catalyst concentration, type of catalyst, types of alcohol, alcohol to oil molar ratio, reaction time and reaction temperature on the yield of biodiesel from non-edible oils. The maximum yield obtained was 95% with Karanja as oil with methanol and KOH as alkali catalyst at oil to alcohol molar ratio of 6:1 in 1 h at 60°C. Special attention is paid to the possibilities of producing biodiesel from non-edible oils.     

Organic municipal solid waste (MSW) as feedstock for biodiesel production: A financial feasibility analysis

The pursuit towards an alternative solution to fossil fuel has facilitated science investigation initiatives that compare various options leading to biodiesel production. Besides conventional feedstock derived from vegetable oils, alternative sources that could be produce in large scale at competitive costs are the main scope of research in this field. This paper investigates the financial feasibility using organic solid waste as a feedstock, which results in the production of biodiesel through the conversion of volatile fatty acids into lipids (VFA). As a result, based on existing references of capital and operating costs, production and extraction yields for VFA and lipids and an internal rate of return of 15% in real terms, we concluded that biodiesel production is competitive compared to subsidized biodiesel traded in regions of Europe and the United States. These results encourage research aims to examine this technology at a larger scale. The adoption of public policies for the urban waste's disposal and collection, to reduced municipality's costs associated to the treatment, is also important for the implementation of these technologies.     

Technical feasibility studies for Langkawi WCO (waste cooking oil) derived-biodiesel

A study has been done to consider Malaysian WCO (waste cooking oil) generated in an eco-tourism island, Langkawi, Malaysia as an alternative feedstock for biodiesel production. This paper presents the results of the comprehensive technical feasibility study for production of biodiesel from WCO feedstock. The results have shown feasibility of recycling WCO into biodiesel that is compliant with international fuel standard ASTM D6751. The study has given an indication on the appropriate processing scheme to be developed for recycling WCO into biodiesel as a substitute fuel for diesel vehicles in Langkawi that would enable the promotion of alternative fuel in the energy mix for long term environment sustainability.     

Improving the low temperature properties of biodiesel fuel

The use of biodiesel as a diesel fuel extender and lubricity improver is rapidly increasing. While most of the properties of biodiesel are comparable to petroleum based diesel fuel, improvement of its low temperature flow characteristic still remains one of the major challenges when using biodiesel as an alternative fuel for diesel engines. The biodiesel fuels derived from fats or oils with significant amounts of saturated fatty compounds will display higher cloud points and pour points. This paper is aimed to investigate the cold flow properties of 100% biodiesel fuel obtained from Madhuca indica, one of the important species in the Indian context. In this paper, the cold flow properties of biodiesel were evaluated with and without pour point depressants towards the objectives of identifying the pumping and injecting of these biodiesel in CI engines under cold climates. Effect of ethanol, kerosene and commercial additive on cold flow behavior of this biodiesel was studied. A considerable reduction in pour point has been noticed by using these cold flow improvers. The performance and emission with ethanol blended Mahua biodiesel fuel and ethanol–diesel blended Mahua biodiesel fuel have also been studied. A considerable reduction in emission was obtained. Ethanol blended biodiesel is totally a renewable, viable alternative fuel for improved cold flow behavior and better emission characteristics without affecting the engine performance.     

Impact of alternative fuel properties on fuel spray behavior and atomization

In order to verify and solve the problem of NOx and PM emissions, it is necessary to directly observe the internal combustion chamber of a diesel engine. Many studies have been performed in recent years to verify the macroscopic and microscopic behavior of the injected fuel spray because observing it is not easy due to the difficulties of the experiment. Researchers have investigated the spray characteristics for various diesel injector nozzles over a wide range of temperatures and pressure, but there is lack of evaluation for the spray characteristics for biodiesel. At a time when rapid rise of fuel prices and depleting hydrocarbon resources of the world have forced us to look for alternative fuels biodiesel produced by transesterification of non-edible vegetable oils is promising to be an important additive/substitute to petro diesel. Biodiesel being an oxygenated and sulfur-free fuel leads to more complete combustion and lower emissions. But, the energy content or net calorific value of biodiesel is less than that of diesel fuel; also it has higher viscosity and density, than diesel fuel. A considerable improvement in these properties can be obtained by mixing diesel and biodiesel and then using the blends. Biodiesel and biodiesel/petro diesel blends, with their higher lubricity levels, are increasingly being utilized as an alternative. Present paper analyzed the correlation of injection parameters that will affect the spray characteristics of biodiesel. Observations for analyzing the effect of injection parameters on spray cone angle, break up length and fuel penetration were made. Finally the performance and emissions tests were studied. Atomization and vaporization of fuel are greatly influenced by viscosity and density of fuel and these properties are temperature dependent. Thus fuel inlet temperature plays a very important role in fuel atomization process. At higher temperature viscosity of fuel decreases which enhances the atomization of biofuels.     

生物柴油特性分析与应用

生产生物柴油的主要原料是可再生的生物资源,生物柴油含氧而基本不合硫和芳香烃,具有良好的燃料品质和环境友好性,从能源战略角度分析,生物柴油是最为重要的代用燃料之一.柴油机不需改动即可使用生物柴油,柴油机使用生物柴油不仅利于改善燃料结构,而且可以降低有害排放.本文对比了生物柴油与矿物柴油的燃料特性,分析了柴油机燃用生物柴油的好处,介绍了生物柴油在国内外的发展情况,指出发展生物柴油的目的并不是要取代矿物柴油,而在于改善矿物柴油的性能,以满足不断严格的排放标准,并对推动我国生物柴油的发展提出了建议.     

New Options for Conversion of Vegetable Oils to Alternative Fuels

Biodiesel from transesterification of vegetable oils is an excellent alternative fuel. There is, however, a need to develop a direct process for conversion of vegetable oils into gasoline-competitive biodiesel and other petroleum products. Methyl esters of vegetable oils have several outstanding advantages among other new-renewable and clean engine fuel alternatives. The purpose of the transesterification process is to lower the viscosity of vegetable oil. Compared to No. 2 diesel fuel, all of the vegetable oils are much more viscous, whereas methyl esters of vegetable oils are slightly more viscous. The methyl esters are more volatile than those of the vegetable oils. Conversion of vegetable oils to useful fuels involves the pyrolysis and catalytic cracking of the oils into lower molecular products. Pyrolysis produces more biogasoline than biodiesel fuel. Soap pyrolysis products of vegetable oils can be used as alternative diesel engine fuel. The soaps obtained from the vegetable oils can be pyrolyzed into hydrocarbon-rich products. Zinc chloride catalyst contributed greatly to high amounts of hydrocarbons in the liquid product. The yield of ZnCl ₂ catalytic conversion of the soybean oil reached the maximum 79.9% at 660 K.     

Potential and challenges for large-scale application of biodiesel in automotive sector

Biodiesel is receiving serious attention globally as a potential alternative fuel for replacing mineral diesel, partially or fully. In this review paper, most prominent methods of biodiesel production commercially, life-cycle analysis and economic issues related to biodiesel, engine performance, combustion and emission characteristics including particulate, engine compatibility issues and effect of biodiesel usage on engine component wear and lubricating oil are comprehensively discussed. Majority of biodiesel produced globally is via base-catalyzed transesterification process since this is a low temperature and pressure process, having high conversion rates without intermediate steps, and it uses inexpensive materials of construction for the plant. Catalyst types (alkaline, acidic or enzymatic), catalyst concentration, molar ratio of alcohol/oil, reaction temperature, moisture content of reactants, and free fatty acid (FFA) content of oil are the main factors affecting biodiesel (ester) yield from the transesterification process. Substantial reduction in particulate matter (PM), total hydrocarbons (THC) and carbon monoxide (CO) emissions in comparison to mineral diesel, and increased brake specific fuel consumption (BSFC) and oxides of nitrogen (NO_X) emissions are reported by most researchers using unmodified compression ignition (CI) engines. This review covers several aspects, which are not covered by previous review articles, such as effect of biodiesel on unregulated emissions, effect of biodiesel on carbon deposits, wear of key engine components, and lubricating oil in long-term endurance studies. It emerges from literature review that even minor blends of biodiesel help control emissions and ease pressure on scarce petroleum resources without sacrificing engine power output, engine performance and fuel economy. This review underscores that future studies should focus on optimization of fuel injection equipment and hardware modifications to develop dedicated biodiesel engines, improve low temperature performance of biodiesel fuelled engines, develop new biodiesel compatible lubricating oil formulations and special materials for engine components before implementing large-scale substitution of mineral diesel by biodiesel globally.     

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

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.