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.     

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.     

Two-stage processes of homogenous catalysed transesterification of high free fatty acid crude oil of rubber seed

Biodiesel is a diesel replacement and renewable fuel that is manufactured from vegetable oils, animal fats or waste cooking oils. The production of biodiesel from edible oil is currently much more expensive than hydrocarbon-based fuel, due to the relatively high cost of edible oils. The cost of biodiesel can be reduced by using non-edible oils instead of edible oils. The purpose of the present study was to develop a method of esterification of non-edible oil like rubber seed oil (Hevea brasiliensis). The high free fatty acid content oil reacts quickly with alkaline catalysts to form soap, which prevents the separation of biodiesel and glycerol. A two-step process was used instead of the simple alkaline catalysed transesterification process. It consisted of an acid catalysed pre-processing followed by the usual alkaline catalysed process. The physical and chemical properties of biodiesel were analysed. The quantification of methyl esters were done by high-performance liquid chromatography.     

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.     

Enhancement in Jatropha-based biodiesel yield by process optimisation using design of experiment approach

Edible and non-edible oils are used for the production of biodiesel from the last so many years and these oils are extracted from their respective seeds. Jatropha oil is used as a feedstock to produce biodiesel for running the Compression Ignition engine. A statistical model is developed to interrelate the trans-esterification process variables for the biodiesel yield using design of experiment approach by selecting central composite design of a response surface methodology. Results shown in this paper indicate that the optimum observed yield of 95.5% has the following reaction conditions: Molar ratio 19.84 (% v/v), reaction time 3 h, reaction temperature 70°C, catalyst concentration 4.18 wt% and stirrer rpm 650. Also, the yield produced is higher when compared with 93.5% which was observed by Lee paper using the same methodology. Moreover, the fuel properties of Jatropha biodiesel are closer to the ASTM standard of biodiesel.     

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.     

Process simulation and life cycle analysis of biodiesel production

Biodiesel is a renewable and sustainable biofuel. There are various production processes to produce biodiesel from different kinds of raw materials. In this study, the environmental impacts of biodiesel production from non-edible Jatropha oil and waste cooking oil (WCO) were investigated and compared using systematic life cycle assessment. The results show that crops growing and cultivation of non-edible Jatropha curcas lead to higher environmental impacts compared to WCO process. However, biodiesel production process from Jatropha oil has better performance because the WCO process needs to consume variety of chemicals and requires a large amount of energy for the pretreatment of raw WCO and further chemical conversion to biodiesel. Results also indicate that the collection mechanism of WCO has significant contributions towards environmental impacts. In general, biodiesel production from Jatropha oil shows higher impacts for damage categories of climate change, human health and ecosystem quality whereas biodiesel production from WCO has more severe environmental impacts for resource category. The total environmental impact is 74% less in case of using WCO as raw material compared to non-edible Jatropha oil.     

Feasibility of edible oil vs. non-edible oil vs. waste edible oil as biodiesel feedstock

Biodiesel has high potential as a new and renewable energy source in the future, as a substitution fuel for petroleum-derived diesel and can be used in existing diesel engine without modification. Currently, more than 95% of the world biodiesel is produced from edible oil which is easily available on large scale from the agricultural industry. However, continuous and large-scale production of biodiesel from edible oil without proper planning may cause negative impact to the world, such as depletion of food supply leading to economic imbalance. A possible solution to overcome this problem is to use non-edible oil or waste edible oil (WEO). In this context, the next question that comes in mind would be if the use of non-edible oil overcomes the short-comings of using edible oil. Apart from that, if WEO were to be used, is it sufficient to meet the demand of biodiesel. All these issues will be addressed in this paper by discussing the advantages and disadvantages of using edible oil vs. non-edible vs. WEO as feedstock for biodiesel production. The discussion will cover various aspects ranging from oil composition, oil yield, economics, cultivation requirements, land availability and also the resources availability. Finally, a proposed solution will be presented.     

Biodiesel production from Jatropha curcas oil

In view of the fast depletion of fossil fuel, the search for alternative fuels has become inevitable, looking at huge demand of diesel for transportation sector, captive power generation and agricultural sector, the biodiesel is being viewed a substitute of diesel. The vegetable oils, fats, grease are the source of feedstocks for the production of biodiesel. Significant work has been reported on the kinetics of transesterification of edible vegetable oils but little work is reported on non-edible oils. Out of various non-edible oil resources, Jatropha curcas oil (JCO) is considered as future feedstocks for biodiesel production in India and limited work is reported on the kinetics of transesterification of high FFA containing oil. The present study reports a review of kinetics of biodiesel production. The paper also reveals the results of kinetics study of two-step acid–base catalyzed transesterification process carried out at pre-determined optimum temperature of 65 and 50 °C for esterification and transesterification process, respectively, under the optimum condition of methanol to oil ratio of 3:7 (v/v), catalyst concentration 1% (w/w) for H₂SO₄ and NaOH and 400 rpm of stirring. The yield of methyl ester (ME) has been used to study the effect of different parameters. The maximum yield of 21.2% of ME during esterification and 90.1% from transesterification of pretreated JCO has been obtained. This is the first study of its kind dealing with simplified kinetics of two-step acid–base catalyzed transesterification process carried at optimum temperature of both the steps which took about 6 h for complete conversion of TG to ME.     

Biodiesel production process optimization and characterization to assess the suitability of the product for varied environmental conditions

In this study, both edible (coconut oil, palm oil, groundnut oil, and rice bran oil) and non-edible oils (pongamia, neem and cotton seed oil) were used to optimize the biodiesel production process variables like catalyst concentration, amount of methanol required for reaction, reaction time and reaction temperature. The fuel properties like specific gravity, moisture content, refractive index, acid value, iodine number, saponification value and peroxide value were estimated. Based on the cetane number and iodine value, the methyl esters obtained from palm and coconut oils were not suitable to use as biodiesel in cold weather conditions, but for hot climate condition biodiesel obtained from the remaining oil sources is suitable.     

Biodiesel from cotton seed oil and its effect on engine performance and exhaust emissions

The use of biodiesel is rapidly expanding around the world, making it imperative to fully understand the impacts of biodiesel on the diesel engine combustion process and pollutant formation. Biodiesel is known as the mono-alkyl-esters of long chain fatty acids derived from renewable feedstocks, such as, vegetable oils or animal fats, for use in compression ignition engines. Different parameters for the optimization of biodiesel production were investigated in the first phase of this study, while in the next phase of the study performance test of a diesel engine with neat diesel fuel and biodiesel mixtures were carried out. Biodiesel was made by the well known transesterification process. Cottonseed oil (CSO) was selected for biodiesel production. Cottonseed is non-edible oil, thus food versus fuel conflict will not arise if this is used for biodiesel production. The transesterification results showed that with the variation of catalyst, methanol or ethanol, variation of biodiesel production was realized. However, the optimum conditions for biodiesel production are suggested in this paper. A maximum of 77% biodiesel was produced with 20% methanol in presence of 0.5% sodium hydroxide. The engine experimental results showed that exhaust emissions including carbon monoxide (CO) particulate matter (PM) and smoke emissions were reduced for all biodiesel mixtures. However, a slight increase in oxides of nitrogen (NO_x) emission was experienced for biodiesel mixtures.     

Biodiesel production by microalgal biotechnology

Biodiesel has received much attention in recent years. Although numerous reports are available on the production of biodiesel from vegetable oils of terraneous oil-plants, such as soybean, sunflower and palm oils, the production of biodiesel from microalgae is a newly emerging field. Microalgal biotechnology appears to possess high potential for biodiesel production because a significant increase in lipid content of microalgae is now possible through heterotrophic cultivation and genetic engineering approaches. This paper provides an overview of the technologies in the production of biodiesel from microalgae, including the various modes of cultivation for the production of oil-rich microalgal biomass, as well as the subsequent downstream processing for biodiesel production. The advances and prospects of using microalgal biotechnology for biodiesel production are discussed.     

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.     

Performance and emission characteristics of a DI compression ignition engine operated on Honge, Jatropha and sesame oil methyl esters

The high viscosity of vegetable oils leads to problem in pumping and spray characteristics. The inefficient mixing of vegetable oils with air contributes to incomplete combustion. The best way to use vegetable oils as fuel in compression ignition (CI) engines is to convert it into biodiesel. Biodiesel is a methyl or ethyl ester of fatty acids made from vegetable oils (both edible and non-edible) and animal fat. The main resources for biodiesel production can be non-edible oils obtained from plant species such as Pongamia pinnata (Honge oil), Jatropha curcas (Ratanjyot), Hevea brasiliensis (Rubber) and Calophyllum inophyllum (Nagchampa). Biodiesel can be used in its pure form or can be blended with diesel to form different blends. It can be used in CI engines with very little or no engine modifications. This is because it has properties similar to mineral diesel. This paper presents the results of investigations carried out on a single-cylinder, four-stroke, direct-injection, CI engine operated with methyl esters of Honge oil, Jatropha oil and sesame oil. Comparative measures of brake thermal efficiency, smoke opacity, HC, CO, NO_X, ignition delay, combustion duration and heat release rates have been presented and discussed. Engine performance in terms of higher brake thermal efficiency and lower emissions (HC, CO, NO_X) with sesame oil methyl ester operation was observed compared to methyl esters of Honge and Jatropha oil operation.     

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.     

Activity of homogeneous and heterogeneous catalysts,spectroscopic and chromatographic characterization of biodiesel: A review

Biofuel has got tremendous attraction for the last decade as an alternative source of energy. Bioethanol and biodiesel are two main products of first generation biofuel. Biodiesel is chemically fatty acid methyl esters prepared from various edible and non-edible oils. It has been used as a substitute to mineral diesel during the last decade. This review is about generation, transesterification, factors affecting transesterification, catalysts (homogeneous and heterogeneous) and physico-chemical characterization of biodiesel by chromatographic and spectroscopic techniques. The alkaline homogeneous catalysts (NaOH or KOH) have been used on commercial scale for production of biodiesel because these are cheap and reaction occurs in less time. The heterogeneous catalysts such as metal oxides, e.g., CaO, MgO, SrO, ZnO, La₂O₃, Mg–Al hydrolalcite have been used for transesterification of vegetable oil due to their easy separation and reuse but these catalysts take more time for completion of reaction. The yield of biodiesel may be affected by alcohol/oil ratio, concentration of catalyst, time required for reaction, temperature free fatty acid moisture. The prepared biodiesel has been characterized by chromatographic techniques like gas chromatography, gas chromatography–mass spectroscopy, high performance liquid chromatography and spectroscopic techniques like nuclear magnetic resonance and infrared spectroscopy.     

Plant oils as fuels for compression ignition engines: A technical review and life-cycle analysis

As an alternative fuel for compression ignition engines, plant oils are in principle renewable and carbon-neutral. However, their use raises technical, economic and environmental issues. A comprehensive and up-to-date technical review of using both edible and non-edible plant oils (either pure or as blends with fossil diesel) in CI engines, based on comparisons with standard diesel fuel, has been carried out. The properties of several plant oils, and the results of engine tests using them, are reviewed based on the literature. Findings regarding engine performance, exhaust emissions and engine durability are collated. The causes of technical problems arising from the use of various oils are discussed, as are the modifications to oil and engine employed to alleviate these problems. The review shows that a number of plant oils can be used satisfactorily in CI engines, without transesterification, by preheating the oil and/or modifying the engine parameters and the maintenance schedule. As regards life-cycle energy and greenhouse gas emission analyses, these reveal considerable advantages of raw plant oils over fossil diesel and biodiesel. Typical results show that the life-cycle output-to-input energy ratio of raw plant oil is around 6 times higher than fossil diesel. Depending on either primary energy or fossil energy requirements, the life-cycle energy ratio of raw plant oil is in the range of 2–6 times higher than corresponding biodiesel. Moreover, raw plant oil has the highest potential of reducing life-cycle GHG emissions as compared to biodiesel and fossil diesel.     

Biodiesel production from neem towards feedstock diversification: Indian perspective

In developing countries like India where 70% of country's petroleum needs are met by import, energy security assumes significance in view of uncertainty of supply and increasing price of petroleum fuels. Fuels of bio origin not only provide energy security, but also reduce emissions of harmful pollutants and greenhouse gases and ensure rural upliftment by increasing employment in agricultural sector. India cannot afford to produce biodiesel from edible oil seeds as it is done in the American and European countries. Extensive focus has been given on producing biodiesel from non-edible sources, specifically from Jatropha. Discrepancies between the expectation and realities regarding Jatropha as a feedstock necessitate efforts for diversification of the feedstocks. Scientific research should therefore be directed towards oilseeds like Karanja, Sal, Mahua, Neem, etc. that are widely available and sustainable to the diverse socio-economic and environmental conditions of rural India. Among them the evergreen neem with its wide availability and various useful uses may be a potential feedstock for biodiesel production. In this paper attempts have been made to overview the morphology of neem tree, various useful uses, physical and chemical characteristics of neem oil and optimized production process for biodiesel production from neem oil.     

Multivariant approach to optimize biodiesel extraction from neem oil using two-stage esterification process and its quality assessment

Finding new biofuel resources and consolidating the preliminary findings on biodiesel extraction are important to optimize mass production. In this paper biodiesel is extracted from non-edible, abundantly available, potential, and viable neem oil. Design of Experiment is employed to optimize the process parameters of the two-stage esterification process. Methanol has the greatest influence in both stages, followed by choice of catalyst and duration. Standard test procedures were followed to ensure the adequacy of the fuel properties, and the results are encouraging in regard to using neem oil as a potentially renewable and sustainable biodiesel source.     

Fractional characterisation of jatropha,neem, moringa,trisperma, castor and candlenut seeds as potential feedstocks for biodiesel production in Cuba

A preliminary investigation on the suitability of various non-edible oil seeds for the integral utilisation of their fractions for production of biodiesel and other products was carried out. The oil seeds considered were jatropha (Jatropha curcas), neem (Azadirachta indica), moringa (Moringa oleifera), trisperma (Aleurites trisperma), castor beans (Ricinus communis) and candlenut (Aleurites moluccana). The highest oil content (62.0% (w/w)) was found in trisperma seeds, but the use of that oil for biodiesel production is restricted by its high content of polyunsaturated fatty acids. The oils of castor beans and moringa contained 86.0% of ricinoleic acid and 70.6% of oleic acid, respectively, while in the oils from the other seeds no predominance of any acid was observed. According to the oil yield and to the fatty acid composition of the oil, jatropha was identified as the most promising oil seed for biodiesel production in Cuba. All the press cakes were rich in protein, the highest content (68.6%) being detected in moringa cake. The investigation revealed that the husks of neem and moringa can be considered potential substrates for ethanol production due to their high cellulose content (approximately 30%). A high concentration (4.3%) of acetyl groups was found in neem husks, what is favourable for the hydrolytic conversion of polysaccharides to simple sugars. A high protein content (15.2%) was detected in moringa husks, which is a positive feature for lowering the cost of nutrient supplementation in ethanolic fermentation.