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Biodiesel Fuels from Vegetable Oils: Transesterification of Cynara cardunculus L. Oils with Ethanol
Abstract
A study was made of the transesterification reaction of Cynara cardunculus L. oil by means of ethanol, using sodium hydroxide and potassium hydroxide as catalysts. The objective of the work was to characterize the ethyl esters for use as biodiesels in compression ignition motors. The operation variables employed were temperature (25−75 °C), catalyst type (sodium hydroxide and potassium hydroxide), catalyst concentration (0.25−1.5 wt %), and ethanol/oil molar ratio (3:1−15:1). Oil mass (200 g), reaction time (120 min), and alcohol type (ethanol) were fixed as common parameters in all the experiments. The evolution of the process was followed by gas chromatography, determining the concentration of the ethyl esters at different reaction times. The biodiesel was characterized by determining its density, viscosity, high heating value, cetane index, cloud and pour points, characteristics of distillation, and flash and combustion points according to ISO norms. The biodiesel with the best properties was obtained using an ethanol/oil molar ratio of 12:1, sodium hydroxide as catalyst (1%) and 75 °C temperature. This biodiesel has very similar properties to those of no. 2 diesel fuel.
... Ethanol is cost competitive with methanol in areas where production is high, such as Brazil [41]. Ethanol also has the advantage of being derived from renewable sources, and it is safer to handle than methanol [54]. Few studies involving biodiesel synthesis in microreactors use ethanol as alcohol [26,28,31,35]. ...
... Leung [11] shows a slight decrease in ester conversion, from 93.5 to 88.8%, by replacing soybean oil for WCO. Anastopoulos et al. [86], Encinar et al. [41] and Encinar et al. [54] used ethanol as the reacting alcohol used in transesterification; however, none of the studies achieved an ester conversion above 94.5%. Two different studies by the same author, Encinar et al. [41] and Encinar et al. [54], demonstrate how the use of WCO in place of refined oil can decrease overall conversions: In the [54] study, Cynara oil was reacted with ethanol for an ester conversion of 94.5%, while the [41] study ethanol reacted with WCO and had an ester conversion of just 72.5%. ...
... Anastopoulos et al. [86], Encinar et al. [41] and Encinar et al. [54] used ethanol as the reacting alcohol used in transesterification; however, none of the studies achieved an ester conversion above 94.5%. Two different studies by the same author, Encinar et al. [41] and Encinar et al. [54], demonstrate how the use of WCO in place of refined oil can decrease overall conversions: In the [54] study, Cynara oil was reacted with ethanol for an ester conversion of 94.5%, while the [41] study ethanol reacted with WCO and had an ester conversion of just 72.5%. The results from this work compare very favorably with the studies in Table 11. ...
This study investigates biodiesel synthesis from waste cooking oil (WCO) using a microreactor completely 3D printed in metal. Production of biodiesel from WCO will inevitably lead to higher levels of free fatty acids (FFAs), since a hydrolysis reaction occurs with the water from food, turning triglycerides into FFAs when the refined vegetable oil is used for cooking. To overcome the negative effects of the FFA content on mass transfer and ultimately tend to decrease the ester conversion, its amount in oil feedstock must be reduced to lower values than 0.5% through a pretreatment step of esterification with an acid catalyst. Therefore, the two chemical processes were here parametrically investigated in an ethylic route: first, the reduction of the FFAs in the WCO using an esterification pretreatment, and then the conversion of the remaining triglycerides through an alkali-catalyzed transesterification. The partial factorial Taguchi analysis was used to explore parametric effects and greatly reduce the number of experiments needed. A biodiesel conversion of 98% was achieved at a temperature of 55 °C which is very close to the industrially acceptable level of conversion, but in only 2 min, which is much lower than the reaction times using traditional batch reactors.
... However, the high molar ratio of alcohol to vegetable oil prevents the separation of glycerin due to an increase in solubility. When the equilibrium is still in solution, glycerin helps move it back to the left, which lowers the formation of esters [21] because part of the glycerol remains in the biodiesel phase, glycerin separation becomes difficult, and the apparent yield of esters drops at a molar ratio of 15:1. Encinar et al. [21]. ...
... When the equilibrium is still in solution, glycerin helps move it back to the left, which lowers the formation of esters [21] because part of the glycerol remains in the biodiesel phase, glycerin separation becomes difficult, and the apparent yield of esters drops at a molar ratio of 15:1. Encinar et al. [21]. Using a 6:1 molar ratio speeds up the reaction rate because presence of excess alcohol reduces viscosity of reaction mixture improving mass transfer between the reactants leading to a faster and more complete reaction [17]. ...
Research on producing biodiesel from leftover cooking oil has increased due to a constant increase in demand for renewable energy sources and the necessity of sustainable waste management. If spent cooking oil is left out in the open, it can cause a number of environmental issues. In this study, a transesterification technique is used to try and convert used cooking oil which is gathered from different sources, into biodiesel. Transesterification, a process that uses waste products to produce valuable renewable energy and glycerol as a by product, has proven to be a potential and sustainable method for production of biodiesel from used cooking oil. Experiments were conducted to produce biodiesel using leftover groundnut and sunflower oil. In order to produce biodiesel from the aforementioned oils, a number of parameters were examined, including temperature of reaction, alcohol-to-oil molar ratio and reaction time. When compared to traditional biodiesel, it exhibits superior qualities in terms of aniline point, flash point,pour point, smoke point, cloud point, and fire point. It is found that the biodiesel yield from waste sunflower oil is more than that of waste groundnut oil. With no engine modifications required, biodiesel may be used in diesel engines in both blended and raw form as an excellent alternative to conventional fuels.
... Table 6 presents these optimal values. Comparing the optimal molar ratios, methanol exhibited a value of 9.27:1, which surpassed the ratio of 6:1 reported by Freedman et al [58] for methanol and was lower than the 12:1 ratio reported by Encinar et al [59] for ethanol in Cynara oil transesterification. When the molar ratio is lower than 6:1, the reaction remains incomplete. ...
... While the transesterification rate increased with temperature, it remained constrained by the boiling point of the reactants. Notably, Encinar et al [59] achieved optimal results at 75°C for ethanolysis of Cynara oil, surpassing the temperature employed in this study. However, it is essential to consider that different oils and different alcohols may necessitate varying temperatures for transesterification. ...
The production of biodiesel from conventional vegetable oils is limited by the high cost and competition with food supply. Therefore, there is a need to explore new and underutilized feedstocks that can provide abundant and low-cost oil for biodiesel production. Livistona jenkinsiana is a palm species that grows in tropical and subtropical regions of Asia. It produces oil-rich fruits that are usually discarded as waste. In this work, biodiesel was produced from Livistona jenkinsiana through transesterification reaction, and the parametric analysis was carried out. The process parameters such as reaction temperature, molar ratio, reaction time, and catalyst amount were studied, and yield (Y) was modelled using response surface methodology (RSM) as a modelling tool in MINITAB@17.1.0 software. A second-order RSM model for biodiesel yield was developed as a function of temperature, catalyst, and the molar ratio, which could predict the biodiesel yield. ANOVA results showed that temperature, catalyst, and molar ratio played an important role in the transesterification process. The optimization result showed that the optimal conditions were attained at a temperature of 61.78 °C, methanol to oil molar ratio 9.25:1, and catalyst concentration of 0.86 wt. %. The highest biodiesel yield predicted was 94.47%. The reaction was carried out at a constant reaction speed of 500 rpm for 1.5 h of reaction time. The physicochemical properties of the produced biodiesel indicate that the biodiesel from Livistona jenkinsiana oil (LJO) is ideal for the production of biodiesel.
... Potassium salts of fatty acids are the products of this hydrolysis. The formation of potassium salts as a product of hydrolysis has been proven to make the reaction mixture more viscous, and therefore reduce the conversion rate [48][49][50]. ...
... Processes 2023, 11, x FOR PEER REVIEW 11 o hydrolysis has been proven to make the reaction mixture more viscous, and there reduce the conversion rate [48][49][50]. In the case of an increase in the content of FFA in the oil, the quality of alcohol more influence on the transesterification process. ...
Countries around the world recognize the numerous social, economic and environmental advantages of promoting liquid biofuels. They invest in its development and introduce tax incentives for its manufacture and tariffs of production regulation. In most studies, the process of synthesizing fatty acid esters takes a long time from 1 to 8 h. In this work, the synthesis of fatty acid esters was carried out in the range of volumetric ratios of ethanol to linoleic type oil in order to increase the kinetics of the process. The main parameters of the synthesis were studied by use of magnetic stirred tank reactors in a parallel reactor system, H.E.L. The synthesis was carried out in the presence of a homogeneous alkaline catalyst. The volumetric ratio of ethanol to oil was maintained at 1:1, 2:1, 3:1, 4:1 and 5:1. The amount of catalyst added to the reaction mixture ranged from 0.25 to 2.5% by the weight of the reaction alcohol. The dryness of ethanol varied from 91 to 99%. Effective process conditions have been established to reduce the reaction time from 2.5 h to 5 min while maintaining a high degree of conversion. The results obtained during the study suggest the possibility of using a continuous reactor to produce fatty acid esters from linoleic raw materials containing up to 16% of free fatty acids. This also means the possibility of using second generation biofuel feedstock.
... Problems related to the homogenization of oils or fats with alcohol to form a single phase at the beginning of the reaction reduce the mass transfer of the system, which can negatively affect the transesterification reaction yield. The inadequacy in contact between oil and alcohol due to their non-polar and polar nature, respectively, can be minimized by agitating the system [19,20]. Several technologies, such as ultrasound, microwaves, cavitation, microchannels, co-solvents, and surfactants, have been studied in recent years to improve the miscibility of the reagents, conversion rate, and efficiency of catalyst and reduce the reaction temperature [19][20][21][22]. ...
... The inadequacy in contact between oil and alcohol due to their non-polar and polar nature, respectively, can be minimized by agitating the system [19,20]. Several technologies, such as ultrasound, microwaves, cavitation, microchannels, co-solvents, and surfactants, have been studied in recent years to improve the miscibility of the reagents, conversion rate, and efficiency of catalyst and reduce the reaction temperature [19][20][21][22]. ...
The prospect of depletion of fossil fuels and the global concern with reducing the emission of polluting gasses have aroused interest from governments and researchers in using alternative fuels. Biodiesel is considered an effective alternative as a partial or total replacement for petroleum-derived diesel because it is biodegradable, emits fewer greenhouse gasses, and is produced from renewable sources. In the biodiesel synthesis, the difference in the polarity of the reactants hinders the homogenization of the reaction system, which can negatively affect the transesterification reaction. Most surfactants used to improve the miscibility of reagents in transesterification reactions are toxic, dangerous, and are required in relatively high amounts. This study explored biodiesel production from palm oil and methanol in a new system containing a coconut oil–based natural surfactant, which is biodegradable, non-toxic, and derived from a fruit that is found worldwide. The experimental design, a full factorial design, was used to optimize the process, and using the thermogravimetric analysis, the isoconversional methods of Flynn–Wall–Ozawa and Kissinger were used in the kinetic study of thermal degradation of the biodiesel. The surfactant was efficient in low amounts, and the optimal conditions for biodiesel production were 30 min reaction time, potassium hydroxide 1 wt%, methanol and oil molar ratio of 8.28:1, and surfactant 1.05 wt%, which yielded 98.64% of biodiesel and 98.04% of fatty acid methyl esters. The properties of the biodiesel were according to EN 14,214. The biodiesel was thermally stable up to 200 °C, and waste generation was less than 2.2%.
Graphical abstract
... With these considerations, and as a continuation of previous works [17][18][19], we carried out a study on the transesterification process of seven different vegetable oils (sunflower, soybean rapeseed, cotton seed, tobacco seed, palm oil, and used frying oil) utilizing ethanol, in order to characterize the ethyl esters and their blends with the diesel fuel obtained for their applications as fuels in internal combustion engines. ...
... These results were qualitatively similar to those obtained by other authors in the ethanolysis of rapeseed oil [22]. In the case of the alkaline catalysis, the literature presents many works relating to these processes [4,[17][18][19]23] . In each case, the more suitable catalyst depends on the type of oil utilized, and the best-suited concentrations are between 0.5 and 1.0 wt. ...
Ethanolysis of four different vegetable oils (sunflower, soybean, cotton seed, and used frying oil) was studied using sodium ethoxide as a catalyst. The ester preparation involved a two-step transesterification
reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. Ethyl esters of four different types of vegetable oils were blended with the diesel fuel at 2 %, 5 %, 10 %, and 20 %, on a volume basis. The experimental results showed that the densities and viscosities of the blends increased with the increase of biodiesel concentration in the fuel blend. Cold flow properties were negatively affected as ethyl ester content was increasing. Distillation characteristics and cetane indexes were not significantly altered. These results are promising, and ethyl esters can be seen as a viable fully renewable alternative to petroleum diesel.
... Different alcohols with different substrates may result in different yield so alcohol-substrate combination should be kept in mind for maximum output. Excess of methanol causes inhibitory effect in the reaction because it changes the stability and configuration of biocatalyst/lipase that can leads to partial or complete inactivation of lipase [60][61][62]. Moreover, it also causes hindrance in separation of glycerol [61,62]. ...
... Excess of methanol causes inhibitory effect in the reaction because it changes the stability and configuration of biocatalyst/lipase that can leads to partial or complete inactivation of lipase [60][61][62]. Moreover, it also causes hindrance in separation of glycerol [61,62]. Methanol inhibition was observed with Novozym ® 435 lipase in transesterification of waste oils [63], microalgae oils, and various vegetable oils [64][65][66][67]. ...
Enzymes such as microbial lipases can be effectively used as biocatalysts for bio‐diesel production in a sustainable manner. Biocatalytic processes to produce bio‐diesel or biofuel is the need of time to reduce the emission of greenhouse gases produced from conventional diesel or fossil fuels. Lipases with excellent biochemical and physiological properties are most commonly used to catalyze the transesterification process for biodiesel production. Lipases obtained from microbes such as bacteria and fungi produce 70%–95% ethanol and methanol. Biodiesel is usually composed of fatty acid alkyl esters which are mono‐alkyl esters of either fatty acid methyl esters or fatty acid ethyl esters depending upon the alcohol (acyl acceptor) being used in the reaction. Factors such as bioreactor type, acyl acceptor, temperature, and glycerol can affect the enzymatic transesterification reaction. Recombinant enzymes such as recombinant lipases can be employed to obtain higher percentage of biodiesel due to their high specificity and biocatalytic activity for different substrates used for biodiesel production.
... Therefore, biofuel is frequently converted using a catalyst under less extreme circumstances. One of the most important variables to have a high biodiesel conversion at a quick reaction time is choosing an effective catalyst with the right concentration [56]. For the transesterification process, homogeneous catalysts like potassium hydroxide, sodium hydroxide, or sulfuric acid have been applied commercially. ...
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... The authors found that at 80 °C, biodiesel yields of 98.8, and 98.9% were produced at molar ratios of oil:acid:methanol of 1:1.9:74 and 1:4.2:162, respectively. Encinar et al. (2002) assessed the research on the transesterification of Cynara cardunculus oil using ethanol and catalysts of sodium and potassium hydroxide. Temperature, catalyst type and its concentration, and ethanol/oil molar ratio were the operation factors used. ...
In recent years, there has been a focused effort to reduce the harmful effects of synthetic and mineral-based lubricants by emphasizing the use of biodegradable-based lubricants. These lubricants play a crucial role in minimizing friction, ensuring smooth operation of machines, and reducing the likelihood of frequent failures. With petroleum-based reserves depleting worldwide, prices are rising, and environmental damage is increasing. However, biolubricants derived from nonedible vegetable oils offer environmental benefits as they are nontoxic, emit minimal greenhouse gases, and are biodegradable. In this study, biolubricants are synthesized from jatropha and jojoba oil using sulphuric acid (H2SO4) and hydrochloric acid (HCl) as catalysts through the transesterification and epoxidation processes. The optimization of influencing parameters is achieved using Taguchi’s orthogonal array, a statistical methodology. By employing design of experiments (DOE), the number of experimental trials is minimized while providing comprehensive details on the impact of control factors such as molar ratio, catalyst concentrations, and temperature. The results obtained from DOE reveal that the best optimized yield for jatropha biolubricant with H2SO4 and HCl catalysts is achieved with a molar ratio of 0.5:1.5, a temperature of 70 °C, and a catalyst concentration of 1.2 ml. The experimental yield for jatropha biolubricant with H2SO4 and HCl catalysts was measured at 226 ml and 238 ml, respectively, while the model predicted yield was 221 ml and 231 ml, respectively. The experimental yield for jojoba biolubricant with H2SO4 and HCl catalysts was recorded at 232 ml and 248 ml respectively, whereas the model predicted yield was 226 ml and 245 ml, respectively. Based on the analysis of variance (ANOVA) results, it is evident that among the three control factors, the molar ratio significantly influences the yield of both jatropha and jojoba biolubricants, as indicated by a p-value of less than 5%. The percentage contribution of the molar ratio in jatropha biolubricant with H2SO4 and HCl catalysts is found to be 98.99% and 97.2%, respectively. Furthermore, the R² value, which exceeds 90%, signifies a strong relationship between the independent and dependent variables. The deviation between the experimental and regression-predicted equations for the yield remains within 2.5% for all combinations of jatropha and jojoba biolubricants. In conclusion, the study successfully prepared biolubricants from jatropha and jojoba-based non-edible vegetable oils and determined the optimal conditions for their production.
Graphical abstract
... Vegetable oils can be used as material to produce methyl or ethyl ester. There are several methods for producing of ester; and the best method is known as transesterification [28][29][30][31][32][33][34][35][36][37][38]. Even a blend of 20% biodiesel and 80% diesel fuel will significantly reduce carcinogenic emissions by 27% and gases that may contribute to global warming up [39,40,41]. ...
zet Bu çalışmada saf dizel yakıtı ve dizel-biyodizel karışımlarının yanma ve egzoz emisyonları incelenmiştir. Araştırmada, menengiç yağından ilk olarak transesterifikasyon yöntemi ile biyodizel elde edilmiştir. Transesterifikasyon işleminden sonra ham menengiç yağı biyodizel viskozitesi, önemli ölçüde azalmış ve ısıl değeri atrmıştır. Menengiç yağı biyodizel üretiminden sonra, hacimsel olarak dizel yakıtı ile karıştırılmış ve B25 olarak adlandırılmıştır. Bu araştırmanın ikinci aşamasında,deneyler dört zamanlı enjeksiyonlu (CI) dizel motoru içinde saf dizel yakıtı ve dizel biyodizel karışımı (B25 yakıt) ile yapılmıştır. Konvansiyonel dizel yakıtı ile karşılaştırıldığında, dizel-biyodizel karışımları düşük karbon monoksit (CO), hidrokarbon (HC) ve karbon dioksitler (CO2) vermiş ancak azot oksit (NOx) emisyonlarının yüksek olduğu görülmüştür. Abstract In this study combustion and exhaust emissions with neat diesel fuel and diesel-biodiesel blends have been investigated. In the investigation, firstly biodiesel from menengic oil has been obtained by transesterification method. The viscosity of raw menengic oil biodiesel, obtained after transesterification, was reduced considerably and heating value was improved. After producing biodiesel from menengic oil, it volumetrically mixed with diesel fuel as a named B25 fuel. In the second phase of this 127 investigation, experiment has been conducted with neat diesel fuel and biodiesel blend (B25 fuel) in a four stroke compression injection (CI) diesel engine. Compared with conventional diesel fuel, diesel-biodiesel blends showed lower carbon monoxide (CO), hydrocarbon (HC) and carbon dioxides (CO 2) but higher oxides of nitrogen (NO x) emissions.
... However, beyond a molar ratio of 10:1, the conversion rate of rapeseed oil decreases slightly, which can be attributed to the diluting effect of methanol, as well as the increase in glycerol concentration in the mixture (Liu et al. 2008). In fact, as the amount of methanol increases, it becomes difficult to separate glycerol from the ester phase, shifting the process's balance in favor of triglyceride synthesis (Encinar et al. 2002). As a result, the methyl ester concentration has decreased for the molar ratio of 12:1, blocking the production of monoglycerides (MGs), diglycerides (DGs), and even triglycerides (TGs). ...
As the demand for sustainable energy sources expands, the production of biodiesel has attracted great attention. The development of effective and ecologically friendly biodiesel catalysts has become an urgent need. In this context, the goal of this study is to develop a composite solid catalyst with enhanced efficiency, reusability, and reduced environmental impact. For that, eco-friendly, and reusable composite solid catalysts have been designed by impregnating different amounts of zinc aluminate into a zeolite matrix (ZnAl2O4@Zeolite). Structural and morphological characterizations confirmed the successful impregnation of zinc aluminate into the zeolite porous structure. Catalytic experiments revealed that the catalyst containing 15 wt% ZnAl2O4 showed the highest conversion activity of fatty acid methyl esters (FAME) of 99% under optimized reaction conditions, including 8 wt% catalyst, a molar ratio of 10:1 methanol to oil, a temperature of 100 °C, and 3 h of reaction time. The developed catalyst demonstrated high thermal and chemical stability, maintaining good catalytic activity even after five cycles. Furthermore, the produced biodiesel quality assessment has demonstrated good properties in compliance with the criteria of the American Society for Testing and Materials ASTM-D6751 and the European Standard EN14214. Overall, the findings of this study could have a significant impact on the commercial production of biodiesel by offering an efficient and environmentally friendly reusable catalyst, ultimately reducing the cost of biodiesel production.
... En este proyecto se sintetizó biodiesel a partir de aceite de soya y de aceite de jatrofa mediante el método de transesterificación, siguiendo el mismo procedimiento reportado por Encinar y colaboradores [13]. La reacción de transesterificación se llevó a cabo en un reactor esférico de 500 mL, al mismo que se le instalo un termómetro y un sistema para condensación; se situó este reactor sobre una parrilla con agitador magnético, se agregaron 200 mL de aceite vegetal de soya y se ajustó la temperatura de la parrilla a 60 °C, en un vaso de precipitado se colocó 40 mL de alcohol (metanol) y 0.7 g de NaOH, se agitó esta mezcla hasta llegar a la homogeneidad; una vez que el aceite llegó a la temperatura de 60 °C, se vacío el metóxido de sodio (metanol + NaOH) dentro del reactor y se provocó la agitación magnética durante 4 horas, una vez pasado este tiempo se dejó reposar el contenido en el reactor hasta su enfriamiento a temperatura ambiente, formándose dos capas en la reacción: la capa superior que consistió de ésteres metílicos (biodiesel) y una capa inferior de glicerina, restos de catalizador sin reaccionar y exceso de metanol. ...
... Biodiesel production involves the reaction of lipids with an alcohol in the presence of an acidic or alkaline catalyst [15]; thus, the catalysts for biodiesel production (classified as acid, base, or enzyme catalysts) have attracted immense attention. As basic catalysts (such as sodium and potassium hydroxide, methoxide, and carbonate) cause high reaction rates, they are generally used for industrial biodiesel synthesis [16]. However, very little water causes basic catalysts to undergo the saponification reaction, making anhydrous conditions essential for basic catalysis [17]. ...
Here, a composite nanoparticle with an acid–base bifunctional structure has been reported for the transesterification of rapeseed oil to produce biodiesel. Triazole-PWA (PWA = 12-tungstophosphoric acid) composite materials with a hexahedral structure are produced using the precipitation method, showing the average particle diameters of 200–800 nm. XPS and FT-IR analyses indicate well-defined chemical bonding of triazole moieties to the PWA. The functionalization and immobilization of PWAs are investigated due to strong interactions with triazole, which significantly improves the thermal stability and even surface area of the heteropoly acid. Furthermore, various ratios of triazole and PWAs are examined using NH3-TPD and CO2-TPD to optimize the bi-functionality of acidity and basicity. The prepared nanomaterials are evaluated during the transesterification of rapeseed oil with methanol to analyze the effect of triazole addition to PWAs according to the different ratios. Overall, the bifunctional triazole-PWA composite nanoparticles exhibit higher fatty acid methyl ester (FAME) conversions than pure PWA nanoparticles. The optimized catalyst with a triazole:PWA ratio of 6:1 exhibits the best FAME-conversion performance due to its relatively large surface area, balance of acidity, and strong basicity from the well-designed chemical nano-structure.
... The reason for the high production rate at 30°C can be attributed to the fact that higher temperatures reduce transesterification and thus lead to soap formation and reduce the separation between the ester layer and the glycerol layer. (12) As shown in figure number (4) The experiment was conducted at different times. It was noted that 30 minutes is the ideal time As 20 minutes, was Not Enough to carry out an esterification reaction, a time of 40 minutes leads to soap formation (15). ...
As a result of the high prices of traditional fuels and the pollution problems resulting from the use of this type of fuel, there was an urgent need to search for actual alternatives that directly contribute to reducing global dependence on traditional fuels and reducing the percentage of pollution. Therefore, biofuels are distinguished in solving part of these problems. This research dealt with fuel production Bio-fuel from grilled chicken oil waste innovatively, we have never found its use, so this research relied on the production of biofuel from grilled chicken oil waste using hexane as a co-solvent through the one-step exchange esterification process hexane is reused again through the distillation process. At a low temperature, it had a major role in increasing the yield, reducing the reaction time and reaction temperature, and reducing the ratio of ethanol used to the oil ratio, as well as improving the standard specifications of the resulting fuel. the fuel produced in this way is suitable for mixing with traditional fuels and for use.
... If the methanol concentration becomes too high, the ethanol will dilute the catalyst which in turn will reduce the biodiesel yield. It is also prudent to reduce the concentration of methanol as a higher alcohol concentration will increase the downstream separation cost of methanol and biodiesel [46]. ...
Algae based third generation biodiesel production is a recent advancement in renewable energy due to its minimal land requirements, cultivation in wastelands etc than food stock based second generation biodiesel production. This paper addresses on the study of the optimum yield of biodiesel produced from oxygenic photosynthetic bacteria-based Spirulina Platensis algae by microwave assisted transesterification. Effect of microwave irradiation time which affects the temperature on the extraction of algal oil and simultaneous in-situ transesterification was investigated for biodiesel production. The response surface methodology using Box Behnken Design was used to analyze constituent parameters like catalyst concentration, alcohol concentration and process parameters like microwave time. Results indicate that microwave assisted transesterification yields at 70.7% of biodiesel production with respect to algae dry weight at an optimum of catalyst concentration of 1.6%, with alcohol concentration of 1:9.7 and microwave irradiation time of 3.2 minutes.
... When the methanol to oil molar ratio was adjusted from 2 : 1 to 8 : 1, the biodiesel produced increase from 78.4% to 97.6% and then declined to 92.3% at 10 : 1. e excess methanol had no significant influence on the yield above a molar ratio of 10 : 1. When the molar ratio of methanol to oil surpassed 9 : 1, glycerol separation became more difficult, leading to lowering of methyl esters yield from 97.6% to 94.5% which agrees with Amish et al. [32] and Encinar et al. [33]. According to Takase et al. [34][35][36][37], excess amounts of methanol in a transesterification reaction leads to dilution of the oil. is phenomenon might have occurred in this study. ...
In this study, catalytic transesterification of Shea butter oil with methanol to biodiesel was carried out. The clay particle was first sieved with a 250 ml sieve and then calcined at 800μC for 8 hours in a furnace. The calcined clay was then modified with 5% each of Zn(NO3)2 and SnCl2 separately for 3 h at 60°C using incipient wetness impregnation method. The slurry compositions were then dried at 120°C overnight in an oven. The modified clay catalysts were subsequently calcined for 3 hours at 600°C. The clay that had been modified with SnO2 and ZnO was assigned SD and ZD, respectively, whereas the clay that had not been doped (control) was assigned as AC. The catalysts were characterized using X-ray Diffractometer (XRD), Brunauer Emmett Teller (BET) surface area, and Scanning Electron Microscopy (SEM). Biodiesel was then produced from each of the catalysts under varying conditions of methanol to oil molar ratio, catalyst concentration, reaction temperature, and reaction time. When compared the performances of the catalysts (activated clay modified with SnO2, ZnO, and the control), activated clay modified with SnO2 resulted in an optimal conversion yield of 99.8% under 8 : 1 methanol to oil molar ratio, 1% catalyst concentration, 60°C of reaction time in 60 minutes. The catalytic performance was affected by the basicity and surface area of the catalysts. The biodiesel produced was comparable to American and European Union standards.
... As a result, many countries, e.g., Indonesia, Thailand, and Colombia, compete in biodiesel production, among which Malaysia provided about 0.17 million tons from 2.7 million tons based upon 23 biodiesel resources in 2011 [8]. However, biodiesel from the vast feedstock category has become a new essential hub for the energy sector due to its attractive features [9,10]. The feedstock selection is a vital concern of biodiesel and is preferred provided it is based on local conveniences, cost-effectiveness, industrial feasibilities, and technical viabilities [11]. ...
Background
Rapid consumption of fossil fuels as well as rising environmental deterioration caused by extreme CO2 emissions has become crucial in searching for a clean and renewable energy source such as biodiesel. The current work is an attempt to produce biodiesel from a potential non-edible feedstock of Aphanamixis polystachya, locally known as ‘Royna’ seed oil in Bangladesh.
Methods
Royna oil was extracted from the seed by Soxhlet extraction method. Biodiesel was synthesized by a three-step process: saponification of oil, followed by acidification of the soap, and esterification of the free fatty acid (FFA).
Results
The result presented showed that royna seed was found to be rich in oil with a maximum yield of 51% (w/w). Several reaction parameters were optimized during biodiesel production in their percentage proportion of oil to a catalyst (1:2), soap to HCl (1:1.5), FFA to an alcohol molar ratio (1:7), and catalyst (1 wt%). As a result, the highest yield of 97% was obtained from 7.5 wt% FFA content oil at 70 °C for 90-min reaction time. ASTM verified standard methods were employed to analyze the physicochemical properties of the as-prepared biodiesel. The structural and surface properties of the royna oil and as-prepared biodiesel were determined by ¹H NMR and FTIR spectroscopic methods indicating a complete conversion of oil to biodiesel.
Conclusions
The study investigated the promising viability of royna oil to biodiesel using a three-step conversion route along with the heterogeneous catalysis system to circumvent the current environmental issues.
... It yields as much as 3.2 units of fuel product energy for every unit of fossil energy consumed in its life cycle compared to 0.83 units for petroleum diesel (Sheehan et al., 1998) [25] . However, the advantages of vegetable oil-derived biodiesel as an alternative fuel include fuel performance and lubricity, a higher cetane rating than petro-diesel, a higher flash point that makes it safe to handle, lower toxicity to plants and animals, reduced exhaust emissions, renewability and biodegradability, etc (Ma and Hama, 1999;Encinar et al., 2002;Zhang et al., 2003;Sivaprakasam and Saravanan, 2007) [2,31,27] . Biodiesel can be blended and used in many different concentrations. ...
This study evaluates the effect of sonication on biodiesel produced by transesterification of methanol and waste Kings vegetable oil in the presence of a heterogeneous clay catalyst. The fuel properties of biodiesel produced were evaluated according to standard methods. The results revealed that the value of the flash point for the sonicated biodiesel at 10 min (128.40℃) was found to be slightly lower than ASTMD-6751 standard (130.00℃) while sonicated at 30 min (146.10℃) and unsonicated (153.80℃) were higher than the petro-diesel value (54.00℃). The fire point value was high in the biodiesel without sonication and at 30 min but lowest at 10 min. Viscosity values (2.67 mm 2 /sec, 1.58 mm 2 /sec and 1.59 mm 2 /sec) showed that the biodiesel was in accordance with the ASTM standard (1.90-6.00 mm 2 /sec). The result also revealed that the cetane number for biodiesel without sonication (45.89) and at 30 min (48.60) was in accordance with the ASTM standard while at 10 min (51.00) was higher than the ASTM standard but within the petro-diesel value. The calorific value without sonication (23.20 MJ/kg) and with sonication (28.40 MJ/kg and 31.80 MJ/kg) revealed that the biodiesel produced posses' high power efficiency. The cloud point values (12.00°C, 8.00°C and 9.00°C respectively) were within the acceptable ASTM standard. The density values of the biodiesel without sonication and sonicated (0.94 g/cm 3 , 0.84 g/cm 3 and 0.80 g/cm 3 respectively) fell within the acceptable ASTMD-6751 standard. These results show that biodiesel from waste Kings vegetable oil when sonicated could serve as an alternative to fossil fuels.
... Even emission rates of hazardous exhaust gases like carbon dioxide, carbon monoxide, smoke, and nitrogen oxide from diesel engine were analyzed after use of biodiesel and its blends. It was found that the direct use of biodiesel in diesel engines causes numerous problems in engines such as poor fuel atomization, incomplete combustion of fuel, deposition of carbon residues on fuel injectors, and engine fouling (Sridharan and Mathai, 1974;Encinar et al., 2002;Williamson and Badr, 1998;Karaosmanoǧlu et al., 2000). Biodiesel produced from seed oils having high free fatty acids, high viscosity, high pour and cloud point results in choking of power injectors, decreases in engine speed, decreases in release of energy, and engine compatibility is reduced (Ali et al., 2016). ...
Algal biofuels are considered a possible source of renewable energy. The combination of microalgal cultivation and biofuel production using a biorefinery approach is projected to dramatically increase the overall cost effectiveness of biofuel production. Technological advances—including optimization of crop conditions, safeguarding algal crops from predators, microalgal biomass harvesting, and other downstream processing technologies—are important and can lead to improved cost effectiveness. Therefore, this chapter will focus on algal-based biofuel and potential challenges, including the crop protection from potential predators, the effect of various medium contents on biomass yield, and cost-effective algal harvesting and future perspectives as well. Since, the minimizing of the costs of biofuel production from microalgal biomass is effective away to attract the commercial application. In conclusion, the chapter provides algal farmers with promising strategies to overcome some potential challenges that limit the economic production of biofuels as clean energy.
... Approximately 6% of the annual Cynara cardunculus L. biomass is from the seeds [119] and these seeds have an oil content of about 25% [120,121]. The oil content of the seeds of Cynara cardunculus L. is very similar to sunflower seeds, making it particularly suitable for biodiesel production [122][123][124]. In addition to routine biodiesel production, a current study has been shown that yeast biodiesel production from Cynara cardunculus L. stalks [125]. ...
In this paper, the regions where Cynara cardunculus L. is cultivated in Turkey are revealed, with data obtained from several locations in Turkey. Furthermore, the installation of active biogas plants in these regions has been identified, and the utilization of Cynara cardunculus L. residues as a biomass source, particularly in Izmir biogas plants, has been investigated. To begin, the amount of Cynara cardunculus L. cultivated in the world and Turkey has been determined. According to the Food and Agriculture Organization of the United Nations (FAO)’s recent data for 2019, approximately 1.6 million tons of Cynara cardunculus L. were produced globally, with Turkey accounting for nearly 2.5% of this quantity. The data from the Biomass Energy Potential Map for Turkey (BEPA) was reviewed, and it was calculated that approximately 40 thousand tons of Cynara cardunculus L. are produced in Turkey each year. Furthermore, the agricultural production of this crop in Turkey generates roughly 225 thousand tons of residues. In comparison to other regions, the Izmir region generates 32.5% of Turkey’s Cynara cardunculus L. residues. However, no research on the evaluation of this residue potential and the utilization of Cynara cardunculus L. residues in biogas production has been conducted to date. As a result, it was aimed at the residual potential of Cynara cardunculus L. in various regions of Turkey, as well as its potential utilization as a biomass resource for biogas plants in these areas. It has been calculated that 1.65% of the Izmir population could supply its energy demands by utilizing the energy equivalent of the Izmir region’s wastes.
... On the other hand, fuel with very low viscosity may not meet the needed lubrication, which causes leakage and increased wear in the fuel injection assembly. High viscosity may form larger droplets on injection resulting in to poor combustion, increased exhaust smoke and emissions (Encinar et al. 2002). (2012) Therefore, it is recommended to blend the ester with conventional diesel so as to meet the appropriate viscosity. ...
Fabaceae is the third largest family in the plant kingdom which comprises around 19,500 species forming 7% of the total flowering plants. Around 8% of them are oil bearing, on which the world seriously relies on its vegetable oil need. This chapter deals with 10 oil bearing species in which 2 are edible and 8 are non-edible. Among them 7 are mostly obscure with reference to their role on biodiesel production. Such species are also taken into active consideration as biodiesel resource as they are emerging as location-specific complementary energy alternatives. Biodiesel prepared from a portion of the edible oil from groundnut (Arachis hypogaea) and soybean (Glycine max) is being in use world over. Among the non-edible sources pongam (Pongamia pinnata) is richly used in biodiesel preparation. Active investigations are pursued during the last one decade on another seven species: African oak (Afzelia africana), babul (Acacia nilotica), diesel tree (Copaifera langsdorffii), mesquite (Prosopis juliflora), shikakai (Acacia concinna), shittim (Acacia raddiana) and brebra (Millettia ferruginea) though large scale economic exploitation is still on progress.
... Since the utilization of used cooking oil does not interfere with food security, it is a highly advantageous raw material to be used in the production of biofuels. Moreover, waste cooking oil is the main waste generated from cooking activities in restaurants and households [2]. ...
The synthesis of the Ni-Mo sulfated zirconia (NiMo-SZ) catalyst and its application to convert waste cooking oil into biofuel was successfully conducted. The synthesis process was started with a sulfation process on the zirconia oxide (ZrO 2 ) using 0.5, 1.0, and 1.5 M sulfuric acid (H 2 SO 4 ) through wet impregnation to obtain sulfated zirconia (SZ). Solid SZ with the highest total acidity value was calcined at temperature 500, 550, 600, 650, and 700 ° C. Solid SZ calcined with the optimum temperature was treated with Ni and Mo metals at 1%, 2%, and 3% (w/w) through a hydrothermal method. Pure ZrO 2 , SZ, and 1, 2, and 3 NiMo-SZ catalysts were used in the hydrocracking of used cooking oil into biofuel. The results showed that the 1.5 M SZ catalyst calcined at 500 °C had the highest acidity value of 3.8137 mmol/g. The 3-NiMo-SZ catalyst had the best activity valuing at 80.54%, while 1-NiMo-SZ produced the best selectivity in producing gasoline fraction until 73.93%.
... Alcohol fuels are produced by fermentation of sugars derived from wheat, corn, sugar beets, sugar cane, molasses and any sugar or starch that alcoholic beverages can be made from fruit waste, etc. The ethanol production methods used are enzyme digestion (to release sugars from stored starches), fermentation of the sugars, distillation and drying (Encinar et al., 2002). The distillation process requires significant energy input for heat (often unsustainable natural gas fossil fuel, but cellulosic biomass such as bagasse, the waste left after sugar cane is pressed to extract its juice, can also be used more sustainably). ...
In the present investigation, Biomethanated distillery spent wash
contain several bacteria that possess better growth ability at 50% dilution
of BMDSW. These bacterial isolates are having the potential to utilize the
BMDSW as a nutrient for the production of PHB and also to reduce the
pollutant load of BMDSW by way of decolourization and COD reduction.
Among the bacterial isolates, Bacillus flexus (DB2) showed good potential
for PHB production. However with regard to decolourization and COD
reduction, the potential was greater for mixed consortia with the following
consortia performing better with regard to decolourization ((Bacillus
flexus (DB2)+B. cereus(APB2)+Pseudomonas aeruginosa(AUB2)+ P.
stutzuri (AUB3)) and COD reduction (B. cereus (APB2)+ P. aeruginosa
(AUB2)+ P. stutzuri (AUB3)).
... However, for ratios over 12:1, the separation of the glycerol formed is challenging. 45 The bottom stream then enters an extractor to remove the glycerol, which leaves the equipment with the appropriate specifications for crude glycerol. ...
Waste oils are a very promising raw material in the biodiesel industry, which is why great efforts have focused on the removal of the free fatty acids (FFAs) present in this source, mainly through the esterification reaction. Many studies have evaluated the influence of different variables on the reaction conversion, such as temperature, catalyst concentration, and alcohol/oil ratio. However, it is still necessary to verify how the esterification is affected by higher water concentration. In this study, different acid‐catalyzed esterification reaction conditions with distinct water concentrations were tested experimentally, and a new rate expression was proposed. This newly obtained reaction kinetics was then used to undertake a complete analysis of the biodiesel production process from waste oil, evaluating the influence of higher water concentrations in the esterification, and including different optimizations and an economic evaluation. Concerning some of the process modifications, it was verified that the inclusion of three energy‐saving heat exchangers reduced utility costs by 40%. In contrast, the inclusion of an ethanol‐recycling distillation column reduced raw material costs by 40%. Different settings were also tested, varying the feed composition and the esterification reaction time and conditions, resulting in a payback period of less than 3 years in any evaluated scenario. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd
... Therefore, there is the scope of using ethanol for producing biodiesel. Ethanol has several advantages to methanol, such as offering better solvent properties and low toxicity relative to methanol [27,28] Furthermore, there is a study reported that the biodiesel formed using ethanol, the fatty acid ethyl ester (FAEE) present a higher cetane number, calorific value, oxidation stability, lubricant characteristics, lower cloud and pour points, and also have lower tailpipe emissions in comparison to the product collected using methanol, fatty acid methyl ester (FAME) [29,30]. ...
In this study, coconut oils have been transesterified with ethanol using microwave technology. The product obtained (biodiesel and FAEE) was then fractional distillated under vacuum to collect bio-kerosene or bio-jet fuel, which is a renewable fuel to operate a gas turbine engine. This process was modeled using RSM and ANN for optimization purposes. The developed models were proved to be reliable and accurate through different statistical tests and the results showed that ANN modeling was better than RSM. Based on the study, the optimum bio-jet fuel production yield of 74.45 wt% could be achieved with an ethanol–oil molar ratio of 9.25:1 under microwave irradiation with a power of 163.69 W for 12.66 min. This predicted value was obtained from the ANN model that has been optimized with ACO. Besides that, the sensitivity analysis indicated that microwave power offers a dominant impact on the results, followed by the reaction time and lastly ethanol–oil molar ratio. The properties of the bio-jet fuel obtained in this work was also measured and compared with American Society for Testing and Materials (ASTM) D1655 standard.
... Nevertheless, it is dutiful to underline that the specific cardoon header described by Pari et al. was specifically developed to prevent the subsequent use of a shredder to manage the left aboveground biomass [28,30]. In fact, as reported above, the cardoon biomass is suitable for bioenergy purposes [60][61][62][63][64] but, unfortunately, the value chain is not yet developed in such a way. Consequently, the cardoon biomass still represents a burden and cost for farmers and contractors, which refuse to invest money on specific equipment, as for instance, the ad-hoc header for the combine harvester. ...
Cardoon seeds have been proved to thrive in the Mediterranean region, even under low input management and its biomass is suitable for several food and industrial uses. Despite that, a proper value chain has not been set properly and uncertainty still lays among producers and industries, particularly concerning the harvesting stage. The present study supports, via field trials, the hypothesis that cardoon seeds can be harvested using a conventional combine harvester equipped with the sunflower header. Theoretical field capacity (TFC), effective field capacity (EFC), and field efficiency (FE) were 2.36 ha h −1 , 2.05 ha h −1 , and 1.82 Mg h −1 , respectively, while harvesting costs were calculated as 69.52 € ha −1. Seed loss was only 3.2% w/w of the potential seed yield. The machinery's performance, costs, and seed loss are comparable with sunflower harvesting, underlying the possibility to use the available technology directly to harvest cardoon seeds.
The utilization of the petroleum products in engines is harmful to the humans as they pollute the environment. Nowadays, extensive research is in process to find an alternative fuel and improve its quality. The nanoparticles are one of the recent technologies that is useful for upgrading the fuel properties. This work aims to find the influence of CuO nanoparticles on performance of diesel engine, emission and combustion characteristics which runs on jojoba biodiesel blend (JB20) as a fuel. Different proportions of CuO nanoparticles (25, 50, and 75 ppm) were dispersed into the JB20 fuel. It is experimentally seen that BTE for the JB20CN50 fuel was higher than that of other Jojoba biodiesel fuel samples. The combustion characteristics such as ignition delay, HRR and cylinder pressure were also determined for analysing the effect of CuO nanoparticles. Engine emission hydrocarbons, CO and smoke emissions were also found lesser when the CuO nanoparticles added to JB20.
The biodiesel industry is a promising field globally, and is expanding significantly and quickly. To create a biodiesel business that is both sustainable and commercially feasible, a number of studies have been conducted on the use of non-edible oils to produce biodiesel. Thus, this study highlights biodiesel synthesis from non-edible plant oils such as pongamia and jatropha using a glycerol separation technique with an AC high voltage method through the transesterification reaction. In this context, non-edible plant oil has emerged as an alternative with a high potential for making the biodiesel process sustainable. Moreover, the study introduces how the created biodiesel fuel behaves when burned in a diesel engine. The results showed that the optimum conditions for creating biodiesel were a temperature of 60 °C, a potassium hydroxide catalyst percentage by weight of oils of 1%, and a stirring time of 60 min at a 5:1 (v/v) ratio of methanol to oil. A high-voltage procedure was used to separate glycerol and biodiesel using two electrodes of copper with different distances between them and different high voltages. The results showed that, for a batch of 15 L, the minimum separating time was 10 min when the distance between the copper electrodes was 2.5 cm, and the high voltage was 15 kV. The density, kinematic viscosity, and flash point of jatropha oil were reduced from 0.920 to 0.881 g/cm3 at 15 °C, from 37.1 to 4.38 cSt at 40 °C, and from 211 to 162 °C, respectively, for the production of biodiesel. Additionally, the density, kinematic viscosity, and flash point of pongamia oil were reduced from 0.924 to 0.888 g/cm3 at 15 °C, from 27.8 to 5.23 cSt at 40 °C, and from 222 to 158 °C, respectively, for the production of biodiesel. The calorific value of jatropha oil was increased from 38.08 to 39.65 MJ/kg for the production of biodiesel, while that of pongamia oil was increased from 36.61 to 36.94 MJ/kg. The cetane number increased from 21 for oil to 50 for biodiesel and from 32 for oil to 52 for jatropha and pongamia biodiesel, respectively. In order to run an air-cooled, single-cylinder, four-stroke diesel engine at full load, the produced biodiesel fuel was blended with diesel fuel at different percentages—10, 20, and 30%—for jatropha and pongamia methyl esters. The produced engine power values were 3.91, 3.69, and 3.29 kW for B10, B20, and B30, respectively, compared with the engine power value of jatropha methyl ester, which was 4.12 kW for diesel fuel (B00); meanwhile, the values were 3.70, 3.36, and 3.07 kW for B10, B20 and B30, respectively, for pongamia methyl ester. The findings suggest that the biodiesel derived from non-edible oils, such as pongamia and jatropha, could be a good alternative to diesel fuel.
Theoretical framework: A biodiesel fuel is made from long-chain fatty acids derived from vegetable oil or animal fat. Similarities between physical-chemical characteristics of diesel and biodiesel make their mixture feasible. Environmental benefits achieved by using biofuels to drive machines has increased their contribution in energetic matrixes. Objective: The aim of this research is to produce soybean and sunflower biodiesel in the laboratory using a transesterification reaction and to examine the biodiesel specifications for utilization in compression ignition engines. Method: The physical-chemical properties of the biodiesel measured in the present work are density, viscosity, cetane index, flash point, pour point, and cloud point. Results and conclusion: For soybean and sunflower biodiesel, density (867 kg/m³, 860 kg/m³), viscosity (5.29 mm²/s, 5.30 mm²/s), Centane index (53.88, 55.66), flash point (187°C and 135.6°C) are reported respectively. Regarding the pour point, cloud point, were only determined for sunflower biodiesel, respectively, -2°C and 13°C. The results indicate that these properties, density, kinematic viscosity, flash point, as determined from the soybean and sunflower biodiesel are within the limits established by The Brazilian National Agency of Petroleum, Natural Gas and Biofuels, Resolution No. 45 of the ANP of 08/25/2014 – DOU 08/26/2014. These values are, respectively, 850-900 kg/m³, 3-6 mm²/s, at least 100°C.The produced biodiesel presented behavior similar to diesel S10 proving its viability of use. Research implications: As a result of such thorough research, we are able to compare many characteristics of soybean and sunflower biodiesel with commercial diesel S10. This research is critical to the performance evaluation of a compression ignition engine and the potential reduction in greenhouse gas emissions associated with conventional diesel.
The objective of the work was to produce biodiesel from soybean,
babassu, and frying oils using two methodologies and to evaluate the use of
proton Nuclear Magnetic Resonance as an analytical tool for assessing the
conversion into methyl esters. Biodiesel samples were produced by
transesterification. According to the results, the 2nd methodology contributes
to the increase of conversion into methyl esters in the order of 22.14% (BOS),
2.64% (BOB), and 10.16% (BOF). 1H NMR was efficacy in determining the
conversions into methyl esters, obtaining the same trend as the gas
chromatography, as well as in the analysis of the fatty acid profiles of the raw materials, indicating a difference in the intensity of the signals in the regions ~
4.1 – 4.3 and ~ 5.3 ppm.
The review primary aims are to provide a first comprehensive overview and a database of various base and acid catalysts derived from apatites for biodiesel synthesis via transesterification of feedstocks containing low levels of fatty acid and esterification of highly acidic feedstocks. To achieve this goal, we present the different outlines of apatite materials and classify the derived catalysts into various categories in order to understand the unique characteristics of each one. This exploration also highlights biodiesel production methods, feedstocks and factors influencing biodiesel yields. Furthermore, we provide mechanistic insights, limitations and future perspectives.
Petroleum-based fuels are well-established products that have served industry and consumers for more than one hundred years. However petroleum, once considered inexhaustible, is now being depleted at a rapid rate. As the amount of available petroleum decreases, the need for alternative technologies to produce liquid fuels that could potentially help prolong the liquid fuels culture and mitigate the forthcoming effects of the shortage of transportation fuels is being sought. The dynamics are now coming into place for the establishment of a synthetic fuels industry; the processes for recovery of raw materials and processing options have to change to increase the efficiency of oil production and it is up to various levels of government not only to promote the establishment of such an industry but to recognise the need for available and variable technology. This timely handbook is written to assist the reader in understanding the options that available for the production of synthetic fuel from biological sources. Each chapter contains tables of the chemical and physical properties of the fuels and fuel sources. It is essential that the properties of such materials be presented in order to assist the researcher to understand the nature of the feedstocks as well as the nature of the products. If a product cannot be employed for its hope-for-use, it is not a desirable product and must be changed accordingly. Such plans can only be made when the properties of the original product are understood. The fuels considered include conventional and unconventional fuel sources; the production and properties of fuels from biomass, crops, wood, domestic and industrial waste and landfill gas.
Spent bleaching earth (SBE) is a waste created by the vegetable oil refining industries that right now have restricted alternatives for advantageous reuse. An overabundance of about 2 million tons for each time of SBE is created worldwide with significant amounts accessible in the Middle East countries where noteworthy volumes of edible oils are developed. SBE is typically disposed of in landfill, which is costly, unfriendly to the environment, and represents an inefficient use of a potentially useful and valuable byproduct. The high oil content of SBE can rapidly oxidize to the point of spontaneous ignition posing fire hazard and a potential threat to the environment. Efforts have been made to transform it into a useful product. Utilizing SBE or the residual oil in SBE for various applications such as wastewater treatment, production of biodiesel, biofertilizer, fuel briquettes and non-fired wall tiles could reduce the waste generated by the edible oil refining industry and improve its sustainability. In this manner, this review compiled and reviewed a full overview of literature on recycling and utilization practices of SBE. Finally, future perspectives and considerations for the viable industrial-scale application of regenerated SBE as an economically significant waste with broad application prospects, are also discussed.
Biodiesel synthesis by using model waste sunflower oil and methanol was performed in presence of zirconium sulfate (ZS) heterogeneous catalyst. The effects of reaction parameters such as methanol/oil molar ratio, catalyst dosage, temperature and time were examined. The most appropriate conditions were found to be 9/1 molar ratio, 3 wt% catalyst dosage, at 115 °C of temperature for 4 h of time with a fatty acid methyl ester yield of 88%. Reusability of the catalyst was examined with X-ray diffraction of unused and used catalyst. Besides, reaction kinetics of simultaneous esterification and transesterification were investigated. The concentration terms of triglyceride and methanol were determined as driving force and adsorption groups. According to suggested Eley–Rideal mechanism adsorbed methanol reacted with triglyceride during the surface reaction step which was supposed to be rate limiting step for overall reaction. The constants of k, KM and KG were calculated as 5.84 × 10–3 L gcat−1 min−1, 1.28 L mol−1 and 2 × 10–3 L mol−1.
THE PURPOSE. The presented work aims to analyze the realities and prospects for the use of working media in the production of biodiesel fuel, including the supercritical fluid state. METHODS. Methods for obtaining biodiesel fuel are considered, including the method of transesterification, as the most common, as well as methods of pyrolysis and the combined process of hydrolysis and esterification. RESULTS. Traditional (industrially used methods for producing biodiesel fuel), as well as methods involving supercritical fluid media at their core, are considered. Along with a description of the state of affairs on the issues under discussion in the world, the results of our own research carried out by the team of authors of this article are also presented. Attention is drawn to the prospects of ultrasonic emulsification of the reaction mixture and the use of heterogeneous catalysts in order to mitigate supercritical fluid conditions for the process of obtaining biodiesel fuel and save energy. The conditions for obtaining biodiesel fuel without free glycerol and converting it into a fuel component are also discussed. CONCLUSION. Transesterification carried out under supercritical fluid conditions provides significant advantages over the traditional process and, especially in terms of the possibility of using a variety of raw materials, including low-quality ones, facilitates the procedure for isolating the final product and, finally, makes it possible to switch from relatively small-scale implementations with batch reactors to high-performance plants with flow reactors.
The aim of this study is to develop novel and an efficient bifunctional heterogeneous catalyst based on the SnO2@Mn-ZIF core shell support decorated with Tungstophosphoric acid (TPA) active moieties. The designed catalyst was characterized with Thermal Gravimetric analysis (TGA/DTA), X-Ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDX) analysis, Fourier transform infrared spectroscopy (FT-IR), Brunauer Emmet Teller (BET) analysis and Temperature Programmed Desorption of ammonia (NH3–TPD) and carbon dioxide (CO2–TPD) for structural and morphological investigation. Effect of crucial parameters such as methanol to oil molar ratio, reaction temperature, reaction time, agitation speed and catalyst dosage were thoroughly studied to develop profitable biodiesel process. The results indicated that Tungstophosphoric acid was well dispersed on the surface of the support. Further, it was noted that the catalyst with 30 wt% Tungstophosphoric acid onto the support formulation provided maximum biodiesel yield of 91.5% under optimum reaction conditions of 6 wt% catalyst dosage with 18:1 methanol to oil molar ratio, 500 rpm stirring speed and reaction temperature of 100 °C for 3 h. Finally the designed catalyst experienced profound stability and was recycled up to five times for biodiesel production without any prior treatment.
In recent years, biodiesel has proven to become a feasible alternative source of energy, due to its attractive benefits such as reduced emissions, renewability, and energy sustainability. The conventional techniques implemented to produce biodiesel vary but aim to address production challenges such as the natural mass transfer limitation of reactants and the governing reaction kinetics prediction of transesterification. In this study, the processing methodologies for novel biodiesel reactors such as Reticulated Vitreous Carbon (RVC) batch reactor and microchannel reactor are extensively evaluated, particularly the kinetic mechanisms and theories of the intensification approaches. The kinetic mechanisms was identified for the RVC reactor and microchannel reactor, along with constructing the mass transfer and glyceride prediction models. These reactors are then benchmarked against the conventional stirred tank reactor to evaluate their respective performances in reaction kinetics, mass transfer, and biodiesel yield. Optical analyses such as thermal imaging and digital microscopy were performed for the RVC reactor and microchannel reactor, respectively. In addition to the qualitative approach for analysis, statistical models such as Pareto, factorial, and response surface methodology were also implemented to characterise the reactors quantitatively. The physical-limiting regime for the benchmark batch reactor was found to be in the range of 0s to 270s, where intensification is significant for yield before transitioning into a reactant-limiting regime. However, the low porosity RVC (20‒30 ppi) combined with high agitation speed (400 rpm) can achieve a high biodiesel yield of 74% within 3 minutes. The physical-limiting regime (0‒180 s) for the RVC reactor was found to be shorten by 10‒20 s against benchmark reactor due to more substantial agitation capabilities caused by micro-turbulences induced from the reticulated surfaces. The microchannel reactor utilises micro-level diffusion and internal circulation to promote mass transfer in transesterification. Higher reaction temperature causes slug flow to transit into an annular flow, resulting in an overall increase in specific interfacial area. The mass fractions of the slug and annular flows change over time due to the production of biodiesel. The magnitude of the volumetric mass transfer coefficients and first-order kinetic constants are in the increasing order of microchannel, benchmark, and RVC reactors. An increase in reaction temperature from 30°C to 45°C shows an improvement of 157.9% and 63.2% for mass transfer using microchannel and RVC reactors, respectively. In contrast, an improvement of 90.0% and 149.9% was observed for kinetic rates in microchannel and RVC reactors, respectively. Overarching insights indicate that the RVC reactor has higher mass transfer and kinetic rates for transesterification reaction, while microchannel reactors are more sensitive to improvement from increasing reaction temperature. The reaction kinetic models discussed in this study provides additional mechanisms to the conventional first-order, second-order kinetics to improve conventional model adequacies.
Cardoon (Cynara cardunculus L.) is a Mediterranean plant and member of the Asteraceae family that includes three botanical taxa, the wild perennial cardoon (C. cardunculus L. var. sylvestris (Lamk) Fiori), globe artichoke (C. cardunculus L. var. scolymus L. Fiori), and domesticated cardoon (C. cardunculus L. var. altilis DC.). Cardoon has been widely used in the Mediterranean diet and folk medicine since ancient times. Today, cardoon is recognized as a plant with great industrial potential and is considered as a functional food, with important nutritional value, being an interesting source of bioactive compounds, such as phenolics, minerals, inulin, fiber, and sesquiterpene lactones. These bioactive compounds have been vastly described in the literature, exhibiting a wide range of beneficial effects, such as antimicrobial, anti-inflammatory, anticancer, antioxidant, lipid-lowering, cytotoxic, antidiabetic, antihemorrhoidal, cardiotonic, and choleretic activity. In this review, an overview of the cardoon nutritional and phytochemical composition, as well as its biological potential, is provided, highlighting the main therapeutic effects of the different parts of the cardoon plant on metabolic disorders, specifically associated with hepatoprotective, hypolipidemic, and antidiabetic activity.
The family Asteraceae (Compositae) consists of over 30,000 known annual, biennial or perennial shrub, vine and tree species. They are found in hot desert and cold or hot semi-desert climates and are distributed in all continents from subpolar to tropical regions except Antarctica. Two species known for its use in biodiesel (cardoon Cynara cardunculus and sunflower Helianthus annuus) are dealt in this chapter. Cardoons are otherwise used in the preparation of enzymes for cheese production and rennet making besides being considered as an ornamental plant. Of late the oils from sunflower seed is being partly diverted to biodiesel production.
The leftover vegetable oils after frying of food at higher temperature is toxic to environment as diminutive of technologies for proper disposal and reuse of waste cooking oil. An highly water soluble and emulsifier-free phosphorylated fatliquor with the emulsion stability of more than 60 minutes from economically cheap deep fried oils on transesterification with highly biodegradable ecologically innocuous and water soluble Poly (ethylene glycol) with p-Toluene Sulphonic acid followed by phosphorylation produces highly water dispersible and stable material for leather applications. The synthesised phosphorylated fatliquors were ascertained for the lubrication of collagen fibres and fibre splitting of goat skin by SEM analysis. The transesterification has confirmed by FT-IR, fat composition oils, COD, BOD, total solid in spent liquor were analysed. Physical characteristics of leathers were analysed by tensile strength, tear strength, elongation and quality assessments by hand evaluation by experts. Acid, iodine, saponification values, particle size of phosphorylated fatliquors, surface wettability, thermal stability of leathers were analysed and the properties compared. The finding can assist an emulsifier-free lubricating process significantly as currently available leather chemicals.
Biodiesel production from nonedible feedstock is a viable alternative to fulfill the energy need and to reduce the emission from constraint fuel. Argemone Mexicana is a weed that grows in the arid zone and contains a high amount of non-edible oil makes it an ideal feedstock for biodiesel synthesis. The motive of the present study is to explore the transesterification of Argemone Mexicana oil using a microwave heat source and a Parametric study, following by optimization of biodiesel yield using response surface methodology employing central composite design. The quadratic model with a high value of R² 99, R²adj 97.60 revealed good agreement with the actual AOME yield. The optimized operating parameters such as temperature, catalyst amount, time, and methanol to oil molar ratio were found to be 58.8°C, 1.03 wt%, 3.56 minutes, and 9.54:01 respectively. The predicted yield of 99.28wt% was in close agreement with an actual yield of 99.03%. The study reveals that catalyst amount, temperature, time, and methanol to oil molar ratio have a significant effect on microwave-assisted transesterification of Argemone oil. Argemone oil methyl esters (AOME) exhibit property close to ASTM standards and it has the potential as an alternative to diesel.
The commercial production of biodiesel and other biofuels is a pursuit central to the modern fuel industry. The chapter reviews various established technologies that are available for producing of biodiesel. These include mainly thermochemical conversion, biomechanical conversion, direct combustion, and chemical reaction. These technologies are hardly comparable as they are used to process different biomass feedstocks and developed to satisfy different aims. Extracting fuels from renewable feedstocks is the only feasible option thus far to cut down on fossil fuels utilization, which also has a positive effect on the global health. The chapter looks at Africa as a case study, with its vast renewable energy sources, and the continent is expectant to reap massive benefits, with the growing attractiveness of biodiesel to replace conventional fuels. The anticipated benefits calls for economically sound and innovative process technologies for commercial production to meet the growing demand and compete with conventional petroleum products. Currently, second-generation biodiesel production is not competitive in Africa due to the associated high cost of production. To reduce the influence of biofuels production on food security, more attention should be dedicated to the development of modern second-generation biodiesel production technologies in Africa, to their optimum potential.
To decrease the cost of biodiesel production, undeveloped nonedible Semen Abutili seed oil (SASO) was first used as a feedstock to prepare biodiesel. Some low-cost liquid lipases were screened and used as green catalysts for biodiesel production via the ethanolysis of SASO. The effect of reaction factors on ethanolysis was optimized by the response surface methodology (RSM). The results demonstrated that SASO was a promising alternative feedstock, and Eversa® Transform 2.0 showed the best performance for biodiesel production from low-quality SASO feedstock (high FFA and phospholipid contents). In addition, Eversa® Transform 2.0 can be reused 3 times without significant loss. The influence of reaction factors on biodiesel yield decreased in the order of reaction temperature > lipase load > reaction time. The maximum biodiesel yield was 94.2 ± 1.3 % under the optimal conditions (lipase load 6%, water content 20 %, 7:1 (mol/mol) ethanol to SASO, 11 h, 37 °C). The kinetic parameters (Vmax and K'm) of the transesterification of SASO were 4.16 × 10−2mol/(L∙min) and 5.27 × 10⁻¹ mol/L, respectively. The Arrhenius equation and activation energy, Ea, of Eversa® Transform 2.0-catalyzed transesterification of SASO were lnV0 = 4.8252–2382.3/T and 19.80 kJ/mol, respectively. The biodiesel produced from SASO was accordance with the ASTM D6751 standard, except for the oxidation stability. Thus, SASO, an undeveloped nonedible low-quality vegetable oil, can be used as a potential feedstock for biodiesel production, and the low-cost liquid lipase Eversa® Transform 2.0 can be used for biodiesel production.
Purity is one of the essential properties of biodiesel. Since the purity parameter depends on different operating conditions, its direct measurement is too hard and can only be obtained for specific ranges of conditions. Therefore, this work considers the least-squares support vector machines (LS-SVMs) that transform operating conditions to a multi-dimensional space to simulate biodiesel purity in wide ranges of operating conditions. Indeed, we develop a reliable LS-SVM approach for modeling the biodiesel purity as a function of catalyst type and its concentration, reaction time, temperature, methanol-to-oil volume ratio, frequency, and amplitude of ultrasonic waves. The designed LS-SVM’s predictive performance is compared with four available artificial intelligence (AI) techniques in reliable literature. The obtained results confirm that the LS-SVM paradigm outperforms other considered AI-based techniques regarding five different statistical criteria. Our LS-SVM model provides AARD = 2.2%, RMSE = 3.46, and R2 = 0.9868 for the prediction of 267 experimental data points, which includes 267 data points. This model is finally employed for investigating the effect of different influential variables on biodiesel purity.
Chicken eggshells contain a high concentration of CaCO 3 compounds, which are potentially transformed to CaO by calcination method. CaO has been used as a heterogeneous catalyst for biodiesel or fatty acid methyl ester production from Moringa seed oil. The purpose of this study is to determine the percentage of CaO which produces the highest methyl ester mass fraction and to find out the characteristics of the biodiesel. Biodiesel was made through a transesterification reaction by using a CaO catalyst that has been calcined at 900°C for 2 hours. This study was conducted using a completely randomized design (CRD) with the independent variable in the form of CaO mass percentages consisting of 5 levels (1, 2, 3, 4, and 5%). CaO catalyst at 3% concentration resulted in a mass fraction of methyl ester of 57.1%. Characteristics of the biodiesel contained water content of 0.3%, acid number of 0.03 mg KOH/g, saponification number of 6.93 mg KOH/g, iodine number of 5.49 g iod/100g, cloud point of 18°C, and pour point of 16°C. Some of the characteristics have fulfilled the standardizations of ASTM and SNI.
The emission of gases from the fleet of vehicles is one of the main sources of the environmental impact of the planet. Reversing this scenario, environmental awareness and a search for alternative sources of energy has been growing exponentially in recent years. In this context, the production of biofuels presents itself as an alternative for the lowest environmental impact, energy, and economy, with emphasis on biodiesel. The scale of production of this biofuel, the options related to the raw materials and their conditions are intertwined with the energy and exergetic efficiencies of the process. Therefore, no work was constructed as an analysis of the biodiesel production processes of soybeans and babassu, in which they were conducted on a laboratory scale. According to the results, the production of soybean biodiesel arose in exergetic efficiency of 73.25% and the production of biodiesel from babassu of 74.72%.
The primary problems associated with using straight soybean oil as a fuel in a compression ignition internal combustion engine
are caused by high fuel viscosity. Transesterification of soybean oil with an alcohol provides a significant reduction in
viscosity, thereby enhancing the physical properties of the renewable fuel to improve engine performance. The ethyl and methyl
esters of soybean oil with commercial diesel fuel additives revealed fuel properties that compared very well with diesel fuel,
with the exception of gum formation, which manifested itself in problems with the plugging of fuel filters. Engine performance
using soybean ester fuels differed little from engine performance with diesel fuel. A slight power loss combined with an increase
in fuel consumption were experienced with the esters, primarily because of the lower heating value of the esters than for
diesel fuel. Emissions for the 2 fuels were similar, with nitrous oxide emissions higher for the esters. Measurements of engine
wear and fuel-injection system tests showed no abnormal characteristics for any of the fuels after the 200-hr tests. Engine
deposits were comparable in amount, but slightly different in color and texture, with the methyl ester engine experiencing
greater carbon and varnish deposits on the pistons.
Vegetable oils and animal fats (triglycerides) were the first liquid fuels used in the rise of civilization, and now again are a potential source of alternate diesel fuel. They are 20 times as viscous as diesel fuel, however, and so form carbon deposits on diesel cylinders and injectors. They are also typically $3–$5/gallon, and so are too expensive to compete economically with diesel today. A number of solutions have been proposed for these problems, including transesterification, dilution, pyrolysis and microemulsification.The viscosity can be lowered by transesterification of the triglycerides with methanol or ethanol to form fatty acid esters. This cleaves the fat molecule and removes the glycerine, yielding a viscosity comparable to that of diesel. The heat of combustion is 95% of that for conventional diesel (on a volume basis). They have a Cetane number of 50–80 (compared to 42 for diesel).The cost of the fuel can be reduced by using waste vegetable cooking oils. There are 350 million gallons of waste vegetable oil produced annually in the U.S.A., and various quantities available in other countries. We have developed a process for making the esters from waste vegetable oils and we call the fuel “M-Diesel”. The oil is reacted with sodium hydroxide dissolved in methanol. A sufficient quantity of alkali is used to neutralize the fatty acids in the waste oil plus 0.3% excess. A batch of 300 gallons was made for testing.We have tested the fuel in a Denver public bus and find power comparable to that of diesel. A 30% blend with diesel reduced smoke opacity to 60% of that from diesel, while neat M-Diesel reduced the opacity to 26% of that of diesel. Tests of 10 and 20% mixtures are now underway.
Transesterification of sunflower seed oil in situ has produced methyl and ethyl esters in yields greater than 40% of the dry seed weight. This figure compares with a typical yield of ca. 30% when the esters were prepared in the conventional manner from preextracted seed oil. 14 references.
Equations are proposed for predicting the cetane number of hydrogenated diesel fuel derived from the catalytic oligomerization of low-chain-length alkenes. The cetane number is a function of the relative amounts of CH3 and CH2 type protons present in the fuel as determined from 1H n.m.r. data. The predictive equations are specific to those used for synthetic fuels and are shown to be superior to those proposed previously.
A study was made of the reaction of transesterification of Cynara cardunculus L. oil by means of methanol, using sodium hydroxide, potassium hydroxide, and sodium methoxide as catalysts. The objective of the work was to characterize the methyl esters for use as biodiesels in internal combustion motors. The operation variables used were methanol concentration (5−21 wt %), catalyst concentration (0.1−1 wt %), and temperature (25−60 °C). The evolution of the process was followed by gas chromatography, determining the concentration of the methyl esters at different reaction times. The biodiesel was characterized by determining its density, viscosity, high heating value, cetane index, cloud and pour points, Ramsbottom carbon residue, characteristics of distillation, and flash and combustion points according to ISO norms. The biodiesel with the best properties was obtained using 15% methanol, sodium methoxide as catalyst (1%), and 60 °C temperature. This biodiesel has very similar properties to those of diesel no. 2.
Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol phase was higher than that in the fatty acid methyl ester (FAME) phase in a simulated system at room temperature. At 65−80 °C, however, the percentage of total methanol in FAME (60% (w/w)) was higher than that in glycerol (40% (w/w)) in a 90:10 (w/w) blend of FAME and glycerol. This coincided with the methanol distribution in the transesterified product. The process for making beef tallow methyl esters should recover methanol using vacuum distillation, separate the ester and glycerol phases, and then wash the beef tallow methyl esters with warm water. At neutral pH, the separation of ester and glycerol and water washing was easier because it reduced emulsion formation.
Cynara cardunculus, the primitive wild form of the artichoke, was used only as a forage. The analysis of the seeds and the stalks of this plant showed that both these parts could be used; the seeds for vegetable oil production and the stalks for paper pulp manufacturing. The first results showed that oil extracted from Cynara seeds has a similar composition as sunflower oil and the paper pulp obtained by chemical pulping of the stalks is of good quality.
This article illustrates a simple method for estimation of cetane indexes of vegetable oil methyl esters from their saponification
and iodine numbers. The range of the calculated values covers all the cetane numbers of vegetable oil methyl esters determined
experimentally. when it was applied to individual fatty acid methyl esters from C8 to C24, a straight line parallel to that of Klopfenstein was obtained.
Transesterification of soybean oil (SBO) and other triglycerides with alcohols, in the presence of a catalyst, yields fatty
esters and glycerol. Di- and monoglycerides are intermediates. Reactions are consecutive and reversible. Rate constants have
been determined for each reaction with a computerized kinetic program. The effects of the type of alcohol, 1-butanol or methanol
(MeOH); molar ratio of alcohol to SBO; type and amount of catalyst; and reaction temperature on rate constants and kinetic
order were examined. Forward reactions appear to be pseudo-first order or second order depending upon conditions used. Reverse
reactions appear to be second order. At a molar ratio of MeOH/SBO of 6:1, a shunt reaction was observed. Energy of activation
was determined for all forward and reverse reactions under a variety of experimental conditions from plots of log k vs 1/T.
Values ranged from 8–20 kcal/mol.
The effects of using blends of methyl and isopropyl esters of soybean oil with No. 2 diesel fuel were studied at several steady-state
operating conditions in a four-cylinder turbocharged diesel engine. Fuel blends that contained 20, 50, and 70% methyl soyate
and 20 and 50% isopropyl soyate were tested. Fuel properties, such as cetane number, also were investigated. Both methyl and
isopropyl esters provided significant reductions in particulate emissions compared with No. 2 diesel fuel. A blend of 50%
methyl ester and 50% No. 2 diesel fuel provided a reduction of 37% in the carbon portion of the particulates and 25% in the
total particulates. The 50% blend of isopropyl ester and 50% No. 2 diesel fuel gave a 55% reduction in carbon and a 28% reduction
in total particulate emissions. Emissions of carbon monoxide and unburned hydrocarbons also were reduced significantly. Oxides
of nitrogen increased by 12%.
Oleic, linoleic and linolenic acids were autoxidized more rapidly than their corresponding methyl esters. Addition of stearic
acid accelerated the rate of autoxidation of methyl linoleate and the decomposition of methyl linoleate hydroperoxides. Therefore,
the higher oxidative rate of FFA’s than their methyl esters could be due to the catalytic effect of the carboxyl groups on
the formation of free radicals by the decomposition of hydroperoxides. Addition of stearic acid also accelerated the oxidative
rate of soybean oil. This result suggests that particular attention should be paid to the FFA content that affects the oxidative
stability of oils.
Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean
and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and
degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of
60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters
was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with
an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils
could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.
High-performance size-exclusion chromatography (HPSEC) was used to evaluate the influence of different variables affecting
the transesterification of rapeseed oil (RSO) with anhydrous ethanol and sodium ethoxide as catalyst. The effect of temperature,
ethanol/RSO molar ratio, catalyst concentration, and time can be interpreted by observing the variations of the reaction medium
composition. HPSEC has made the quantitation of ethyl esters, mono-, di-, and triglycerides and glycerol possible. The best
results for laboratory-scale reactions were obtained at 80°C with a 6:1 molar ratio of EtOH/RSO and 1% of NaOEt by weight
of RSO.
Methyl fatty esters derived from vegetable oils are a promising fuel for direct injection diesel engines. This study’s purpose
was to identify a heterogeneous catalyst to selectively produce methyl fatty esters from low erucic rapeseed oil. Most experiments
were at atmospheric pressure and approximately the corresponding boiling point temperature of the mixture, 60–63 C. However,
the catalytic activity of an anion exchange resin was tested at 200 C and 68 atm (1000 psig) and at 91 C and 9.2 atm (135
psig). All samples were analyzed by thin layer chromatography with samples from the elevated temperature and pressure experiments
also analyzed by mass spectroscopy. The most promising catalyst examined was CaO·MgO. The activities of the catalysts CaO
and ZnO appear to be enhanced with the addition of MgO, therefore the transesterification reaction mechanism may be, in this
instance, bifunctional. The anion exchange resin catalyst at 200 C and 68 atm generated substantial amounts of both methyl
fatty esters and straight-chain hydrocarbons, even though these reactions did not go to completion. At 91 C and 9.2 atm the
cracking also occurred but at a substantially reduced rate, and no transesterification was noted.
Palm oil was transmethylated continuously at 70°C in an organic solvent with sodium methoxide as a catalyst. The optimum ratio
of toluene to palm oil is 1∶1 (v/v). When the methanol-to-oil molar ratio was 13∶1, transmethylation was 96% complete within
60 seconds. At higher molar ratio (17∶1), transmethylation was 99% complete in 15 seconds. For lower molar ratios of methanol-to-oil
(9∶1 and 5.8∶1), yields of palm oil methyl ester (POME) were 84 and 58%, respectively. Benzene was also a good solvent for
transmethylation, but the yield of POME was slightly lower than toluene. Tetrahydrofuran did not accelerate transmethylation.
Vegetable oils have heat contents approximately 90 % of that of diesel fuel and are alternative fuel candidates. A major obstacle deterring their use in the direct-injection diesel engine is their inherent high viscosities, which are nearly 10 times that of diesel fuel. Solution to the viscosity problem has been approached in at least four ways:(1) dilution, (2) microemulsification, (3) pyrolysis and (4) transesterification. Dilution procedures have been only partially successful in giving a fuel that passes the 200 h EMA test. Microemulsification is a relatively new approach and has yielded fuels that pass the 200 h EMA test. Pyrolysis gives fractions with compositions similar to No. 2 diesel fuel. Transesterification with methanol, ethanol or butanol produces alternative fuels which could be used in times of emergency.
Efforts are under way in many countries, including India, to search for suitable alternative diesel fuels that are environment friendly. The need to search for these fuels arises mainly from the standpoint of preserving the global environment and the concern about long-term supplies of conventional hydrocarbon-based diesel fuels. Among the different possible sources, diesel fuels derived from triglycerides (vegetable oils/animal fats) present a promising alternative to substitute diesel fuels. Although triglycerides can fuel diesel engines, their high viscosities, low volatilities and poor cold flow properties have led to the investigation of various derivatives. Fatty acid methyl esters, known as biodiesel, derived from triglycerides by transesterification with methanol have received the most attention. The main advantages of using biodiesel are its renewability, better-quality exhaust gas emissions, its biodegradability and given that all the organic carbon present is photosynthetic in origin, it does not contribute to a rise in the level of carbon dioxide in the atmosphere and consequently to the greenhouse effect.
The technical and economic aspects of using vegetable oils as alternative sources for diesel fuels have been studied extensively during the past two decades. Although much of the recent research and development on the production and use of diesel fuel substitutes has been carried out in developed countries, the need for such substitutes and the potential for their production is much greater in developing countries.This report will review some of the results obtained from using vegetable oils and their derivatives as fuel in compression ignition engines and examine opportunities for their broader production and use. It will include some historic background, as well as current and potential yields of candidate crops, the technology and economics of vegetable oil conversion to diesel fuel, the performance of various oils, the potential inherent in diesel fuel coproduction, environmental considerations, and other research opportunities.Vegetable oils will not entirely displace petroleum as a source of diesel fuel. There are, however, technical, economic, and environmental considerations that can lead to their wider use in this application.