Production of biodiesel from Citrus limetta seed oil

The production of biodiesel from edible oils may cause negative impact to any country through food crisis which may lead to economic imbalance. Hence, this study focuses on viability of extracting the oil from the Citrus limetta seeds for biodiesel production for the first time. Composition of C. limetta oil was determined by gas chromatography. C. limetta biodiesel was produced by simple transesterification process, and further physiochemical properties were analyzed as per the standards. This study also describes the suitable characterization and optimization parameters used for conversion of C. limetta seed oil into biodiesel.     

The influence of free fatty acid intermediate on biodiesel production from soybean oil by whole cell biocatalyst

The whole cell of lipase-producing Rhizopus oryzae was employed as biocatalyst for transesterification of soybean oil containing oleic acid. The free fatty acid (FFA) intermediate, playing an important role in the kinetics of transesterification of soybean oil, was thoroughly investigated and characterized. The conversion was more than 97% at the initial FFA content of 5.5%. A high content of FFA could protect the lipase from denaturation. The 34.6 percent of FFA with the optimal 26-mg mL⁻¹ methanol resulted in a specific reaction rate of 420 mg h⁻¹g-dry cell⁻¹. In addition, the methanol/FFA ratio at 0.83-1.7 provides a good indication of the fatty acid methyl esters conversions for different initial FFA contents. In the transesterification process, more FFA intermediate present would become beneficial to conversion of retrograde feedstock to biodiesel. The immediately generated and original FFA content become the major rate-determining factor in the FFA-mixed transesterification process.     

Pressurized ultrasonic production of biodiesel from Jatropha oil: optimization and energy analysis

The present study deals with the development of a biodiesel production reactor based on pressurized ultrasonic cavitation technique. Transesterification of Jatropha oil takes place by passing low-frequency ultrasonic irradiation in the reaction mixture flowing at pressurized conditions in the sonochemical reactor. Reaction variables such as reaction time, molar ratio, catalyst concentration, and pressure of the reaction mixture were investigated to find the optimal parameters for biodiesel production. The energy requirement decreases with increase in pressure. Very low value of Specific Energy Consumption (0.018 kWh/kg) and significantly high value of Energy Use Index (598.83) are obtained when the pressure of reaction mixture is 15 bar. Increasing the pressure thereafter, leads to nominal gains. Ultrasonic irradiation at high-pressure condition has an additional advantage of rapid reaction and lower requirement of alcohol to oil molar ratio and catalyst concentration. Fifteen bar pressure is optimal for biodiesel production.     

大豆油制备生物柴油的工艺探索

试验研究了大豆油在催化剂（NaOH）的作用下与甲醇发生转脂化反应生成脂肪酸甲酯（生物柴油）的工艺条件。试验结果表明，该转脂化反应的最佳操作条件：NaOH用量为大豆油量的1％、油醇摩尔比为1：6、搅拌时间为50min、反应温度为50～60℃、水的含量必须控制在油重的0．1％以下。     

Toward estimation of biodiesel production from castor oil using ANN

Nowadays, a green replacement for the conventional petrodiesel introduced as biodiesel in which its economical production way is using feedstock. Also, environmentally friendly fuels attracted more attention due to the serious global warming problem. In the present study, two different artificial intelligencebased modeling was utilized to predict the production of biodiesel from castor oil. Also, a comparison between the two methods was carried out, and the more applicable method for the prediction of biodiesel production was introduced. To this end, biodiesel production yield from castor oil assumed to be the target of the model and various parameters such as temperature (T), time (S), methanol to oil molar ratio, and catalyst weight (C) expected as input parameters. ANN modeling shows high accuracy and robustness for the prediction of biodiesel production, and statistical parameters such as coefficient of determination and root-mean-square error are 0.9984 and 1.13, respectively.     

利用超临界技术制备生物柴油的研究现状

分析了超临界技术制备生物柴油的反应机理,重点阐述了温度、醇油比、压力、水、游离酸对超临界法制备生物柴油的影响.研究表明:超临界技术制备生物柴油在反应时间、对原料要求和产物回收等方面均具有传统碱催化法无法比拟的优势.展望了超临界技术制备生物柴油的工业应用前景,并对超临界技术制备生物柴油的研究提出了建议.     

Biodiesel production from degummed Jatropha curcas oil using constant-temperature ultrasonic water bath

This paper studied tri-basic potassium phosphate for transesterification process with degummed crude Jatropha curcas oil using constant-temperature, ultrasonic water bath generating low-intensity pulses with good energy distribution converting the maximum amount of biodiesel. Tri-basic potassium phosphate is suitable for J. curcas oil when the free fatty acid (FFA) content is less than 2%. The optimal reaction levels are catalyst 1.0 wt%, temperature of 50°C, and methanol-to-oil molar ratio of 12:1. The yield is 98% after 45 min, at 20 kHz frequency. The catalytic activity is found similar to potassium hydroxide and the catalyst solubility is only 4.27 ppm.     

大豆酸化油制备生物柴油的研究

试验研究了大豆酸化油在复合酸催化剂的作用下与甲醇发生转酯化和酯化反应生成脂肪酸甲酯(生物柴油)的最佳反应条件.试验结果表明,该酯化及转酯化反应的最佳操作条件:复合酸催化剂的用量为大豆油质量的5%、油醇摩尔比为1:6、反应时间为6h、反应温度为65℃.     

Tribological behavior of diesel/biodiesel blend from waste cooking oil and ethanol

One kind of novel biodiesel waste cooking oil ethyl ester (WCOEE) was prepared via transesterfication reaction between waste cooking oil and ethanol. The tribological behavior of diesel/WCOEE blend was evaluated with a four-ball tribometer. The wear resistance, extreme pressure, and friction reduction of the blend were improved with increasing WCOEE. The optimal content of WCOEE in the blend was 20 vol%. It was also found that free fatty acids (FFAs) had a positive effect on the wear resistance of blend. The lubrication improvement of the blend was ascribed to the formation of polyester film and high polarity of fatty acid ethyl ester.     

氨基磺酸非均相催化菜籽油及废油脂制备生物柴油

采用正交试验和单因素试验的方法研究了氨基磺酸催化菜籽油及废油脂与甲醇的酯交换过程,考察了醇油物质的量比、催化剂用量、反应温度和反应时间对反应收率的影响。结果表明:菜籽油酯交换的最佳反应条件为醇油物质的量比6∶1,氨基磺酸用量为原料油质量的1.0%,反应温度60℃,反应时间20 min,此工艺条件下,脂肪酸甲酯的收率达到95.6%;废油脂酯交换的最佳反应条件为醇油物质的量比8∶1,氨基磺酸用量为原料油质量的1.0%、反应温度65℃,反应时间30 min,此工艺条件下,脂肪酸甲酯的收率达到87.5%。利用红外光谱表征了菜籽油和生物柴油的结构,气相色谱分析了生物柴油的组成。     

One-step production of biodiesel through simultaneous esterification and transesterification from highly acidic unrefined feedstock over efficient and recyclable ZnO nanostar catalyst

Zinc oxide (ZnO) nanostar synthesized by simple and up-scalable microwave-assisted surfactant free hydrolysis method was applied as catalyst for biodiesel synthesis through one-step simultaneous esterification and transesterification from high free fatty acid (FFA) contaminated unrefined feedstock. It was found that ZnO nanostar catalyst was reacted with FFA to yield zinc oleate (ZnOl) as intermediate and finally became zinc glycerolate (ZnGly). With the re-deposition of ZnGly back to the ZnO nanostar catalyst at the end of the reaction, the catalyst can be easily recovered and stay active for five cycles. Furthermore, the rate of transesterification is highly promoted by the presence of FFA (6 wt.%) which makes it an efficient catalyst for low grade feedstock like waste cooking oil and crude plant oils.     

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

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

Optimization of biodiesel production from waste fish oil

The present study deals with the production of biodiesel using waste fish oil. The research assesses the effect of the transesterification parameters on the biodiesel yield and its properties, including temperature (40–60 °C), molar ratio methanol to oil (3:1–9:1) and reaction time (30–90 min). The experimental results were fitted to complete quadratic models and optimized by response surface methodology. All the biodiesel samples presented a FAME content higher than 93 wt.% with a maximum, 95.39 wt.%, at 60 °C, 9:1 of methanol to oil ratio and 90 min. On the other hand, a maximum biodiesel yield was found at the same methanol to oil ratio and reaction time conditions but at lower temperature, 40 °C, which reduced the saponification of triglycerides by the alkaline catalyst employed. Adequate values of kinematic viscosity (measured at 30 °C) were obtained, with a minimum of 6.30 mm²/s obtained at 60 °C, 5.15:1 of methanol to oil ratio and 55.52 min. However, the oxidative stability of the biodiesels produced must be further improved by adding antioxidants because low values of IP, below 2.22 h, were obtained. Finally, satisfactory values of completion of melt onset temperature, ranging from 3.31 °C to 3.83 °C, were measured.     

酯交换法制备生物柴油及其在我国的实践

生物柴油是一种对环境友好的可再生燃料,以其是好的环境效应受到越来越多的关注。综述并比较了生物柴油的各种化学制备方法,介绍了该产业的国内外生产应用情况,指出了生物柴油的优势,分析了生物柴油在生产厦使用过程中存在的一些问题并对生物柴油的未来研究与发展作了展望。     

Preparation of biodiesel from nonedible oils using a mixture of used lipases

Biodiesel was synthesized from nonedible oils using a lipase mixture composed of used and discarded Candida rugusa, Candida antactica-B (Novozyme-435), Pseudomonas cepacia, Rhizopus oryzae, and porcine pancreas Type II lipase. To avoid the lipase deactivation stepwise addition of 6 mmol of methanol to 1 mmol of oil lead to 93% biodiesel yield. Addition of 10 wt% of silica gel to the reaction mixture resulted in 97% biodiesel. The lipase mixture was recycled for five times and at the end of the fifth cycle 86% biodiesel was formed.     

Potential of waste palm cooking oil for catalyst-free biodiesel production

Disposal of waste palm cooking oil (WPCO) via an environmental-friendly route is of major importance in the quest for sustainable development. In this study, WPCO was utilized instead of refined vegetable oils as the source of triglycerides for biodiesel production. WPCO contains several impurities, such as water and free fatty acids, which limit its application in catalytic transesterification processes. Consequently, a catalyst-free process using supercritical methanol was employed to investigate the potential of WPCO as an economical feedstock for biodiesel production. The parameters that influence the reaction, including reaction time, temperature and the molar ratio of alcohol to oil, were investigated. For comparison purposes, refined palm oil (RPO) was also subjected to supercritical methanol reaction and it was found that both processes produced comparable optimum yields of 80% at their respective optimum conditions. Hence, it can be concluded that WPCO has high potential as an economical and practical future source of biodiesel.     

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

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

Biocatalytic production of biodiesel from cottonseed oil: Standardization of process parameters and comparison of fuel characteristics

The enzymatic production of biodiesel by transesterification of cottonseed oil was studied using low cost crude pancreatic lipase as catalyst in a batch system. The effects of the critical process parameters including water percentage, methanol:oil ratio, enzyme concentration, buffer pH and reaction temperature were determined. Maximum conversion of 75–80% was achieved after 4 h at 37 °C, pH 7.0 and with 1:15 M ratio of oil to methanol, 0.5% (wt of oil) enzyme and water concentration of 5% (wt of oil). Various organic solvents were tested among which a partially polar solvent (t-butanol) was found to be suitable for the reaction. The major fuel characteristics like specific gravity, kinematic viscosity, flash point and calorific value of the 20:80 blends (B20) of the fatty acid methyl esters with petroleum diesel conformed very closely to those of American Society for Testing Materials (ASTM) standards.     

Biodiesel production from two stage esterification of simarouba glauca seed oil and its characterization

In this work, biodiesel was produced from simarouba glauca seed oil through a two-stage acid-alkali esterification process. Concentrated sulphuric acid and sodium hydroxide were used as catalysts for acid and alkaline catalyzed esterification process, respectively. The free fatty acid content of the oil was reduced from 3.5 to 0.2%. The major properties of oil and its biodiesel were studied. Upon two-stage esterification, kinematic viscosity was reduced from 45.75 to 3.1 cSt and the acid value was reduced from 6.9348 to 0.4 mg KOH/g. The measured physio-chemical properties are within the limits set by ASTM biodiesel standards.     

Crystallization behavior of fatty acid methyl esters and biodiesel based on differential scanning calorimetry and thermodynamic model

Biodiesel is mainly composed of methyl palmitate (MeC16), methyl stearate (MeC18), and methyl oleate (MeC18:1). In order to explore the crystallization behavior of biodiesel, the thermal parameters of the three fatty acid methyl esters, their binary mixtures, and biodiesel have been analyzed based on the differential scanning calorimeter. Supposing that biodiesel is a complex solution of various fatty acid methyl esters, the saturated fatty acid methyl esters MeC16 and MeC18 are treated as solutes and the unsaturated fatty acid methyl ester MeC18:1 is served as the solvent; thus a thermodynamic model according to the solid–liquid equilibria for predicting the crystallization onset temperature has been established. As a result, the model is effectively verified when the estimated crystallization onset temperatures for four types of actual biodiesel are compared with the experimental results.