Optimization of transesterification for methyl ester production from chicken fat

In this study, low cost feedstock chicken fat was used to produce methyl ester. After reducing the free fatty acid level of the chicken fat less than 1%, the transesterification reaction was completed with alkaline catalyst. Potassium hydroxide, sodium hydroxide, potassium methoxide and sodium methoxide were used as catalyst and methanol was used as alcohol for transesterification reactions. The effects of catalyst type, reaction temperature and reaction time on the fuel properties of methyl esters were investigated. The produced chicken fat methyl esters were characterized by determining their viscosity, density, pour point, flash point, acid value, methanol content, heat of combustion value, total-free glycerin, mono-di-tri glycerides, copper strip corrosion and ester yield values. The measured fuel properties of the chicken fat methyl ester met EN 14214 and ASTM D6751 biodiesel specifications when using potassium hydroxide and sodium hydroxide catalysts with high ester yield.     

油酸异丁酯的合成及其对生物柴油降凝效果研究

油酸与异丁醇在离子液体催化剂的作用下发生酯化反应制备油酸异丁酯。研究了催化剂用量、醇酸配比、反应时间、反应温度等对酯化反应转化率的影响,并通过测定凝固点、冷滤点、粘度来考察脂肪酸异丁酯对生物柴油的降凝效果。结果表明,当催化剂用量为2%,醇酸体积比2∶1(摩尔比6.8∶1),反应温度100℃,反应时间3 h,转化率达到95.6%。降凝实验结果表明,把一定量的脂肪酸异丁酯添加到生物柴油中可有效地降低生物柴油的凝固点、冷滤点,改善其低温流动性能。     

生物柴油低温流动改进剂复配研究

采用碱催化法制备菜籽油生物柴油和棕榈油生物柴油,对其主要品质指标进行分析;考察了添加不同的柴油低温流动改进剂及其复配物对生物柴油低温流动性能的影响。结果表明,柴油低温流动改进剂能够改善生物柴油低温流动性能;将其进行复配后,能表现出协同效应,取得更好的降滤效果,尤其能使饱和脂肪酸甲酯含量高的棕榈油生物柴油冷滤点降低8℃;不同生物柴油对柴油低温流动改进剂或其复配物感受性存在较大差异,不饱和脂肪酸甲酯含量高,且脂肪酸甲酯种类较多、分布较广的菜籽油生物柴油对单一低温流动改进剂感受性好,而饱和脂肪酸甲酯含量高,且脂肪酸甲酯种类分布较集中的棕榈油生物柴油对复配物感受性好。     

Alkali catalyzed transesterification of safflower seed oil assisted by microwave irradiation

The safflower (Carthamus tinctorius L.) oil was extracted from the seeds of the safflower that grows in Diyarbakir, SE Anatolia of Turkey. Biodiesel has been prepared from safflower seed by transesterification of the crude oil under microwave irradiation, with methanol to oil molar ratio of 10:1, in the presence of 1.0% NaOH as catalyst. The conversion of C. tinctorius oil to methyl ester was over 98.4% at 6 min. The important fuel properties of safflower oil and its methyl ester (biodiesel) such as density, kinematic viscosity, flash point, iodine number, neutralization number, pour point, cloud point, cetane number are found out and compared to those of no. 2 petroleum diesel, ASTM and EN biodiesel standards. Compared with conventional heating methods, the process using microwaves irradiation proved to be a faster method for alcoholysis of triglycerides with methanol, leading to high yields of biodiesel.     

超声波法制备生物柴油

在超声波条件下,以大豆油为原料,氧化钙为催化剂,利用正交试验研究了催化剂用量、油醇比、反也时间和反应温度等对生物柴油产率的影响。南实验得最佳工艺条件为：油醇比（质量）为0．9：1,反应时间为30min,反应温度为45℃,催化剂用量为0．9％（占原料油用量的质量分数）。在该条件下制备的生物柴油收率可达96％,其凝点为-2．2℃闪点为112℃,运动粘度为3．93mm／s,其性能与0号石化柴油比较接近。     

Synthesis of biodiesel fuel from safflower oil using various reaction parameters

Biodiesel fuel is gaining more and more importance because of the depletion and uncontrollable prices of fossil fuel resources. The use of vegetable oil and their derivatives as alternatives for diesel fuel is the best answer and as old as Diesel Engine. Chemically biodiesel fuel is the mono alkyl esters of fatty acids derived from renewable feed stocks like vegetable oils and animal fats. Safflower oil contains 75-80% of linoleic acid; the presence of this unsaturated fatty acid is useful in alleviating low temperature properties like pour point, cloud point and cold filter plugging point. In this paper we studied the effect of various parameters such as temperature, molar ratio (oil to alcohol), and concentration of catalyst on synthesis of biodiesel fuel from safflower oil. The better suitable conditions of 1:6 molar ratio (oil to alcohol), 60 degrees C temperature and catalyst concentration of 2% (by wt. of oil) were determined. The finally obtained biodiesel fuel was analyzed for fatty acid composition by GLC and some other properties such as flash point, specific gravity and acid value were also determined. From the results it was clear that the produced biodiesel fuel was with in the recommended standards of biodiesel fuel with 96.8% yield.     

Improving the economics of biodiesel production through the use of low value lipids as feedstocks: vegetable oil soapstock

Semirefined and refined vegetable oils are the predominant feedstocks for the production of biodiesel. However, their relatively high costs render the resulting fuels unable to compete with petroleum-derived fuel. We have investigated the production of fatty acid methyl esters (FAME; biodiesel) from soapstock (SS), a byproduct of edible oil refining that is substantially less expensive than edible-grade refined oils. Multiple approaches were taken in search of a route to the production of fatty acid methyl esters from soybean soapstock. The most effective method involved the complete saponification of the soapstock followed by acidulation using methods similar to those presently employed in industry. This resulted in an acid oil with a free fatty acid (FFA) content greater than 90%. These fatty acids were efficiently converted to methyl esters by acid-catalyzed esterification. The fatty acid composition of the resulting ester product reflected that of soy soapstock and was largely similar to that of soybean oil. Following a simple washing protocol, this preparation met the established specifications for biodiesel of the American Society for Testing and Materials. Engine emissions and performance during operation on soy soapstock biodiesel were comparable to those on biodiesel from soy oil. An economic analysis suggested that the production cost of soapstock biodiesel would be approximately US$ 0.41/l, a 25% reduction relative to the estimated cost of biodiesel produced from soy oil.     

微藻生物柴油的制备及其性能指标评价分析

以微藻毛油为原料,采用近临界醇解(SRCA)工艺制备微藻生物柴油,并分析了微藻生物柴油的各项指标.分析结果表明:微藻生物柴油的密度、运动黏度、闪点、含硫量、硫酸盐灰分、含水量、机械杂质、铜片腐蚀、十六烷值、酸值、游离甘油和总甘油等12项指标符合GB/T 20828-2007对调和用生物柴油BD100的要求;10％蒸余物...     

邻苯二甲酸酯的合成及其性能研究

以邻苯二甲酸酐和脂肪醇为原料,硫酸氢钠为催化剂酯化合成了一系列邻苯二甲酸酯。考察了脂肪醇的链长度、类型及支链醇含量等因素对合成酯性能的影响,进而得出其结构与性能的变化规律,并为高性能油品的合成提供理论依据。结果表明,随着脂肪醇链长的增加,合成酯的粘度和粘度指数逐渐增大,倾点和闪点也呈升高趋势;碳原子数目相同的支链醇酯较直链醇酯具有更高的粘度、倾点和闪点以及更低的粘度指数;在直链醇中引入支链醇,所得合成酯的粘度增大,粘度指数减小,倾点和闪点升高;且随着支链醇含量的增加,合成酯的粘度总体呈增大趋势,粘度指数逐渐减小,倾点和闪点呈锯齿型变化。     

Analysis of Sterol Glycosides in Biodiesel and Biodiesel Precipitates

Biodiesel is produced by the transesterification of vegetable oils with short chain alcohols, usually in the presence of an alkali catalyst. Minor components in biodiesel exist as a result of unreacted reagents, by-products, additives, and auto-oxidation products, such as water, free glycerin, bonded glycerin, free fatty acids, catalysts, residual alcohol, unsaponifiable matter (plant sterols, antioxidants, and hydrocarbons), soaps and polymers. The biodiesel properties, such as cold flow properties, acid number, cetane number, and oxidative stability are oftentimes significantly affected by these minor components. Sterol glycosides, as one of the most important minor components in biodiesel, and due to their polarities and limited solubility, can accelerate precipitate formation even at room temperature and possibly block fuel filters. In this paper, reversed phase high-performance liquid chromatography with an Evaporative Light Scattering Detector (ELSD) is evaluated for the analysis of sterol glycoside (SG) content in not only biodiesel precipitates but also in biodiesel. SG was found to be a major component in soy biodiesel precipitates and an SG peak was found in biodiesel after concentration by centrifugation.     

生物柴油降凝方法的研究

以废油脂为原料通过酯交换法制备了生物柴油,测定其凝点为-2℃,闪点为114.5℃,说明生物柴油比-10号柴油具有更高的安全性,但其凝点限制了它的使用范围。采用不同的方法改善生物柴油的低温流动性能,结果表明以生物柴油降凝剂及-10号柴油对生物柴油进行混合降凝的方法,能有效降低生物柴油的凝点,并使其低温流动性能得到改善。     

Ozonized vegetable oil as pour point depressant for neat biodiesel

The use of ozonized vegetable oils as pour point depressant for neat biodiesel was evaluated. Ozonized vegetable oils (1-1.5% by weight) were effective in reducing the pour point of biodiesel prepared from sunflower oil, soybean oil and rapeseed oil to −24, −12 and −30 °C, respectively. Cloud point however remained unaffected. In the case of palm oil biodiesel, significant reduction was observed in cloud point but not in pour point. Statistical analyses showed that neat biodiesel and biodiesel treated with ozonized vegetable oils showed no significant difference in other properties including density and viscosity. Although ozonized vegetable oils increase the flash point of biodiesel, the values are still within the limits set by the standards in the US and Europe. Lowest reduction in pour point was observed in cases where the biodiesel and the ozonized samples were prepared from the same vegetable oil. Hence, a correlation may exist between the nature of the biodiesel and ozonized oil. Microscopic analysis at low temperature revealed that ozonized vegetable oil impede agglomeration of biodiesel into network of solidified material giving crystals with sizes around 10 μm.     

From organic waste to biodiesel: Black soldier fly, Hermetiaillucens, makes it feasible

Biodiesel is a renewable and environmentally friendly liquid fuel. However, the feedstock, predominantly crop oil, is a limited and expensive food resource which prevents large scale application of biodiesel. Development of non-food feedstocks are therefore, needed to fully utilize biodiesel’s potential. In this study, the larvae of a high fat containing insect, black soldier fly (Hermetiaillucens) (BSFL), was evaluated for biodiesel production. Specifically, the BSFL was grown on organic wastes for 10 days and used for crude fat extraction by petroleum ether. The extracted crude fat was then converted into biodiesel by acid-catalyzed (1% H₂SO₄) esterification and alkaline-catalyzed (0.8% NaOH) transesterification, resulting in 35.5 g, 57.8 g and 91.4 g of biodiesel being produced from 1000 BSFL growing on 1 kg of cattle manure, pig manure and chicken manure, respectively. The major ester components of the resulting biodiesel were lauric acid methyl ester (35.5%), oleinic acid methyl ester (23.6%) and palmitic acid methyl ester (14.8%). Fuel properties of the BSFL fat-based biodiesel, such as density (885 kg/m³), viscosity (5.8 mm²/s), ester content (97.2%), flash point (123 °C), and cetane number (53) were comparable to those of rapeseed-oil-based biodiesel. These results demonstrated that the organic waste-grown BSFL could be a feasible non-food feedstock for biodiesel production.     

油酸异丙酯的合成及其对生物柴油低温流动性研究

油酸与异丙醇在对甲苯黄酸催化剂的作用下发生酯化反应制备油酸异丙酯。单因素研究催化剂用量、醇酸配比、反应时间、反应温度等对酯化反应得率的影响规律,并通过测定凝固点、冷滤点、粘度来考察脂肪酸异丙脂对生物柴油的降凝效果。结果表明,催化剂的量3%,醇酸体积比2∶1（摩尔比8.2∶1）,反应温度80℃,反应时间4 h,酯化率达到90.5%。降凝实验结果表明把一定量的脂肪酸异丙酯添加到生物柴油中可有效地降低生物柴油的凝固点、冷滤点,改善其低温流动性能。     

Ester content evaluation in biodiesel from animal fats and lauric oils

A modified method for the determination of ester contents of biodiesel based on EN 14103 has been developed. The method includes natural contents of heptadecanoic acid ester, which are found in animal fats and interfere with the standard method, into the calculation of ester content values. As a result, biodiesel samples prepared from waste animal fats and oils showed an increase in ester content between 2 and 7 wt‐% compared to values measured according to EN 14103. Furthermore, modifications of the GC temperature program made it possible to include also short‐chain fatty acid esters C₈–C₁₂, which can be found in coconut and palm kernel oil, into the calculation. Measurements showed that the ester content of such biodiesel differs by more than 40 wt‐% compared to EN 14103 determinations. However, also the stability of the internal standard solution methyl heptadecanoate influences the values of ester content. It can be demonstrated that after a period of 7 days, an ester content decrease of about 2 wt‐% can be observed. Therefore, the use of almost freshly prepared standard solutions should be recommended.     

固体碱法制备生物柴油及其性能

用共沉淀法制备了水滑石,焙烧后得到Mg-Al复合氧化物,以此为催化剂进行菜籽油的酯交换反应,正交实验表明该酯交换反应的小试最佳工艺条件为： 反应温度65 ℃、醇油摩尔比6∶1、反应时间为3 h,催化剂加入量为菜籽油质量的2%,脂肪酸甲酯（生物柴油）含量为95.7%.得到的生物柴油低温流动性能好,闪点高达170 ℃,氧化安定性好,主要性能指标符合0#柴油标准,可以和0#柴油以任何比例调和.     

Use of an Adsorption Process for Purification of Pollock-Oil-Based Biodiesel Comprises Methyl Esters

The quality of biodiesel from crude pollock oil and the effect of a purification process on the physicochemical properties of pollock oil biodiesel were evaluated. Unpurified pollock oil (PO) was transesterified to biodiesel from pollock oil (BPO) using methyl alcohol (1:6 molar ratio) and NaOH (1 % w/w of the oil weight); and the resulting fatty acids methyl esters (FAME) were purified with 10 % (w/w) activated earth to yield purified biodiesel from pollock oil (PBPO). The samples were evaluated for yield, FAME composition, free fatty acids (FFA), peroxides value (PV), moisture, bulk density, cloud point, flash point, free and total glycerin, color, rheological properties, and minerals. BPO and PBPO were evaluated for the kinetics of lipid oxidation. The transesterification and purification processes had no effect on the FAME composition of PO. The yield of PBPO was significantly (P < 0.05) reduced after the transesterification and purification processes. Moreover, the transesterification process significantly (P < 0.05) reduced the FFA, moisture, bulk density, flash point, total glycerides, redness, viscosity, arsenic and silicon content in PO. Meanwhile, the purification process significantly (P < 0.05) reduced the PV, redness, and sulfur content of BPO. The flash point of BPO was significantly (P < 0.05) increased by the purification process from 79 to 84 °C. PO, BPO, and PBPO behaved as non-Newtonian and Newtonian fluids at 0 and 25 °C, respectively. BPO showed a lower oxidation rate and activation energy compared to those of PBPO. BPO and PBPO met the ASTM biodiesel standard D6751 for moisture, bulk density, cloud point, free and total glycerin, Na, P, and S. The study demonstrated that high viscosity crude pollock oil could be converted into low viscosity purified pollock oil biodiesel.     

桐油制备生物柴油的工艺研究

以四川桐油为原料,研究了生产生物柴油过程中的酯交换反应条件的影响。结果表明,当甲醇和油脂的物质的量之比超过6∶1后,桐油转化率提高范围很小。当油脂中含有少量游离脂肪酸和水分时,通过甘油虽可测定油脂的转化率,但是后处理时乳化严重,甲酯的损失较大从而影响甲酯的收率。反应温度对反应的转化率影响较大。通过测定桐油生物柴油的物性,表明桐油生物柴油的低温流动性良好,可以作为低温流动性改进剂与其它油脂制备的生物柴油混合使用。闪点为194℃,硫含量为70.75μg/g。     

叔戊醇体系酶促大豆油制备生物柴油

叔戊醇作为反应介质,固定化脂肪酶Novozym 435催化大豆油与甲醇的转酯反应制备生物柴油。叔戊醇消除了反应底物甲醇及反应副产物甘油对酶活的负面影响。定量分析表明,叔戊醇与油脂的体积比为1,甲醇与油脂的摩尔比为3,2%脂肪酶,反应体系含水量2%,40 ℃、180 r/min条件下反应15 h,生物柴油得率可达97%。在最适条件下反应进行160批次,酶仍保持了较高的活性和良好的稳定性。     

Analysis of the Content of Fatty Acid Methyl Esters in Biodiesel by Fourier-Transform Infrared Spectroscopy: Method and Comparison with Gas Chromatography

The increasing importance of sustainability in energy production has led to a global commitment to the use of fuels derived from renewable biological sources, such as biodiesel produced from plant crops or biomass residues, that do not compete with human food for their production. For a biofuel to be considered biodiesel, it must satisfy the specifications described in the UNE 14214, with the UNE-EN 14103 referring to the determination of fatty acid methyl ester content. This standard applies gas chromatography as an analytical technique. Gas chromatography is a widely used technique in the analysis of methyl ester although it has a number of drawbacks such as: long analysis times, a high consumption of high-quality gases and internal standards, does not allow the analysis of different compounds with the same column, etc. From an industrial production point of view, is necessary to know the fatty acid methyl ester content in biodiesel samples quickly. This paper studies the development of an analytical method using Fourier transform infrared spectroscopy (FTIR) as alternative to gas chromatography (GC), since it is a simple, rapid, and precise analytical technique to quantify fatty acid methyl ester content in biofuel samples.