美国大豆生产、科研、推广和市场体系(续四)

(接续三)2.1.2.3生物柴油生物柴油是通过酯基转移作用(transesterification)把脂或植物油中的甘油脱去后生产的长链脂肪酸单烷基酯(甲酯)。生物柴油的基本工艺是在豆油中加甲醇和氢氧化钠,经过几次水洗步骤,把甘油分离出去。1 L豆油可生产出0.95 L生物柴油,每1浦氏耳大豆(27.24     

豆油乙二醇乙醚酯生物柴油燃料特性研究

以乙二醇乙醚和精制大豆油在金属钠催化下合成出了豆油乙二醇乙醚酯生物柴油,考察了该生物柴油作为替代燃料在性能方面与柴油的差别;研究了作为柴油添加剂,其加入量对混合燃料性能的影响.结果表明,豆油乙二醇乙醚酯生物柴油的燃料特性达到了国外生物柴油生产标准,可以直接作为柴油使用,也可与矿物柴油掺舍使用,提高了柴油的使用性能.     

大豆油甲酯-柴油混合燃料特性研究

近年来,生物柴油作为一种无毒的、可生物降解的、可再生的柴油机代用燃料倍受关注.为优化生物柴油的应用,对比分析了大豆油甲酯生物柴油与柴油混合液的低温流动性、雾化和蒸发性、安定性、腐蚀性、清洁性和互溶性.结果表明:与柴油相比,B5、B10、B15、B20、B25和B30的凝点和冷滤点保持不变;闪点、20℃运动粘度、40℃运动粘度、密度和50%馏出温度分别平均增加26.8%、7.2%、10.8%、1.3%和12.6%,而90%和95%馏出温度基本不变;胶质和残碳分别平均增加62.3%和6.5%;硫含量平均降低15.7%,但酸度平均升高4.1%;灰分平均增加22.7%.但机械杂质平均降低13.7%.经分析,大豆油甲酯生物柴油与柴油混合液基本符合国家标准GB252-2000对轻柴油的要求.     

淀粉 脂类复合物对蓝色小麦淀粉流变性的影响

为了解淀粉脂类复合物对南阳彩色小麦淀粉糊流变特性的影响,利用黏度分析仪测定了月桂酸、豆蔻酸、棕榈酸和硬脂酸与小麦淀粉结合形成复合物后淀粉糊的流变特性。结果表明,分别将1.0%、2.0%和3.0%的脂肪酸添加到蓝色小麦淀粉中,在95℃下分别蒸煮5、10和15 min,复合指数随蒸煮时间的延长和脂肪酸用量的增加而提高,随脂肪酸碳链的增加而降低;黏度系数随复合物的增加而增加,而流变指数则随复合物的增加而降低;在四种脂肪酸中,月桂酸与淀粉形成复合物的能力最强,对小麦淀粉的流变特性影响最大;添加月桂酸2%、蒸煮10 min形成的复合物最好。     

超临界甲醇法制备大豆生物柴油

本文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.与其他化学法相比,超临界甲醇法的反应时间从1～8 h降低到4 min,对原料油的要求也低,可使水含量及酸值较高的废油未经处理即可制得转化率98以上的生物柴油.分析了反应机理,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.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.     

不同保存体系低氨浓缩天然胶乳的性能研究

低氨浓缩天然胶乳能在一定程度上缓解高氨胶乳带来的氨污染问题,并在多种乳胶制品中获得越来越广泛的应用。本研究采用BCT-2、HY、HM和LS 4种天然胶乳保存剂与氨复合保存制备低氨浓缩胶乳,并与高氨浓缩胶乳进行对比分析,研究不同保存体系低氨浓缩胶乳性能之间的差异。结果表明,4种保存体系对低氨浓缩胶乳保存效果良好,均能达到GB/T 8289—2016国家标准的要求。其中,BCT-2保存的低氨浓缩胶乳挥发脂肪酸值（VFA No.）最低,但胶乳黏度值最高,机械稳定度（MST）最低,稳定性最差;此外,橡胶粒子平均粒径较高;热稳定性和氧化锌机械稳定性（ZST）较低;干胶膜强度较高。HY保存的低氨浓缩胶乳VFA No.较低,黏度最低,MST和热稳定度最高;浓缩胶乳预硫化速度最快;预硫化胶乳黏度最低,MST和热稳定度最高;硫化胶膜强度较高。HM保存的低氨浓缩胶乳黏度较低;MST较高,稳定性良好;浓缩胶乳干胶膜强度最低;浓缩胶乳预硫化速度最慢。LS保存的低氨浓缩胶乳VFA No.较高,黏度值较高;MST较低,稳定性较差;橡胶粒子粒径最小;浓缩胶乳干胶膜和硫化胶膜强度均最高;干胶膜热稳定性最好。对比分析表...     

响应面法优化大豆油下脚料制备生物柴油工艺的研究

随着全球性能源的日益短缺与环境的逐渐恶化,生物柴油作为一种无毒、可生物降解和再生的替代燃料正受到越来越多的关注.研究了利用大豆油下脚料(油脚、皂脚混合物)制取生物柴油的工艺过程.先用乙醚室温下萃取下脚料,料液比1∶2(g∶mL),萃取时间2 h.离心后分为3层,上层有机相再经丙酮萃取分离出磷脂和中性油,磷脂作为高附加值副产品回收再利用以降低生物柴油的生产成本.分离出的皂相经酸化转化为混合脂肪酸,混合脂肪酸用于酸催化的酯化反应.利用响应面法对酯化反应工艺参数进行了优化,并得到回归方程.方差分析结果表明:在各影响因素中,醇酸摩尔比对转化率的影响最大,其次是反应温度和反应时间,醇酸摩尔比和反应温度的交互作用显著.酯化反应优化后的工艺条件为醇酸摩尔比为5∶1,催化剂(H2SO4)添加量3%(wt.%),反应温度为87℃,反应时间4.74 h,在此条件下转化率达到92.5%.     

新疆棉子生物柴油理化特性分析

新疆是我国植棉大省,具有发展生物柴油的巨大资源优势。试验以酯交换技术转化棉子油并进行全项目检测分析,研究新疆棉子转化生物柴油技术和理化特性,为新疆棉子资源优势转化生物柴油产业化提供参考。1材料和方法1.1材料。棉子油由新疆天成油脂有限公司生产,棕榈酸、硬脂酸、油酸、亚油酸、亚麻酸分别占总脂肪酸的24.0%、1.8%、17.7%、56.1%和0.4%,皂化值191.2mg.kg-1,碘价1116g.kg-1,酸价0.085mg.kg-1。实验室研究用分析纯,中试生产所用甲醇、氢氧化钠及稀硫酸等均为工业级。1.2方法。制备方法:采用碱催化酯交换法,以棉子油转化生产生物柴油…     

绿色液体燃料-大豆生物柴油的制备研究

大豆生物柴油是一种对环境友好的、可再生的生物质燃料,大豆生物柴油的应用可以减少人类对矿物燃料的依赖,而且可以大大减少对环境的污染.试验分别利用精制大豆油和煎炸废油成功制得符合国内外现有质量标准的大豆生物柴油.     

甘蓝型油菜芥酸及其它脂肪酸数量性状的遗传分析

本文以6×6的不完全双列杂交试验,对各脂肪酸的配合力和部分遗传参数进行了分析和估算,并对各脂肪酸杂种优势间的关系进行了分析。结果表明:七种主要脂肪酸的遗传均受加性效应影响;硬脂酸、亚麻酸和花生烯酸在一定程度上受非加性效应的影响;芥酸、油酸和亚油酸的广义、狭义遗传力均较高;油酸杂种优势与亚油酸、花生烯酸杂种优势间有极显著的负相关。据此,作者对品质育种和杂种优势利用提出了一些建议。     

Synthesis of Jatropha curcas oil-based biodiesel in a pulsed loop reactor

Jatropha curcas oil (JCO) has a high content of free fatty acids and has been used extensively as a feedstock in biodiesel production. In the present study, the transesterification reaction of JCO to Jatropha curcas methyl ester (biodiesel) was performed in a continuous pulsed loop reactor under atmospheric conditions. The JCO was pre-treated prior to the reaction to reduce the free fatty acid content to below 1% (w/w). The operating parameters of the loop reactor were optimised based on the conversion of the JCO to Jatropha curcas biodiesel and included reaction temperature, molar ratio of oil to MeOH, reaction time and oscillation frequency. The findings show that the highest reaction conversion of 99.7% (w/w) was achieved using KOH catalyst and 98.8% conversion was obtained using NaOCH₃ catalyst. The optimal operating conditions were a molar ratio of 6:1, an oscillation frequency of 6 Hz, temperature of 60 °C, feedstock FFA content of 0.5% (w/w) and only 10 min of reaction time. As a commercial commodity, the physical properties of biodiesel were analysed, and they compared well with the characteristics of fossil-based diesel fuel.     

Variability assessment in Pongamia pinnata (L.) Pierre germplasm for biodiesel traits

Wide variability in oil content was observed in 75 germplasm accessions of Pongamia pinnata (L.) Pierre collected from Telengana region of Andhra Pradesh, India. Out of these, fatty acid profiles of 21 accessions with varying seed oil content were examined. Large variation was observed in stearic, oleic and linoleic fatty acid composition i.e. 1.83–11.50%, 46.66–65.35% and 12.02–32.58% respectively while less variation i.e. 9.25–12.87% was found with palmitic acid content. Saponification number (SN), iodine value (IV) and cetane number (CN) of fatty acid methyl esters of oils varied from 183.3 to 200.91, 74.78 to 100.98 and 50.85 to 59.11 respectively. Fatty acid composition, IV and CN were used to predict the quality of fatty acid methyl esters of oil for use as biodiesel. Fatty acid methyl esters of oils of P. pinnata accessions DORPP 49, 72 and 83 were found most suitable (CN more than 56.6) for use as biodiesel and they meet the major specification of biodiesel standards of USA, Germany and European Standard Organization. The range of variability found for various biodiesel standards in accessions of P. pinnata can be utilized for the establishment of plantations of promising genotypes through clonal means for increased productivity.     

Evaluation of Camelina sativa oil as a feedstock for biodiesel production

The oilseed crop Camelina sativa (camelina) has lower production costs than oilseed rape in some climates. For this reason, the production of biodiesel-grade methyl ester from camelina oil was evaluated. The evaluation included quality assessment of esters produced in laboratory and pilot plant, an examination of methods of improving ester low-temperature properties, and vehicle trials. Laboratory esterifications gave ester yields similar to rape-seed oil. Six 350 kg batches of unrefined camelina oil with acid values from 3 to 6 were esterified in a pilot plant. Ester-specific properties were satisfactory with one exception; the iodine number of 155 far exceeded the value of 120 required by the relevant EU standard. Fuel-specific properties of the camelina methyl esters were largely within specification, though low-temperature behaviour could be a problem in some climates. This problem could be overcome by the use of suitable pour-point depressants or by blending with diesel oil. In vehicle tests, the reduction in fuel economy with camelina ester was similar to that with biodiesel from other feedstocks. The high iodine number of camelina methyl ester did not lead to a more rapid deterioration of the lubricating oil. However, it was concluded that further engine trials would be needed before the use of camelina ester as an undiluted vehicle fuel could be recommended.     

Synthesis of a base-stock for electrical insulating fluid based on palm kernel oil

This report presents a method for synthesizing base-stock for green industrial product from a vegetable oil with a high composition of unsaturated fatty acids. Epoxy methyl ester of palm kernel oil was synthesized from laboratory purified palm kernel oil using a two-step reaction and the products were used as a base-stock for green electrical insulation fluid. Epoxidized palm kernel oil was first prepared through epoxidation reaction involving purified palm kernel oil, acetic acid and hydrogen peroxide in the presence of amberlite as catalyst which lasted for 4 h. It was then followed by transesterification reaction involving the epoxidized product and methanol in the presence of sodium hydroxide as catalyst to synthesize the corresponding epoxy methyl ester. The thermal and electrical breakdown properties of the epoxy methyl ester demonstrated significantly improved properties for its use as raw material for bio-based industrial products such as electrical insulation fluids.     

Synthesis and characterization of hazelnut oil-based biodiesel

The demand for diesel fuel far exceeds the current and future biodiesel production capabilities of the vegetable oil and animal fat industries. New oilseed crops that do not compete with traditional food crop are needed to meet existing energy demands. Hybrid hazelnut oil is just such an attractive raw material for production of biodiesel. Hazelnut oil was extracted from hybrid hazelnuts and the crude oil was refined. Hazelnut oil-based biodiesel was prepared via the transesterification of the refined hazelnut oil with excess methanol using an alkaline catalyst. The effects of reaction temperature, time and catalyst concentration on the yield of diesel were examined, and selected physical and chemical properties of the biodiesel were evaluated. The biodiesel yield increased with increasing temperature from 25 to 65 °C and with increasing catalyst concentration from 0.1 to 0.7 wt%. The increase in yield with reaction time was nonlinear and characterized by an initial faster rate, followed by a slow rate. Hazelnut oil-based biodiesel had an average viscosity of 8.82 cP at 25 °C, which was slightly higher than that of the commercial soy-based diesel (7.92 cP at 25 °C). An approximate 12 °C higher onset oxidative temperature and a 10 °C lower cloud point of hazelnut oil biodiesel than those of its commercial soy counterpart indicated a better oxidative stability and flowability at low temperature. The average heat of combustion of hazelnut oil biodiesel was 40.23 kJ/g, and accounted for approximately 88% of energy content of diesel fuel. The fatty acid composition of hazelnut oil-based biodiesel was the same as the nature oil.     

Synthesis and physical properties of mono-estolides with varying chain lengths

Saturated mono-estolide methyl esters and enriched saturated mono-estolide 2-EH esters were synthesized from oleic and different saturated fatty acids under three different synthetic routes. Estolide numbers (EN), the average number of fatty acid units added to a base fatty acid, varied with synthetic conditions. The attempts at obtaining saturated mono-estolide 2-EH esters, EN = 1, via distillation proved to be challenging, which lead to estolide samples with EN > 1 and the pour point values followed the same trend as the high EN estolides. The other synthetic routes provided saturated mono-estolide methyl esters with EN = 1. The resulting pour point values showed a linear relationship between the saturated capping chain length and pour point. As the saturated capping chain length increased the pour points also increased (higher temperatures): C-2 capped ?30 °C, C-10 capped ?12 °C, and C-18 capped 3 °C.The saturated mono-estolide methyl ester viscosities also showed an increase in viscosity at 40 and 100 °C as the saturated chain lengths increased. The viscosities for the C-4 saturated mono-estolide methyl ester was 9.5 cSt at 40 °C and 2.6 cSt at 100 °C, while medium chain length derivations (C-10 saturated mono-estolide methyl ester) were 19.7 cSt at 40 °C and 4.2 cSt at 100 °C, and at the longer chain length derivations (C-18 mono-estolide methyl esters) were 27.6 cSt at 40 °C and 10.7 cSt at 100 °C. In general, a new series of saturated oleic mono-estolide methyl esters were synthesized and physical properties were collected. The physical property data indicated that both chain length and EN affect low temperature properties.     

Physicochemical properties of stillingia oil: Feasibility for biodiesel production by enzyme transesterification

The physicochemical properties, fatty acids profile and triglyceride compositions of the stillingia oil were analyzed. The stillingia oil was found to contain 98.79% neutral lipids, 0.22% phospholipids and 0.99% glycolipids, which exhibited varying contents of fatty acids. The major triglyceride was double linoleic acid linolenic acid triglyceride, which accounted for approximately 79.49% of the total triglycerides. Preparation of biodiesel from stillingia oil was investigated by enzyme transesterification with methanol as the acyl acceptor. The results showed that lipase type (Novozym 435, Lipozyme TLIM and Lipozyme RMIM), reaction systems (in solvent-free and tert-butanol system) and operational parameters (lipase loading, reaction time, temperature, and molar ratio of alcohol to oil) influenced the biodiesel yield. Fuel properties of biodiesel from stillingia oil were evaluated and all were in acceptable range for use as biodiesel in diesel engines, and had remarkable flash point and satisfactory cold flow properties. It was concluded that stillingia oil was an alternative potential feedstock oil for biodiesel production.     

Variation in oil content and fatty acid profile of Calophyllum inophyllum L. with fruit maturity and its implications on resultant biodiesel quality

Variation in oil content and fatty acid profile (FAP) of Calophyllum inophyllum; a potential biodiesel feedstock species were studied at different maturity stages and biodiesel quality parameters were estimated based on the FAP. A steady increase in oil content was observed with maturity. Variation in palmitic (16:0) and linoleic (18:2) acids followed exactly opposite trends where palmitic acid content has decreased and linoleic acid content has increased 77 days after anthesis. Oleic acid (18:1) content has shown a steady increase. Stearic acid (18:0) content remained steady up to 68 days after anthesis and then felt slightly in 77 days after anthesis. Linoleic and eicosanoic acids were found to exist in low concentrations demonstrated very little compositional variation with fruit maturity. Estimated biodiesel parameters of all maturity stages were found to comply with industrial standards. Even though 48 days after anthesis had the most ideal FAP for biodiesel production, ∼77 days after anthesis is preferred point to harvest due to higher oil content.     

Methyl ester of Sal oil (Shorea robusta) as a substitute to diesel fuel—A study on its preparation, performance and emissions in direct injection diesel engine

Many research reported vegetable oil as a potential substitute for diesel engines with its ester form known as biodiesel. The biodiesel can be prepared by different process using vegetable oil and alcohol. The common process used for biodiesel preparation is known as transesterification. This paper presents the transesterification of Sal oil (Shorea robusta) into Sal oil methyl ester (SOME) and its performance in direct injection diesel engine. Several process parameters such as catalyst quantity, molar ratio of alcohol, reaction temperature and reaction time were studied and the optimized process conditions are amount of catalyst (NaOH) - 0.25 wt%, alcohol (methanol) - 150% excess, reaction temperature - 65 °C and reaction time - 1.5 h. The studies with SOME as fuel in the direct injection diesel engine shows that the exhaust emissions such as CO, HC and NO_x are reduced by 25%, 45% and 12%, respectively compared to diesel without significant difference in thermal efficiency. Based on this study it is concluded that the SOME can be used as fuel without any modifications in the engine and hence this biodiesel can be a potential substitute to standard diesel fuel.     

Preparation of biodiesel from Idesia polycarpa var. vestita fruit oil

The feasibility of producing biodiesel from Idesia polycarpa var. vestita fruit oil was studied. A methyl ester biodiesel was prepared from refined I. polycarpa fruit oil using methanol and potassium hydroxide (KOH) in an alkali-catalyzed transesterification process. The experimental variables investigated in this study were catalyst concentration (0.5–2.0 wt.% of oil), methanol/oil molar ratio (4.5:1 to 6.5:1), temperature (20–60 °C) and reaction time (20–60 min). A maximum yield of over 99% of methyl esters in I. polycarpa fruit oil biodiesel was achieved using a 6:1 molar ratio of methanol to oil, 1.0% KOH (% oil) and reaction time for 40 min at 30 °C. The properties of I. polycarpa fruit oil methyl esters produced under optimum conditions were also analyzed for specifications for biodiesel as fuel in diesel engines according to China Biofuel Systems Standards. The fuel properties of the I. polycarpa fruit oil biodiesel obtained are similar to the No. 0 light diesel fuel and most of the parameters comply with the limits established by specifications for biodiesel.