Epoxidation of Unsaturated Fatty Acid Methyl Esters in the Presence of SO_3H-functional Brφnsted Acidic Ionic Liquid as Catalyst

The epoxidation of unsaturated fatty acid methyl esters(FAMEs)by peroxyacetic acid generated in situ from hydrogen peroxide and acetic acid was studied in the presence of SO3H-functional Brnsted acidic ionic liquid (IL)[C3SO3HMIM][HSO4]as catalyst.The effects of hydrogen peroxide/ethylenic unsaturation ratio,acetic acid concentration,IL concentration,recycling of the IL catalyst,and temperature on the conversion to oxirane were studied.The kinetics and thermodynamics of unsaturated FAMEs epoxidation and the kinetics of oxirane cleavage of the epoxidized FAMEs by acetic acid were also studied.The conversion of ethylenic unsaturation group to oxirane, the reaction rate of the conversion to oxirane,and the rate of hydrolysis(oxirane cleavage)were higher by using the IL catalyst.

Boosted Biodegradability and Tribological Properties of Mineral Base Oil by Methyl Diethanolamine Fatty Acid Esters

Methyl diethanolamine fatty acid esters, viz. methyl diethanolamine octanoate and methyl diethanolamine oleate,were prepared. Their impacts on the biodegradability and tribological properties of mineral base oil 400 SN were evaluated by a tester for fast evaluating the biodegradability of lubricants and by a four-ball tester, respectively. The results showed that methyl diethanolamine octanoate and methyl diethanolamine oleate both could markedly promote the biodegradation of the oil and improved its tribological properties. The improvement of biodegradability was attributed to the enhanced growth and quantity of microbes by methyl diethanolamine fatty acid esters. The worn surfaces were analyzed by a scanning electron microscope(SEM) equipped with an energy dispersive spectrometer(EDS) and an X-ray photoelectron spectroscope(XPS). The results indicated that the enhancement of friction-reducing and anti-wear properties of the mineral oil was attributed to the formation of complicated boundary lubrication films composed of species such as Fe_2O_3, Fe_3O_4 and organic nitrogen-containing compounds with a structure of –C-N-or R-NH_2.

Effects of Yttrium Doping on the Performance of Ru-Based Catalysts for Hydrogenation of Fatty Acid Methyl Ester

The highly dispersed supported ruthenium-yttrium (Ru-Y) bimetallic catalysts were prepared by impregnation method and their catalytic performance for hydrogenation of ester was fully investigated. The catalyst was characterized by X-ray diffraction and field emission scanning electron microscopy. The results show that the average particle diameter of the bimetallic crystallites was less than 10 nm. The effects of the reaction temperature, the hydrogen pressure, the amount of catalyst and the proportion of yttrium in catalyst on the hydrogenation of ester were studied. The experimental results show that the introduction of yttrium not only changed the chemical and textural properties of ruthenium-based catalyst but also controlled the formation of Ru-Y alloy. The Ru-Y catalyst (Ru-2%Y/TiO2) exhibited high catalytic activity and good selectivity towards the higher alcohols. Under optimal reaction conditions of 240°C and 5 MPa hydrogen pressure, the conversion of palm oil esters was above 93.4% while the selectivity towards alcohol was above 99.0%.

Ternary Liquid-Liquid Equilibrium for Systems of Fatty Acid Methyl Ester(Methyl Palmitate/Methyl Stearate)+Ethanol+Glycerol at Atmospheric Pressure

Liquid-liquid equilibrium data of two ternary systems methyl palmitate+ethanol+glycerol and methyl stearate+ethanol+glycerol at(318.2 and 333.2)K and atmospheric pressure were measured. The values of distribution coefficient and selectivity were calculated, which indicates that glycerol can be separated from fatty acid ester by using ethanol as an extraction solvent. The consistency of the isothermal tie-line data were checked by the Othmer-Tobias equation. The correlation coefficients R2 are higher than 0.993,9 for all the fitted curves. The NRTL activity coefficient model was applied to the correlation of the measured tie-line data. The root mean square deviation(RMSD)values are less than 0.007 for all the systems, which shows a good predictive capability of this model for such systems.

Determination of the Fatty Acid Profile of Breast Milk from Nursing Mothers in Bungoma County, Kenya

The fatty acid profile in breast milk of nursing mothers who participated in a Cohort for Vitamin A (COVA) study at the fourth and ninth month of lactation was investigated. Breast milk samples were collected by manual expression and stored at - 20°C until analysis. The fat was extracted from the milk and methylated using the American Oil Chemists’ Society (AOCS) Official Methods with modifications. The separation, identification and quantification of the fatty acid methyl esters was performed by gas chromatography coupled with mass spectrometry (GC-MS). Fat contents of human milk increased significantly between the fourth and ninth month of lactation 0.38 and 1.21 mg·mL-1 respectively;P 0.05) than the average percent of the total unsaturated FAs (48.93%). Similarly, at the 9th month the percentage average of the total saturated fatty acids (15.18%) was significantly lower (P < 0.05) than the average percent of the total unsaturated FAs (31.05%). The results obtained in this study demonstrated that the fat content in breast milk significantly increased in the 9th compared to the 4th month of lactation. The fatty profile was also significantly different with the omega 6 being the dominant at the 9th month compared with the omega - 9 being dominant at the 4th month of lactation.

NiMoRe/HZSM-5催化剂的制备及其催化脂肪酸甲酯加氢脱氧

使用浸渍法制备了5 kg NiMoRe/HZSM-5催化剂,结合X射线衍射(XRD)、扫描电子显微镜(SEM)、电感耦合等离子原子发射光谱(ICP-OES)等表征手段对催化剂进行理化性质分析,并对该催化剂用于硬脂酸甲酯加氢脱氧反应的最佳条件进行探究。研究结果表明:相比3种商用催化剂,NiMoRe/HZSM-5中金属Ni具有较小颗粒,且分散均匀,BET比表面积(S_(BET))更大,为239.1 m^(2)/g,具有更好的催化活性。在温度260℃、0.3 g催化剂用量、反应时间4 h、初始H 2压力3 MPa的最优反应条件下,原料转化率和烷烃选择性均为100%,且催化剂稳定性较佳,第5次循环原料转化率仍高达96.1%,加氢脱氧(HDO)反应的选择性(S HDO/DCO),即HDO反应与脱羧脱羰(DCO)反应的比值由1.2降至0.56。将催化剂NiMoRe/HZSM-5用于脂肪酸甲酯无溶剂条件下的加氢脱氧反应放大实验后进行中试,采用2.8 L固定床对25 kg脂肪酸甲酯进行连续加氢性能评价,经过15循环后脂肪酸甲酯的转化率达到98%。

丙磺酸型碗状碳微球制备及在餐厨废油酯交换反应中的性能研究

以碗状碳微球(BHC)为载体,合成了以烷基为磺酸基键合位点的丙磺酸型碗状碳微球(PA-CBHC-Si)。X射线光电子能谱仪、扫描电子显微镜和傅里叶变换红外光谱分析表明,三步改性分别逐步丰富BHC表面羧基(—COOH)、巯基(—SH)、磺酸基(—SO_(3)H)官能团含量,且改性过程保留了载体的原始形貌。PA-CBHC-Si的酸密度高达8.5mmol/g,活性中心—SO_(3)H于300℃开始分解,具有良好的热稳定性。PA-CBHC-Si可作为煎炸废油与甲醇酯交换反应的催化剂,醇油摩尔比为16∶1,剂油比为0.02的催化体系于130℃反应4h,脂肪酸甲酯产率为84.53%。

Role of inflammatory lipid and fatty acid metabolic abnormalities induced by plastic additives exposure in childhood asthma

Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure,but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the disease.We have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry,and its relationships with the dysregulation of lipid metabolism in asthmatic,bronchitic(acute infammation)and healthy(non-infammation)children.Eight PAEs and nine OPFRs congeners were found in the serum of children(1–5 years old)from Shenzhen,and their total median levels were 615.16 ng/m L and 17.06 ng/m L,respectively.Moreover,the serum levels of mono-methyl phthalate(MMP),tri-propyl phosphate(TPP)and tri-n-butyl phosphate(TNBP)were significant higher in asthmatic children than in healthy and bronchitic children as control.Thirty-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data,and the alterations of infammatory characteristic lipids and fatty acids including palmitic acids,12,13-Di HODE,14,21-Di HDHA,prostaglandin D2 and Lyso PA(18:2)showed significant correlated with high serum levels of MMP,TPP and TNBP.These results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting infammatory lipid and fatty acid metabolism,and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.

蛋白核小球藻原位催化制备生物柴油的研究

化石燃料是全球能源供应的主要来源,在过去的几十年里,由于人口和能源需求的增加,导致能源消耗和CO_(2)排放量迅速增加,加剧了全球气候变化。利用生长迅速、含油量高、对环境友好的蛋白核小球藻(Chlorella pyrenoidosa)催化转化生物柴油具有很大发展潜力,可以实现“碳中和”及可持续发展。传统的两步酯交换法制备生物柴油在经济环境上是不可行的,脱水干燥和脂质提取过程消耗了大量能源和成本,采用“一步”原位酯交换方法替代传统的两步酯交换将微藻转化为低成本高附加值产品,可以实现高生物柴油产率及高C16、C18脂肪酸甲酯组分含量,产生高质量的生物柴油,具有生态和经济效益。

Effect of natural and synthetic antioxidants on oxidative stability of FAMEs obtained from hevea brasiliensis

Biodiesel(fatty acid alkyl esters),an alternate to fossil fuel,has the tendency of autoxidation and hence requires antioxidants for long term storage.The influence of synthetic and natural antioxidants on the oxidative stability was analysed for fresh FAMEs(fatty acid methyl esters)obtained from hevea brasiliensis at 140 C.Higher activity was observed for synthetic antioxidants following the order of GA】BHT】DTBP】Q】GT-M】PH-M】GT-C,whereas the oxidative stability of stored FAMEs samples measured at 110 C reveals a nearly inverse trend.Storage stability was tested for the FAMEs obtained from hevea brasiliensis stored at 30 C,after addition of synthetic and natural antioxidants—butylated hydroxytoluene(BHT),2,6-di-tert-butylphenol(DTBP),quercetin(Q),gallic acid(GA),methanol extracts from green tea(GTM),pomegranate hull(PH-M),and chloroform extract of green tea(GT-C).Antioxidant activities above 1500 ppm was in the order of DTBP】BHT】GA】GT-C】GT-M】Q】PH-M.Synthetic antioxidants have been found more efficient to improve the storage stability of FAMEs obtained from hevea brasiliensis.DTBP in particular has the highest protection factor.

掺混纳米粒子对脂肪酸甲酯乙醇混合燃油的蒸发及微爆特性的影响

通过添加脂肪酸甲酯和乙醇的混合物,研究了不同浓度的Fe_(3)O_(4)纳米颗粒(0.05%,0.5%,1%,2%)的蒸发过程.在正常重力条件下,分析比较了纳米流体液滴在773K和873 K两种温度下的蒸发特性,并与脂肪酸甲酯和乙醇二元混合物的蒸发特性进行了比较.结果表明,纳米流体燃料受环境因素的影响很大,在773 K和873 K环境温度下的瞬态加热阶段,燃料发生了明显的微爆炸,平衡蒸发阶段遵循d^(2)定律.在873 K的环境温度下,低浓度的纳米粒子会缩短液滴燃料的寿命,高浓度的纳米粒子容易剧烈运动而累积成核,并最终在液滴的表面形成多空的球形壳,抑制了液滴的蒸发.在773 K的环境温度下,高浓度的纳米粒子从环境温度吸收大量热量,从而加速了液滴的蒸发.

磺酸型中空多孔碳微球基固体酸催化煎炸废油的酯交换反应

以中空多孔碳微球(HPCMs)为载体,依次经过酰胺化、H_(2)O_(2)氧化和氯磺酸磺化后制得磺酸型中空多孔碳微球基固体酸(SHPCMs)催化剂,借助SEM、TEM、氮气物理吸脱附、XPS、TG和boehm滴定法等对催化剂的理化性质进行了表征.结果表明,该催化剂具有中空多孔结构,表面成功接枝磺酸基团,表面酸量为13.0 mmol/g,比表面积为11.5 m^(2)/g,平均孔径为4.39 nm,在酯交换反应中表现出良好的催化性能,在最佳反应条件下(反应温度120℃、反应时间7 h、醇油物质的量之比16∶1),脂肪酸甲酯的产率为98.60%.

低泡沫环氧丙烷封端脂肪酸甲酯乙氧基化物在铝材低温除油中的应用

以环氧丙烷(PO)封端脂肪酸甲酯乙氧基化物(FMEE)为主成分,TX-10为乳化剂,乙二胺二邻苯基乙酸钠(EDDHA-Na)为螯合剂,伯烷基磺酸钠(PAS-80)为渗透剂,获得适用于铝材的低温乳化、除灰、防回沾三种性能均衡的除油剂。通过正交试验确定了PO封端FMEE、TX-10、PAS-80、EDDHA-Na的较佳质量比为3∶2∶1∶1。将30g/L该除油剂与10g/L硫酸复配使用时,不仅可获得良好的除油效果,还能降低硫酸的使用量。

磺酸型固体酸的制备及其催化油脂合成脂肪酸甲酯的研究进展

主要阐述了制备磺酸型固体酸的方法,重点分析以不同材料为载体的磺酸型固体酸在催化合成脂肪酸甲酯中的应用和性能,旨在为磺酸型固体酸的合成及高效利用提供参考。

芝麻酚与季铵盐共催化环加成反应合成植物油基环状碳酸酯

旨在为植物油基环状碳酸酯产品的制备提供新的研究思路,以环氧大豆油脂肪酸甲酯和二氧化碳为原料,在催化剂季铵盐和氢键供体的作用下,合成植物油基环状碳酸酯。通过单因素实验对植物油基环状碳酸酯的合成条件进行优化,对反应动力学进行了分析,同时对产物植物油基环状碳酸酯进行了红外表征。结果表明:植物油基环状碳酸酯最佳合成条件为以芝麻酚为氢键供体、四丁基溴化铵与芝麻酚物质的量比2∶1、四丁基溴化铵用量10%(以原料环氧键物质的量计)、反应温度120℃、反应压力1.0 MPa、反应时间10 h,在此条件下植物油基环状碳酸酯的产率达91.4%;反应动力学分析表明,芝麻酚的加入降低了反应的活化能,有利于植物油基环状碳酸酯的合成;红外光谱表征结果证明成功合成了产物。综上,实现了无溶剂条件下高效合成植物油基环状碳酸酯。

液体脂肪酶法制备脂肪酸甲酯的条件优化

以液体脂肪酶催化地沟油制备脂肪酸甲酯。以酯化率为考核指标,在单因素试验基础上,通过响应面法优化制备工艺参数。结果表明:以地沟油质量为基准,最佳工艺参数为醇油摩尔比5.18∶1、加酶量5.04%、加水量0.08%,在此条件下获得实际酯化率为88.35%。液体脂肪酶法制备脂肪酸甲酯,具有安全环保、反应条件温和、酶用量少、生产成本低等优点。

基于两步法的植物油制备脂肪酸酰胺研究

以植物油合成脂肪酸酰胺是实现生物质资源高值化利用的一种重要方式。本文开发了两步反应技术(碱催化甲酯化反应合成脂肪酸甲酯,脂肪酸甲酯发生酰胺化反应生成脂肪酸酰胺),以六种不同的植物油(菜籽油、棕榈油、花生油、橄榄油、大豆油和山茶油)为原料合成脂肪酸酰胺。以菜籽油为典型植物油原料,系统考察了酰胺化反应过程中温度、时间、氨气压力和硅胶用量等工艺参数的影响,得出最佳工艺条件:反应温度130℃、反应时间15 h、起始氨气压力0.5 MPa、硅胶0.6 wt%。在最佳工艺条件下,进一步以棕榈油、花生油、橄榄油、大豆油和山茶油为底物合成脂肪酸酰胺,结果表明所测植物油的棕榈酸酰胺、硬脂酸酰胺、油酸酰胺、亚油酸酰胺和亚麻酸酰胺产率在79.5%~96.6%之间。研究表明开发的两步法技术对不同植物油合成脂肪酸酰胺具有很好的普适性,为规模化应用不同种类植物油合成脂肪酸酰胺创造了条件。

采用Peng-Robinson方程和体积平移的脂肪酸甲酯液相密度预测

为了提高经典的Peng-Robinson立方型状态方程(PR方程)预测脂肪酸甲酯高压液相密度的精度,并为生物柴油的进一步工程应用提供可靠的密度预测方法,在对文献中发表的19种饱和脂肪酸甲酯和6种不饱和脂肪酸甲酯的常压液相密度实验数据进行收集的基础上,采用体积平移法对PR方程进行了修正。分析发现,体积平移量与所研究的脂肪酸甲酯中的碳原子数、双键数以及温度存在一定的规律,并获得了其定量关系式,得到了可以预测同系列脂肪酸甲酯液相密度的体积平移的PR方程(VTPR方程)。结果表明,利用所提VTPR方程计算得到的脂肪酸甲酯常压密度与实验数据的总体相对偏差为0.30%。将所提VTPR方程用于预测脂肪酸甲酯高压条件下的密度,预测值与实验数据的总体相对偏差为0.50%,可以满足实际工程的需要。

气相色谱法测定生物柴油中酯含量的方法研究

当前环保型能源越来越被关注,生物柴油便是其中之一,能够作为普通柴油的代替燃料。与普通柴油不同,生物柴油是内部添加了酸性或碱性的催化剂,能够促动醇与酯元素产生反应。由C14~C24脂肪酸甲酯以及其他微量杂质组成。与普通柴油一样,生物柴油具备普通柴油的基本属性以及功能,而假设将生物柴油与石油调和则能够得到B-5、B-20等型号的混合(生物与石油)柴油。尽管生物柴油与其他油脂相比能够起到相对环保的作用,但其甘油酯的含量难以稳定,过多的甘油酯会间接侵蚀发动机,容易破坏载体自身的使用生命。这也是导致生物柴油限量生产的主要原因。

柴油中脂肪酸甲酯检测方法的变化及不确定度评定

针对GB/T 23801-2021中脂肪酸甲酯(FAME)检测方法的变化进行了比较,并对新方法的检测能力和准确性进行了研究。通过对方法的检出限和定量限进行测定,得出方法的检出限和定量限分别为0.003 6,0.012 0 g/L,表明该法能够准确灵敏地检测柴油中FAME含量。对不确定度的来源进行了全面分析,对每一种不确定度分量和合成不确定度进行了评定,得出方法合成相对不确定度为0.052 1,当k=2(置信概率为95%)时,扩展不确定度为0.276 g/L,测定结果为(2.649±0.276)g/L。标准曲线拟合和标准溶液配制为不确定度产生的主要因素。