微乳化柴油制备及其节油率与稳定时间的研究

用烷基苯磺酸钠、失水山梨醇油酸酯和MOA多元复配乳化剂制备了微乳化柴油。此柴油微乳液粒径在60 nm左右,乳液颗粒分布均匀,且实验重复性好。在温度为45℃,搅拌时间为60 min,乳化剂质量分数为4%,水质量分数为15%条件下,对制得的微乳化柴油的十六烷值、闪点、黏度等理化性能指标进行了测定,均满足0#普通柴油国标标准。通过柴油发电机组台架试验,微乳化柴油最高节油率约为7.5%,比纯柴油烟度降低83.1%,NOx排放量比纯柴油降低86.5%。研究了该微乳化柴油的热稳定性,通过微乳化柴油高温稳定时间(80℃)与常温稳定时间之间的近似关系推得其常温稳定时间。此种方法相对于传统测定常温稳定时间的方法而言,可节省大量检测时间。经实验证明,高温稳定时间在30 min以上的柴油微乳液,可以储存1年以上。     

新型高效柴油乳化剂研究

本文介绍了乳化柴油的制备及其乳化剂的研究,并将柴油微乳液的成本与0#纯柴油做了比较.本实验令油酸为主剂,浓氨水为助剂,正丁醇为助溶剂.结果表明:微乳化柴油的最大掺水量、透明度以及稳定性都与油酸与浓氨水体积比、正丁醇用量、乳化温度、乳化方式及乳化时间等均有关系.     

无醇微乳化柴油的研究

采用无醇复配乳化剂,在常温下制备油包水(W/O)型微乳化柴油,并绘制柴油-乳化剂-水的拟三元相图,通过对拟三元相图分析,考察亲水亲油平衡(HLB)值对无醇微乳化剂增溶性的影响;对微乳液中的水滴粒径、表面张力进行测试,考察HLB值与掺水量对微乳液水滴粒径、表面张力的影响,并对微乳液的稳定性进行分析。结果表明:无醇复配乳化剂微乳化性能较好,乳化剂用量为10.2%时,微乳体系的增溶水量为22.1%;当复配乳化剂的HLB=7.5时,体系拟三元相图的面积最大,且制得微乳液的水滴平均粒径与表面张力最小;当乳化剂用量为5%时,含水量为12%的微乳液能保持180 d外观透明。     

柴油乳化技术国内外发展现状分析

乳化柴油是将水和柴油通过乳化剂和乳化设备形成的油包水(W/O)型乳液,与普通柴油相比,乳化柴油具有燃烧性能好、能耗低、污染少、经济效益好等优点。本文综述了柴油乳化技术的发展、特点,对微乳化柴油的节油降污机理、及其乳化剂的制备技术做了论述,分析和研究了乳化柴油的应用前景。     

柴油乳化的研究及其进展

传统乳化柴油的研究与应用情况及其存在的问题,乳化柴油的节能降污机理以及微乳化的机理,乳化剂的选择和用量、乳化工艺对乳化柴油的稳定性的影响,乳化柴油对环境的改善,柴油微乳化工艺中微乳液的形成及微乳化柴油的特点。     

乳化柴油研究及其应用进展

介绍了乳化柴油的节能降污机理,阐述了乳化剂的选择和用量、极性物、掺水率和乳化设备对柴油乳液的影响,对乳化柴油的稳定性、燃烧性能、腐蚀性、节能和环保等性质在应用中的发展进行了概述．认为通过添加少量有机极性物(如乙醇)制成微乳液可以改善乳液的稳定性、降低乳液黏度以改善其燃烧性能。并对乳化柴油的发展趋势进行了展望,指出生物微乳化柴油是今后乳化柴油发展的一个重要方向。     

乳化剂对乙醇乳化柴油稳定性的影响

以高速分散器为乳化设备,0#柴油和无水乙醇为主要原料制备了乙醇乳化柴油乳液。考察了乳化剂的类型、HLB值和用量等对乳液稳定性的影响。实验结果表明,以油酸和壬基酚聚氧乙烯醚复配为乳化剂、HLB值为8、乙醇含量小于15%,调整内、外相密度近似相等可提高乳液稳定性,提出密度可以作为配制乙醇乳化柴油的参考依据。     

聚醚砜超滤膜乳化法制备乳化柴油

采用平均孔径为25 nm的聚醚砜超滤(UF)膜,以去离子水为分散相,以0#柴油为连续相,分别以Tween-20和Span-80为分散相及连续相的乳化剂,采用膜乳化法制备W/O型乳化柴油。UF膜乳化法制备的乳液比传统乳化方法稳定时间提高2～2.5倍,而相同条件下乳化剂用量减少了50%～65%。此外,考察了UF膜法制备乳化柴油过程中的各工艺参数对乳液液滴大小、分布及稳定性的影响规律,结果表明:当乳化剂质量分数高于0.5%,连续相流速在2.0～5.0 m/s范围内,跨膜压差为0.02 MPa时,乳液分散系数α达到0.12～0.3,液滴尺寸为30～65 nm。     

操作条件对柴油微乳液制备及稳定性的影响

利用微乳化剂Span 80(失水山梨醇单油酸酯)、D 08/1021(双烷基氯化铵),助乳化剂正戊醇,自来水制备出了柴油微乳液;进一步探讨了温度、加料方式、搅拌方式等对制备微乳液的影响.结论为温度在30-35℃时制备的微乳液澄清较快,而加料方式以及加料过程中的搅拌对微乳液的制备无影响.对所制备的微乳液样品进行稳定性验证:先混配制得微乳化剂,再将柴油和微乳化剂混合均匀,搅拌一段时间后加入水,再搅拌一段时间后加助乳化剂正戊醇,操作温度控制在30℃,由此制得的柴油微乳液澄清较快,且稳定性高.     

撞击流-旋转填料床制备丙烯酰胺反相乳液及其稳定性研究

以撞击流-旋转填料床为乳化设备,煤油为有机介质,山梨醇酐油酸酯(Span 80)和烷基酚聚氧乙烯醚(OP-10)为复配乳化剂制备了丙烯酰胺反相乳液,研究了超重力因子、撞击速度、油水体积比、乳化剂质量分数、复配乳化剂HLB值以及丙烯酰胺单体质量分数对乳液稳定性的影响,并与搅拌式乳化装置进行了对比研究。结果表明:在超重力因子为65.32,撞击速度为12.58 m/s,V(油相)∶V(水相)=1∶1,乳化剂质量占乳液总质量的5%,复配乳化剂HLB值为6.0,丙烯酰胺单体质量占单体水溶液总质量的15%的条件下,所制备乳液平均粒径为664 nm,稳定性系数达0.973;对比研究发现,采用撞击流-旋转填料床制备的乳液稳定性好,粒径小,分散均匀,乳化时间短,为连续化制乳过程。     

微乳柴油的性能研究

对由柴油、水及乳化剂组成的微乳柴油进行了电导率、粘度、粒径、稳定性及腐蚀性、密度和凝点等性能研究。结果表明:微乳柴油体系为牛顿型流体;温度升高,体系粘度降低;表面活性剂质量分数增大,粘度也逐渐增大;粘度的变化同水量的变化规律基本一致;粒径均在100nm左右;腐蚀性、密度和凝点均符合国家标准;室温时稳定期在6个月以上。     

柴油微乳液拟三元相图的研究

绘制了复合表面活性剂(D0821/Tx-4/AEO-3)/正戊醇/柴油/水体系在不同温度及不同正戊醇质量分数时的一系列拟三元相图。结果表明,正戊醇质量分数及温度对拟三元相图及水最大增溶量有很大影响,醇量太大或太小形成的微乳区面积均较小;温度升高,微乳区面积及水最大增溶量也大大减少;随着正戊醇质量分数的增大,每一个温度下的微乳区及其最大增溶水量都逐渐向AEO-3/正戊醇/油角漂移。     

Effect of Branched Alcohols on Phase Behavior and Physicochemical Properties of Winsor IV Microemulsions

The microemulsion phase behavior and physicochemical properties of surfactant–water–alcohol–oil systems are the pioneer laboratory study as a function of alcohol, water content and temperature to develop an experimental investigation for a better understanding of the microstructure of a single phase microemulsion and its stability under reservoir condition during hydraulic fracturing to recover the residual trapped oil. Viscosified surfactants are used as an efficient proppant conducting medium in hydraulic fracturing applications. The physicochemical properties of microemulsions are very helpful for characterization of microemulsions to justify their abilities and screening of surfactants. In the study, two branched alcohols, 2-methyl butan-2-ol, 3-methyl butan-1-ol selected as the cosurfactant in the proposed microemulsion system and their effect in tailoring the viscosity of microemulsions were studied. Microemulsion regions elucidated from Winsor’s pseudophase model of an oleate surfactant show a signatory distribution pattern of components between different domains with non-polar and asymmetric geometry of cosurfactant directs macromolecular alignments; their alignment contributes to a viscous microemulsions (gel) regime. The effect of surfactant and alkali, and the experimental temperature on the rheological properties of the lamellar mesophase were investigated. Phase transit regions and exact microemulsion and viscous microemulsion magnitudes were elucidated with the help of conductivity and viscosity studies of the ternary system as a function of the aqueous fraction and were in good agreement with Winsor’s pseudophase model. Dynamic and steady shear rheological studies showed that the gel is viscoelastic in nature, sustain viscosity and elastic modulus values appropriate for proppant suspension under high shear conditions. The proppant suspension and thermal behavior of ideal gel composition was found to be suitable for Coal Bed Methane and soft rock, clay reservoir stimulation.     

柴油微乳液的制备及性能研究

采用油水法并结合超声分散法,在30℃下以油酸为表面活性剂、二乙基二乙醇胺为主剂,以甲醇和乙醇作为助剂,采用甲醚和乙醚作为溶剂,制备出最大增溶水量为26.16%的柴油微乳液,对柴油微乳液进行了运动粘度、稳定性、腐蚀性、密度、静置燃烧等理化性能的检测。结果表明,制备出的柴油微乳液具有较低的运动粘度,比0#柴油具有更优异的耐低温性能;室温稳定时间为205~424 d;各样品的腐蚀度均为1A级,不会对内燃机造成腐蚀。该柴油微乳液成本较低,具有广泛的应用前景。     

吐温-80/正丁醇/环己烷/水系微乳液性能及对木材的渗透能力

考察了吐温-80/正丁醇/环己烷/水系微乳液各组分及其质量比对其形成的影响,通过电导率、表面张力和动态光散射(DLS)表征体系的物化性质。结果表明,以吐温-80为表面活性剂,正丁醇为助表面活性剂,环己烷为油相形成的微乳区较大。微乳体系的电导率随含水量的增加呈现规律性变化,可以判断微乳液的3种类型(油包水型、双连续型和水包油型);不同类型的微乳液均具有较低的表面张力(约24.6 mN/m)和粒径(小于100nm),且粒径随体系含水量的增加而增大。此外,采用液体吸收法考察了微乳液对木材的渗透能力,与普通溶剂相比,微乳液具有很强的渗透能力,特别是对于双连续型微乳液,10 min时,对马尾松和桉木的渗透能力分别达70%和50%。     

Effect of Alkyl Sulfate on the Phase Behavior of Microemulsions Stabilized with Monoacylglycerols

In this study the effect of an anionic surfactant (sodium dodecyl sulfate SDS) and oils (hydrocarbons: C12–C16) on the formation and phase behavior of the systems of oil/monoacylglycerols (MAG):SDS/propylene glycol/water has been investigated. The effects of the surfactant mixture on the phase behavior and the concentration of water or oil in the systems were studied at three temperatures (50, 55, 60 °C). Electrical conductivity measurement, FT-IR spectroscopy and differential scanning calorimetry methods were applied to determine the structure and type of the microemulsions formed. The dimension of microemulsion droplets was characterized by dynamic light scattering. It has been stated that the concentration of SDS has a strong influence on the shape and extent of the microemulsion areas. Addition of an ionic surfactant to the mixture with MAG promotes an increase in the area of microemulsion formation in the phase diagrams, and these areas of the isotropic region change with the temperature. It was shown that the presence in the systems of a surfactant more hydrophilic than MAG caused an increase in water content in the microemulsions. It was found that, depending on temperature and concentration of the surfactant mixture, it was possible to obtain a W/O type microemulsion with a dispersed particles size distribution ranging from 20 to 50 nm and containing about 17–38% water in the system. Among different alkanes (from C12 to C16), hexadecane embedded microemulsions showed a maximum water solubilization capacity.     

柴油微乳化技术研究

考察了不同种类的醇、阳离子表面活性剂与非离子表面活性剂以及非离子表面活性剂与非离子表面活性剂不同配比对形成柴油微乳液水增溶量的影响。结果表明：正戊醇为最佳助剂，碳链太长、太短或带支链均不易于形成微乳液；复配体系D0821／AEO3要比D1221／AEO3增溶效果好，与TX-4／AEO3和D0821／TX-4／AEO3体系进行对比，确定D0821／TX-4／AEO3为最佳复配体系，不仅增溶的水量多，成本也大大减少。在m(D0821)：m(TX-4)：m(AEO3)为15：14：21时，最大增溶水的质量分数将近29％，总表面活性剂质量分数6％多，正戊醇质量分数3％多。     

Biodiesel production via peanut oil extraction using diesel-based reverse-micellar microemulsions

Vegetable oils have been studied as a feasible substitute for diesel fuel, and short term tests using neat vegetable oils have shown results comparable to those of diesel fuel. However, engine problems arise due to the high oil viscosity after long-term usage. Vegetable oil/diesel blending as biodiesel fuel has been shown to be one technique to reduce vegetable oil viscosity. The goal of this research is to demonstrate the feasibility of producing this biodiesel fuel via vegetable oil extraction using diesel-based reverse-micellar microemulsions as an extraction solvent. In this extraction technique, peanut oil is directly extracted into the oil phase of the microemulsion based on the “likes dissolve likes” principle and the product of the extraction process is peanut oil/diesel blend. The results show that diesel-based reverse micellar extract oil from peanuts more effectively than both diesel and hexane alone under the same extraction condition. An extraction efficiency of 95% was achieved at room temperature and short extraction time of 10 min in just a single extraction step. The extracted peanut oil/diesel blend was tested for peanut oil fraction, viscosity, cloud point and pour point, which all meet the requirements for biodiesel fuel.     

Microemulsions with Mixed Nonionic Surfactants and Flavor Oil

The microemulsion systems composed of water/sucrose laurate/ethoxylated mono-di-glyceride/peppermint oil were formulated and characterized using electrical conductivity and small-angle X-ray scattering. The solubilization capacity of water in the oil is dependent on the surfactant mixing ratio. A static percolation phenomenon was observed in these systems and the water volume fraction percolation threshold was determined. A progressive transformation of water-in-oil to bicontinuous microemulsions, occurring upon dilution with water was revealed for equal amounts of sucrose laurate and ethoxylated mono-di-glyceride in the microemulsions. The periodicity, that is a characteristic length for the domain size of the microemulsions, increases linearly with the increase in the water volume fraction, whereas the correlation length, that is also a characteristic length for the domain size, increases with the increase in the water volume fraction up to a certain value then decreases.     

Optimized Microemulsion Systems for Detergency of Vegetable Oils at Low Surfactant Concentration and Bath Temperature

Triglycerides and vegetable oils are amongst the most difficult oils to remove from fabrics due to their highly hydrophobic nature; this is all the more challenging as cold water detergency is pursued in the interest of energy efficiency. Recently, extended surfactants have produced very encouraging detergency performance at ambient temperature, especially at low surfactant concentration. However, the salinity requirement for extended surfactants was excessive (4–14%) and there is limited research on extended‐surfactant‐based microemulsions for cold water detergency (below 25 °C). Therefore, extended‐surfactant‐based microemulsions are introduced in this study for cold temperature detergency of vegetable oils with promising salinity and surfactant concentration. The overall goal of this study is to explore the optimized microemulsion formulations with low surfactant and salt concentration using extended surfactant for canola oil detergency at both 25 and 10 °C. It was found that microemulsion systems achieved good performances (higher than those of commercial detergents) corresponding to IFT value 0.1–1 mN/m with the surfactant concentration as low as 10 ppm and 4% NaCl at 25 °C, and as low as 250 ppm and 0.1% (1000 ppm) NaCl at 10 °C. In addition, microemulsion systems were investigated with a different salt (CaCl₂, or water hardness, versus NaCl) at 10 °C, demonstrating that 0.025% CaCl₂ (250 ppm) can produce good detergency; this is in the hardness range of natural water. These results provide qualitative guidance for microemulsion formulations of vegetable oil detergency and for future design of energy‐efficient microemulsion systems.