The determination of water in crude oil and transformer oil reference materials

The measurement of the amount of water in oils is of significant economic importance to the industrial community, particularly to the electric power and crude oil industries. The amount of water in transformer oils is critical to their normal function and the amount of water in crude oils affects the cost of the crude oil at the well head, the pipeline, and the refinery. Water in oil Certified Reference Materials (CRM) are essential for the accurate calibration of instruments that are used by these industries. Three NIST Standard Reference Materials (SRMs) have been prepared for this purpose. The water in these oils has been measured by both coulometric and volumetric Karl Fischer methods. The compounds (such as sulfur compounds) that interfere with the Karl Fischer reaction (interfering substances) and inflate the values for water by also reacting with iodine have been measured coulometrically. The measured water content of Reference Material (RM) 8506a Transformer Oil is 12.1+/-1.9 mg kg(-1) (plus an additional 6.2+/-0.9 mg kg(-1) of interfering substances). The measured water content of SRM 2722 Sweet Crude Oil, is 99+/-6 mg kg(-1) (plus an additional 5+/-2 mg kg(-1) of interfering substances). The measured water content of SRM 2721 Sour Crude Oil, is 134+/-18 mg kg(-1) plus an additional 807+/-43 mg kg(-1) of interfering substances. Interlaboratory studies conducted with these oil samples (using SRM 2890, water saturated 1-octanol, as a calibrant) are reported. Some of the possible sources of bias in these measurements were identified, These include: improperly calibrated instruments, inability to measure the calibrant accurately, Karl Fischer reagent selection, and volatilization of the interfering substances in SRM 2721.     

Determination of residual oil in diesel oil by spectrofluorimetric and chemometric analysis

Multivariate calibration (PLS), principal components analysis (PCA) and linear discriminant analysis (LDA), associated to synchronous spectrofluorimetry, were used to identify and quantify non-transesterified residual vegetable oil in diesel oil with the addition of 2% of biodiesel (B2). The addition of residual oil, one of the easiest ways of adultering fuel, damages engines and leads to tax evasion. Using this method, the samples of diesel oil, B2, and B2 contaminated with residual oil were classified correctly and separated into three well-defined groups. The quantification of residual oil in B2 was carried out in the 0-25% (w/w) band, RMSEC and RMSEP values ranging from 0.26 to 0.48% (w/w) and 1.6-2.6% (w/w), respectively. The method is highly sensitive and efficient to identify and quantify this type of adulterant in which 100% of the samples were correctly classified and the average relative error was approximately 4% in the range 0.5-25% (w/w).     

延长油田长2原油组分特征研究

采用柱层色谱分离法、热重法、傅立叶红外光谱、紫外光谱和偏光显微分析等表征方法,对采自延长油田某采油厂长2层原油样品进行了组分分离和分析,并对其热重行为、饱和烃组分结蜡行为等进行了研究.研究结果表明,在原油热重反应过程中,低温下主要是其轻、中组分(饱和烃、芳香烃)及水分的物理蒸发,高温下主要是重组分(胶质、沥青质)的物理蒸发及化学反应.显微分析发现原油中的胶质、沥青质等强极性组分使饱和烃组分冷却结晶时的蜡晶分散度增大,尺寸相对减小,颗粒数明显增多,蜡晶形状由片状三维网络结构变为颗粒状,因而蜡晶之间的联结度减弱,不易缔合形成大块蜡晶聚集体,说明该原油中的极性组分可以有效抑制原油的结蜡.     

Spray-dried oil powder with ultrahigh oil content

We report a new facile route to the production of solid oil powders with an oil weight content of as high as 90% or beyond. The proposed method starts from a standard protein-stabilized oil-in-water emulsion in which a protein monolayer absorbed at the oil-water interface is successively cross linked by a thermal treatment. The emulsion is then spray dried as for ordinary emulsions, however without the addition of hydrocolloids typically needed when spray drying liquid oil dispersions. This leads to a final solid oil powder in which the total mass is constituted of oil, proteins, and eventual buffer salts and in which the elasticity of the cross-linked protein monolayer is alone sufficient to stabilize the powder and to limit any oil leakage. To best illustrate the potential in food applications and to preserve the food-grade nature of the constituents, we have used thermal denaturation at 80 °C for 15 min to cross link a β-lactoglobulin-stabilized olive oil-in-water emulsion and to produce the corresponding solid oil powder. Because of the simplicity and flexibility of the proposed pathway, the present method can be used inexpensively to convert any type of hydrophobic liquid into the corresponding solid powder and is then particularly suitable for cosmetic, pharmaceutical, medical, biotechnological, and food applications.     

顶空气相色谱-质谱测定橄榄调和油中橄榄油含量

建立了测定橄榄调和油中橄榄油含量的顶空气相色谱-质谱分析方法。对样品量、加热温度、加热时间、进样量、进样模式、色谱柱进行了优化。通过化学计量学方法发现了橄榄油的特征化合物。取1.0 g样品放置于20 m L顶空瓶中,在180℃加热振摇2 700 s,取1.0 m L顶空气体进样,通过HP-88色谱柱分离和质谱检测。结果表明,方法的线性范围为0~100%(橄榄油含量),线性相关系数(r2)大于0.995,检出限为1.26%~2.13%,模拟橄榄调和油中橄榄油含量测定的偏差为-0.65%~1.02%,相对偏差为-1.3%~6.8%,相对标准偏差为1.18%~4.26%(n=6)。该方法不使用任何溶剂,操作简单、快速、环保,灵敏度和准确度高,适用于橄榄调和油中橄榄油含量的测定。     

Investigation on stabilization of foam in the presence of crude oil for improved oil recovery

A major concern, in the foam flooding projects, is the stability of foam in the presence of oil. In this study we chose three foaming agents with different behaviors in the oil-bearing environments and examined their performance in terms of the emulsified oil and the pseudoemulsion films. The results indicate that the state of the emulsified oil or the pseudoemulsion films has a significant impact on foam stability. Two hypothesizes suggest that the role of emulsified oil played in foam stabilization can be summarized as increasing the emulsion stability and creating the viscous liquid phase, and interfacial adsorption and viscoelastic layers of pseudoemulsion films present a strong correlation with the foam stability. From the foam flooding experiments, the oil-enhanced foam is deemed to be more efficient in the oil displacement and the liquid diversion.     

Detection of hazelnut oil in virgin olive oil by assessment of free sterols and triacylglycerols

Free sterols were evaluated as factors for discriminating between genuine virgin olive oil and hazelnut-mixed virgin olive oil. Numeric analyses of the results amplified the differences between groups. The application of this method to virgin olive oil samples and their mixtures with 10% hazelnut oil distinguished between genuine and nongenuine virgin olive oil with statistical certainty. Triacylglycerol analysis was tested for the same purpose by using parameter deltaECN42, but although it possessed a discriminating capacity, it alone could not distinguish the aforementioned groups with sufficient certainty. Free delta7-sterols data were combined with deltaECN42 data into a single discriminating function to improve differentiation and bring more ruggedness, and for detection of low amounts (10%) of hazelnut oil in virgin olive oil. In fact, the values obtained by addition of delta7-sterol data and deltaECN42 data showed a higher discriminating capacity than single parameters. In a single operation the method produced all the oil fractions necessary for analysis of free sterols and triacylglycerols with ECN42. Solid-phase extraction was applied in substitution of traditional chromatography on a silica column.     

Thermal analysis of coals,oil shales and oil sands

Instances where differential scanning calorimetry and thermogravimetry have been applied to the study of coals, oil shales and oil sands are reviewed. Work carried out in this laboratory and model studies culled from the literature are used as examples to illustrate a particular application. The topics covered include characterization, assay, thermal stability determination and simulation of processing conditions.     

痕量动物油和植物油的区分检验研究

采用碱催化甲酯化的前处理方法,应用气相色谱-质谱联用技术对动物油和植物油的区分检验进行了研究。实验检出了6种主要脂肪酸:肉豆蔻酸、棕榈油酸、棕榈酸、亚油酸、油酸、硬脂酸。分析了动物油与植物油在成分及相对含量上的差异,并且找出了动物油和植物油在不饱和度上的差别。根据动物油与植物油的差异点,可以对动物油和植物油进行区分。     

镁铁水滑石的制备及其对小球藻油脂合成生物柴油的催化性能

用改良尿素法制备了镁铁水滑石(MgFe-LDH),对其在小球藻油脂合成生物柴油反应中的催化性能进行了研究。利用XRD、FT-IR、SEM及FT-IR拟合、去卷积分析等技术对所制备的MgFe-LDH进行了表征,考察了pH值、Mg/Fe摩尔比、反应温度和时间对其结构和性能的影响。结果表明,Mg/Fe摩尔比为3或4、pH值为9.5,在110 ℃条件下反应10 h,所制备的MgFe-LDH(Mg3Fe或Mg4Fe)结晶度最高,粒径均匀,结构规整。与Mg/Fe摩尔比为2的MgFe-LDH(Mg2Fe)相比,Mg3Fe或Mg4Fe在完全分解焙烧时,其层板结构保持稳定,具有较高的晶体结晶度、较多的催化活性位和较高的催化活性。以Mg3Fe金属氧化物为催化剂,在醇/油摩尔比为6时反应1.5 h,生物柴油产率可达87％;该催化剂循环使用3次,仍具一定催化活性。     

Determination of total chlorine in waste oil

Summary A simple method has been developed to determine the concentration of organic chlorine in waste oil. The determination is based on the conversion of organic chlorine to inorganic chloride by reaction with sodium biphenyl followed by extraction with nitric acid and a mixture of nitric acid and water. The concentration of chloride is determined by direct potentiometry with an ion-selective electrode. The limit of determination amounts to 3·10^–5 mol·l^–1 chloride ions with a standard deviation of 3.5%. Different samples of waste oil have been analyzed and the results have been compared to those obtained by combustion in a H₂/O₂ flame followed by potentiometric titration with silver nitrate.     

胜利超稠油的乳化降黏机理研究

研究了胜利油田滨南超稠油单56-4X4高黏的内在原因。油品性质分析结果表明,影响其高黏度的主要因素有两个:胶质、沥青质的总含量超过30%;有机杂原子O、N、S及过渡金属Ni等形成的配位络合物增加了沥青质分子的内聚力。实验筛选出的降黏剂OP-10对该超稠油降黏率高达99.59%。通过FT-IR、SEM、分子量和偶极矩等分析对比了降黏剂作用前后胶质、沥青质的结构性质变化,结果表明,OP-10使胶质、沥青质的氢键缔合作用减弱,部分拆散沥青质的堆积结构,从而使胶质、沥青质的分子量和偶极矩减小,分析得到降黏剂分子能渗透及分散胶质、沥青质的堆砌聚集体。偏光显微镜对乳状液及蜡晶微观形态的分析表明,降黏剂OP-10使超稠油乳状液由W/O型反相为O/W型而起到降黏作用;使蜡晶的聚集形态由细小均匀转变为尺寸较大的絮凝体,破坏蜡晶的三维网络结构,促进稠油黏度的下降。     

紫外可见分光光度法鉴别掺兑潲水油的花生油

研究了潲水油、花生油、调和油和葵花籽油的紫外可见光吸收光谱。实验表明,根据光谱曲线形状差异和吸光度大小可以鉴别掺兑潲水油的花生油,并能定量检测。该方法具有仪器简单、检测快速、费用低廉等优点。     

颗粒粒径对油页岩热解产油率的影响

以桦甸油页岩为原料研究了颗粒粒径对油页岩热解产油率的影响。将油页岩破碎、筛分得到<0.074、0.074~0.125、0.125~0.25、0.25~0.5、0.5~1和1~3 mm不同粒级样品,再将0.25~0.5、0.5~1和1~3 mm大粒级样品粉碎制得对应的细粉样品,采用低温干馏法和热重分析分别测定表征样品的油产率和有机质含量。结果表明,油产率随着粒径减小逐渐降低,从1~3 mm下的11.92%降到<0.074 mm下的6.14%。热重分析表明,有机质含量随着粒径降低而降低,且油产率与有机质含量有明显的线性关系。0.25~0.5、0.5~1和1~3 mm样品经粉碎后油产率降低、气产率升高,但变化值均小于1%。在破碎过程中有机质选择性地富集在大粒级样品中,且页岩油二次反应程度随着粒径的减小而增大,使得页岩油产率随着粒径的降低而降低,且有机质选择性富集是主导因素。     

Essential oil composition and antiradical activity of the oil of Iraq plants

This study examined the antiradical activity and chemical composition of essential oils of some plants grown in Mosul, Iraq. The essential oils of myrtle and parsley seed contained α-pinene (36.08% and 22.89%, respectively) as main constituents. Trans-Anethole was the major compound found in fennel and aniseed oils (66.98% and 93.51%, respectively). The dominant constituent of celery seed oil was limonene (76.63%). Diallyl disulphide was identified as the major component in garlic oil (36.51%). Antiradical activity was higher in garlic oil (76.63%) and lower in myrtle oil (39.23%). The results may suggest that some essential oils from Iraq possess compounds with antiradical activity, and these oils can be used as natural antioxidants in food applications.     

LC-GC analysis of the aromatics in a mineral oil fraction: Batching oil for jute bags

Aromatics of a C₁₅? C₃₀ mineral oil fraction, the “batching oil” used for producing jute fabrics, were analyzed for estimating the toxicity of oil transferred from jute bags to foods. Group-type pre-separation according to ring systems occurred on a LC NH₂ column with pentane and small additions of methanol as eluent. LC fractions were characterized by LC-GC-MS and quantitated by LC-GC-FID. The oil contained 23% aromatics and 1% “polars”; some 99.5% of the aromatics were alkylated.