Gasoline classification by source and type based on near infrared (NIR) spectroscopy data

In this paper, we have tried to classify 382 samples of gasoline and gasoline fractions by source (refinery or process) and type. Three sets of near infrared (NIR) spectra (450, 415, and 345 spectra) were used for classification of gasolines into 3 or 6 classes. We have compared the abilities of three different classification methods: linear discriminant analysis (LDA), soft independent modeling of class analogy (SIMCA), and multilayer perceptron (MLP) - to build effective and robust classification model. In all cases NIR spectroscopy was found to be effective for gasoline classification purposes. MLP technique was found to be the most effective method of classification model building.     

Excellent Properties of Dimer Fatty Acid Esters as Biolubricant Produced by Catalyst‐ and Solvent‐Free Esterification

Currently most technologies available to produce esters require acid or base catalysts for esterification or transesterification reactions. Production of dimerate esters (DE) exhibiting potential as a biolubricant for low temperature applications using catalyst‐ and solvent‐free approaches is presented in this article. Hydrogenated C₃₆ dimer acid and alcohol are reacted under the following conditions: dimer acid/alcohol (1:4.5 molar ratio), 150–200 °C, 24 h, 3Å molecular sieve (15% w/w). The performances of four DE species—dibutyl, dihexyl, di‐(2‐ethylhexyl), and dioctyl dimerate—as lubricant base stocks are evaluated by kinematic viscosity, viscosity index, cloud and pour point (cold flow properties) as well as oxidative stability, and compared with commercial synthetic lubricant base stock and DE, Radialube 7121. High viscosity indexes ranging between 129 and 138 are observed for the synthesized DEs, which are comparable with two commercial base stock, polyalpha olefin (PAO), and polyolester (POE). Significantly low pour point, less than ?42 °C, is observed for di‐(2‐ethylhexyl) dimerate attributed to the branching of the side chain. The DEs are categorized as ISO VG 68 based on their viscosity according to ISO 3448 classification and show potential as biolubricant with high viscosity index and excellent cold flow properties. Practical Applications: DFAE obtained have high potential to be used as lubricant base stock for equipment and machinery operating at extremely low temperature.     

Determining Frying Oil Degradation by Near Infrared Spectroscopy Using Chemometric Techniques

A rapid method for the determination of some important physicochemical properties in frying oils has been developed. Partial least square regression (PLS) calibration models were applied to the physicochemical parameters and near infrared spectroscopy (NIR) spectral data. PLS regression was used to find the NIR region and the data pre-processing method that give the best prediction of the chemical parameters. Calibration and validation were appropriated by leave one out cross validation and test set validation techniques for predicting free fatty acids (FFA), total polar materials (cTPM; measured by chromatographic method and iTPM measured by an instrumental method), viscosity and smoke point of the frying oil samples. For PLS models using the cross validation techniques, the best correlations (r) between NIR predicted data and the standard method data for iTPM in oils were 93.79 and root mean square error of prediction (RMSEP) values were 5.53. For PLS models using the test set validation techniques, the best correlations (r) between NIR predicted data and standard method data for FFA, cTPM, viscosity and smoke point in oils were 92.58, 94.61, 81.95 and 84.07 and RMSEP values were 0.121, 3.96, 22.30 and 8.74, respectively. In conclusion, NIR technique with chemometric analysis was found very effective in predicting frying oil quality changes.     

润滑油基础油粘度性能的近红外光谱研究

本文采用傅立叶（FT）近红外光谱仪,在近红外长波光谱范围内,测定了不同润滑油基础油的近红外光谱,分别建立润滑油基础油40℃粘度、100℃粘度和粘度指数3项指标的偏最小二乘和BP神经网络近红外光谱分析的校正模型。研究数据表明,近红外光谱能够获得与润滑油基础油粘度相关的光谱信息。人工神经网络方法作为一种处理非线性问题的数据分析手段,能较好的定量研究近红外光谱信息与润滑油基础油之间的关系。     

Post‐oligomerization of α‐olefin oligomers: A route to single‐component and multicomponent synthetic lubricating oils

This article describes a synthetic route to single‐component and multicomponent base stocks for synthetic lubricated oils. The synthesis was carried out in two stages. First, oligomers of α‐olefins (1‐hexene, 4‐methyl‐1‐pentene, and 1‐decene) were prepared via reactions catalyzed by metallocene catalysts. The distribution of the oligomers with respect to their oligomerization number could be controlled by the reaction temperature. The oligomer mixtures were then fractionated, and the lightest components, dimers and trimers, were separated. Finally, the latter materials, branched α‐olefins containing vinylidene double bonds, were further oligomerized with cationic catalysts. One such material prepared in the two‐stage process, the dimer of the 1‐decene dimer (C₄₀ product), has a kinematic viscosity of 6.4 cs at 100°C and a viscosity index of 147. It represents the first example of a single‐component base stock for synthetic lubricating oils. The post‐oligomerization procedure was performed on unfractionated oligomer mixtures as well, leading to an improved distribution of the final materials with respect to the carbon atom number. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Performance of higher poly(alkyl lactate acrylate)s as viscosity modifiers in vegetable oils

Recently, bio-derived materials such as vegetable oils are significantly employed in lubricating oil formulations due to its high flash point, high lubricity, low evaporation loss, renewability, biodegradability, and eco-friendliness when compared to mineral oil. We investigated the performance of seven poly(alkyl lactate acrylate)s as viscosity modifiers in two vegetable oils, namely, coconut oil and sunflower oil, which differ in the percentage of polar compounds and degree of unsaturation. Poly(alkyl lactate acrylate)s having alkyl as hexyl to dodecyl group in different concentrations between 1 and 2 wt% were added to coconut and sunflower oil and parameters such as thickening power or Q factor, kinematic viscosity (μ), and viscosity index (VI) were calculated. The μ values at 40°C and 100°C of vegetable oils studied were lower than commercially available SAE20W40 engine oil, but the VI of coconut and sunflower oil was higher by about 22%. Value of Q factor higher than 1, indicated that these poly(alkyl lactate acrylate)s were VI improvers. VI increased with increase in the polymer concentration in both the vegetable oils. The length of the alkyl side chain of these polymers and the polarity of vegetable oil had predominant effect in determining the values of VI of vegetable oils. By using these polymer additives, VI was improved by 85.5% in coconut oil and by 61.7% in sunflower oil. Varying the concentration and alkyl group of these additives, one can largely modify the viscosity ranges enabling them to be used in different lubricating applications.     

Physical and Chemical Characterizations of Normal and High-Oleic Oils from Nine Commercial Cultivars of Peanut

Density and viscosity data as a function of temperature (5–100 °C) were collected for oils (normal and high-oleic) from nine cultivars of peanut. Density decreased linearly (R ² ≥ 0.99) with increasing temperature for all oils, whereas viscosity (dynamic or kinematic) decreased exponentially with increasing temperature. At any particular temperature, dynamic viscosity increased linearly (R ² ≥ 0.95) with decreasing oil density among the various oils. Slopes of the linear fits (with units of kinematic viscosity) for dynamic viscosity versus density plots decreased in an exponential fashion as the measurement temperature decreased. High-oleic oils had both the lowest densities and highest viscosities, with viscosity differences being most apparent at cooler temperatures. Increasing contents of oleic acid, decreasing contents of linoleic acid, and decreasing contents of palmitic acid were each associated with decreased density and increased viscosity among the oils. Two of the three high-oleic oils had the significantly (p < 0.05) highest content of total tocopherols, while the other high-oleic oil was statistically grouped with the oils having the 2nd highest total tocopherol content. This suggests a link between increased total tocopherols and high-oleic peanut oils; however, no obvious linear correlations were observed in tocopherol content and oil physical properties (density or viscosity). The use of trade names in this publication does not imply endorsement by the United States Department of Agriculture-Agricultural Research Service.     

环保芳烃油对溶聚丁苯橡胶工艺性能的影响

研究几种环保芳烃油（TDAE）对溶聚丁苯橡胶（SSBR）工艺性能的影响,并与芳烃油（DAE）进行对比。试验结果表明：以TDAE替代DAE,随着油品运动粘度或芳烃含量的增大,SSBR生胶及混炼胶的门尼粘度先减小后增大;胶料的门尼焦烧时间延长,硫化速度减慢,t90随油品芳烃含量的减小而逐渐延长,自粘性较好,出口膨胀率减小;硫化胶的物理性能无明显差异。     

Application of principal-component analysis on near-infrared spectroscopic data of vegetable oils for their classification

In the near-infrared (NIR) spectra of oil, information about fatty acid composition is concentrated in the range of 1600–2200 nm. Principal-component analysis (PCA) was applied on the standardized full NIR spectral data of this region for vegetable oils to totally capture the NIR spectral pattern. Nine varieties of vegetable oils (soybean, corn, cottonseed, olive, rice bran, peanut, rapeseed, sesame and coconut oil) could be successfully classified from their PCA scores. Examining the contribution of wavelengths to PCA scores showed that wavelengths with a high loading weight were assigned to characteristic absorption regions that correspond to specific fatty acid moieties. This classification is related to the fatty acid composition of an oil, and it can be carried out rapidly and easily after eigenvectors were obtained.     

Synthesis of Dimer Acid 2-Ethylhexyl Esters and their Physicochemical Properties as Biolubricant Base Stock and their Potential as Additive in Commercial Base Oils

Previously synthesized C36-dimer acids (DA) have been esterified (97 ± 0.2% conversion at 120 °C for 72 hours) with 2-ethylhexanol (2-EH) to produce a new class of C52-DA 2-EH esters that have potential application in biolubricant formulations such as base oils and additives. Investigation of physicochemical and lubricant properties showed the bio-based esters have good solubility in commercial base stocks such as polyalpha olefin (PAO-6) (>20 w/w) and high-oleic sunflower oil (HOSuO) (>20 w/w). The neat C52-DA 2-EH esters displayed a three- to eightfold higher kinematic viscosity and comparable viscosity index (VI = 134) as a commercial base stock, PAO-6 (VI =137). Both C52-DA 2-EH esters, whose parent C36-DA were synthesized with two different zeolite catalysts, were oxidatively stable above 176 °C. Blending C52-DA 2-EH esters in HOSuO improved the pour point (PP) of HOSuO from −18.8 to −21.0 °C at 1% w/w and the cloud point (CP) from −6.3 to −10.6 °C at 8% w/w of C52-DA 2-EH ester 1. A similar trend was observed for C52-DA 2-EH ester 2, indicating that the esters possess PP depressant (PPD) characteristics in HOSuO blends. Blending C52-DA 2-EH esters in PAO-6 increased the VI of PAO-6, which is an indication that the bio-based esters were acting as VI improvers (VII). It was concluded that C52-DA 2-EH esters can be employed commercially as bio-based base oils and as PPD and VII additives in lubricant formulations.     

Sulfonation of base oils as corrosion inhibitor for temporary protection of steel in atmospheric environment

Base oil corrosion temporary protective coatings were synthesized. These coatings contain of inhibitor agent, antioxidant agent, and base oil as main bed. Inhibitor agents were prepared by sulfonation of Iran traditional mineral base oils. Iran traditional base oils were SAE10, SAE30 and SAE40. They are sulfonated at different temperatures with oleume as reactive agent. Sulfonation efficiency and production quality of this process are evaluated in different conditions. Neutralization of sulfonate groups were complied with calcium hydroxide to achieved hydrophilic salt groups of calcium sulfonate. Final products are used as inhibitor agents in base oils to prepare temporary protective coatings. They are applied to 1020 steel panels by dipping method.     

Kinematic viscosity of biodiesel fuel components and related compounds. Influence of compound structure and comparison to petrodiesel fuel components

Biodiesel, defined as the mono-alkyl esters of vegetable oils and animal fats is an alternative diesel fuel that is steadily gaining attention and significance. One of the most important fuel properties of biodiesel and conventional diesel fuel derived from petroleum is viscosity, which is also an important property of lubricants. Ranges of acceptable kinematic viscosity are specified in various biodiesel and petrodiesel standards. In this work, the kinematic viscosity of numerous fatty compounds as well as components of petrodiesel were determined at 40 °C (ASTM D445) as this is the temperature prescribed in biodiesel and petrodiesel standards. The objective is to obtain a database on kinematic viscosity under identical conditions that can be used to define the influence of compound structure on kinematic viscosity. Kinematic viscosity increases with chain length of either the fatty acid or alcohol moiety in a fatty ester or in an aliphatic hydrocarbon. The increase in kinematic viscosity over a certain number of carbons is smaller in aliphatic hydrocarbons than in fatty compounds. The kinematic viscosity of unsaturated fatty compounds strongly depends on the nature and number of double bonds with double bond position affecting viscosity less. Terminal double bonds in aliphatic hydrocarbons have a comparatively small viscosity-reducing effect. Branching in the alcohol moiety does not significantly affect viscosity compared to straight-chain analogues. Free fatty acids or compounds with hydroxy groups possess significantly higher viscosity. The viscosity range of fatty compounds is greater than that of various hydrocarbons comprising petrodiesel. The effect of dibenzothiophene, a sulfur-containing compound found in petrodiesel fuel, on viscosity of toluene is less than that of fatty esters or long-chain aliphatic hydrocarbons. To further assess the influence of the nature of oxygenated moieties on kinematic viscosity, compounds with 10 carbons and varying oxygenated moieties were investigated. A reversal in the effect on viscosity of the carboxylic acid moiety vs. the alcohol moiety is noted for the C10 compounds compared to unsaturated C18 compounds. Overall, the sequence of influence on kinematic viscosity of oxygenated moieties is COOH≈C-OH>COOCH₃≈CO>C-O-C> no oxygen.     

Evaluation of partially hydrogenated methyl esters of soybean oil as biodiesel

Biodiesel, an alternative fuel derived from vegetable oils or animal fats, continues to undergo rapid worldwide growth. Specifications mandating biodiesel quality, most notably in Europe (EN 14214) and the USA (ASTM D6751), have emerged that limit feedstock choice in the production of biodiesel fuel. For instance, EN 14214 contains a specification for iodine value (IV; 120 g I₂/100 g maximum) that eliminates soybean oil as a potential feedstock, as it generally has an IV >120. Therefore, partially hydrogenated soybean oil methyl esters (PHSME; IV = 116) were evaluated as biodiesel by measuring a number of fuel properties, such as oxidative stability, low‐temperature performance, lubricity, kinematic viscosity, and specific gravity. Compared to soybean oil methyl esters (SME), PHSME were found to have superior oxidative stability, similar specific gravity, but inferior low‐temperature performance, kinematic viscosity, and lubricity. The kinematic viscosity and lubricity of PHSME, however, were within the prescribed US and European limits. There is no universal value for low‐temperature performance in biodiesel specifications, but PHSME have superior cold flow behavior when compared to other alternative feedstock fuels, such as palm oil, tallow and grease methyl esters. The production of PHSME from refined soybean oil would increase biodiesel production costs by US$ 0.04/L (US$ 0.15/gal) in comparison to SME. In summary, PHSME are within both the European and American standards for all properties measured in this study and deserve consideration as a potential biodiesel fuel.     

Synthesis and Characterization of Novel Polyol Esters of Undecylenic Acid As Ecofriendly Lubricants

Three novel esters of undecylenic acid (UA) were synthesized using the following polyols: linear diglycerol (DG), pentaerythritol monomethylether (PEME), and trimethyloltoluene (TMT). They were characterized through density, viscosity, thermo-oxidative stability, melting point (m.p.), miscibility with mineral oils, and toxicity to evaluate their potential as ecofriendly lubricants. Trimethylolpropane (TMP) triundecylenate was also synthesized and characterized as a reference ester. Esters’ densities were in the range 0.93–0.97 g cm⁻³. The PEME ester showed a kinematic viscosity of 25.2 cSt at 40°C, only slightly higher than that of TMP ester (24.7 cSt), both of them near the ISO VG 22 class, while DG and TMT esters were near the ISO VG 32 class, with viscosities of 28.3 and 37.1 cSt, respectively. PEME and TMT esters were similar in thermo-oxidative stability and more stable than their corresponding oleate esters. The m.p. of TMT ester was remarkedly low (−54°C), showing its potential for very cold temperature applications. TMT ester was found to be nontoxic against Artemia salina (LC₅₀ > 1000 μg mL⁻¹), an initial indication of nontoxicity of UA esters in aquatic media. The synthesized esters showed potential to be applied as ecofriendly lubricants.     

Monitoring PV in corn and soybean oils by NIR spectroscopy

NIR spectroscopy was used successfully in our laboratory to monitor oxidation levels in vegetable oils. Calibration models were developed to measure PV in both soy and corn oils, using partial least squares (PLS) regression and forward stepwise multiple linear regression, from NIR transmission spectra. PV can be measured successfully in both corn and soy oils using a single calibration. The most successful calibration was based on PLS regression of first derivative spectra. When this calibration was applied to validation sample sets containing equal numbers of corn and soy oil samples, with PV ranging from 0 to 20 meq/kg, a correlation coefficient of 0.99 between titration and NIR values was obtained, with a standard error of prediction equal to 0.72 meq/kg. For both types of oil, changes occurred in the 2068 nm region of the NIR spectra as oxidation levels increased. These changes appear to be associated with the formation of hydroperoxides during oxidation of the oils.     

Testing various mixing rules for calculation of viscosity of petroleum blends

Seventeen mixing rules reported in the literature used for predicting kinematic viscosity of petroleum and its fractions were examined for accuracy by comparing the estimated values with the experimental viscosities of four crude oils (21.31, 15.93, 12.42 and 9.89°API gravity) and their blends with a diluent (diesel) at several proportion. Tested mixing rules were classified as pure mixing rules, mixing rules with a VBI parameter, and mixing rules with an additional parameter. The results indicated a general trend to fail as the crude oil API gravity decreased, although at high temperature of analysis the predictions improved. After calculating standard errors for all predictions, only four of these rules showed acceptable accuracy (Chevron, Walther, Einstein and Power law), nevertheless no rule was capable of estimating viscosity for all the crude oils, highlighting that predicting viscosity is a challenging task. This general result led a further analysis for testing the accuracy of mixing rules in predicting viscosity for light distillates (naphtha, diesel and vacuum gas oil) and their blends; basically the same results were found, although a fifth rule (Chririnos) showed good agreement with experimental values.     

Near infrared spectral patterns of fatty acid analysis from fats and oils

A near infrared (NIR) spectral pattern of oil contains information about fatty acid composition, because NIR absorption bands around 1600–1800 nm and 2100–2200 nm are due to the straight carbon chain andcis double bonds, respectively. This study was undertaken to build a foundation for the rapid determination of the fatty acid composition in oil by an NIR method. First, NIR spectra of pure triglycerides were measured and characterized. Fatty acid compositions could be estimated roughly by comparing the spectra of fats and oils (butter fat, pig milk fat, soybean oil and palm oil) with those of pure triglycerides. Secondly, the NIR spectra of these fats and oils were reconstructed by summation of the triglyceride spectra, which are multiplied by factors corresponding to the fatty acid composition of the sample determined by gas chromatography. The calculated spectra agree with the originals, especially for that of soybean oil. However, in order to reconstruct spectra precisely, it may be necessary to reevaluate the loading weight of each triglyceride, which was equal in this study. Part of this study was presented at the 3rd International Conference on Near Infrared Spectroscopy on June 28, 1990, Brussels, Belgium.     

Rapid quantitation of fish oil fatty acids and their ethyl esters by FT‐NIR models

Consumption of fish oil and dietary supplements containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has steadily increased because of their reported health benefits. A rapid procedure based on Fourier Transform Near Infrared Spectroscopy (FT‐NIR) models was developed for analysis of fish oil and their ethyl ester derivatives to replace the time consuming GC method. Inclusion of fish oil or ethyl esters containing varied concentrations of OA, EPA, and DHA into the FT‐NIR classification models made possible their classification and quantification. Accurate GC analysis is essential in developing reliable quantitative models since FT‐NIR is matrix dependent. Development of FT‐NIR models based on 30 m PEG capillary GC column results, as recommended by the official GC method for analysis of marine oils, proved problematic, since these columns did not resolve many geometric isomers compared to 100 m highly polar cyanopropyl polysiloxane columns. Depending on the content of geometric isomers in fish oils and ethyl esters, the levels of long‐chain n‐3 PUFA would be overestimated if the model used were based on the results from a 30 m column. The FT‐NIR method was found to be applicable to all fish oil and ethyl ester samples, except when fatty acids were outside the range examined, or contaminants were present. The FT‐NIR method was applicable to analysis of in‐plant intermediates provided contaminants were absent, or identified so they could be incorporated into the model. The FT‐NIR method was suitable to evaluate the shelf life of n‐3 PUFA concentrates.     

润滑油基础油粘度指数回归分析与优化控制

以西江原油为例,通过多项式回归拟合润滑油基础油粘度指数随运动粘度的分布曲线,一元线性回归基础油运动粘度与原料运动粘度的关系,并对回归方程及其系数进行显著性检验,从而获得有效而精简的回归方程。根据这两个回归方程推算出基础油粘度指数与原料运动粘度的关系,直接用于指导常减压装置基础油原料运动粘度的优化控制,也为原油资源筛选、调配、单贮单炼、混兑混炼等生产管理决策提供依据和参考。     

Experimental investigation and development of new correlation for influences of temperature and concentration on dynamic viscosity of MWCNT-SiO2 (20-80)/20W50 hybrid nano-lubricant

In current research, MWCNT-SiO_2/oil hybrid nano-lubricant viscosity is experimentally examined. By dispersing 0.05%, 0.1%, 0.2%, 0.4%, 0.8% and 1% volume of MWCNTs and SiO_2 nanoparticle into the engine oil SAE 20W50, the temperature and solid volume fraction consequences were studied. At 40 to 100 ℃ temperature, the viscosities were assessed. The results indicated Newtonian behavior for the hybrid nano-lubricant. Moreover, solid volume fraction augmentation and temperature enhanced the viscosity enhancement of hybrid nano-lubricant. At highest solid volume fraction and temperature, nano-lubricant viscosity was 171% greater compared to pure 20W50. Existed models lack the ability to predict the hybrid nano-lubricant viscosity. Thus, a new correlation regarding solid volume fraction and temperature was suggested with R-squared of 0.9943.