Characterization of Crude Oils by Gel Permeation Chromatography

Abstract

The classical method of dividing crude oil into narrow molecular-weight cuts—distillation—is not practical in the high-boiling region. Thus, gel permeation chromatography was evaluated as a technique for characterizing the high-molecular-weight portion of crude oils. Crude oils, stripped to 180[ddot]C, were separated in a dual-column GPC system. The fractions obtained provided information concerning the amounts of material with molecular weights between 400 and 3000. Gross estimates were made of the proportion of ring and nonrmg carbons in these fractions. The latter estimates were obtained by relating molecular weights determined on the fractions to a calibration plot made up from data on model compounds.     

A Rapid Method of Identification and Assessment of Total Crude Oils and Crude Oil Fractions by Gel Permeation Chromatography

Abstract

“Fingerprint” chromatograms of crude oils have been obtained using a simple gel permeation chromatographic system with a differential re-fractometer as detector and tetrahydrofuran as solvent. The elution time is less than 1 hr using a sample size of about 6 mg and the repeatability is good. When toluene is used as solvent, a different profile is obtained which is again unique for each crude oil.

The applications of this technique to crude oil assessment and composition of crude oil mixtures will be discussed since the “fingerprints” obtained have been shown to be unique for the 50 crude oils examined. Various crude oil fractions, e.g., gas oils and waxy distillates, have also been investigated. Chromatograms of oil pollution samples from the UK have indicated that certain types of pollution can be identified although present experience with a wide range of sample types is limited.     

Chromatographic Studies of Soybean Oils

Six varieties of soybean cultivated in Pakistan have been studied. These contain 15.9-20.1% oil and their fatty acid composition as determined by GLC is myristic (0.2-0.4%), palmitic (11.7-13.9%), stearic (1.2-5.4%), oleic (21.2-31.8%), linoleic (41.2-53.4%), arachidic (0.2-0.6%), behenic (0.2-0.6%) and lignoceric (0.3-0.5%).     

Chromatographic Studies of Cottonseed Oils

Eight varieties of cottonseed cultivated in Pakistan have been studied. These contain 11.6-24.0% oil and their fatty acid composition as determined by G.L.C. is C_14:0 (0.7-2.0%), C_14:1 (0-0.3%), C_16:0(28.3-43.1%), C_16:1 (0.3-2.7%), C_18:0 (0.3-8.5%), C_18:1 (16.2-32.0%), C_18:2 (31.3-41.2%) and C_20:0 (0.2-0.3%).     

Effect of Resins on Asphaltene Self‐Association and Solubility

In previous studies, asphaltenes and resins have been treated as two distinct fractions of a crude oil. The asphaltenes were assumed to be the only self‐associating fraction. However, there is evidence that resins also participate in this self‐association. In this study, molar masses of mixtures of asphaltenes and resins were measured with vapour pressure osmometry. Precipitation from the same mixtures dispersed in solutions of toluene and pentane were also measured. The data were modelled with previously developed self‐association and precipitation models. Model results with asphaltenes and resins characterized as a single distribution and as individual components are compared. The data and the modelling suggest that asphaltenes and resins are better characterized as a single distribution of self‐associating components.     

Chromatographic Detection of Silicones in Vegetable Oils

The method is based upon separation of silicone in the oil by thin layer Chromatography on silica gel layer, using the solvent system petroleum, ether—diethyl ether = 98:2 (v/v) and visualisation of the spots developed by means of Rhodamin B reagent. Under the described condition separation of silicones seems to be free from interference from other non-silicone containing materials. The limit of detection was approximately 2 γ.     

色谱树脂法分离纯化两性霉素B方法研究

以色谱树脂为填料,对两性霉素B粗品进行层析柱分离,层析液进一步结晶纯化,得到高纯度两性霉素B精粉,对上柱条件和结晶条件进行了优化。得到优化的工艺条件为:选择色谱三号树脂为填料,层析柱高径比7,上样量1.5 g·(100 g填料)~(-1),过柱速度5 mL·min~(-1),层析液加入1.0‰甘油,并调溶液pH值为5.3～5.6,结晶,过滤,用适量乙醇、丙酮挖洗,最后干燥得到纯度大于98.5%的两性霉素B精粉。该分离纯化工艺条件稳定,流程简单,适于规模化生产。     

Molecular Structure Models of Asphaltene in Crude and Upgraded Bio‐Oil

The average molecular formula of asphaltene was calculated from the main functional groups of asphaltene determined by Fourier transform infrared spectroscopy, the average molecular weight found by gel filtration chromatography, and values of ultimate analysis. A series of average structure parameters were determined by ¹H NMR and ¹³C NMR spectrum integrals, followed by establishing the structure models of asphaltene according to the Brown‐Ladner method. Reduction of molecular weight of asphaltene was observed after bio‐oil upgrading, and the oxygen‐containing functional groups were apparently less than that of crude bio‐oil while the number of aromatic rings was increased. The upgraded bio‐oil had a lower molecular weight, lower oxygen content, and higher aromaticity compared with crude bio‐oil.     

原油破乳剂的开发与进展

本文介绍了原油的破乳机理、破乳剂类型和破乳剂的发展，还介绍了国内开发和应用破乳剂的概况２。     

原油破乳剂现状及其选择评价方法

综述了国内外原油破乳剂的主要品种及其性能情况,介绍了原油破乳剂的选择及评价方法。在此基础上。给出了原油破乳剂复配的主要思路。     

Column Chromatographic Determination of Unsaponifiable Matter in Fats and Oils

A column chromatographic method for determination of unsaponifiable matter (UM) in fats and oils has been developed. The procedure involves saponification of the oil and elution or UM through a mixed bed consisting of an upper layer of calcium oxide and a lower layer of basic aluminium oxide, using diethyl ether as the eluting solvent and finally quantitation of UM by weight. The method eliminates tedious and time-consuming extraction steps and the consequent problems due to possible emulsion by hydrolysis, UM contents of fats and oils can be determined with very good to excellent accuracy. The relative standard deviation for 6.0 per cent to 0.5 per cent of UM in oils is in the range of 0.5–2.0. The method is simple, readily adaptable, fairly rapid and is equally applicable to soap samples.     

Chromatographic Instrumentation and Detection of Gel Permeation Effluents

Abstract

The basic instrumentation required for gel permeation chromatography are described. The various choices for sample injectors, pumping systems, detectors, and recording techniques are discussed and critically evaluated. Column choice, construction, etc., are omitted since these items are very well covered by other Symposium papers.     

环氧树脂的凝胶反应研究

合成了新型含异氰脲酸酯基的环氧树脂 (ISEP)以及它的柔性固化剂 (TPA) ,对两者的粘度与温度的关系进行了研究。根据Arrhenius公式进行了线性拟合 ,计算了粘流活化能 (△Eη)和指前因子 (K)。ISEP的△Eη为 7 31× 10 4J/mol,K为 3 74× 10 -9;TPA的△Eη为 5 77× 10 4J/mol,K为 4 35× 10 -6。以ISEP和TPA为主体树脂和固化剂组分 ,制得了环氧树脂胶片 ,考察了固化催化剂HA对胶片性能的影响 ,确定了最佳用量为 2 6 %。对不同温度下凝胶反应的放热行为和凝胶时间也进行了研究 ,通过对凝胶时间和温度的线性拟合 ,得到凝胶反应的表观活化能 (Ea)为 85 9 3J/mol,K为 1 9838× 10 -8。通过凝胶时间和凝胶反应的放热量 ,确定了合适的固化温度为 5 0℃。     

国内胶衣与彩胶树脂市场现状概述

在不饱和聚酯树脂业中有一种特殊性能的树脂叫胶衣树脂。它是为改善玻璃纤维增强不饱和聚酯树脂基玻璃钢制品的外观质量和保护结构层的材质不受外界环境介质侵蚀而研制开发的 ,故胶衣树脂的主要作用是对玻璃钢制品的表面装饰和对结构层的保护。中国加入世贸组织 ,对中国的ＦＲＰ企业机遇大于挑战 ,目前亚洲 (去除日本 )人均复合材料的消耗量只有 0 3ｋｇ左右 ,非常低 ,因此 ,复合材料的发展在亚洲具有很大的潜力和空间。近几年中国的ＦＲＰ将有长足发展 ,ＦＲＰ的增长速度会以超过国家经济发展平均增长速度而发展 ,但对ＦＲＰ制品质量的要…     

不同原油界面活性组分的分离及表征

用极性分离法将胜利油田孤东1#、孤东4#原油和大庆原油分离为饱和分、芳香分、胶质、沥青质组分(S、Ar、R、As)。孤东1#和孤东4#沥青质组分质量分数(14.43%、11.35%)明显高于大庆原油沥青质组分质量分数(0.09%),而饱和分组分质量分数(47.08%、46.54%)低于大庆原油饱和分质量分数(68.08%)。孤东1#和孤东4#原油的原油组分(S、Ar、R、As)氧的质量分数、酸值由大到小的排序为:沥青质>胶质Ⅰ>芳香分>饱和分。而大庆原油的原油组分酸值由大到小的排序为:胶质Ⅰ>沥青质>芳香分>饱和分;大庆原油的饱和分组分中氧质量分数较低,饱和分中氧质量分数在原油氧中所占比例最高(0.375%),饱和分中的氧化物对大庆原油的界面活性影响不可忽视。在3种原油所有原油组分中,孤东1#原油沥青质的酸值最大(16.45 mg KOH/g沥青质),说明孤东1#原油沥青质组分含有较多酸性基团,反应活性较强。色-质分析结果表明,孤东原油饱和分正构烷烃在C10-C37呈双正态分布,大庆原油饱和分正构烷烃主要分布在C10-C38,基本呈正态分布。     

壳聚糖层析凝胶洗脱条件优化

以壳聚糖为原料,经交联还原,制备了一种新型层析凝胶。为更好地应用该层析凝胶,对其洗脱条件进行了优化。确定了最佳洗脱体系是三羟甲基氨基甲烷(以下简称为tris HCl)溶液,体系的pH=9 05。考察了层析凝胶的颗粒度、洗脱液流速、离子强度、pH等条件对分离效果的影响,得到壳聚糖生物层析凝胶洗脱条件为:120～140μm壳聚糖层析凝胶装柱,用c(NaCl)=0 05mol/L的tris HCl(pH=9 05)洗脱,控制2 0～3 0mL/min流速。中性蛋白酶经壳聚糖层析凝胶一次层析,可分离得到4个组分,总酶活收率达90%以上,而用SepharoseCL-6B的对比实验只获得一个组分,酶活收率只有43 11%。     

混合原油相容性及对加工过程的影响

针对炼油厂不同类型原油混炼的工艺,考察了不同类型的原油混合时的相容性,并进一步研究了混合原油相容性对蒸馏及热加工过程的影响,实验发现原油组成是影响原油混合时相容性的主要因素,实验结果表明处于不相容状态的混合原油,蒸馏时轻质馏分收率较理论值偏低,常压渣油热加工过程结焦率增加。     

浅述色谱分离树脂在生化产品纯化上的工业应用

就离子交换色谱分离树脂在生化产品如葡萄糖-果糖、多元醇和核苷酸分离精制等纯化过程中的原理及其应用作了简要介绍,并就色谱分离工艺对树脂的性能要求及合成工艺进行了初步探讨。     

Variations in the Chromatographic Properties of Different Silica Gel Samples

Abstract

Silica gels for adsorption chromatography differ widely in their performance, depending upon the nature of the starting silica and its subsequent treatment. A general theory of the origin of these differences (and their control) is proposed in terms of the structure of the silica surface. Variations in the activity, selectivity, and linear capacity of different silica samples are readily understandable in terms of this theory. Details are provided for the initial evaluation, optimum treatment (activation and deactivation), and final standardization of silica adsorbents.     

Bio-based Epoxy Resins from Epoxidized Plant Oils and Their Shape Memory Behaviors

In this study, bio‐based epoxy materials containing functionalized plant oil, such as epoxidized soybean oil (ESO) and epoxidized linseed oil (ELO), were processed with 4‐methylhexahydrophthalic anhydride (MHPA) as a curing agent. In the presence of tetraethylammonium bromide, the curing reaction of epoxidized plant oil and MHPA proceeded at 130 °C to give transparent plant oil‐based epoxy materials. The resulting bio‐based epoxy materials exhibited relatively soft and flexible characters, due to the aliphatic chains of plant oil. The thermal and mechanical properties of the ESO/MHPA polymers depended on the feed molar ratio of anhydride to oxirane. The mechanical properties such as tensile strength and Young's modulus of the ELO/MHPA polymer increased, compared with those of the ESO/MHPA polymer. The glass transition temperature of the ELO/MHPA polymer was higher than that of the ESO/MHPA polymer, because of the high oxirane number of ELO. Furthermore, the ELO/MHPA polymer showed excellent shape memory property.