Characterization of Different Molecular Weight Fractions Separated from Utah Maltenes by Gel Permeation Chromatography

ABSTRACT

Maltenes derived from Utah bitumens were separated by gel permeation chromatography ( OPC) into fractions having number average molecular weights ( MW) in the range from 300 to 11985. The fractions were examined by vapor pressure osmometry, absorption spectrometry in the visible region as well as proton and carbon -13 NMR. The results are reported in comparison with those for the corresponding fractions separated from Athabasca maltenes. Utah fractions appeared to be more aliphatic with longer average aliphatic chains lengths. Branched and alicyciic types were more abundant in Utah samples, especially those with low MW, There was an apparent difference in the hydrocarbon structure of both Utah and Athabasca maltenes GPC     

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C-450°C temperature interval. Thermal degradation continues to finish until 650°C.     

Characterization of Thermally Degraded Asphaltene Fractions Using Gel Permeation Chromatography

Abstract

Petroleum asphaltene goes through three stages of mass reduction under thermogravimetric analysis from 25°C to 1,000°C at a heating rate of 1°C/min. The products from thermal degradation of asphaltene at three different temperature intervals are collected. Two residual fractions left in the sample cup are also obtained at two specific temperatures. The collected fractions and the residual fractions are characterized using gel permeation chromatography. The fraction collected between 25°C and 350°C demonstrates similar molecular weight distribution to that collected between 350°C and 450°C, with both fractions showing a typical molecular weight distribution for polymeric material. The fraction collected between 450°C and 650°C illustrates three different molecular weight distributions. The chromatogram of the residual fraction obtained at 350°C resembles that of the undegraded asphaltene. The residual fraction obtained at 450°C also demonstrates three different molecular weight distributions. The experimental data indicate that the mass reduction of asphaltene heated from 25°C to 350°C is mainly due to the evaporation of low boiling point and/or low molecular weight substances in asphaltene. Thermal decomposition and coke production occur significantly in the 350°C–450°C temperature interval. Thermal degradation continues to finish until 650°C.     

凝胶渗透色谱法测定PAN分子量及其分布

针对聚丙烯腈 (PAN)在二甲基甲酰胺溶剂中的缔合作用 ,通过加入硝酸钠使PAN能够按照分子量大小进行凝胶渗透色谱分离 ,本文考察了准确测定PAN分子量的色谱条件 ,并与激光光散射法的结果进行了对照 ,误差小于 2 .5 % ,并且重现性也非常好 ,相对标准偏差小于 1.6 %     

凝胶渗透色谱法测定HDPE的分子量及分子量分布

采用示差折光及粘度双检测器凝胶色谱系统,利用普适校正原理,不需要Mark常数K、a值,直接测定了高密度聚乙烯(HDPE)的分子量及分子量分布;优化选择了色谱柱组合、样品浓度、柱温等色谱条件并给出分子量分布曲线。     

凝胶渗透色谱法测定HDPE分子质量及分子质量分布

以窄分布聚苯乙烯为标样,建立了用凝胶渗透色谱(GPC)表征高密度聚乙烯分子质量及其分布的方法,考察了在注射体积一定时样品浓度对测定结果的影响,开展了重复性实验,测定了高密度聚乙烯的分子质量及其分布。实验结果表明:GPC谱图呈双峰模式的试样一般分子质量分布较宽;样品溶液浓度在1.0mg/mL-2.5mg/mL范围内对测定结果没有明显影响。     

凝胶色谱法测定7000F平均分子量及分子量分布

根据７０００Ｆ在凝胶色谱柱上的淋洗特点,确定了测定其分子量及分子量分布试验条件,采用示差和粘度双检测凝色谱系统,利用谱适校正方法,不需要Ｍａｒｋ常数Ｋ、α值,可直接测定数均分子量,重均分子量,粘均分子量并给出分子量分布曲线。     

采用凝胶渗透色谱法快速测定润滑油沉积物

研究了用凝胶渗透色谱法（GPC）快速确定涡轮润滑油中的沉积物。该方法可测定在不同氧化时间下油样中抗氧剂的含量和相对分子质量分布的变化情况。对涡轮润滑油氧化安定性实验结果与GPC谱图中相对分子质量分布的分析对比发现,油品的氧化降解越严重,其中的抗氧剂聚合物相对分子质量就越大,相对分子质量分布也越宽。将△S／S（△S为相对分子质量高于800的增加峰值区域面积,S为新鲜油的峰值区域面积）值作为评价油品沉积物抑制能力的指标。该数值与油样氧化过程中生成的沉积物数量有很好的一致性。     

凝胶色谱法测定破乳剂分子量及分子量分布的研究

采用凝胶色谱(GPC)法,研究了以多乙烯多胺为起始剂支化线型类破乳剂分子量及其分布测定的方法,用渐近法校正来标定GPC柱,建立了测定分子量分布的校正曲线.GPC法测定结果与VPO法相比,其相对误差均在±10%以内,在国内首次得到了GPC测得破乳剂的分子量分布曲线.     

Interfacial and Thermal Characterization of Asphaltenes Separated from Crude Oils Having Different Geological Origins

Abstract

Three crude oils having different geological origins, namely, DK from Eocene (Sylhet limestone and Langpar), SL from Barail (Oligocene), and JN from Tipam (lower Miocene), were selected. Asphaltenes were separated and characterized. Fourier transform infrared (FTIR) spectroscopy showed the presence of polar groups. Interfacial tension studies of the asphaltenes between benzene–water, toluene–water, and xylene–water showed the lowest interfacial tension with SL asphaltenes in a toluene–water system. Thermogravimetric analysis of asphaltenes indicates greater thermal degradation for DK asphaltenes. Asphaltenes were pyrolyzed and the pyrolyzed products were analyzed by gas chromatography/mass spectrometry (GC/MS). Based on the distribution pattern of n-alkanes in pyrolyzed product of asphaltenes, crude oils, and kerogens, it was concluded that crude oil and asphaltenes originate from the same source and asphaltenes are the unconverted parts of kerogens.     

窄分布聚苯乙烯的分子表征

一系列窄分布聚苯乙烯试样的平均分子量和分子量分布用NMR、VPO、粘度和SEC作了表征。本工作运用了表征方法的一些新发展,如VPO仪器常数的恰当订定,SEC扩展效应的改正,广义特性粘数方程的应用以求得各个分子参数。各试样用不同方法所得的结果相互印证,说明这些试样可作为多种用途的工作标准使用。     

气相色谱法测定低分子量氧化聚乙烯膜的透气系数

氧化聚乙烯(OPE)的非离子型或阳离子型水乳液涂膜在水果上保鲜性能优异。为研究OPE膜的保鲜效果,作者自行设计并安装了一套色谱法测透气性装置,测定OPE的低分子量膜的透气系数。试验将OPE制成乳液涂在聚乙烯薄膜上,先测聚乙烯膜的透气系数,然后在同样温度下测复合膜的透气系数。两者的相对平均偏差均小于0.5％。     

Characterization of Asphalt Fractions by NMR Spectroscopy

Abstract

Petroleum asphalt was separated into saturates, naphthalene aromatics, polar aromatics, and asphaltenes using the Corbett method. These asphalt fractions were characterized by H-1 and C-13 nuclear magnetic resonance spectroscopy (NMR). The spectra of saturates illustrate only traceable quantities of aromatic hydrogen and aromatic carbon. Naphthalene aromatics, polar aromatics, and asphaltenes all have broad bands in the aromatic regions of both H-1 and C-13 NMR spectra. These broad bands demonstrate the presence of polycondensed aromatic rings present in the structure of naphthalene aromatics, polar aromatics, and asphaltenes. Based on available literature, numerous NMR resonance bands are identified. The quantitative estimations for various kinds of protons and carbons in the asphalt fractions are compared.     

高分子聚合物凝胶的性能研究与应用

传统的修井作业井筒内流体容易进入地层,造成储层的污染。针对储层的污染问题,以天然大分子纤维素为骨架分子,接枝共聚水溶性丙烯酰胺单体,研制出一种高分子聚合物凝胶,并对该聚合物凝胶进行机理分析和性能评价。结果表明,该聚合物凝胶的成胶时间在30～600 min可控,破胶时间在1～30 d;在160℃下表观黏度仅为100 mPaws,便于现场施工注入。通过加入交联剂和催化剂控制合理的成胶时间,成胶后的聚合物凝胶完全失去流动性,能够形成高强度的凝胶塞,具有较高的承压强度。聚合物凝胶具有较好的抗污性能,对强酸、强碱、高矿化度盐水以及原油污染能保持较强的稳定性。聚合物凝胶在施工结束后能够破胶为低黏度的流体,通过连续油管或者泥浆泵循环出井筒。该聚合物凝胶在威远区块204H7-3页岩气井的修井作业中进行了应用,在120℃、45 MPa下,80 m聚合物胶塞,最高承压达72.82 MPa。聚合物凝胶较传统机械封堵,及水泥塞封堵有比较明显的优势,在修井作业、恶性漏失、封堵出水层等方面具有较好的应用前景。      

原油中高分子量生物标志化合物的特征

高温气相色谱 (HTGC)技术使我们确定烃特征的水平扩展到了原油中的C\- 1 2 0。研究中观察到 ,原油之间蜡中烃(>C2 0 )有很明显的变化 ,甚至假定的同源有机质之间也存在这样的变化。在高温气相色谱技术开发之前 ,由于常规气相色谱的分析局限 ,确定含有C4 0 以上烃的微晶蜡的特征达不到分子级别。利用高温气相色谱进行高倾点原油的常规筛选表明 ,高分子量烃(>C4 0 )在绝大多数原油中非常普遍 ,可能占原油的 2 %。为了对这些高分子化合物进行初步的研究 ,我们在本项目中研究了它们的一般分子结构和分子式。初步结果表明 ,主要的高分子化合物包括正烷烃、甲基支链烷、烷基环戊烷、烷基环己烷和烷基环烷的同系物。     

Characterization of Asphaltenes and Resins Separated from Water-in-Oil Emulsions

Abstract

Knowledge of the properties and behavior of asphaltenes and resins is indispensable for the design of preventive and curative measure for emulsion problems created by the presence of asphaltene, resins, and other organic and inorganic solids. In order to understand the phenomena of water-oil emulsions formed in Kuwaiti oil fields and determine the factors involved in the stabilization of these emulsions, the role of asphaltenes, resins and wax separated from various samples of oil field emulsions formed in Burgan oil field have been evaluated. Physicochemical properties of asphaltenes, resins, wax, and de-asphalted de-resined (DADR) oil samples have been studied via FT-IR, ¹H, and ¹³C NMR, elemental analysis, and differential scanning calorimetry (DSC). These emulsion samples contain different amounts of water ranges from 24 to 35%, asphaltene content ranges from 0.9 to 1.7%, and resin content from 3.7 to 4.6%. IR-FT spectra were performed to identify the various functional groups which have an effect on the stability of water-oil emulsions. The freezing behavior of an emulsion was characterized by differential scanning calorimetry to determine whether the water in the emulsion is free water or emulsified water.     

Characterization of Asphaltenes and Resins Separated from Water-in-Oil Emulsions

Knowledge of the properties and behavior of asphaltenes and resins is indispensable for the design of preventive and curative measure for emulsion problems created by the presence of asphaltene, resins, and other organic and inorganic solids. In order to understand the phenomena of water-oil emulsions formed in Kuwaiti oil fields and determine the factors involved in the stabilization of these emulsions, the role of asphaltenes, resins and wax separated from various samples of oil field emulsions formed in Burgan oil field have been evaluated. Physicochemical properties of asphaltenes, resins, wax, and de-asphalted de-resined (DADR) oil samples have been studied via FT-IR, ¹H, and ¹³C NMR, elemental analysis, and differential scanning calorimetry (DSC). These emulsion samples contain different amounts of water ranges from 24 to 35%, asphaltene content ranges from 0.9 to 1.7%, and resin content from 3.7 to 4.6%. IR-FT spectra were performed to identify the various functional groups which have an effect on the stability of water-oil emulsions. The freezing behavior of an emulsion was characterized by differential scanning calorimetry to determine whether the water in the emulsion is free water or emulsified water.     

用GPC-[η]法测定氯丁胶的长链支化度

采用GPC-[η]方法计算工业生产的氯丁胶的支化度以及各种平均分子量。在制定通用校准线时使用修改的逐步回归程序,在迭代法解方程时也进行了特殊处理。不论计算精度和计算速度都得到满意的结果。本方法可以在工厂推广应用。     

原油和烃源岩中高分子量烷烃的气相色谱定量分析

介绍了HP6890气相色谱仪测定高分子量烷烃的定量方法，测定高分子量烷烃的碳数可达100，用正构烷烃标样nC20,nC30,nC40,nC50,nC60以及nC4D50作为内标对原油和烃源岩中低含量的高分子量烷烃进行定量。测得nC60的质量校正因子约为nC30的83%。对南阳油田3个典型高蜡原油样品和一个烃源岩样品中的高分子量烷烃进行了定量测定，3个原油样品中nC40以上的高分子量烷烃的含量分布在22.8-38.0mg/g油。平均占nC22以上正构烷烃总量的16%。东10井烃源岩（2765.5m）中nC40以上的高分子量烷烃占nC22以上正构烷烃总量的32.9%，比同构造、同层位的东12井原油高出约1倍，这可能与运移效应有关。     

NMR Characterization of Size Exclusion Chromatographic Fractions from Asphalt

Abstract

Size exclusion chromatography was used to separate an asphalt into nine fractions, and these fractions were then investigated by ¹H and ¹³C NMR. From the integration of the spectra, various molecular structural parameters were calculated. The aromatic carbon to nitrogen and the aromatic carbon to sulfur ratios were determined for six of the fractions. The catenation (linear and circular) of the aromatic ring structure was determined for six fractions. It appears that circular catenation is more probable for the high molecular weight fraction. For the lower molecular weight fraction, both linear and circular catenation are equally probable.