Heavy oil as an emulsion: Composition,structure, and rheological properties

Recent works devoted to studying the structure and rheological properties of water/oil disperse systems have been reviewed. Contemporary understandings of crude heavy oil as a water-in-oil emulsion have been discussed. Data on the mechanism of the stabilizing effect of natural lipophilic surfactants and ultradispersed particles of different natures contained in oil have been presented. Methods that are used to improve the transport characteristics of heavy oil—in particular, the formation of low-viscosity oil-in-water emulsions—have been listed. Colloidal and rheological properties of heavy oil-in-water emulsions, which are increasingly applied for pipeline transportation of oil, have been considered.     

Chromatographic isolation of vanadyl porphyrins from heavy oil resins

A broad fraction of petroleum vanadyl porphyrins of high spectral purity was isolated from heavy oil resins with high vanadium content using a two-step chromatographic method. At the first step, the primary concentrate of vanadyl porphyrins was separated from the resins on the silica gel column. At the second step, it was further purified by the gradient elution through the column packed with sulfo-cationite. According to UV—VIS spectroscopy, this technique allows one to isolate up to 70% of vanadyl porphyrins with the spectral purity corresponding to the best results of other purification methods providing only narrow fractions of vanadyl porphyrins of comparable purity. Deoxophylloerythroetioporphyrin (DPEP) and etioporphyrin (Etio) series of vanadyl porphyrins with the carbon number range of C₂₈—C₄₂ and DPEP/ Etio ratio equal to 1.18 were identified by MALDI-TOF mass-spectrometry.     

Phase behaviour of heavy petroleum fractions in pure propane and n-butane and with methanol as co-solvent

This work reports phase equilibrium experimental results for heavy petroleum fractions in pure propane and n-butane as primary solvents and using methanol as co-solvent. Three kinds of oils were investigated from Marlim petroleum: a relatively light fraction coming from the first distillation of crude petroleum at atmospheric pressure (GOP – heavy gas oil of petroleum), the residue of such distillation (RAT) and the crude petroleum sample. Phase equilibrium measurements were performed in a high-pressure, variable-volume view cell, following the static synthetic method, over the temperature range of 323 K to 393 K, pressures up to 10 MPa and overall compositions of heavy component varying from 1 wt% to 40 wt%. Transition pressures for low methanol and oil concentrations were very close for GOP, RAT, and crude Marlim when using propane as the primary solvent. Close to propane critical temperature, two and three-phase transitions were observed for GOP and Marlim when methanol was increased. When n-butane was used as primary solvent, all transitions observed were of (vapour + liquid) type with transition pressure values smaller than those obtained for propane.     

Recent trends of industrial catalysts for resid hydroprocessing in Japan

To meet the gradual changes in petroleum demand, in particular a reduced demand for heavy fuel oil, advanced technology for resid hydroprocessing is now extremely necessary. The catalyst technology for resid hydroprocessing in Japan, especially fixed bed type of hydrodesulfurization and hydroconversion, is reviewed in this article.     

废轮胎热解油重质馏分制备的道路沥青老化性能研究

针对废轮胎热解油重质馏分(＞350℃)组成上具有蜡含量低,芳香分、胶质和沥青质含量高的特点,研究了废轮胎热解油重质馏分采用蒸馏法生产道路沥青的可行性。结果表明,废轮胎热解油中＞420℃、＞430℃、＞440℃三种渣油的性质可以满足不同牌号道路石油沥青老化实验前的技术指标,特别是延展性能优异,但是抗老化性能较差。渣油老化前后的族组成、官能团、氢分布及分子量分布变化表明,渣油在老化过程中存在氧化反应以及脱氢缩合反应,使渣油的化学组成发生变化,即芳香分、胶质含量减少,沥青质含量明显增加,使得沥青胶体体系中分散相明显增多而分散介质相对减少,造成热解油的渣油抗老化性能较差。     

Thermal evaluation of heavy crude oil by simultaneous TG-DSC-FTIR: Part 2

In this work a continuous investigation of the thermal behavior of two heavy crude oils, P2 and P4, from Brazilian basin was performed using simultaneous technique TG-DSC-FTIR. In previous publication—Part 1, about these same oils at nitrogen atmosphere, it was identified for P2 sample that the main evolved component was 1-dodecyl-4-octyl-cyclohexane at 450 °C and for P4 sample the main component was evolved at 340 °C referent to 1-methyl cyclohexene. The simultaneous technique TG/FTIR was also performed for the present study in synthetic air atmosphere and was more elucidative than analysis in nitrogen atmosphere. For heavy oil P2, there was identified the presence of carbon dioxide, carbon monoxide and 4-methylcyclohexanone at 382 °C. Whilst for sample P4 the gaseous components evolved at 454 °C were carbon dioxide, carbon monoxide and 1-methylcyclohexene. Also differences in TG analysis for both samples were observed regarding the number of components. In air atmosphere crude oil P2 exhibited three decomposition stages, in nitrogen were only two. Four stages were exhibited on the thermogravimetric curve for oil P4 in synthetic air, while in nitrogen atmosphere there were three stages. Thus, this study has a unique character regarding the use of combined simultaneous techniques as STA/FTIR to identify components in heavy oil which may contribute to upgrade methods referring to crude oil composition.     

驱油用磺酸盐表面活性剂的研究进展

综述了驱油用石油磺酸盐、重烷基苯磺酸盐、脂肪醇聚氧乙烯醚磺酸盐及磺酸盐双子表面活性剂四种磺酸盐表面活性剂的研究进展,指出了这四种表面活性剂在油田应用中存在的问题以及未来的发展方向;阐述了油水乳化提高原油采收率的机理,初步分析了影响表面活性剂乳化能力的因素,强调了从分子结构的角度研究表面活性剂性能的重要性.     

分子模拟技术在石油相关领域的应用

分子模拟技术是近些年发展起来的一门新兴计算化学技术.它在辅助物质设计及分子结构理解方面所取得的一系列显著成绩使得它开始在与石油相关的油田化学、催化剂研制、高分子设计、化学工程以及重质油特征研究等方面有越来越广泛的应用.     

Influence of Interaction Between Heavy Oil Components and Petroleum Sulfonate on the Oil–Water Interfacial Tension

The purpose of this study is to obtain the interaction between heavy oil components and petroleum sulfonate (NPS). In this article, the effects of pH, NaCl concentration, and NPS on the oil–water interfacial tension (IFT) of Gudao crude oil and its polar components were investigated. The results show that the NPS concentration corresponding to turning point of IFT is 0.001 g·mL^?1. This is lower than the CMC of NPS (0.0015 g·mL^?1) as there is a positive synergetic effect between NPS and the active substances of crude and its components, and the strength of their interaction depends on the interfacial activity of crude components. In simulated system of crude and polar components with 0.1 wt% NPS, at basic condition, the acidic substances in the polar components create naphthenates (the component whose acid number is higher creates more naphthenates), leading to lower IFT, so the interaction between heavy oil components and NPS is stronger in the basic condition. Proper concentration of NaCl in the stimulated systems improved the hydrophile-lipophile balance of emulsifier (NPS), accelerated the well-regulated adsorption of NPS in oil–water interface, and increased the interfacial activity of NPS, the interaction between heavy oil components and NPS was also enhanced.     

Biocatalytic removal of nickel and vanadium from petroporphyrins and asphaltenes

Asphaltenes from a crude oil rich in heavy metals (Castilla crude oil) were fractionated and partially characterized. Biocatalytic modifications of these fractionated asphaltenes by three different hemoproteins: chloro-peroxidase (CPO), cytochrome C peroxidase (Cit-C), and lignin peroxi-dase (LPO) were evaluated in both aqueous buffer and organic solvents. The reactions were carried out in aqueous buffers, ternary systems of toluene: isopropanol: water, and aqueous-miscible organic solvent solutions with petroporphyrins as substrate. The petroporphyrins were more soluble in the ternary systems and aqueous miscible-organic solvent systems than in the aqueous buffer systems. However, only the CPO-mediated reactions were effective in eliminating the Soret peak in both aqueous and organic solvent systems. The effects of CPO-mediated reactions on the release of the metals complexed with the porphyrins and asphaltenes were also determined. Chloroperoxidase was able to alter components in the heavy fractions of petroleum and remove 53 and 27% of total heavy metals (Ni and V, respectively) from petroporphyrin-rich fractions and asphaltenes     

Comparison of hexane and petroleum ether to measure surface oil content

Many studies have measured surface oil on potato chips and spray dried powders using either petroleum ether or hexane. This study compared the effectiveness of the 2 solvents using aluminum squares to ensure oil stays on the surface of the sample during the measurement. Aluminum squares were sprayed with soybean oil, and surface oil was measured immediately and after 1 day. Each of the 8 aluminum samples were individually dipped for 1-2 s in either hexane or petroleum ether. For immediately extracted samples, there was no significant difference in the amount of oil extracted using either hexane or petroleum ether. For 1-day-old samples, hexane extracted more oil than petroleum ether. Neither method extracted all of the surface oil.     

A Study of Thin Liquid Films as Related to the Stability of Crude Oil Emulsions

In this paper, we report the influence of surface-active compounds on the stability of crude oil emulsions using the apparatus designed for bilayer lipid membrane studies. The results obtained show that natural surface-active materials in crude oil, such as petroleum acids and asphaltenes, play a pivotal role. The ionized acids formed by the reaction between the petroleum acids and the alkali can decrease the interfacial tension and accelerate the thinning as well as the breakdown of the thin liquid film. The asphaltenes can adsorb onto the interface and improve the stability of the film. The order of the stability of the films between crude oil and alkaline solutions is found to be as follows: crude oil with asphaltenes removed (ii) 相似文献   

含油污泥的热解特性研究

利用热重 傅里叶变换红外光谱联用仪与管式电阻炉对含油污泥热解特性进行了研究,分析了热解过程及影响因素（污泥性质与升温速率）,并由气体析出特性研究了热解机理。结果表明,热解过程包括水分挥发、轻质油挥发、重质油热解、半焦炭化与矿物质分解五种反应,矿物油反应集中发生在220℃～480℃。污泥性质影响因素中,产生环节最为显著,罐底泥、污水污泥失重明显而落地油泥失重不明显,矿物质组分含量越高,挥发分转化率越低;而污泥的油源基属影响较小。升温速率越大,反应进行的越快,挥发分转化率降低。热解机理包括矿物油含氧官能团裂解,链烃及侧链上的断链,环化、芳构化以及缩合脱氢。     

热解重油加氢裂化制取高芳潜石脑油的研究

以哈密热解焦油重质馏分悬浮床加氢裂化后的轻质油为原料,对其性质进行了分析,轻质油保留了煤的基本单元结构特点,富含芳烃类和环烷烃类化合物,氮含量较高;采用200 mL固定床精制-裂化串联装置,对轻质油原料进行了加氢裂化制取石脑油的研究;反应压力15 MPa下,考察了不同温度对加氢裂化反应的影响。结果表明,适宜的裂化段温度为390℃,此温度下,180℃馏分转化率为53.69%,氢耗5.13%,180℃石脑油收率56.8%,裂化后石脑油主要以C_(6-9)类烃类物质为主,其中,环烷烃含量为71.99%,芳烃含量3.13%,芳潜值70.1;以最佳工艺条件下产出裂化石脑油为原料,进行了催化重整制取BTXE的研究,采用石油系中间基石脑油作为对比,裂化石脑油重整后BTXE类物质总产率为55.85%,较石油基石脑油生成量高25.53%,彰显了煤基油的优势和特点,验证了煤热解重油裂化石脑油是制取BTXE类物质良好的原料。     

Utilization of associated petroleum gas via small-scale power generation

The utilization of associated petroleum gas via power generation in modern gas piston engines or gas turbines involves some difficulties due to a significant content of heavy C₅₊ hydrocarbons which are prone to detonation and soot and tar formation. Two pretreatment technologies were described for associated petroleum gas utilization via power generation. Selective oxycracking of heavy hydrocarbons in associated petroleum gas allows their conversion to lighter and high octane molecules. The conversion of associated petroleum gas into syngas with the use of volumetric radiant matrix not only enables utilization of associated petroleum via power generation but also opens prospects for its complete utilization with production of synthetic liquid hydrocarbons via Fischer-Tropsch synthesis route.     

Extended characterization of a vacuum gas oil by offline LC‐high‐temperature comprehensive two‐dimensional gas chromatography

In a context of environmental preservation, purification and conversion of heavy petroleum cuts into high‐quality fuel becomes essential. The interest for the characterization of those very complex matrices becomes a trendy analytical challenge, when it comes to get molecular information for the optimization of industrial processes. Among new analytical techniques, high‐temperature 2‐D GC has recently proved its applicability to heavy petroleum matrices, but lacks in selectivity to separate all chemical groups. To gain resolution, heart cutting is demonstrated for LC separation of saturated, aromatic and polar compounds prior to high‐temperature 2‐D GC. Therefore, an extended global resolution was obtained, especially by a better distinction of saturated compounds. This includes iso‐paraffins and biomarker polynaphthenic structures, which are impossible to quantify with MS methods. This new way to analyze heavy petroleum fractions gives innovative opportunities for the construction of global weight distributions by carbon atoms number and by chemical families. This can right now be employed for quantitative analysis of heavy petroleum fractions and for studying conversion processes.     

Effect of Alkanolamide on Interfacial Tension and Loss of Petroleum Sulfonates for Enhanced Oil Recovery

Experimental studies are conducted in order to elucidate the mechanisms of monoethanolamide responsible for synergism on lowering interfacial tension and decreasing loss due to adsorption on surface of reservoir sand and precipitation with multivalent cations in model oil/water/surfactants/brine systems. The interfacial tensions between solutions containing crude oil and monoethanolamide, petroleum sulfonates, or mixture of monoethanolamide and petroleum sulfonates at different ratios are studied without any alkali added in the solution. The results show significant synergic effect between monoethanolamide and petroleum sulfonates can reduce the interfacial tension to ultralow. Adsorption isotherms of monoethanolamide, petroleum sulfonates and mixture solution are determined to assess the effect of monoethanolamide on reducing the loss of petroleum sulfonates in formation. Static adsorption experiments indicate that the loss of petroleum sulfonates for adsorption and precipitation can be reduced on a great degree when monoethanolamide is mixed with petroleum sulfonates. The core-flooding tests show that the enhanced oil recovery with the formulation of surfactants of 0.3 wt% petroleum sulfonates and 0.2 wt% monoethanolamide can be increased by 26.6% without any alkali added in the flooding solution.     

Determination of petroleum sulfonates in crude oil by column-switching anion-exchange chromatography

A column-switching anion-exchange chromatography method was described for the separation and determination of petroleum monosulfonates （PMS） and petroleum disulfonates （PDS） in crude oil that was simply diluted with the dichloromethane/methanol （60/40）. The high performance liquid chromatography （HPLC） system consisted of a clean-up column and an analytical column, which were connected with two six-port switching valves. Detection of petroleum sulfonates was available and repeatable. This method has been successfully applied to determine PMS and PDS in crude oil samples from Shengli oil field.     

Sulfur speciation of Kuwaiti crude oils fractions using two-dimensional gas chromatography

The main objective of this study is to develop a methodology for sulfur compounds speciation using two-dimensional gas chromatography coupled with a flame ionization detector and sulfur chemiluminescence detectors. The methodology enhances the ability to detect and quantify the refractory sulfur in petroleum distillates, and it was utilized to screen the molecular differences between distillates of two Kuwaiti heavy crude oils from different reservoirs but with similar physical properties. Despite the similarity in the physical properties, the detailed comparative analysis indicated significant differences in molecular composition, which suggests substantial differences in crude oil processability based on the reactivity of the detected compounds. The distillates that have been considered in this study include heavy naphtha, kerosene, and gas oil. The compositional differences between the distillates were observed using the two-dimensional gas chromatography system with an in-house developed method. This method groups the sulfur compounds into thiols, benzothiophenes (BTs), and dibenzothiophene (DBTs), and it can handle any atmospheric distillate up 365 °C. Furthermore, the method includes the possibility of identifying and quantifying a total number of 44 sulfur species, which covers the previously mentioned sulfur groups.     

沥青－重油共炭化反应机理的研究Ⅱ．共炭化反应前后重油的结构分析及共炭化机理的推断

催化裂化轻柴油重组分─—三线芳烃和中温煤焦油沥青进行共炭化反应，改善了沥青的炭化性能。研究了共炭化反应前后三线芳烃的结构变化，结果表明：在共炭化过程中三线芳烃发生烷基取代基的Ｃ＿２～Ｃ＿３位键断裂，体系形成的烷基侧链和氢自由基转移至煤焦油沥青分子中，使沥青中烷基侧链含量增加，并产生一些环烷结构。共炭化作用的机理主要为共炭化剂的短烷基侧链转移和在热解及聚合时生成氢自由基的氢转移作用。