Characteristic Properties of a Locally Produced Paraffinic Oil and Its Suitability as a Heat-Transfer Fluid

The thermo-physical properties of a paraffinic mineral oil produced in a local refinery were experimentally determined over a wide temperature range of 30-360°C to determine its suitability for use as a heat-transfer fluid. The effect of temperature on the physical characteristics of the oil and two synthetic organic heat transfer fluids was evaluated at high temperatures (180-360°C). Comparison of the main properties of the mineral oil with other heating fluids revealed its compatibility with synthetic organic fluids, some other paraffinic and mineral oils employed as heat-transfer fluids. The study further confirmed that the investigated mineral oil which was produced locally can be used to replace the imported synthetic oils in heat transfer systems operating at a maximum application temperature of 310°C, as indicated by the thermal stability test.     

High Temperature Thermal Stability Investigation of Paraffinic Oil

The physical and thermal properties of paraffinic oil were investigated at 250-360°C to determine its suitability for use as a heat-transfer fluid. Thermal stability test was conducted at 360°C for a period of 480 hr in a stainless steel high-pressure autoclave. The paraffinic oil offered sufficient thermal stability for a period of about 300 hr and then became unstable resulting in thermal break down or cracking of the oil. Degradation of the oil led to the formation of gases, liquid components, and solid coke of about 5 wt.% of the starting material. The distillation test performed on the liquid components showed that the composition varied from light naphtha to heavy bituminous material.

The paraffinic oil compared favorably with synthetic organic fluids and the typical properties revealed its suitability as a heating fluid in a system with maximum usage temperature of 310°C as indicated by the thermal stability test. Comparative evaluation of the general properties of the tested paraffinic oil with other paraffinic and mineral oils of different product formulations showed excellent agreement. From these results, it is concluded that the paraffin oil sample produced by the local refinery is suitable for use as a potential thermal fluid at temperatures below 315°C, which is quite adequate for many industrial applications.     

Downhole Upgrading of Extra-heavy Crude Oil Using Hydrogen Donors and Methane Under Steam Injection Conditions

Abstract

An extra-heavy crude oil underground upgrading process is described which involves the downhole addition of a hydrogen donor additive under steam injection conditions (280–315°C and residence times of at least 24-h). Laboratory experiments showed a 4° increase in the API gravity (from 9 to 12°) of the upgraded product, a two-fold reduction in the viscosity and, an approximately 8% decrease in the asphaltene content with respect to the original crude. Further increases on the temperature led to products with improved properties reaching 15°API at 315°C. It was found that the presence of the natural formation (catalysts) and methane (natural gas) is necessary to enhance the properties of the upgraded crude oil. From GC and GC-MS results a reaction pathway is proposed that involves hydrogen transfers from tetralin to the extra-heavy crude oil resulting in the formation of 1,2-dihydronaphthalene. This compound is then transformed into naphthalene, further upgrading of crude oil through hydrogen donation. The results of the experiments carried out in the presence and absence of the mineral formation and with an inert solid (SiC) strongly indicate that the former acts as a catalyst and not as a heat transfer matrix. Isotopic labeling studies (CD₄ and ¹³CH₄) give evidences that, most probably, methane is involved in the upgrading reactions.     

Catalytic Dewaxing for Lube Oil Production

Abstract

The selective cracking of long-chain normal paraffin's of medium neutral raffinate, derived from a lube oil-phenol extraction unit, by the catalytic dewaxing technique over H-ZSM-5 and NiMo-H-mordenite catalysts was studied. The runs were conducted to produce lube oils with acceptable cold flow properties. The influences of zeolite types, metals loading, and operating reactor temperatures (290°C–475°C) can have a great effect on cracking high pour point n-paraffins into lower ones, and hence a reduction in pour points. An increase in temperature (between 290°C and 375°C) increased wax conversion (percent dewaxing) on H-ZSM-5 compared with NiMo-H-mordenite catalysts due to its higher cracking activity. As a result, large amounts of C₁-C₄ gases and C₅-170°C naphtha were produced. The low pour point lube oils produced from catalytic dewaxing over H-ZSM-5 compared with NiMo-H-mordenite catalyst indicates that the former was more selective for removing wax components than the later. On the other hand, high concentrations of aromatics were obtained on both catalysts, since the waxy paraffins are converted to lower boiling products. The reduction in dewaxed pour points (Δpp) was observed to be in the range of 38°C–42°C over H-ZSM-5, compared to 37°C–40°C over NiMo-H-mordenite at the same reaction temperature ranges (290°C–375°C), but NiMo-H-mordenite has advantages at higher temperature ranges (above 375°C) in pour point reduction (Δpp range: 41°C–42.5°C). The addition of bimetallic components to the mordenite-catalyst enhances its activity, and the rate of normal paraffin cracking was increased due to the hydrogenolysis activity of the active metals. This means that the bimetallic H-mordenite catalyst has the advantage over H-ZSM-5 in its refining activities (hydrodesulfurization [HDS] and hydrodenitrogenation [HDN]) under the tested operating conditions. These results may be attributed to shape-selective discriminating behavior due to differences in zeolite pore openings (i.e., 6.5 × 7.0 Å for mordenite and 5.3 × 5.6 Å for ZSM-5). In other words, a combination of isomerization and selective cracking reactions of high n-paraffins may occur during the dewaxing process using NiMo-H-mordenite catalyst. The influences of process parameters (temperature, pressure, and liquid hourly space velocity [LHSV]) on the relations between wax conversion to maintain maximum low pour points and maximum dewaxed oil yields or minimum yields of the least desired gases were optimized to produce dewaxed lube oils of acceptable characteristics.     

Experimental Investigation of Contact Angles Under Oil-Microbial Solution on Carbonate Rocks

Abstract

Contact angles are used to measure the wetting behavior of two immiscible fluids on a solid surface. Fluids are considered wettings if their contact angles with surface are less than 90°, and they are considered nonwetting, if their contact angles are greater than 90°. Because of its influence on other petrophysical properties of reservoir rocks, such as relative permeability, capillary pressure, and the residual oil saturation after a flood, wettability and its direct measure, the contact angle, play a significant role in affecting the recovery from both primary and improved recovery processes. In this work, contact angle alteration occurring in microbial enhanced oil recovery processes (MEOR) are quantified and described, along with a study of the factors that would enhance such contact angle alteration. An experimental method for the measurement of contact angles has been developed in which the contact angle is measured as a function of time. Measurements of contact angle and interfacial tension for four different types of UAE crude oil and four different mineralogical rock composition over a range of microbial concentration, salinity, and temperature are reported. Results showed that contact angles for the studied systems increased with temperature, crude oil sulfur concentration and microbial concentration up to a certain concentration, beyond which the bacteria concentration exhibited no effect on the contact angle. Crude oils containing low asphaltene concentration produced a stable contact angle and oils containing high asphaltene concentration produced surfaces with unstable wettability. The mineralogical composition of limestone rocks had no effect on the contact angle of microbial-oil system.     

THE EFFECT OF VISBREAKING CONDITIONS ON THE STABILITY OF SOME IRAQI LONG RESIDUES

ABSTRACT

A study has been done to investigate the change in the stability of residue during thermal process (visbreaking) at different cracking severity using flocculation ratio method. For this purpose, three long residues (350°C+) of different crude oils were used. The obtained results were discussed as a function of reaction temperature and residence time. Moreover, the stability was correlated with the nature and chemical composition of the feedstock.We observed that the intermediate paraffinic base feedstock (type A) was more stable than the other two asphaltenic base (Types B & C) when visbreaking temperature was 460°C. At higher temperatures, a sudden and large decrease in the stability of type A visbroken products was observed while only a gradual decrease in the stability of the other two products was noticed when visbreaking process was carried out at the same operating conditions.     

矿物基础油中不同烃类分子对其物理性质的影响

本文以不同类型且有一定粘度跨度的8类矿物基础油为研究对象,并选取了3种PAO合成油及烷基萘作为纯组分的对比例,系统考察了基础油中各烃类对密度、粘度、粘度指数等几项物理性质的影响,并尝试从理论的角度进行了分析。结果表明：随链烷烃的增加,密度、折射率、分子量均线性下降,粘度则呈指数降低;环烷烃对各项性质的影响不明显,但多环烷烃与分子量线性正相关,而与粘度则是指数正相关;芳烃的影响与链烷烃正好相反;碳数相近时,低芳烃基础油的粘度指数正比于链烷烃含量,但高芳烃基础油则随2环及以上多环芳烃的增加而急剧线性下降,这也正是环烷基油粘温性能极差的根本原因。     

High Temperature Corrosion Tests for Kerosene and Gas Oil Samples

Abstract

A preliminary investigation has been carried out on the corrosive nature of some commercial kerosene and gas oil samples. Experimental tests were conducted on the rate of corrosion of iron and galvanized steel specimens immersed in the oil samples at temperatures varying from 200° to 260°C. The results confirmed that acidity is an important factor in corrosion of metals and that temperature is a great contributing factor. Temperature significantly increased the corrosion rates resulting in manifold increases in metal losses from 1.80 to 4.70 for kerosene samples and 1.50 to 4.20 for the gas oils indicating that kerosene was more corrosive. The results of the present work provided supporting data to the corrosion problems encountered in the oil industry. It is revealed that temperature can appreciably contribute to the corrosivity of kerosene and gas oils in burners, heat exchangers, storage tanks, and other ancillary equipment.     

LIQUEFACTION OF BEYPAZARI LIGNITE USING NiCl2-KCl-LiCl CATALYSTS. 1. DIFFERENCE IN SOLID AND MOLTEN SALT CATALYSIS

ABSTRACT

Liquefaction of Beypazan lignite in tetralin using NiCl₂-KCl-LiCl (14:36:50 molar percentages) as catalyst was investigated. Effects of the catalyst/lignite ratio and temperature were determined in experiments done at 275°C, 300°C and 360°C. Liquid products were separated into oils, asphaltenes and asphaltols by a solvent extraction method. Yield of liquefaction increased with temperature in all experiments, the highest yield was observed in experiments performed at the eutectic temperature of the catalyst mixture. The highest yields of oils were 20% and 30% with a catalyst/coal ratio of 0.5 at 275°C and 300°C, respectively. The activity of the catalyst increased in experiments in which the catalyst was molten. The yield of asphaltenes were not affected with increases in the catalyst/coal ratio in the experiments done at 275°C or 300°C in which the catalyst mixtures were in solid state. Asphaltene yields decreased from 25% to less than 5% with increasing values of catalyst/coal ratio and the asphaltol yields remained constant at 10% between catalyst/coal ratios of 0.25 and 1.00 and suddenly increased to 30% and 40% for catalyst/coal ratios of 1.50 and 2.00, respectively, at 360°C. The molecular weights of the oils decreased from 340 to a minimum value of 245 as the catalyst/coal ratio was increased from 0 to 1.00 in experiments done at 360°C where the catalyst was molten. As the catalyst/coal ratio was further increased from 1.00 to 2.00 the molecular weight increased to 310.It seemed that the N1Cl₂-KCl-LiCl catalyst mixture in all catalyst/coal ratios was more efficient in molten phase than it was used as a solid mixture.     

Correlation Between Properties of Asphaltenes and Precipitation Conditions

Abstract

Asphaltenes from three crude oils were precipitated by using a pressurized system. Different conditions during the precipitation of asphaltenes were studied: pressure was varied between 15 and 45 kg/cm² and temperature between 40°C and 100°C. The effect of contact time and solvent-to-oil ratio was also studied in the range of 0.5–6 hr and 2:1 to 5:1 mL/g, respectively. Asphaltenes properties were analyzed as a function of pressure and temperature. It was found that in a deeper way temperature influences the asphaltenes properties than pressure in the range studied in this work. Asphaltenes properties were highly dependent on the nature of crude oil. Various correlations were developed and experimental and calculated asphaltenes contents and properties were in good agreement with absolute error less than 0.2%.     

CHANGE OF PHYSICAL AND THERMAL DECOMPOSITION PROPERTIES OF IN SITU HEAVY OIL WITH STEAM TEMPERATURE

ABSTRACT

Ikiztepe crude oil was subjected to four different steam temperatures during steam injection which was applied as an enhanced oil recovery process on a linear limestone model saturated with oil. Produced oils were characterized using density, viscosity measurements, pyrolysis experiments utilizing TGA and elemental analysis runs. Results showed that produced crude oils change in measured characteristics as compared to the original oil. These changes include an increase in H/C, and cracking activation energy, decrease in density, viscosity and amount of residue remaining after cracking (coke). Also, decrease in asphaltene amount, changes in the elemental composition of asphaltenes and increase in the cracking activation energies were observed at 225 °C run. These measurements show that the produced oils get lighter and differ compositionally from the original oil as steam temperature increases. Decrease in elemental sulphur amount is one of the major changes when environmental considerations are concerned. Residual oil left in the limestone pack on the other hand shows an increase in the low temperature oxidation (LTO), fuel deposition (FD) and high temperature oxidation (HTO) activation energies as determined from TGA combustion experiments on the samples taken from the pack after steam injection experiments.     

Compatibility Tests for Some Model SAE 30–50 Engine Oil Formulations and Correlation of Properties

Abstract

A series of laboratory tests have been conducted on commercially available model engine oils of SAE 30–50 grades obtained from different oil companies operating in Nigeria. Experimental analysis showed that these model oil formulations conform to certain standards governing their constituents and performance. All the samples have high viscosity index of 100 and above. Their pour points indicate low temperature fluidity and suitability to be used in cold weather conditions. Data correlation shows that viscosity and viscosity gravity constant (VGC) can be adequately used to characterize the oil samples. The semi-logarithmic plot of VGC against viscosity at 40°C produced the best correlation. The study further proves that VGC should find a wider application as a correlating parameter for the physical property of model oils.     

Preparation of synthetic hydrocarbon oil by high-pressure hydrocracking of ethylene-propylene copolymers

Degradation reactions of ethylene-propylene copolymers at a high temperature (380–430°C) and a high pressure (180–220 atm) in the presence of a nickel catalyst and hydrogen have been studied. In contrast to the previously known processes, the degradation reactions have been conducted simultaneously with hydrogenation reactions. The effects of temperature, pressure, and time on the yield of each fraction have been examined. As a result, optimal process conditions have been found for each fraction. The physicochemical properties of the lube oil fraction (C₁₈–C₂₅) used as a base oil have been studied. It has been found that as in the case of oils derived from ethylene-propylene copolymers by other methods, these oils have a high viscosity index (VI > 95), a high flash point (T _f > 210°C), and a low pour point (T _p < ?50°C).     

LIQUEFACTION AND THE CHARACTERIZATION OF COAL DERIVED LIQUIDS OF MENGEN LIGNITE

ABSTRACT

The liquefaction characteristics of Mengen lignite has been investigated in the presence of cobalt-molybdenum on alumina catalyst in a 1 lt batch autoclave system with anthracene oil used as solvent. The experiments were carried out in the range of 15–60 atm for initial hydrogen pressure, 360–440°C for reaction temperature, 1–5 for solvent to coal ratio and 0–20% of coal for catalyst loading which were chosen as process variables. Coal particle size and reaction time were kept constant as below 200 mesh and 30 minutes respectively, (Erdem 1987)

The product was analyzed in terms of total conversion, liquid yield and liquid product distribution determined as preasphaltenes, asphaltenes and oils. The oil fraction was further separated by column chromatography while the asphaltenes were separated into basic and acid/neutral fractions. The preasphaltenes were divided into two fractions as carbene (CS₂ solubles) and carboid (CS₂ insolubles). (Inanç 1989)

The oil yield is mostly affected by the catalyst loading which shows to a certain extent that the conversion of asphaltenes to oils is a catalytic step. The selected process variables showed a positive trend with respect to the yield of hexane eluted oil which is the desired product of liquefaction.     

导热油基础油的烃类结构对其热稳定性的影响

利用质谱分析对导热油基础油的结构组成进行了分析,研究了7种基础油的烃类结构对热稳定性的影响。结果表明:高温矿物型导热油的热稳定性与基础油的烃类组成有关,环烷烃热稳定性好,链烷烃和芳烃较差,且烃类组成与变质率之间存在定量关系,可较好地指导高温导热油基础油的选用。     

Interaction of Chloroprene and Nitrile- Butadiene Rubber with Lubricating Greases and Base Oils

1 IntroductionChloroprene and nitrile-butadiene rubbers are twocommodity rubber types distinguished by their chemical sta-bility and mechanical endurance.As compared to generalpurpose synthetic rubbers,such as isoprene or styrene-bu-tadiene,chloroprene(CR)and nitrile-butadiene(NBR)rub-bers have much better chemical and weathering resistanceand can withstand contact with fuel and mineral oils.Theyalso have good elongation properties as well as adequate re-silience,tensile and compression char…     

植物油用做液压油基础油的研究

研究了低芥酸菜籽油、花生油、葵花籽油、橄榄油、蓖麻油和玉米油等植物油用做生物降解液压油基础油的性能。结果表明,植物油以特殊分子结构,使其具备了不同于矿物基础油的性能,它除具有生物可降解性外,速具有粘度指数高,粘温性能好,好的低温流动性、极压抗磨性、水解安定性和对材料的配伍性的特性。但氧化安定性很差,有可能通过植物油改质或加入高效氧化抑制剂来提高,植物油的抗氧化性能。植物油可用做环保型液压油基础油,     

The Effects of Multi-component Thermal Fluids on the Viscosity of Offshore Heavy Oil

Multi-component thermal fluids stimulation is a feasible way to recover offshore heavy oil reservoir. As a new technology, its mechanism of enhanced oil recovery should be understood through systematic simulation experiments and quantitative analysis. Laboratory experiments were carried out to investigate the effects of temperature, natural gas, and various gases (N₂, CO₂, or N₂+CO₂) on the viscosity of heavy oil from Nanbao block of Bohai offshore oilfield. The results show that in the range of 56°C (reservoir temperature) to 120°C, natural gas saturated and degassed oils are all very sensitive to temperature, and the viscosity is reduced by more than 90% when heated to 120°C; under lower temperature condition, injection of 5MPa N₂, N₂+CO₂, or CO₂ can significantly reduce the viscosity of natural gas saturated heavy oil, with a viscosity reduction ratio of about 20%, 50%, and 80%, respectively, at 56°C. Therefore, heavy oil production by viscosity reduction can be achieved by raising temperature or through gas injection. Taking into account the equipment, heat loss, and cost of steam injection, the technology of moderate heating, auxiliary gas injection is very promising for the recovery of Nanbao heavy oil.     

Deep Desulfurization of Light Oil Using the Imitating Silver Salt ILs Method

Abstract

Sulfides in oils are harmful in many ways, in particular, deterioration of the environment resulting from sulfur dioxide. A novel desulfurization process for light oil has been investigated. A mixture consisting of benzothiophene (BT), dibenzothiophene (DBT), and oil fractions (235°C–270°C) refined by acid–alkali treatment was employed for alkylation desulfurization tests in a nitrogen atmosphere. The results showed that at a reaction temperature of 30°C, ratio of bromoethane (CH₃CH₂Br) to sulfur of 30:1 (mol/mol), ratio of silver tetrafluoroborate (AgBF₄) to sulfur of 6:1 (mol/mol), and reaction time of 16 hr, the desulfurization yield could reach 76.3%.     

Rheological Properties and Composition of Some Vacuum Distillates Derived from Indian Crudes

Abstract

Three vacuum distillates boiling range 400°C–530°C derived from Bakrola, Dholka, and PY-3 crudes of Gujarat region (India) were subjected to urea adduction to isolate n-paraffin components from them. The deparaffinized base oils obtained after removal of n-paraffin components from the distillate fractions were further fractionated into various hydrocarbon-type constituents viz iso + cyclo paraffins, aromatics, and polar components by column chromatography. The influence of various hydrocarbon-type components thus separated on rheological characteristics (pour point and viscosity temperature behavior) of deparaffinized base oil was investigated. This study was done by preparing base oil blends by adding separated hydrocarbon-type constituents in various concentrations to different base oils and characterizing them. The effect of change of solvent matrix on the rheological characteristics was also determined. The study demonstrated the role of solid n-paraffins for variation in pour point and viscosity temperature behavior of the waxy distillate fractions.