Crude Oil Mixtures Research Articles

Some considerations regarding the influence of working conditions on the corrosion wear of the injection water treatment plant equipment

One of the methods used for the secondary exploitation of oil deposits is the water injection. The injected water is obtained after the separation of the well extracted fluid that contains a mixture of crude oil, water, gases and solid particles. Prior to injection, water must meet the following requirements: a high degree of purity obtained thought the lowest possible mechanical and oil content; lower degree of aggressiveness (corrosion); the highest stability; compatibility with the fluids and minerals in the reservoir formation; low oxygen content and bacteria. The fulfilment of these requirements must be ensured by the water treatment plant whose equipment is subjected to corrosion wear. The equipment degradation are occurring mainly at pipelines and connecting elements of the flotation skid, in the form of advanced corrosion wear because the water injection contains an inconsistent composition mixture of dissolved gases, hydrocarbons, solid particles. The paper presents the regression analyses that emphasize the influence of chemical water composition and fluid speed on the corrosion rate of the different equipment parts. The corrosion rates were obtained using metallic samples according with the NACE SP0775-2013 standard that were placed in different points of the plant. The paper results can be used both at the water plant exploitation and also to next studies concerning the effectiveness of the corrosion inhibition on the corrosion rate.

Phase Behavior for Crude Oil and Methane Mixtures: Crude Oil Property Comparison

A wide variation in composition and thermodynamic properties is expected for different reservoir fluids, from simplest one containing only methane and light compounds, to those with high compositional complexity. In this work, phase behavior of six different reservoir fluids recombined with methane was compared and contrasted. From our past work [Romero Yanes et. al. (2019), DOI:10.1016/j.fuel.2019.115850], a low asphaltene crude oil (28.0 °API, 0.68 wt % n-C7 asphaltenes), here referred as BRO, has presented a complex phase behavior when mixed with methane, especially when methane content is around 75.0 mol%. Based on these results, it was studied in this work the phase behavior of six different crude oil mixed with 75.0 mol% of methane. Samples main characteristics can be summarized as follows: a light condensate fluid (P1, 44.0 °API, and not detected n-C7 asphaltenes), three medium crude oils [(P2, 30.8 °API, and 0.09 wt % n-C7 asphaltenes); (P3, 26.0 °API, and 0.54 wt % n-C7 asphaltenes); and (P4, 25....

In vitro digestibility of ruminant diet in response to protected feed substitution

Excessive degradation high protein feed in the rumen can reduce nutrient utilization efficiency of feed in post rumen. Protected feed is expected to increase the undegraded proteins that enter and absorbed in the intestine. In vitro study was conducted to determine whether the protected feed can reduce rumen degradability as well as improving post-rumen degradability of feed. The protected feed used in this study was soybean meal and crude palm oil mixture (4: 1), added with 0.3% Agromix. Independent sample t-test was used to compare 2 treatments (T1/control = commercial ration; T2 = commercial ration with 4.4% protected feed substitution). Each dietary treatment was done in 6 replications. Both dietary treatments were tested for their digestibility using a 2-stage in vitro technique. Results showed that pH of rumen did not change. Compared to the T1, T2 showed lower (P<0.05) digestibility of dry matter (DMD), organic matter (OMD), and crude protein (CPD) in the rumen. In the post rumen, T2 showed greater (P<0.05) DMD, OMD and CPD than T1. It concluded that protected feed substitution effectively decreases digestibility in the rumen and increases post-rumen digestibility, imply that protected feed substitution can improve the nutrient utilization in the post rumen.

Measurements and modelling of the viscosity of six synthetic crude oil mixtures

The viscosity and density are reported for six synthetic mixtures, composed of up to 13 components, designed to match a light, dead crude oil of API 32° and molar mass of approximately 184 g mol−1. The measurements were made in the liquid region at temperatures between (323 and 398) K and in the pressure range from 1 MPa to 70 MPa. The viscosity was measured with a vibrating-wire viscometer, while the density was measured by means of a vibrating U-tube densimeter. The density and viscosity data have expanded relative uncertainties of 0.12% and 1.2%, respectively with a coverage factor of 2.We have used the measured viscosity data to test the predictive power of the four viscosity models, the extended hard sphere (EHS), one-component EHS (1-cEHS), three-component EHS (3-cEHS) and Vesovic-Wakeham (VW), that have their basis in kinetic theory and the molecular description of the fluid. Two of the models (EHS and VW) require full compositional description of the mixture, while the other two belong to a new family of models which dispense with full compositional characterization, but retain molecular description. On average the EHS and VW models predict the viscosity data with lower deviations than 1-cEHS and 3-cEHS models, but all four models represent the data with uncertainty of 5–10%.

Characterizing Crude Oil Toxicity to Early-Life Stage Fish Based On a Complex Mixture: Are We Making Unsupported Assumptions?

Numerous studies of the water-soluble fraction (WSF) from crude oil have concluded that polycyclic aromatic hydrocarbons (PAHs) are the primary causative agents for early life stage (ELS) fish toxicity. Noteworthy is the lack of studies demonstrating that the sum of PAHs are capable of causing toxic effects in ELS fish at the low levels claimed (0.1-5 μg/L) without being part of a complex crude oil mixture. Crude oil and the WSF are composed of thousands of other compounds that co-occur and likely contribute to crude oil toxicity. Based on the available data, it appears that the syndrome of effects (lower heart rate, edemas, and morphological abnormalities) for ELS fish exposed to the aqueous fraction of a crude oil mixture is commonly observed in studies exposing fish embryos to high concentrations of a variety of compounds and may be a nonspecific response. We conclude that the available data support the hypothesis that this syndrome of effects is likely the result of baseline toxicity (not receptor based) due to membrane disruption and resulting alteration in ion (e.g., calcium and potassium) homeostasis. We acknowledge the possibility of some compounds in the WSF capable of causing a specific receptor based toxicity response to ELS fish; however, such compounds have not been identified nor their receptor characterized. Concluding that PAHs are the main toxic compounds for crude oil exposure is misleading and does not result in guideline values that can be useful for environmental protection. Water quality guidelines for any single chemical or suite of chemicals must be based on a complete understanding of exposure concentrations, mechanism of action, potency, and resulting response. This review focuses on the toxic effects reported for fish embryos and the purported toxic concentrations observed in the aqueous phase of an oil/water mixture, the known levels of toxicity for individual PAHs, a toxic unit approach for characterizing mixtures, and the potential molecular initiating event for ELS toxicity in fish. This review also has implications for a large number of studies exposing ELS fish to a variety of compounds at high concentrations that result in a common baseline toxic response.

Experimental study of the phase behavior of methane and crude oil mixtures

Phase behavior of reservoir fluids is crucial for an efficient production development project. In this paper, a new dataset of phase transitions of Brazilian pre-salt crude oil mixed with methane systems is presented and phase behavior discussed under different analytical technics. A series of mixtures of a dead crude (API 28.0, 0.68 wt% of asphaltenes) with 65.0, 67.5, 70.0, 72.5, and 75.0 mol% of methane were studied by constant mass expansion in a PVT cell, coupled with a high-pressure microscopy (HPM). Pressure-volume data shows slight phase transition, with a not evident break due to difference on compressibility, specially by increasing methane molar content. For this reason, beside of visual observation, a near-infrared (NIR) transmittance was used for a proper identification of bubble point pressure. NIR transmittance also allow the detection of phase transitions above bubble point, that was confirmed by intermediate of by HPM analysis. A dispersion of fine particles was detected, and it was associated with asphaltenes onset, for the systems with high content of gas (72.5 and 75.0 mol% of methane). NIR transmittance along with micrographs taken during system pressurization confirm a low asphaltene hysteresis redissolution, with no flocs and mayor aggregates formation and rapid redissolution after system pressurization. This phenomenon could be related to the low content of asphaltenes on the crude oil sample.

Transcriptomic response and hydrocarbon accumulation in the eastern oyster (Crassostrea virginica) exposed to crude oil

The adverse effect of crude oil on marine invertebrates is well known. To have a better understanding of its effects on marine invertebrates, Crassostrea virginica was exposed to different concentrations (50, 100 and 200 μg/L) of a mixture of super-light and light crude oil for two weeks, evaluating the transcriptomic response of the digestive gland using RNA-Seq and their accumulation in soft tissues. A total of 33,469,374 reads were assembled, which resulted in 61,356 genome assemblies (‘Genes’). Trinotate was used for transcript annotation. At the end of this process, 86,409 transcripts were maintained, comprising a broad set of enzymes from xenobiotics metabolism, oxidative stress, stress and immune responses, and energetic metabolism. The enrichment analysis revealed a change in biological processes and molecular functions, finding from 100 to 200 μg/L. Moreover, the differential gene expression analysis showed a dose-dependent transcriptional response, generally up to 100 μg/L and in some cases up to 200 μg/L, which suggested that oysters' response decreased after 100 μg/L; the analysis of crude oil presence in soft tissues indicated that C. virginica is a suitable candidate for ecotoxicology. Finally, these results should contribute to expanding current genomic resources for C. virginica. Furthermore, they will help to develop new studies in aquatic toxicology focused on knowledge in depth of metabolic pathways, jointly with other approaches (such as proteomics) to allow obtaining a complete idea about the eastern oyster response to crude oil.

Impact of Different Oil Mixtures on Foam in Porous Media and in Bulk

Foam can be applied to enhance oil recovery from a reservoir. Currently, to understand and model the behavior of foam in an oil reservoir, experiments need to be conducted in the presence of the specific crude oil, and extrapolating from one crude oil to another is not possible. It is therefore desirable to model the impact of a crude oil on foam solely based on the crude-oil composition. This would allow one to efficiently screen reservoirs for foam application. Here we investigate the behavior of foam in the presence of a crude oil and in the presence of mixtures of pure components, which we choose based on the gas chromatography analysis of the crude oil as well as its total acid number and total base number. To analyze the impact of an oil mixture on bulk foam we shake test tubes with surfactant solution and either a mixture of pure oil components or crude oil and analyze foam height and liquid height over time. We also conduct experiments in a porous medium, where we coinject mixtures of pure components, surfactant solution, and gas. We fix the oil injection rate and vary the ratio of the gas to surfactant solution. We use the following organic compounds (OC) to represent the crude oil: toluene (an aromatic), oleic acid (an organic acid), octanol (an organic base), methylcyclohexane (a cycloalkane), dimethyl sulfoxide (an organosulfur), n-octane, and hexadecane. However, when one or all of the first components is added to a 50/50 (vol %) mixture of n-octane and hexadecane, in proportions similar to their presence in the crude oil, the impact of the oil mixture on foam (both in bulk and in porous media) is only slightly different from the impact of the n-octane and hexadecane mixture. We formed a “synthetic” crude oil, with its composition mimicking the composition of a crude oil and its total acid/base number. Although the pure OC and synthetic crude oil weaken foam in bulk and in porous media, their impact on foam was less severe than the impact of the crude oil on the foam. Based on the composition of an oil mixture and the impact of its components, separately, on foam, it is not clear how to predict the impact of the oil mixture on foam in bulk or porous medium. However, in our case we find a good correlation between the foam apparent viscosity in porous media and the product of the bulk foam half-life and initial volume. One implication is that if either the half-life or initial volume of bulk foam is poor, the foam performs poorly in the porous medium.

Modeling of wax and asphaltene precipitation in crude oils using four-phase equilibrium

A thermodynamic model is developed for predicting wax and asphaltene precipitation in crude oil mixtures with up to four phases, i.e. vapor, liquid, wax-rich and asphaltene-rich. The model adopts the experimentally supported hypothesis that asphaltenes precipitate before waxes with decreasing temperature and aggregate as the nucleus of wax crystals. The simplified perturbed chain statistical associating fluid theory (sPC-SAFT) equation of states (EOS) is applied in order to describe phase behavior in crude oils. In this research, a characterization method is proposed for mixtures containing asphaltenes and waxes using the sPC-SAFT EOS. And a correlation is modified for prediction of binary interaction parameter for the sPC-SAFT based on measured binary solid solubilities of twelve n-alkane mixtures. The universal quasi chemical activity coefficient (UNIQUAC) model is used to account for the non-ideality of the wax-rich phase. It is shown that the cloud point and the amount of wax and asphaltene precipitates obtained in the proposed model have an excellent agreement with the experimental data.

Evaluation of foam performance at different temperature for enhanced oil recovery process

PurposeApplication of foam in enhanced oil recovery requires a production of foam that is strong and stable enough to withstand a long period. There are numerous factors that may affect the performance of foam, among which is temperature. Therefore, this study aims to observe the foam performance at different temperature by evaluating the foamability and the stability of the foam.Design/methodology/approachIn this study, bulk foam test using FoamScan was conducted to examine the effect of temperature on foam in the presence of crude oil. Nitrogen gas was sparged through the mixture of crude oil, an in-house developed surfactant, and sodium chloride solution as the brine at different temperatures to produce foam at a certain height. The crude oil was extracted from an oilfield in East Malaysia and the in-house developed surfactant was a mixture of amphoteric and anionic surfactants. A camera continuously recorded the height of foam during the generation and the collapse of the foam. The foamability and foam stability properties of each sample were taken as the indicators for foam performance. Furthermore, the entering, spreading and bridging analysis was run to observe the effect of the presence of crude oil on foam performance.FindingsIn general, the higher the temperature, the less stable the foam is. As the stability of foam is associated with the rate of liquid drainage, it was observed that as temperature increases, the rate of liquid drainage also increases. On the other hand, the entering, spreading and bridging analysis shows that there is entering of oil droplet happening on the interface of foam film that may promote the rupture of the foam film even more.Originality/valueIt was found that the temperature has a small impact on foamability, whereas the foam stability was significantly affected by the temperature. Therefore, it can be concluded that foamability is not necessarily interrelated to foam stability, contradicting to the findings of few authors.

Molecular dynamics simulation of the microscopic mechanisms of the dissolution, diffusion and aggregation processes for waxy crystals in crude oil mixtures

To ensure the safe and economic operation of a waxy crude oil production process, the microdynamic mechanism and thermodynamic characteristics of the wax gelation process need to be revealed at nanoscale. The molecular dynamics model was established to characterize the phase transition and gelation behavior of waxy molecules in a multiphase system (including oil, asphaltene and water). The relative error between the simulated results and experimental data measured by Dutour et al. (2002) was less than 5%. Under the coupling effect of different operation parameters, the molecular dynamics simulation was employed. The simulated results showed that the spherical paraffin crystals underwent the processes of dissolution, diffusion and aggregation. After which waxy cluster crystals with larger amount but smaller volume were formed, which would be deposited on the inner wall under the concentration gradient. The influence mechanisms of different operating parameters on wax gelation were analyzed. And it was found that the increase in temperature and water cut decrease the wax precipitation, while the increase in pressure enhance the wax precipitation rate. Furthermore, by means of hydrogen bonding and the effect of similar dissolution, water and asphaltene molecules also affect the wax precipitation process at the molecular scale. The investigations in this study provide theoretical support for the paraffin removal and control in a waxy crude oil production system.

Hybrid GMDH-type neural network to predict fluid surface tension, shear stress, dynamic viscosity & sensitivity analysis based on empirical data of iron(II) oxide nanoparticles in light crude oil mixture

The effects of different parameters including nanoparticles mass fraction and temperature were investigated on rheological behavior and surface tension of iron(II) oxide/light crude oil nanofluid. Iron(II) oxide was dispersed in light crude oil by using ultrasonic processor. TEM images was provided in order to assess the size and morphology of iron(II) oxide nanoparticles. In addition, DLS analysis and Zeta potential test were performed on nanofluid for estimation of nanoparticles size distribution within the basefluid and stability of nanoparticles, respectively. The results of this study showed that for iron(II) oxide/light crude oil nanofluid the value of surface tension reach to its minimum value at the condition where nanoparticles mass fraction was chosen to be 2.0 wt% and temperature was set on 70 °C. These results showed that for iron(II) oxide/light crude oil nanofluid the rheological behavior of nanofluid is non-Newtonian at temperature of 40 °C and the suspension behave as a rheoplexy fluid in which by increasing the shear rate higher dynamic viscosity of nanofluid observed. Furthermore, nanofluid behaves as a Newtonian fluid for the temperature of higher than 55 °C. Finally, a comprehensive correlation was obtained for estimation of relative dynamic viscosity of nanofluid by hybrid group method of data handling (GMDH)-type neural network method. The correlation presented in this study shows that for the relative dynamic viscosity of iron(II) oxide/light crude oil as a function of nanoparticles mass fraction and temperature, the amount of the total deviation of calculated data from experimental values is less than 10%.

A major leak in a crude oil tank: Predictable and unexpected root causes

A 2000 m3 washer tank at a crude oil treatment plant suffered a structural collapse, involving total loss of integrity. A fast fracture initiated in a sector of the shell with a severe thickness reduction due to combined internal and external corrosion. The fracture bent and propagated horizontally, at the shell-roof intersection and at the joint between second and third courses, causing the almost instant opening of a large window. Due to the large initial leakage flow, the containment enclosure wall could not hold the spilled mixture of water and crude oil. The fast leaking wave damaged the breakwaters at the top of the wall, overpassed the enclosure and pushed out a sliding gate, thus causing total liquid leakage. Fracture and computational fluid dynamics models were developed to understand the origins of the failure, as well as to reconstruct the sequence of events. Deficiencies in tank construction, maintenance adequacy, and corrosion prevention were found to be the main root causes of the failure.

Improving the Efficacy of Abamectin Using Neem Oil in Controlling Tomato Leafminers, Tuta absoluta (Meyrick).

Tomato leafminers, Tuta absoluta pose a control challenge against dozens of chemical pesticides including abamectin as a result of increase in resistance with time. This study aimed at improving the field performance of abamectin using crude neem oil. The oil was obtained from the healthy neem seeds by cold pressing method. A total of 10 larvae were used in each bioassay experiment. Abamectin at 1000 ppm caused corrected mortality of 79% and its concentration that kills half of the experimental larvae (LC50) was 363 ppm. The crude neem oil at concentration of 2500 ppm caused corrected mortality of 61% with LC50 at 1089 ppm. The 1:1 mixture of abamectin and crude neem oil (without heating) at concentration of 1000 ppm gave 83% as highest corrected mortality and LC50 at 251 ppm. The findings from bioassay experiments revealed that, both neem oil and abamectin are potential pesticides; however their performance was even high after mixing. It was the synergism effect that gave the mixture high performance.

Fluorescence Hyperspectral Imaging of Oil Samples and Its Quantitative Applications in Component Analysis and Thickness Estimation.

The fast response and analysis of oil spill accidents is important but remains challenging. Here, a compact fluorescence hyperspectral system based on a grating-prism structure able to perform component analysis of oil as well as make a quantitative estimation of oil film thickness is developed. The spectrometer spectral range is 366–814 nm with a spectral resolution of 1 nm. The feasibility of the spectrometer system is demonstrated by determining the composition of three types of crude oil and various mixtures of them. The relationship between the oil film thickness and the fluorescent hyperspectral intensity is furthermore investigated and found to be linear, which demonstrates the feasibility of using the fluorescence data to quantitatively measure oil film thickness. Capable of oil identification, distribution analysis, and oil film thickness detection, the fluorescence hyperspectral imaging system presented is promising for use during oil spill accidents by mounting it on, e.g., an unmanned aerial vehicle.

Study of Influences of Fracture Additives on Stability of Crude Oil Emulsion

Background: A hydraulic fracture is a key technology to increase production of the low permeability oil fields. Fracture additives such as gels, friction reducers, pH adjusters and clay stabilizers were injected into the underground. While more than 50% of the fracture fluid remains underground. The residue of fracture fluid comes out with the produced liquid (a mixture of crude oil and water) in the subsequent oil recovery process, which results in a highly stable crude oil-water emulsion. Objective: The stability and stable mechanism of the emulsion with fracture fluid have been experimentally investigated. Materials and Methods: The influences of fracture additives and components of crude oil on the stability of emulsion were investigated by bottle test and microscopic examination. The interfacial tension and modulus of dilation were explored by a spinning drop interfacial tension meter and an interface expansion rheometer, respectively. Results: The fracture additives played the key role on the emulsion stability. On one hand, the interface energy of oil-water was reduced by friction reducer (IFT was decreased from 24.0 mN/m to 1.9 mN/m), which was a favor for the formation of an emulsion. On the other hand, the dilational modulus of crude oil-water film was increased by hydroxypropyl guar and pH adjuster (Na2CO3) to form a viscoelastic film, which resulted in a highly stable emulsion. Conclusion: The residual fracture fluid accompanied by produced liquid resulted in a highly stable emulsion. The emulsion with fracture additives was difficult to be broken, which may affect the normal production of the oil field. A positive strategy such as developing demulsifier with high efficient should be put onto the schedule.

Studying the fragmentation mechanism of selected components present in crude oil by collision-induced dissociation mass spectrometry.

Structural characterization of individual compounds in very complex mixtures is difficult to achieve. One important step in structural elucidation is understanding the mass spectrometric fragmentation mechanisms of the compounds present in such mixtures. Here, different individual compounds presumed to be present in a complex crude oil mixture have been synthesized and structurally characterized by tandem mass spectrometry (MS/MS) studies. Model compounds with different aromatic cores and various substitutents were synthesized. Major effort has been put into producing isomerically pure compounds to better understand the fragmentation pattern. Each synthesized compound has been subjected to MSn studies using either a triple quadrupole or a linear ion trap mass spectrometer with electrospray or atmospheric pressure photoionization. The results are used to analyze individual compounds from a complex vacuum gas oil (VGO). The synthesized compounds and a chromatographically simplified vacuum gas oil were used for structural analysis. The major fragmentation mechanism is the benzylic cleavage of the aliphatic side chain. Each side chain can be separately removed from the aromatic core by using MSn methods. At the end of a series of fragmentations, the base aromatic core structure remains and can be chararcterized. By defining the fragmentation mechanism in complex oil samples it was possible to structurally characterize individual compounds present in a chromatographically simplified VGO. The compounds consist of an aromatic core with aliphatic side chains. Cleavage of all side chains can be achieved by MSn measurements, allowing characterization of the remaining core structure.

Comparative study of the physical and chemical properties of the crude oil mixture of the El-Wafa field in practically and through the use of an advanced program [Aspen HYSYS

The accuracy in measuring the physical properties of any crude oil has become a very difficult task because the price of crude oil in the global market depends on it in addition to the process of producing lubricating oil , chemical products and refinery. Accordingly, this research effort focuses on comparative study of Libyan crude oil (El-Wafa field) by measuring the physical and some chemical properties experimentally and by Aspen HYSYS V8.4 programs. Also, test the possibility to know the volume percentage of the production of lubricants from this crude oil by the two methods mentioned above.Test carried out on these measurements practically and theoretically the physical properties are include: normal boiling point, pour point, Specific gravity (Sp. gr.), standard density (API), dynamic viscosity , kinematics viscosity , molecular weight, Acentric factor and Watson factor (K or Kw ). Some chemical properties have also been experimentally measured, for example the sulphur content ( wt.%), Asphaltenes content( wt.%) , water and sediment content (vol.%), Conradson carbon residue ( wt.%) , salt content (as NaCl, mg\L), ash content(wt. %) and metals content ( wt.%).The results from the tests showed that, there is a very small convergence between the results of calculations of physical properties by use this modern software with experimental measurements in the lab to the crude oil of El-Wafal field up to 99% and this blend is not suitable for production the lubricated oil at atmospheric distillation column. Also, the results observed that’s the useful mole percentage of lubricated oil cutoff has volume percentage range not significant from 1 to 1.8% for this type of Libyan crude oil. Through practical and theoretical results possible to classify this type of crude oil as Brent mix according to the global market for the sale of crude oil, which is characterized by its lack of sulfur element and metals in addition to its standard relative density API is very high more than 55.

Targeted nanoparticle binding & detection in petroleum hydrocarbon impacted porous media

Targeted nanoparticle binding has become a core feature of experimental pharmaceutical product design which enables more efficient payload delivery and enhances medical imaging by accumulating nanoparticles in specific tissues. Environmental remediation and geophysical monitoring encounter similar challenges which may be addressed in part by the adoption of targeted nanoparticle binding strategies. This study illustrates that engineered nanoparticles can bind to crude oil-impacted silica sand, a selective adsorption driven by active targeting based on an amphiphilic polymer coating. This coating strategy resulted in 2 mg/kg attachment to clean silica sand compared to 8 mg/kg attachment to oil-impacted silica sand. It was also shown that modifying the surface coating influenced the binding behaviour of the engineered nanoparticles – more hydrophobic polymers resulted in increased binding. Successful targeting of Pluronic-coated iron oxide nanoparticles to a crude oil and silica sand mixture was demonstrated through a combined quantitative Orbital Emission Spectroscopy mass analysis supported by Vibrating Scanning Magnetometer magnetometry, and a qualitative X-ray micro-computed tomography (CT) visualization approach. These non-destructive characterization techniques facilitated efficient analysis of nanoparticles in porous medium samples with minimal sample preparation, and in the case of X-Ray CT, illustrated how targeted nanoparticle binding may be used to produce 3-D images of contaminated porous media. This work demonstrated successful implementation of nanoparticle targeted binding toward viscous LNAPL such as crude oil in the presence of a porous medium, a step which opens the door to successful application of targeted delivery technology in environmental remediation and monitoring.

English

Crude oil emulsions constitute a major challenge in oil field operations. To resolve this challenge, many researchers have studied crude oil emulsion demulsification patterns in the presence of various demulsifiers. Research is ongoing for discovery of locally sourced biodegradable and inexpensive demulsifiers. The aim of this research is to demusify heavy crude oil emulsion, using locally sourced biodegradable citrus concentrates. The effects of juice concentrates have therefore been studied from three citrus fruit varieties lime, grape and orange on emulsion produced from Basra heavy crude oil. Oil-in-water emulsions were produced from a mixture of heavy crude oil and deionized water in a ratio of 1:100. The mixture was mixed at 13,000 rpm for 5 min. The emulsion formed was mixed with various volumes of juice concentrate (0.05 to 2.0 mL) at 13,000 rpm for 1 min. Demulsification patterns were monitored for a period of 60 min at 5 min interval using the bottle test method. Results show that lime concentrate used at the experimental volumes proved to be an effective demulsifier. Grape concentrate stabilized the emulsion at lower concentrate volumes, but higher volumes resulted in the production of two different emulsions with the less dense emulsion having chocolate colour, showing a typical case of emulsion inversion to water-in-oil (W/O). The orange concentrate caused water in oil emulsion whose stability increased with increasing concentrate volume to be formed. In conclusion, the lime concentrate could be used in breaking crude oil emulsions while the grape and the orange concentrates may be used as emulsifiers in oil spill clean-up or in food and cosmetic Industries. Key words: Demulsifier, emulsion, emulsifier, grape, lime, orange.