PURIFICATION OF WASTE FORMATION WATER FROM OIL BY SIMULTANEOUS DESTRUCTION OF REVERSE AND DIRECT OIL EMULSIONS USING NANODEMULSIFIERS

Accurate measurement of the concentration of oil in effluent discharged from ships is necessary so that water pollution regulations are not violated. Detergents used to clean machinery and deck surfaces aboard Navy ships often end up in bilge water and pass through gravitational and coalescence type oil/water separators. These detergents interfere in the solvent extraction and infrared (IR) spectrometry measurement technique for quantifying oil in water. They will absorb the IR energy at the wavelength used in quantifying oil; therefore, a method which can remove such interference, yet accurately measure the concentration of oil in water, is needed. A technique of eluting the solvent extract through silica gel removed most of this interference. Aqueous samples containing Navy oils and a non-ionic detergent in concentrations up to 1000 milligrams per liter were used to evaluate this technique. The solvent extract of these aqueous samples was filtered through silica gel and the IR absorbance of the effluent at 2,930 reciprocal centimeters was measured. The results demonstrated that this technique can yield the true concentration of oil in detergent laden water as long as the ratio of the concentration of detergent to oil is less than 10 to one. This technique can also be applied to quantify oil in water that does not contain detergent.

: The Scranton Army Ammunition Plant (SCAAP) in Scranton, PA, is one of the few industrial facilities capable of forging large caliber projectiles used by the military. To keep the hot (2300 F) freshly forged projectiles from sticking to the forge, a mineral oil based lubricant that has graphite suspended in it is used to lubricate the forge. The spent forging oil along with cooling water collects in trenches under the forges and is sent to an oil water separator (OWS), and the recovered sludge is landfilled. However, the OWS functioned poorly and the concentration of oil in the discharge water often exceeded the permitted limit. During the course of the project, SCAAP installed a skimmer that captures much of the oil, which is recycled. However, even after skimming, the concentration of oil in the water exceeds the discharge limit permitted by the Scranton Sewer Authority. In addition to Scranton, treatment plants, wash racks, fuel depots, industrial operations, and maintenance facilities at U.S. Department of Defense (DoD) activities annually generate millions of gallons of wastewater contaminated with thousands of tons of oily sludge. Collecting and disposing non-recyclable oily sludge is increasingly costly and time consuming. In the Navy, the yearly operation and maintenance (O&M) costs associated with OWSs and bilge oily wastewater treatment system (BOWTS) units are estimated to be $24 million, and the Army estimates that the cost for disposing of oily sludge generated at wash racks alone is $150,000 per base. In the civilian sector, the U.S. Environmental Protection Agency (USEPA) estimates that oily sludge disposal costs $2 billion per year. As an alternative to the current practice (landfill disposal), which is increasingly costly and restricted, on-site bioremediation offers attractive cost savings and eliminates long-term liability associated with landfill disposal.

PAH metabolites in bile, cytochrome P4501A and DNA adducts as environmental risk parameters for chronic oil exposure: a laboratory experiment with Atlantic cod

A fluorescent optical fiber measuring system used to measure the concentration of the mineral oil in water is put forward in this paper according to the mechanism that the mineral oil in watercan emit fluorescence when excited by ultraviolet light. The pulse xenon lamp is used as excitation light source, while the linear CCD is adopted as the fluorescent signal of photoelectric detection components instead of the traditional photomultiplier tube in the system, combining with the optical fiber sensor technology and weak signal detection technology. It also equipped with the data acquisition card to realize data receiving and A/D conversion, using micro computer to store and display the data. This in turn realizes the accurate measurement of the concentration of mineral oil in water. The fluorescence optical fiber measuring system that used to measure the concentration of the mineral oil in water has the characteristics of simply structure, high sensitivity, wide linear range, probe passive and so on. The experimental result shows that this method is completely feasible.

The remarkable stability of water–in–crude oil emulsions is due to the presence of a complex adsorbed layer at the surfaces of the dispersed droplets. Except for its role as a steric barrier, little is known about the in situ properties of this interfacial structure. In this study, new insights into the adsorbed layer are provided by direct micrometre–scale measurements. At low crude content in the bulk where, according to interfacial tension isotherms, there should be little or no surfactants on the droplet surface, the adsorbed layer displays pronounced rigidity and is capable of preventing coalescence and coagulation of the droplets. Such interfaces are highly dissipative and can be well described by the Boussinesq–Scriven model. As the supply of surface active materials in the bulk (i.e. the crude content) increases , the adsorbed layer transforms from a rigid structure to a fluid interface. This fluid layer continues to inhibit coalescence, although signs of weak interdroplet adhesion begin to appear. Under area compression, the fluid interface will discharge micrometre–sized emulsion droplets into the oil phase via a ‘budding’ mechanism.

It has been suggested that oil migrates through reservoir sands in the form of a fine, disperse emulsion of oil in water, and that oil accumulations occur where the stream enters finer-grained rock such as silt or shale. In order to investigate the possible mechanisms, stable emulsions of oil in water were prepared without the use of wetting agents. They consisted of droplets 1/2 to 1-1/2 microns in diameter, in a concentration of 20 to 40 parts of oil per million of water. These emulsions passed freely through filter paper and ordinary passed freely through filter paper and ordinary sand. A plastic tube containing glass beads of 200-microns diameter included a bed 1/2-cm thick of crushed beads 37 to 88 microns in diameter. When the emulsion was passed through this tube, up to 80 percent of the oil was screened out at the coarse-fine interface. The amount removed depended on the contrast in grain size, the nature and the preferential wettability of the media. Similar results occurred when quartz sand was used as the coarse, and crushed sand as the fine medium. This screening did not occur as a result of capillary effects., because the pores were many times the diameter of the droplets. The oil collected as a result of flocculation of the droplets into strings and clusters., and the oil saturation in the pores consisted of masses of droplets with very little coalescence. Possibly electrostatic forces are more important Possibly electrostatic forces are more important than capillary in the behavior of fine, disperse, oil-in-water emulsions. our current ideas on multiphase flow in porous media may not apply to disperse emulsions. Introduction The physical mechanisms of the migration of oil, including the expulsion of oil from the source rock, its migration, and its accumulation in the reservoir rock, are very poorly understood. Most authorities believe that the expulsion of water from compacting shale causes regional flows of water within the pores of the enclosing sediments, and the water somehow carries the oil with it. Hydrocarbons heavier than decane have such a low solubility in water that it is inconceivable that large quantities could have migrated as true solutions. Most subsurface waters have near normal oil-water interfacial tension, so that migration in "solubilized" form as suggested by Baker is improbable. Conventional reservoir mechanics require that oil occupy more than 15 percent of the pore volume in order to exist as a continuous, mobile component. No doubt migration in the continuous phase has occurred frequently, especially secondarily when previously formed oil accumulations have been shifted by tilting of the reservoir rocks. However, such movements should leave residual oil saturations and staining in the flow paths.

The oil production is typically impacted by issues related to the formation of stable water in oil (W / O) emulsions, which have high viscosity and delay water separation. The stability of these emulsions is controlled by the surfactant characteristics of species present in crude oil, which form a molecular layer at the oil & water interface, preventing coalescence between the dispersed droplets. Therefore, a fundamental objective of oil production is to understand which species contribute to the formation of stable emulsions and to determine the best way to treat them. In this context, the primary objective of this paper is to characterize isolated species from the interfacial material (IM) of crude oil and water in oil emulsions, using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, through electrospray in negative mode as an ionization source technique [ESI (-) FT ICR MS] and evaluate their relationship to emulsion stability, thereby contributing to an understanding and improving the efficiency of water separation. In this study, a concentration of 66.6% water per gram of silica gel content was used to achieve optimal performance. The samples emulsion, crude oil, and centrifugally separated oil - were prepared as 5% solutions in heptol (50 : 50 v / v heptane : toluene). The previously prepared wet silica was added to these solutions, and the mixtures were transferred onto glass columns. Elution was carried out using different solvents to separate two fractions: Fraction 1 (more non polar), eluted with heptol, and Fraction 2 (more polar), eluted with methanol : toluene (1 : 2 v / v). The results revealed that the interfacial material isolated from the emulsions contained higher concentrations of oxygen- and sulfur-containing acidic compounds compared to the original crude oil. These compounds are known to contribute to emulsion stability. Overall, the methodology proved effective in isolating interfacially active species from water in oil emulsions and other petroleum samples, fulfilling the objectives of the study.

Using a 53 mm test pipeline, emulsions containing up to 67% Lloydminster heavy crude oil in water hare been transported in laminar and turbulent flow. In combination with viscometry and velocity distribution measurements, the experiments showed that a homogeneous model was appropriate for laminar flows 0/ emulsions with median droplet sizes near 30 microns. Turbulent flow pressure drops could be interpreted with a conventional turbulent pipe flow model. Introduction Pipeline flow of oil in water emulsions occurs widely in field operations and has also been studied systematically in laboratory conditions. Zakin et. al(1) used oils with specific gravities between 0.78 and 0.923 in emulsions formed in a colloid mill. The emulsions were non-Newtonian at oil concentration of 50% by weight and above. Turbulent flow pressure drops were between 8 and 26% lower than values predicted from their laminar flow behaviour and the Dodge-Metzner correlation for turbulent non-Newtonian friction losses. Pal and Rhodes(2) used a mineral oil of comparatively low viscosity and inferred effective viscosities from the laminar and turbulent flow pressure gradients, assuming Newtonian fluid behaviour. With 45% and 55% oil in water emulsions, laminar flow effective viscosities were significantly lower than those in turbulent flow. The droplet size was unknown, however. With heavy crudes, inversion (3,4) of an oil in water emulsion to a water-in-oil emulsion can occur during pipeline flow with a catastrophic increase in pressure drop. On the other hand, Layrisse et. al. (5) found stable emulsions for a wide range of concentrations (to 65% oil) and shear rates with droplets whose mean diameters ranged between 6 and 86 µm. Good agreement was found between viscosities inferred from pipeline pressure drops and values measured with Couette viscometers. The rheology was strongly dependent on droplet size, however, with non Newtonian behaviour evident for smaller droplets, lower shear rates and the highest oil concentration. Turbulent flow predictions appeared to be within ± 20% of the expected values. In contrast with these results, Wyslouzil et. al. (6) found pipeline pressure drops to be significantly lower than values predicted using measured viscosities, in both the laminar and turbulent regions. The deviation was attributed to droplet migration away from the wall, producing a region of depleted concentration. With prolonged recirculation in a closed loop, an instabitity occurred which resembled the inversion reported by Gillies et. al.3. The initial droplet size of the Wystouzil experiments was in the range of 5–10 µm. Gillies and Shook(4) reported experiments conducted with high oil concentrations using laminar flows. Differences between viscometer and pipeline flow viscosities were also attributed to droplet migration and evidence for this was obtained in the form of velocity distributions measured with pitot tubes. In contrast with the droplets in the Wyslouzil et. al. experiments, the droplets were too large to allow their size to be determined photographically. A subsequent investigation, using the same oil, surfactant and preparation technique showed that the volume mean droplet size was approximately 120 microns in the Gillies and Shook (4) experiments.

Alginate-based poly ionic liquids for the efficient demulsification of water in heavy crude oil emulsions

Water-soluble and emulsified petroleum products were removed from water using ultrafine aluminium oxyhydroxide (AOH) and fibrous materials (polypropylene, carbon fibre and basalt) in static and dynamic modes. The adsorption values of water-soluble petroleum products with AOH decrease in the series: diesel fuel – crude oil – gasoline. The efficiency of water purification from dissolved hydrocarbons amounts to 98% for diesel fuel in static modes. Sorption of petroleum products from emulsions is significantly greater and amounts to 15 mg/g of adsorbent under static conditions. The purification efficiency of water containing up to 100 mg/L of petroleum products amounts to 90%. Increasing AOH/emulsion ratio we shorten time of water-oil emulsion destruction and decrease residual concentration of oil in water. The efficiency of the removal of dissolved hydrocarbons and gasoline is about 80% in the dynamic purification process and that of an emulsion – about 90%. At the thickness of a filtering layer of only 1 cm AOH effectively removes both dissolved and emulsified petroleum products. One can use fibrous filtering materials to filter water-oil emulsions. It is shown that filtration of emulsions through the filters filled with carbon fibre and compressed basalt fibre with clay-cellulose binder increases purification efficiency up to 70-80%. Carbon fibre and compressed basalt fibre sorbents proved to be the most effective materials; the purification degree at their application amounts to 70-80%. Compressed basalt fibre is effective in a wide range of linear filtration rates (3-6 m/h) and a minimal thickness of filtering layer is 1 cm without any noticeable loss of purification quality. Combining of ultrafine AOH and fibrous filtering materials in a multilayered adsorbing filter allows one to purify water from petroleum products with various dispersion degrees in a wide concentrationrange. The filter is regenerated with live steam.

According to the Lambert-Beer laws, the fluorescence spectra of oil in water were investigated by measuring excitation-emission matrixes with FS920 fluorescence spectrometer. On the basis of the three-dimensional fluorescence spectra of oil in water, the excitation wavelength of 290nm and emission wavelength of 324nm were chosen for the quantitative analysis of oil in water. The results show that the concentration of oil in water is linearly proportional to the fluorescence intensity in the range of 1ppm-100ppm, and the measurement model of concentration is obtained with the linear correlation coefficient of 0.9993. The artificial samples has also been tested and the results are satisfactory. The recovery is in the range of 92%-106%. The research provides experimental basis for the quantitative analysis of multi-component oil in water.

Chemical flooding has been suggested as an efficient conformance control technique to develop many of thin post-CHOPS heavy oil reservoirs in Western Canada. In-situ formation of oil in water emulsions due to the effect of surfactant/natural soap has been reported as the main mechanism behind chemical EOR. In this work, the effect of surface-modified silica NPs to enhance the efficiency of surfactant to emulsify heavy oil (14,850 mPa.s and 980 kg/m3 at 25 °C, from the Luseland field) in water has been investigated. Bulk fluid screening experiments were conducted using different surfactants and surface-modified silica NPs for selecting the best heavy oil emulsifier. Complementary experiments such as interfacial/surface tension, NP zeta potential and size measurements, and elemental analysis were conducted to understand the interactions between NPs and surfactant molecules. In the absence of NPs, concentration of both anionic and cationic surfactants should be tuned within a narrow window, near CMC, to create stable heavy oil in water emulsions. It was found that there is a threshold for IFT, obtained at the CMC, which should be met to have stable oil in water emulsions. The created oil in water emulsions break easily at surfactant concentrations higher than the CMC, yielding IFTs higher than the threshold. This observation was also seen in a system containing dodecane. At the CMC of both anionic and cationic surfactants, the IFT between dodecane and an aqueous phase is negative, producing stable dodecane in water emulsions for over three months. In the presence of surface-modified silica NPs heavy oil emulsification is achieved at surfactant concentrations much lower than the CMC. In this case, IFT is remarkably (54 %) reduced, well below the threshold value, due to the combined effect of 2 wt. % negatively-charged silica NPs and only 0.1 wt. % anionic surfactant. These results suggest that the repulsive interaction between negatively-charged NPs and anionic surfactant may result in pushing the surfactant molecules back towards the oil-water interface to enhance IFT reduction.

Using a 53 mm test pipeline, emulsions containing up to 67% Lloydminster heavy crude oil in water have been transported in laminar and turbulent flow. Pressure drops, droplet size distributions, viscometry and velocity distribution measurements were made. The results showed that a homogeneous model was appropriate for emulsions with median droplet sizes near 30 microns. Introduction Pipeline flow of oil in water emulsions occurs widely in field operations and has also been studied systematically in laboratory conditions. Zakin et al.(1), used oils with specific gravities between 0.78 and 0.923 in emulsions formed in a colloid mill. The emulsions were non-Newtonian at oil concentrations of 50% by weight and above. Turbulent flow pressure drops were between 8% and 26% lower than values predicted using their laminar flow behaviour. These predictions used the Dodge and Metzner(2) correlation for turbulent non-Newtonian friction which has been largely supplanted by those of Wilson and Thomas(3) and Thomas and Wilson(4). Pal and Rhodes(5) used a mineral oil of comparatively low viscosity and inferred effective viscosities from the laminar and turbulent flow pressure gradients, assuming Newtonian fluid behaviour. With 45% and 55% oil in water emulsions, laminar flow effective viscosities were significantly lower than those in turbulent flow. The droplet size was unknown, however. With heavy crudes, inversion(6,7) of an oil-in-water emulsion to a water-in-oil emulsion can occur during pipeline flow with a catastrophic increase in pipeline pressure drop if the oil wets the pipe wall. On the other hand Layrisse et al.(8), found stable emulsions for a wide range of concentrations (to 65% oil) and shear rates with droplets whose mean diameters ranged between 6 and 86 ?m. Good agreement was found between viscosities inferred from pipeline pressure drops and values measured with Couette viscometers. The rheology was strongly dependent on droplet size, however, and non-Newtonian behaviour was evident for smaller diameters, low shear rates and high oil concentrations. Turbulent flow pressure drops appeared to be within 20% of the predicted values. In contrast with these results, Wyslouzil et al.(9), found pipeline pressure drops to be significantly lower than values predicted using measured viscosities, in both the laminar and turbulent flow regions. The disparity was attributed to droplet migration away from the wall, producing a region of depleted concentration. With prolonged recirculation in a closed loop, an instability occurred which resembled the inversion reported by Gillies et al.(6) The initial droplet size in the Wyslouzil experiments was in the range of 5 – 10 µm. Gillies and Shook(7) have reported experiments conducted with high oil concentrations in laminar pipe flow. Differences between the apparent viscosities in pipe flow and those measured in a Couette viscometer were also attributed to droplet migration and evidence for this was obtained in the form of velocity distributions measured with a pitot tube. In contrast with the droplets in the Wyslouzil et al. experiments, the droplets were too large to allow their diameters to be determined photographically.

The in-situ formation of oil in water emulsions can contribute to the oil mobilization when combined with Steam-Assisted Gravity Drainage (SAGD). The produced fluids in SAGD operations and sand pack SAGD experiments often show the existence of both oil in water and water in oil emulsions. Due to the opaque nature of sand packs, however, it is unclear whether the emulsions are formed in-situ during the flow through porous media or in the production tubing. This study aims at understanding the impact of a surfactant known as "High-temperature Emulsifying Agent" (HEA) as an additive on the SAGD process and the possibility of forming preferred oil in water emulsions. The high-temperature fluid flow experiments are performed in 2.5D glass micromodels which are placed in a custom built compact high pressure-high temperature (HPHT) visual cell. Hot water and HEA solution (3000 ppm concentration) at 82 °C are injected at a constant rate of 5 μl/min. The injected fluid first displaces bitumen in the form of an advancing finger, forming a condensate-bitumen interface which is slowly advancing towards the production port at the bottom end of the model. Hot water initially displaces bitumen from the pores leaving a film of bitumen on the grain surfaces which is eventually removed as the injection continues. Water droplets dispersed in bitumen are observed at the areas experiencing high shear forces, i.e., near the main two-phase front and close to the production port. In contrast to the hot water process, no oil film is observed during the HEA injection. In the presence of HEA solution, oil in water emulsion is formed at the condensate-bitumen interface and ahead of the interface deep in the oil zone. The latter could be the result of corner flow which promotes the fast distribution of HEA solution throughout the model, ahead of the main water-oil interface. This work provides insights on the role of surfactants in forming oil in water emulsions in steam-based bitumen production. A novel HPHT visual cell enables the rapid assessment of solvent-surfactant-steam recovery processes and a better understanding of the active emulsifying mechanism in this system.

We examine the applicability of ureasolutions as a novel cost-effectivechemical for enhanced oil recovery processes. Two sandpack floodingexperiments were conducted using 5 and 10 wt % urea solutions. Anotherflooding experiment was also carried out using the same sandpack withfresh water and used as a reference. Supporting experiments such asinterfacial tension (IFT), viscosity of water in oil (W/O) emulsions,total acid number (TAN), and Fourier-transform infrared (FTIR) spectroscopywere conducted to confirm the generation of in situ surfactants byreacting urea solutions with the naphthenic acids in bitumen and evaluatetheir impact on the oil recovery. The analyses of FTIR, IFT, TAN,and viscosity measurements support the generation of in situ surfactantsthat leads to the formation of stable water in oil emulsions and hencea more stable displacement front resulting in higher oil recovery.