Oil-water Separation System Research Articles

Research on working condition diagnosis method of downhole oil-water separation system with sucker-rod pump

Compared with the rod-pumping oil production system of the conventional pumping unit, the structure of the down-hole oil-water separation system from the rod pump is more complicated, and the down-hole working conditions are worse. Existing technology no longer meets the needs of its downhole condition diagnosis. It seriously affected the production output and economic benefits of the oil field. Because of this, a fault pre-diagnosis method for the downhole oil-water separation system from the rod pump was proposed. Through the theoretical calculation of oil well production and pump efficiency. After field investigation and collection of many suspension point indicators diagrammed for comparison and analysis, the injection pump’s failure probability was 90% above. At this time, the extraction pumps work normally. Therefore, a reverse calculation method is proposed: establish and solve the static/dynamic load model of the production pump, and obtain the load-displacement function of the production pump. The load-displacement function of the suspension point derived from the suspension point indicator diagram is subtracted from the calculated load-displacement function of the production pump to obtain the load-displacement function of the injection pump so that the working condition diagnosis can be performed according to the injection pump work diagram. In the application of 18 wells within the field, the judgment result of injection pump failure and the result of pump inspection coincided with 91.3%, which verified the correctness of the calculation model. This method provides necessary theoretical guidance for the field application and working condition diagnosis of rod pump downhole oil-water separation system and is of great significance for improving the comprehensive benefit of oilfield production.

Fabrication of Photo-Responsive Mesh Membrane with Surface-Engineered Wettability for Oil-Water Separation and Photocatalytic Degradation of Organic Pollutants.

A photo-responsive TiO2-coated stainless-steel mesh membrane (TiO2@SSM), possessing unique surface wettability, was fabricated. This TiO2@SSM membrane is found to be capable of separating oil and water from oily water and has the potential to carry out photocatalytic self-cleaning and/or the degradation of organic pollutants present in water. The fabrication of TiO2@SSM is quite simple: titanium dioxide (TiO2) nanoparticles were spray-coated onto stainless steel microporous mesh (SSM) substrates and annealed at the temperature of 500 °C. The fabricated TiO2@SSM membrane was structurally and morphologically characterized by XRD, FE-SEM, EDX, and elemental mapping. The contact angle measurements using a goniometer showed that the fabricated TiO2@SSM membrane surface is superhydrophilic and superoleophilic in air and superoleophobic under water. This is a favorable wetting condition for the water passing oil-water separation membrane, and this water passing property of the membrane eased the common problem of the fast clogging of the membrane by oil. An oil-water separation efficiency of about 99% was achieved, when the TiO2@SSM membrane was used as the separating medium in the gravity-driven oil-water separation system, unlike the uncoated stainless steel mesh membrane, which allowed both oil and water to pass together. This confirmed that the oil-water separating functionality of the membrane is attributed to TiO2 coating on the stainless steel mesh. The photocatalytic degradation property of the TiO2@SSM membrane is an added advantage, where the membrane can be potentially used for self-cleaning of the membrane's surface and/or for water purification.

Facile fabrication of super-wettable mesh membrane using locally-synthesized cobalt oxide nanoparticles and their application in efficient gravity driven oil/water separation

A functional cobalt (II, III) oxide (Co3O4) nanoparticle coated stainless steel mesh membrane for the application of oil-water separation was fabricated by facile spray coating, where the coating material Co3O4 nanoparticle was locally synthesized by co-precipitation method. The fabricated membrane exhibited the unique surface wettability of in-air superhydrophilicity with static contact angle, θWA= 0°, in-air superoleophilicity with static contact angle θOA= 0°, and underwater superoleophobicity with static contact angle θOW= 160°. The contrasting water and oil wettability of the membrane surface is quite congenial for the separation of oil and water in immiscible oil-water mixture. When this membrane was used as a filtering medium in gravity driven oil water separation system, oil phase retained on the feed side of the membrane, while the water phase permeated through the membrane. In this process, the oil-water separation efficiency as high as 99 % was achieved, which is quite significant considering the simplicity of the membrane fabrication. Also, the membrane remained quite intact in terms of retaining the same level of separation efficiency even after 10 consecutive oil-water separation cycles, which shows the mechanical, structural and chemical robustness of the membrane. The results of this oil-water separation process is explained in the light of the observed surface wettability, that emerge from the three different interfacial energies and hierarchical surface roughness brought about by the spray coating. FESEM images of the membrane surface confirmed the uniform distribution of Co3O4 nanoparticles with average particle size of ∼ 30–50 nm, and the XRD pattern revealed the typical rhombohedral crystal shape of Co3O4. The elemental and chemical compositions of the surface were further substantiated by XPS and FTIR spectra respectively.

Effect of quercetin and oil water separation system on formation of β-carboline heterocyclic amines during frying process of braised chicken drumsticks

The effect of quercetin and oil water separation system on the formation of heterocyclic amines (HAs) was investigated during the frying process of braised chicken drumsticks. The results showed that two β-carboline HAs (β-CHAs) were detected in the chicken samples: 9H-pyrido [3,4-b] indole (Norharman) and1-methyl-9H-pyrido [3,4-b] indole (Harman). β-CHAs content in the chicken samples increased as the cycle times of the frying oil rose (P < 0.05). The addition of quercetin and use of oil water separation system significantly inhibited the formation of Harman (27.3% and 28.2%; P < 0.05) and Norharman (28.7% and 64.1%; P < 0.05), respectively, and the combined use of the two treatments had a better effect (47.0% and 80.2%; P < 0.05). It can be attributed to the lower consumption of β-CHAs precursors (tryptophan) and reduced generation of the intermediates (carbonyl compounds and 1,2,3,4-Tetrahydro-β-carboline-3-carboxylic acid). This provides a promising way for reducing β-CHAs during the frying process of braised chicken products.

Effect of Pore Size and Hydrophobic Coating on Oil-Water Separation System for Grease Trap

Public concern towards solidification of fat, oil, and grease (FOG) through disposed wastes into the drainage system is an unresolved issue to this day. The use of skimmer to separate oil and water form their mixture is a less comprehensive solution. This paper aimed to design the concept and fabricate oil-water separation medium, as well as to analyse the effect of different pore sizes of wire mesh and coating respectively. Water separation system is designed based on Pugh Method, while stainless steel wire mesh is used in analysing the water repellent and oil absorption characteristics. Titanium dioxide is used as coating. Surface characterization and contact angle of droplet were observed using scanning electron microscope and contact angle measurement tools. Hydrophobicity of uncoated stainless steel of wire mesh will increase if the pore size of wire mesh is decreasing in size. The more layers of coating increase the hydrophobicity of the wire mesh in increments with contact angle more than 100⁰. For the cooking oil droplet to expeditiously spread over the mesh surface and rapidly permeate through the mesh less than 1 second, showed the oleophilic nature of the mesh.

Experimental Study on a Novel Axial Separator for Oil–Water Separation

In order to ease the pressure on oil price, the downhole oil–water separation system has been adopted to preseparate the output production. However, both the gravity separator and the conventional ...

Rapid fabrication of textured membrane with super-wettability using simple spray-coating of Pd-doped WO3 nanoparticles for efficient oil-water separation

In this work, a membrane based, water passing, and gravity driven oil-water separation system using a separating membrane, with superhydrophilic-underwater superoleophobic surface wettability is presented. The surface with this unique wettability was realized by spray coating, locally synthesized palladium-doped tungsten oxide nanoparticles on the stainless steel mesh membranes. When oil water mixture comes in contact with the coated surface, the oil-water-solid system enters into Cassie wettability state, due to the micro-nano-hierarchical surface roughness. In the Cassie state, the water partially comes in contact with the air filled pits repels the oil in the oil water mixture, and this leads the surface to become under water superoleophobic. When the coated membrane of the uniquely engineered wettability is used in the oil water separating system, the water in the oil water mixture instantly passed through the membrane, while retaining the oil content on the top, which led to the oil water separation efficiency as high as 99.99 %. In addition to the improved separation efficiency, the fouling up of the membrane is almost completely eliminated, as the oil practically does not come in contact with the membrane surface, and this ensures the durability of the membrane for multiple uses. The reclaimed water could be contaminated with oil borne bacteria, which needs to be removed, and as palladium doped WO3 is a proven visible light active photo-catalyst, the coating of this particular material can pave a way to develop a multi-functional system, that can simultaneously carry out oil-water separation, and demineralization of organic pollutants from the filtered water, with visible light irradiation. The morphological and structural characterizations of the surface along with the wettability studies were carried out to elucidate the high separation efficiency of the coated membrane.

In situ oils/organic solvents cleanup and recovery using advanced oil-water separation system

Removing contaminants from wastewater is critical towards resolving global water pollution problems. However, the variety of oily contaminants composition, and the unsatisfactory performance and efficiency of current separation systems are still big challenges, thus developing efficient and scalable oil-water separation (OWS) methods is needed. Here, the performance of a novel pilot-scale oil-water separator skimmer (OWSS) prototype is fully investigated using an upflow fixed bed column system packed with polypropylene (PP) fibrous sorbent materials for dual continuous OWS and in situ oils/organic solvents recovery. The mechanism of oil sorption by the PP fibrous sorbents, as well as capillary and vacuum assisted oil flow within the inter-fiber voids is fully explored. A series of pilot-scale column experiments were performed with different bed heights (7.5–30 cm) and using different types of oil/solvent in order to determine their influence on the oil flux, OWS efficiency and recovered organic solvent purity. The OWSS provided excellent and stable performance. A trade-off relationship between oil flux and OWS efficiency can be obtained: The maximum flux was attained at the lowest sorbent bed height (7.5 cm), while the maximum OWS efficiency (>99%) was achieved at the highest sorbent bed height (30 cm). The materials’ morphology and wettability were examined showing outstanding stability and recyclability, which demonstrates their efficient integration into the overall OWSS. This study is expected to provide significant insights into the feasibility and scalability of an advanced, environmentally friendly, and relatively cost-effective OWS system, towards promising industrial implementation to overcome large-scale oil spill cleanup and oily wastewater treatment shortcomings.

Fully Automatic Solar Powered Oil-Water Separation System for Grease Trap Controlled by Arduino: A Conceptual Design

Pipeline clogging in food premises frequently emerges, particularly in small range restaurants. Fat, oil and grease (FOG) disposed from food premises becoming root cause for this issue and pollute drainage system. The aimed of this project was to remove the FOG from wastewater and with automatic oil disposal system using renewable energy. Power input system was improved by designing and developing the solar tracker system for automatic oil disposal grease trap controlled by Arduino and light radiation sensor. The solar tracker was designed based on engineering design methodologies including the survey, house of quality (HOQ), morphological chart and pugh method to ensure the engineering criteria achieved with the concern of customers satisfaction. Light radiation sensor was used to improve the efficiency of solar tracker by detecting the location of sun and Arduino will give a command to the motor based on a signal received from a light radiation sensor. Dual axis solar panel with light radiation sensor gave significant reduction in terms of time consumption used to absorb energy from the sun with average amount of voltage of approximately 1.82 volt compared to fixed solar panel which has average amount of voltage of approximately 1.35 volt. The newly designed dual axis solar tracker also has advantage on flexibility where it can be put at different angle and places.

Gravity-driven and high flux super-hydrophobic/super-oleophilic poly(arylene ether nitrile) nanofibrous composite membranes for efficient water-in-oil emulsions separation in harsh environments

Nanofibrous membranes with super-wetting feature exhibit promising application for oil/water emulsion separation, but achieving durability and high separation efficiency in harsh environments remains challenging. Herein, we developed a facile and effective strategy to prepare super-hydrophobic/super-oleophilic nanofibrous composite membranes, which perfectly integrated the two processes of electrospinning and fixing hydrophobic TiO2 nanoparticles to the surface of interconnected poly(arylene ether nitrile) (PEN) nanofibers using EVO-STIK serious glue. As a result, the constructed super-hydrophobic PEN/P–TiO2 nanofibrous composite membranes (WCA = 165 ± 2.4°) exhibited excellent separation efficiency (99.75 ± 0.12%) under gravity drive, with extremely high separation flux of 6853.65 ± 274 L/m2·h for surfactant-free emulsions and 3531.62 ± 231 L/m2·h for surfactant-stabilized emulsions. More importantly, the obtained PEN/P–TiO2 nanofibrous composite membranes showed stable super-hydrophobic feature and oil/water emulsion separation performance in harsh environments such as strongly corrosive solutions, physical damage, and high/low-temperature systems. Therefore, the super-wetting nanofibrous membranes with easy-handling, durable, and efficient oil/water separation performance could find potential application for emulsified oil-water separation system in harsh environments.

Hydrophobically modified chitin/halloysite nanotubes composite sponges for high efficiency oil-water separation.

A high-performance oil-water separation device that built by environment-friendly materials is a promising strategy to solve water pollution problem. In this study, we developed an oil-water separation system with chitin/halloysite nanotubes (C/HNTs) composites. C/HNTs were crosslinked by epichlorohydrin and freeze-dried, then a porous sponge was formed. The C/HNTs sponge was modified to be hydrophobic via immersing into bromohexadecane ethanol solution. The surface structure, mechanical properties, microstructure, oil absorption and oil-water separation ability of the C/HNTs sponge were investigated. The addition of HNTs significantly increased the compressive strength of chitin sponge without influence on porous structure. IR spectra indicated the successful coating of bromohexadecane on the C/HNTs sponge surface, which enabled the hydrophobicity and lipophilicity of this construct. The inside construct of the C/HNTs sponges were full of interconnected pores, and the pore size ranged from 250 to 500 μm. The absorption capability for various oil and grease were measured, including methylbenzene, sunflower seed oil, carbon dichloride, n-hexane, chloroform and acetone. It is found that the total amount of chloroform absorbed by a C/HNTs sponge was ~11.23 times of the sponge's weight, and the absorption for hexane was ~3.94 times of the sponge's weight. The sponge also exhibited an excellent oil-water separation ability with as high as 98.7% separation efficiency. All the results suggested that the chitin/HNTs sponges with improved mechanical property would have a great potential in oil-water separation.

Simultaneous complementary oil-water separation and water desalination using functionalized woven glass fiber membranes

A simple simultaneous complementary oil-water separation and water desalination system is designed using grafted glass fiber (GF) membranes. Non-fluorinated trialkoxysilanes are grafted to form superhydrophobic and superhydrophilic GF membranes, respectively. Zwitterion sulfobetaine was also synthesized and grafted on the glass fiber to make a superhydrophilic glass fiber membrane. The superwetting grafted GF membranes which are superhydrophobic had a water contact angle of 152° and high separation efficiency (>99%) for ten cycles and the superhydrophilic had an underwater oil contact angle of 156° and high separation efficiency (>98%) for ten cycles. The zwitterionic glass fiber membrane also exhibits excellent removal performance for heavy metal ions and nitrate ions from the water layer. This method is simple and scalable, and provides a versatile way for designing devices that achieve both oil/water separation and water desalination simultaneously.

Underwater superoleophobic modified polysulfone electrospun membrane with efficient antifouling for ultrafast gravitational oil-water separation

Abstract A superoleophobic underwater modified electrospun membrane is produced via a novel effective modification method, to overcome the hydrophobicity and fouling propensity of the electrospun polysulfone (PSf) membrane. In which the fabricated PSf electrospun membranes were immersed in different NaOH concentrations (0, 0.1, 0.5, and 1 M) at different temperatures (25, 50, 75, and 100 °C) for different time (1, 3, 5, 7 h) to produce 64 modified membranes. Based on the characterization of the modified membranes, the best-modified membrane was chosen and was investigated in the oil-water separation system. More importantly, the best-modified membrane (M64) exhibits underwater superoleophobic feature and it could effectively separate soybean oil and hexane-water mixtures with a superior water flux of 11,865 and 14,016 LMH after the 5th cycle under a gravity-driven process, respectively. Moreover, the membrane possesses remarkable oil-water separation efficiency with more than 99.99% of oil rejection, where soybean oil and hexane content in the filtrate after the 5th cycle were less than 3 and 1 ppm, respectively, which is lower than the acceptable limit of 10 ppm. Also, the modified membrane exhibited antifouling properties with a water flux recovery ratio of 94 and 96.8% after the 5th filtration cycles of soybean oil and hexane-water mixtures. Overall, this study introduces a simple and effective method to overcome the hydrophobicity of the PSf electrospun membrane and enhance the antifouling property.

A new submarine oil-water separation system

In order to solve the oil field losses of environmental problems and economic benefit caused by the separation of lifting production liquid to offshore platforms in the current offshore oil production, from the most basic separation principle, a new oil-water separation system has been processed of adsorption and desorption on related materials, achieving high efficiency and separation of oil and water phases. And the submarine oil-water separation device has been designed. The main structure of the device consists of gas-solid phase separation device, period separating device and adsorption device that completed high efficiency separation of oil, gas and water under the adsorption and desorption principle, and the processing capacity of the device is calculated.

Main devices design of submarine oil-water separation system

In the process of offshore oil production, in order to thoroughly separate oil from produced fluid, solve the environment problem caused by oily sewage, and improve the economic benefit of offshore drilling, from the perspective of new oil-water separation, a set of submarine oil-water separation devices were designed through adsorption and desorption mechanism of the polymer materials for crude oil in this paper. The paper introduces the basic structure of gas-solid separation device, periodic separation device and adsorption device, and proves the rationality and feasibility of this device.

Pouring‐type gravity‐driven oil–water separation without water bridge

Oil pollution brings great challenge to environmental protection. Utilising oil-water separation device to separate and recycle oils is an environment-friendly approach to dispose mixtures containing oils. Pouring-type gravity-driven oil-water separation method based on extremely wettable materials is an interesting area of research because of its high separation velocity, selectivity and purity. However, the presence of water bridge results in low separation efficiency. Herein, the authors first synthesised a facile etching method and a dipcoating method to fabricate contrary extreme wettability sponges including superhydrophilic-underwater-superoleophobic (SHI-U-SOO) sponge and superhydrophobic-superoleophilic (SHO-SOI) sponge. Accordingly, they designed a three-way oil-water separation system whose left and right bottom tubes were installed with the SHI-U-SOO sponge and the SHO-SOI sponge, respectively. Water and oil separately flow out from the left and right tubes, thereby eliminating the water bridge and increasing separation efficiency, and still having ideal separation selectivity and separation purity. The developed three-way oil-water separation system has promising application prospects in disposing oil spills, oil leakage from factories and industrial effluents.

Effects of geometrical parameters of an oil-water separator on the oil-recovery rate

As the economical and environmental damages due to the accidental oil-spills in marine environment increase gradually, more active countermeasure needs to be developed. In this respect, in the present study, we propose a new design of oil-water separation system and investigate the effects of several geometrical features on the oil-recovery rate, based on a two-dimensional numerical simulation. The working mechanism of current separator is to utilize the density difference between the oil and water, which is strengthened by adding momentum to the oil-water mixture flow through a “U-shaped” passage. Along the flow passage, we locate additional parts such as baffle plate, weir plate, and water outlet. While optimizing the conditions of these to maximize the oil recovery, it is found that the formation and stable retention of water layer between the water outlet and weir plate is critical to separate and store the above-layered oil. Finally, these findings are further confirmed with a basic experimental test with a three-dimensional oil-water separator model.

Fabrication and Wettability Study of WO3 Coated Photocatalytic Membrane for Oil-Water Separation: A Comparative Study with ZnO Coated Membrane

Superhydrophilic and underwater superoleophobic surfaces were fabricated by facile spray coating of nanostructured WO3 on stainless steel meshes and compared its performance in oil–water separation with ZnO coated meshes. The gravity driven oil-water separation system was designed using these surfaces as the separation media and it was noticed that WO3 coated stainless steel mesh showed high separation efficiency (99%), with pore size as high as 150 µm, whereas ZnO coated surfaces failed in the process of oil-water separation when the pore exceeded 50 µm size. Since, nanostructured WO3 is a well known catalyst, the simultaneous photocatalytic degradation of organic pollutants present in the separated water from the oil water separation process were tested using WO3 coated surfaces under UV radiation and the efficiency of this degradation was found to be quite significant. These results assure that with little improvisation on the oil water separation system, these surfaces can be made multifunctional to work simultaneously for oil-water separation and demineralization of organic pollutants from the separated water. Fabrication of the separating surface, their morphological characteristics, wettability, oil water separation efficiency and photo-catalytic degradation efficiency are enunciated.

Underwater superoleophobic mesh based on BiVO4 nanoparticles with sunlight-driven self-cleaning property for oil/water separation

There is an increasingly significant issue on oil/water separation in modern chemical industry and environmental protection on account of the frequent oil spills and large amounts of oily industrial wastewater. Herein, we demonstrate an underwater superoleophobic BiVO4 coated mesh with sunlight-driven self-cleaning property for oil/water separation. The as-prepared coating has micro/nano structures and shows underwater superoleophobicity for various oils and organic solvents. It also exhibits excellent durability against abrasion, cavitation erosion and ultra-low temperature. Such coating can be used in separation of oil/water mixtures and further applied in a continuous oil-water separation system. More importantly, the BiVO4 coating can decompose organic contaminants in water and those absorbed on the surface under simulated solar irradiation, thus make both water and the coating clean. All these features make the BiVO4 coated mesh an ideal candidate for potential application in water contamination treatment.

Structural optimization of downhole oil-water separator

Downhole oil-water separator is the most important component of downhole oil-water separation system. Its structure has great effects on oil concentration of underflow (OCU) thus requiring further optimization. This work aims to propose an optimization method for the structural optimization of downhole oil-water separator that consists of two series de-oiling hydrocyclones. Firstly, the significant factors influencing OCU are identified by two-level Plackett-Burman Design (PBD) with twelve factors. Then the central levels of the five significant factors identified from PBD are determined by steepest ascent design. Secondly, response surface methodology (RSM) is used to establish the second order model between the OCU and five significant factors for the implementation of particle swarm optimization (PSO). Finally, the optimal structural parameters are obtained by PSO algorithm. Computational fluid dynamics (CFD) is employed to calculate the OCU for each particular case and analyze the separation performance variations before and after optimization. The simulation results show that compared with the original geometry and the best geometry in CCF design, the OCU of the optimized decreases. And the separation performance of the optimized geometry is remarkably improved for the oil droplets whose particle sizes are smaller than 35.78µm. Furthermore, laboratory experiments have been conducted to validate the proposed optimization method. The experimental results confirm that the OCU also reduces following the proposed optimization method. It can be summarized that PSO algorithm combined with PBD, steepest ascent design and RSM can be an effective method for the structural optimization of the downhole oil-water separator.