Oil Separation Efficiency Research Articles

Hybrid aerogels derived from banana peel and waste paper for efficient oil absorption and emulsion separation

Developing separation materials for rapidly oil absorption and emulsions separation is urgently needed and remains a great challenge. Here, a biomass-derived banana peel/waste paper (BPWP) hybrid aerogel with hierarchical porous structure has been successfully fabricated via combination of freezing-cast, freeze-drying and pyrolysis approach, for application in oil adsorption and water-in-oil emulsions separation. In this hybrid system, the microsheets that derived from banana peel immobilize were immobilized on surface of the waste paper fibers, forming a hierarchical structure. The resulting BPWP aerogels exhibit a compression strain of 75%, high-hydrophobicity (WCA of 149.3°)/underair superoleophilicity (OCA of 0°), and high porosity, which can absorb of free oils in water with high oil sorption capacity of 35–115 times its own weight. Moreover, these aerogels effectively separate various surfactant-stabilized water-in-oil emulsions driven solely by gravity, with high separation efficiency above 99.6% and higher fluxes of up to 8550 L m−2 h−1 than traditional filtration membranes with pressure driven, even the sizes of emulsified droplets are smaller than the pore size of the BPWP aerogels. More importantly, the BPWP aerogels exhibit a superior antifouling property and regenerability for emulsion separation, which match well with the requirements for treating the real emulsions. Due to the advantages of banana peel/waste paper aerogels in rich source and high oil separation efficiency, the obtained banana peel/waste paper aerogel can be a potential candidate in industrial applications and environmental protection. This work opens up a new avenue for design new hierarchical biomass-derived aerogels for a variety of applications including energy storage, sensors and pressure-sensitive electronics.

Use of bacterial biosurfactants as natural collectors in the dissolved air flotation process for the treatment of oily industrial effluent.

The aim of the present study was to investigate the separation of oil from water using a bench-scale DAF prototype with the addition of biosurfactants isolated from Pseudomonas cepacia CCT6659 and Bacillus cereus UCP1615. The best operating conditions for the DAF prototype were determined using a central composite rotatable design. The results demonstrated that the biosurfactants from P. cepacia and B. cereus increased the oil separation efficiency from 53.74% (using only microbubbles) to 94.11 and 80.01%, respectively. The prediction models for both DAF-biosurfactant systems were validated, showing an increase in the efficiency of the DAF process from 53.74% to 98.55 and 70.87% using the formulated biosurfactants from P. cepacia and B. cereus, respectively. The biosurfactant from P. cepacia was selected as the more promising product and used for the treatment of oily effluent from a thermoelectric plant, achieving removal rates ranging between 75.74 (isolated biosurfactant) and 95.70% (formulated biosurfactant), respectively.

Facile fabricate a bioinspired Janus membrane with heterogeneous wettability for unidirectional water transfer and controllable oil–water separation

A novel smart Janus membrane for unidirectional water transfer and oil–water separation is facilely fabricated by coating graphene nanoplatelets (GNs) onto one side of polyethylene terephthalate (PET) fabric through high-temperature and high-pressure method and subsequently grafting phosphoric acid (HP) into the other side of PET fabric. Results suggest that the prepared HP–PET–GNs Janus membrane with heterogeneous surface wettability attributed to the hierarchical structure of membrane shows special unidirectional water transfer property. The water droplet can penetrate across the membrane from the GNs-coated (hydrophobic) side to the HP-grafted (hydrophilic) side, and be blocked to pass through the membrane from hydrophilic side to hydrophobic side. Moreover, the HP–PET–GNs Janus membrane is found to have the maximum water flux and separation efficiency of 2073 ± 207 Lm−2h−1 and 99.5 ± 0.2% for methylbenzene–water mixture, and the maximum oil flux and separation efficiency of 3113 ± 52 Lm−2h−1 and 99.6 ± 0.1% for carbon tetrachloride–water mixture, respectively. The water separation efficiency and oil separation efficiency could arrive at 99.0 ± 0.1 and 99.3 ± 0.2% even after 10 separation cycles, respectively. It is revealed that the obtained Janus membrane has excellent separation capability for separating the layered oil–water mixtures and possesses wonderful recyclability.

Polyphenylene sulfide microfiber membrane with superhydrophobicity and superoleophilicity for oil/water separation

To dispose the increasing oil pollution, tremendous effective ways have been proposed to deal with the oil/water mixture. In this study, polyphenylene sulfide (PPS) microfiber membrane was firstly employed as the substrate for separation. Polyethylene wax (PEW) powder and polytetrafluoroethylene (PTFE) ultrafine powder were simply and effectively introduced on the PPS membrane by employing one-step spray-coating method. The as-prepared membrane displayed excellent oil affinity and water-repellent behaviors. Significantly, the obtained membrane showed long-term stability under various extreme conditions such as strong acid, alkali, salt solutions and high temperature. Moreover, this membrane could maintain high oil flux (above 3500 L/m2 h) and separation efficiency (above 98%) even after 20 cycles of oil/water separation and isolate a wide range of oil/water mixture effectively. The fabrication of superhydrophobic and superoleophilic PPS microfiber membrane presented here can be easily scaled up on a large scale, which will provide attractive potential in practical oil/water separation.

A Novel Architecture for Carbon Nanotube Membranes towards Fast and Efficient Oil/water Separation

Carbon nanotubes (CNT) are robust and proven as promising building blocks for oil/water separating membranes. However, according to classic fluid dynamic theory, achieving high permeation flux without sacrificing other membrane properties is a formidable challenge for CNT membranes, because of the trade-off nature among key membrane parameters. Herein, to relieve the trade-off between permeation fluxes, oil rejection rate, and membrane thickness, we present a new concept to engineer CNT membranes with a three-dimensional (3D) architecture. Apart from achieving high oil separation efficiency (>99.9%), these new oil/water separating membranes can achieve water flux as high as 5,500 L/m2.h.bar, which is one order of magnitude higher than pristine CNT membranes. Most importantly, these outstanding properties can be achieved without drastically slashing membrane thickness down to nanoscale. The present study sheds a new light for the adoption of CNT-based membranes in oil/water separation industry.

Synthesis of activated charcoal from saw-dust and characterization for adsorptive separation of oil from oil-in-water emulsion

ABSTRACTThe paper represents the synthesis process of charcoal from saw dust by chemical activation with different chemical agents like phosphoric acid, zinc chloride, and ferrous sulfate heptahydrate. The synthesized charcoal samples were analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, and BET surface analyser. The adsorption capacity of different charcoal samples was tested to separate oil from the oil-in-water emulsion. Effects of different parameters like adsorbent dosage, contact time and temperature on adsorption of oil from oil-in-water emulsion by synthesized charcoals have been investigated. Under optimized condition, the oil separation efficiency is more than 98%, though it also depends on the initial concentration of oil in the emulsion. Isotherm and kinetic study on adsorption of oil from oil-in-water emulsion have also been studied. Three widely applied isotherm models viz., Langmuir, Freundlich, and Temkin were used to analyze the experimental adsorption data. Different adsorption kinetic models were considered to model the experimental data. Thermodynamics parameters were also evaluated for the adsorption of oil onto the charcoal samples.

Effect of CuFe2O4 Nanoparticles on Fronth Stability in Wastewater Treatment by Flotation

Flotation is a method applied very often in wastewater treatment. One way of improving the efficiency of wastewater treatment by flotation is increasing the quantity and stability of foam. For this purpose, in this paper was studied CuFe2O4 oxide nanomaterial for treatment of wastewater containig oil as pollutant. CuFe2O4 was prepared by coprecipitation method and their structural and morphological characterisation was done by XRD and TEM analyses. In order to evaluate their potential of application in wastewater treatment by flotation were invesigated the separation efficiency of oil from wastewater and the quantity and foam stability.

Novel and recyclable demulsifier of expanded perlite grafted by magnetic nanoparticles for oil separation from emulsified oil wastewaters

Oily wastewater has become a serious environmental problem and attracted global concern. Traditional methods are limited by their low separation efficiency, complicated instrument setup and high energy usage. Therefore, it is imperative to develop cost-effective materials or technologies for treating emulsified oil wastewaters. In this study, the expanded perlite (EP) was firstly modified by 3-aminopropyl triethoxysilane (APTES) to form the EP@APTES, and then magnetic Fe3O4 nanoparticles (NPs) were further grafted onto the surface of EP@APTES to synthesize the novel composite of EP@APTES-Fe3O4. The synthesized EP@APTES-Fe3O4 was employed as an environmentally friendly and recyclable demulsifier for treating emulsified oil wastewaters and its demulsification performance was evaluated. Especially, the effects of pH, demulsifier dosage and salt concentration on oil separation efficiency have been studied detailedly. The demulsification mechanism was also explored. Results showed that synthetic EP@APTES-Fe3O4 has favorable demulsification performance. The oil absorbance in the aqueous phase decreased to the lowest value when 500 mg/L of EP@APTES-Fe3O4 was added into the emulsified wastewaters. Besides, the demulsification efficiency has little difference at different salt concentrations, suggesting the favorable salt resistance of EP@APTES-Fe3O4. What’s more, the EP@APTES-Fe3O4 can be recycled up to 4 cycles without showing significant decrease in emulsion separation efficiency, which can be ascribed to the facts that the EP@APTES-Fe3O4 has good amphiphilicity and can reach the oil-water interface to contact the molecules of asphaltenes and resins; besides, it was positively charged under the conditions of pH 2.0, 4.0 and 6.0, and oil droplets could be effectively attached to the EP@APTES-Fe3O4 via electrostatic attraction. In conclusion, EP@APTES-Fe3O4 can be easily synthesized and recycled, providing a promising and cost-effective demulsifies to remove oil from the emulsified oil wastewater.

Numerical Simulation of Labyrinth Oil and Gas Separator in Vehicle Engine

The working process of oil and gas separator is a very complex gas-liquid two-phase separation movement; it is difficult to obtain internal flow condition using analytical method. In this paper, with DPM, SIMPLE algorithm and random walk model, velocity distribution, pressure distribution, oil droplets motion trajectory and separation efficiency were analyzed by numerical simulation method. This analysis is helpful to understand flow law of gas-liquid two-phase fluid in oil and gas separator，and then optimize separator structure, short its development cycle, which has important application value in engineering.

Oil–Water Separation Using Superhydrophobic PET Membranes Fabricated Via Simple Dip‐Coating Of PDMS–SiO2 Nanoparticles

AbstractThe surfaces of commercially available polyester (PET) and polypropylene (PP) are superhydrophobically modified via the deposition of polydimethylsiloxane (PDMS)‐coated SiO2 nanoparticles (P‐SiO2) and PDMS binder. The adhesion of P‐SiO2 is stronger on PET than on PP due to a stronger chemical interaction between PET and PDMS, which is attributed to the higher surface energy of PET than PP. The waterproof ability and oil separation rate of the P‐SiO2‐coated PET (dip‐PET) membranes are studied as a function of membrane thickness, and the influence of oil viscosity on the oil separation efficiency is investigated. Optimal membrane thickness should be selected in a given environment for the facile oil–water separation and the dip‐PET membrane is chemically stable and can be used repetitively for oil–water separation. Finally, an automated prototype instrument is introduced for the dip‐coating process. It is suggested that our dip‐PET is a promising solution for oil–water separation in real‐world oil‐spill applications.

Recyclable and biodegradable superhydrophobic and superoleophilic chitosan sponge for the effective removal of oily pollutants from water

Superhydrophobic and superoleophilic chitosan sponge (MCTCS) was successfully prepared via a facile freeze-drying method with the assistance of TPP/citral crosslinking and octadecanethiol modification. The three dimensional porous structure endowed the MCTCS sponges with large pore volume and good compressive property. Moreover, the MCTCS sponge could effectively absorb oil with an absorptive capacity up to 60 times of its own weight. More importantly, the MCTCS sponge could selectively absorb the emulsified oils in water effectively, and achieve continuous oil–water separation with the assistance of peristaltic pump. The oil and water separation efficiency was up to 99%. Furthermore, the MCTCS sponge still maintained a highly absorptive capacity after being reused for many cycles and possessed ideal biodegradability. It was believed that the superhydrophobic/superoleophilic chitosan sponge would be a promising absorbent material for the removal of oil from water in environmental remediation.

Improving the performance of silica-based crossflow membranes by surface crystallization for treatment of oily wastewater

Today, hundreds of billions of barrels of oily wastewater is generated per day by a wide range of industrial applications. Depending on its hazardous nature, it is not possible to reuse or discharge the wastewater without any treatment. This study exhibits the fabrication of a ceramic filter, which is designed to obtain high recovery with high filtrate rate during the treatment of oily wastewaters. Tubular type ceramic filter was fabricated using an extrusion technique from local silica source, glass waste, and some organic additives. The length of the ceramic filter is 200 mm where the outer diameter and wall thickness are 12 and 3 mm, respectively. Dried samples were sintered at a temperature of 900, 950, and 1000 °C for 1 and 3 h of time, respectively. The effects of sintering conditions on the crystalline phase pore size and distribution, porosity, and permeability is discussed. The fabricated filters have high corrosion resistance for acidic (pH = 1.5) and basic (pH=13) conditions (<1% mass loss in both acid and basic media). The filtration performances of the ceramic filters are investigated by crossflow microfiltration via transmembrane pressure of 0.5–1 bar for synthetic oily wastewater. The relatively coarse pore size of the ceramic filter produced than the alternatives of the literature, achieves the oil separation efficiency rate up to 99.75%, which is attributed to the surface properties of the produced filter where the surfaces are negatively charged. According to the results, it could be said that the fabricated ceramic filter has high potential for microfiltration applications (oil level of the filtrate obtained is as less as 2 mg/L) and can be used as a support for ultrafiltration and nanofiltration technologies.

Effect of different filtration materials on oil and water separation efficiency

The key to remove oily wastewater by coarse graining is the selection of filtration materials. In this paper, the four kinds of filtration materials were tested the efficiency of oil and water separation, which are walnut shell, ceramsite, oil sand and polyethylene. The results of laboratory experiments showed that walnut shell and oil sands as oil-soluble media had higher separation efficiency. With the increase of sewage flow velocity, the separation efficiency of porous media decreases. With the increase of the thickness of the porous medium, the separation efficiency increases, and the separation efficiency can reach 100% when the thickness reaches a certain value.

A flexible, robust and antifouling asymmetric membrane based on ultra-long ceramic/polymeric fibers for high-efficiency separation of oil/water emulsions.

Polymeric and ceramic asymmetric membranes have dominated commercial membranes for water treatment. However, polymeric membranes are prone to becoming fouled, while ceramic membranes are mechanically fragile. Here, we report a novel concept to develop asymmetric membranes based on ultra-long ceramic/polymeric fibers, with the combined merits of good mechanical stability, excellent fouling resistance and high oil/water selectivity, in order to meet the stringent requirements for practical oil/water separation. The ultra-long dimensions of ceramic nanofibers/polymeric microfibers endow this novel membrane with mechanical flexibility and robustness, due to the integrated and intertwined structure. This membrane is capable of separating oil/water emulsions with high oil-separation efficiency (99.9%), thanks to its nanoporous selective layer made of ceramic nanofibers. Further, this membrane also displays superior antifouling properties due to its underwater superoleophobicity and ultra-low oil adhesion of the ceramic-based selective layer. This membrane exhibits high water permeation flux (6.8 × 104 L m-2 h-1 bar-1) at low operation pressures, which is attributed to its 3-dimensional (3D) interconnected fiber-based structure throughout the membrane. In addition, the facile fabrication process and inexpensive materials required for this membrane suggest its significant potential for industrial applications.

Polydopamine-mediated all-in-one device with superhydrophilicity and superhydrophobicity for one-step oil/water separation and pollutant purification

Polydopamine (Pdop) is coated on copper mesh (Cu mesh/Pdop). Upon heat treatment of the Cu mesh/Pdop, Pdop particles are newly formed at the surface of the Cu mesh/Pdop, which is used as a superhydrophilic mesh. After octadecylamine (ODA) is coated on the heat-treated Cu mesh/Pdop, hierarchical and strong ODA crystals are formed by special interactions between the ODA and the Pdop. The surface morphologies of the ODA crystals are tuned by varying the amount of Pdop particles. Similar results are obtained when the sponge is used as a template in lieu of the Cu mesh, and this sponge is used as a superhydrophobic sponge. A self-floating all-in-one device that simultaneously coexists in water as well as in oil is also prepared by combining the Pdop particle-mediated superhydrophilic mesh and superhydrophobic sponge composites. The self-floating all-in-one device simultaneously exhibits excellent removal performance for heavy metal ions in the water layer and excellent separation efficiency of oil in the oil layer due to its amphiprotic nature.

Optimization of separation of oil from oil-in-water emulsion by demulsification using different demulsifiers

ABSTRACTSeparation of oil from oil-in-water emulsion is a major challenge in petroleum industries during the producing and refining process. The authors investigated characterization of oil-in-water emulsion and subsequently separation of oil from emulsion using different chemical dimulsifiers. The effect of settling time, pH, temperature, and demulsifier dosage on oil separation efficiency has been studied. It was observed that as time, temperature, and chemical dosage increased oil separation efficiency increased. Droplet size distribution of emulsions illustrated that the demulsifier could lead to the breakup of crude oil-in-water emulsions by flocculation and coalescence. More than 98% oil separations were observed with some demulsifiers under optimum operating conditions.

Separation of oil products from aqueous emulsion sewage using a modified nylon–polyaniline membrane

Nylon–polyaniline (nylon–PANI) membranes with different polymerization times have been prepared, and the surface of modified membranes has been investigated. The permeateflux of the initial and modified membranes has been determined with distilled water and aqueous emulsion sewage containing oil products. The specific permeability of the membranes decreases with the increasing time of membrane treatment with ammonium persulfate. The efficiency of oil separation from Inkam-1 emulsion by a nylon membrane was much lower than that by the modified nylon–PANI membranes. The highest oil separation efficiency was observed in a nylon–PANI15 membrane. In general, a nylon–PANI membrane much worse rejected oil products from an Inkam-1 emulsion than from aqueous emulsion sewage. The particle size of the dispersed phase of emulsions has been studied before and after purification by membranes. A membrane with high specific permittivity and separation efficiency can be chosen by varying the polymerization time of nylon–PANI membranes depending on the particle size of oil products in the emulsion.

Digital Prototyping Methodology for Cyclonic Multiphase Flow Separation

Safety and reliability are fundamental requirements for gas turbine engines. Continuous health monitoring and diagnostics devices are prime enablers for the same, and gaining a lot of attention for advancements. Oil debris monitoring is one of the important elements of an engine condition monitoring system. The cyclone separator is the key component of the debris monitoring system which separates air, oil and solid particles. The separation efficiency of various phases determines the cyclone performance and is governed by highly turbulent swirling flow field. Further, the particle capture efficiency depends on successful capturing of the flow field. Cyclone performance enhancement requires a detailed understanding of turbulent swirling multiphase flow field with free and forced vortex interactions. This poses a significant challenge for physical prototyping and demands detailed computational models to resolve the anisotropic structure of a turbulent flow field with multiphase interaction. Detailed investigation of various computational models such as turbulence models, multiphase models, and drag models has been carried out to capture the complex flow physics. A structured computational approach helped to establish a CFD methodology having a close match with experimental findings for all the performance parameters of three phase separation. The methodology is validated with the experimental results with the variation between CFD and experiments observed to be less than 10% for all four performance parameters namely pressure drop, air separation efficiency, oil separation efficiency and particle capture efficiency.

Functionalized Cellulose Networks for Efficient Oil Removal from Oil⁻Water Emulsions.

The separation of oil from water in emulsions is a great environmental challenge, since oily wastewater is industrially produced. Here, we demonstrate a highly efficient method to separate oil from water in non-stabilized emulsions, using functionalized cellulose fiber networks. This is achieved by the modification of the wetting properties of the fibers, transforming them from oil- and water-absorbing to water-absorbing and oil-proof. In particular, two diverse layers of polymeric coatings, paraffin wax and poly(dimethylsiloxane)-b-poly(ethylene oxide) (PDMS-b-PEO) diblock copolymer, are applied on the surface of each individual fiber by a two-step dip adsorption process. The resulting cellulose networks exhibit superhydrophilicity and underwater superoleophobicity and they are mechanically reinforced. Therefore, the described treatment makes cellulose fiber networks excellent candidates for the filtration and subsequent removal of oil from oil-in-water non-stabilized emulsions with oil separation efficiency up to 99%. The good selectivity, reproducibility, and cost effectiveness of the preparation process leads to the production of low cost filters that can be used in oil–water separation applications.

Treatment of surfactant-stabilized oily wastewater using coalescing bed of bagasse fly ash (BFA) as a low-cost filter medium: modelling and optimization of process parameters

In the present study, surfactant-stabilized oily wastewater was separated using a low-cost agricultural waste, bagasse fly ash (BFA) in a packed coalescing bed. Factors such as pH (A), BFA bed height (B) and flow rate of emulsion (C) were the most significant process parameters, affecting the oil separation efficiency by the BFA coalescing bed. The effect of the above parameters on the removal efficiency of BFA coalescing bed was investigated by three-level-three-factor (33) Box–Behnken Design model using response surface methodology. A second-order polynomial model equation was proposed with a high correlation coefficient (R2 = 0.9942), which explained the parametric interactions significantly well. About 84.8% of oil removal efficiency was achieved under optimal parametric conditions: pH0 3, 100 mm bed height and 0.145 dm3/min flow rate. BFA, being almost a free waste material, can be effectively used for the treatment of oily wastewaters.