Oil-water System Research Articles

A fully-implicit hybridized discontinuous Galerkin spectral element method for two phase flow in petroleum reservoirs

A hybridized discontinuous Galerkin method with high order spectral element discretization is presented for modeling multiphase immiscible 2D fluid flow in petroleum reservoir simulations. The time dependent nonlinear governing equations for reservoir simulation are presented, and a fully coupled implicit time stepping procedure is implemented using a high order W-Rosenbrock algorithm. For incompressible fluids considered in the present study, the governing PDE's include an elliptic PDE for the pressure field and a parabolic convective diffusion equation for the saturation (water volume fraction) in a two phase oil-water system. The PDE systems are coupled through the highly nonlinear relative permeability and capillary pressure functions relating the fluid velocities of individual species to the individual species pressures and saturations. With HDG/spectral element (HDGSEM) spatial discretization of the coupled governing equations, the system constitutes an index 1 differential algebraic equation. It is shown that the W-Rosenbrock algorithm in combination with the HDGSEM method yields an efficient and effective solution procedure which demonstrates robust, high order temporal accuracy.Numerous physical tests cases are presented demonstrating that the versatility of this approach is sufficient to address the challenges in modeling heterogeneous permeability fields and geologic features of arbitrary shape with discontinuous permeability functions. It is also capable of resolving the sharp time dependent displacement fronts in oil-water systems encountered in secondary oil recovery. It is demonstrated that the high order polynomial basis functions (up to 12th order) used in the HDGSEM algorithm have the ability to resolve complex geometry and achieve accurate results utilizing a simple Cartesian mesh for non-conforming geological features. Eliminating the need to re-grid and conform the mesh to the boundaries of different geological features greatly simplifies the workflow for petroleum engineers.

Construction of Gemini composite based on TiO2 pillared montmorillonite for efficient oil-water separation

Owing to the changeable components of oil–water system and the inflexible limitation of available materials during oil–water separation, the treatment of oily wastewater with wide pH, large discharge and high COD value remains a great challenge. In this study, a simple strategy was used to construct Gemini composite based on TiO2 pillared montmorillonite. The resultant montmorillonite-based Gemini composite (QATMt-x) exhibited high surface area (116.54 m2 g−1), surface potential (18.8 mV at pH2), good acid and alkali resistance, amphiphilic-multifunctional surface, and defective layered structure and, as a result, delivered high capability (ED ≥ 96 %) and long cyclic life for oil–water separation. More significantly, detailed mechanism studies reveal that the crucial reasons of oil–water separation on microemulsion and aqueous containing organic contaminant are demulsification through electron capture of the grafted chitosan, and adsorption by lipophilic saturated alkanes, titanium hydrates, (metal) hydroxyl and amine group, respectively. Hence, QATMt-x is particularly suitable for efficient demulsification in acidic media (pH 2) and for the adsorption of ecotoxic organic substances (e.g., perfluorooctanoic acid, methyl blue). In short, construction of Gemini surfactants based on low-cost inorganic carriers would offer new strategies in exploring amphipathic dual-functional layered structures for simultaneously efficient separation of multisystem oil–water scenarios.

A Gemini-Type Superwettable Separator for Consecutive Purification of Water and Oil Phases from Oil-Water Mixtures and Emulsions.

Oil pollution results from daily activities and a variety of industries have caused not only severe environmental problems but also wastage of valuable petrochemical resources. Separation based on superwettable materials holds promise; however, practical applications of a single type of superwettable materials were often limited due to their ability in treatment of complicated oil-water systems. Herein, a Gemini-type separator was created through the cooperation of two kinds of superwettable sand particles with opposite wettability, i. e., one is superhydrophobic whereas the other is superhydrophilic. Cooperatively by the two types of superwettable sand, consecutive separation and purification of both water and oil phases from complicated oil-water systems (e. g., water mixed with a lighter or denser oil, water emulsified in oil, oil emulsified in water, and/or a combination of them in one batch) could be achieved with high flux and superior efficiency just in one single operation unit.

Inhibitory influence of amino acids on the formation kinetics of methane hydrates in oil-water and oil-brine systems

This experimental study evaluates the inhibition performance of kinetic hydrates inhibitors (KHIs) of three amino acids, namely: glycine, proline, and alanine. It includes the performance comparison with the conventional inhibitor i.e., polyvinyl pyrrolidine (PVP) on methane (CH4) hydrate in oil systems in two different systems, i.e., deionized and brine water systems. The experiments were conducted in a high-pressure hydrate reactor replicating subsea pipeline conditions, i.e., the temperature of 274 K, pressure 8 MPa, and concentration of 1 wt%, by applying the isochoric cooling technique. The formation kinetics results suggest that all the studied amino acids effectively worked as kinetic inhibitors by potentially delaying CH4 hydrate formations due to their steric hindrance abilities. The interesting phenomenon was observed that the different studied amino acids behave differently in the brine-oil and deionized water-oil systems due to their side chain interaction. In a deionized water-oil system, glycine gives the highest inhibition performance by reducing the hydrate formation risk. On the contrary, in the brine-oil system, proline showed a significant inhibition effect. It should be noted that both glycine and proline were giving almost similar inhibition performance compared to the conventional hydrate inhibitor PVP, however glycine and proline significantly reduced CH4 consumption into hydrate due to their high surface active under CH4 conditions, which strengths the surface tension of the liquid/CH4 interface.Furthermore, according to the findings, it shows that increased side alkyl chain lengths of amino acids increase the efficacy of their kinetic hydration inhibition performance due to better surface adsorption abilities. The amino acids' ability to suppress growth is also linked strongly with hydrophobicity and alkyl side chain length. The findings of this study contribute significantly to current efforts to limit gas hydrate formation in offshore pipelines, particularly in oil-dominant pipelines.

PH/temperature-responsive salt-tolerant Pickering emulsion formed by PNIPAM-modified chitosan particles

HypothesisNatural polymer chitosan (CS) has been widely used as emulsifier due to its good stability, salt-resistant, and stimuli-responsive demulsification. However, chitosan is a hydrocarbon structure molecule containing -NH3+ and -OH with low surface activity, which is mainly suitable for some specific oil-water systems such as corn oil and sunflower oil. Appropriate hydrophilic-hydrophobic modification of chitosan by PNIPAM not only increases its surface activity but also introduces a temperature response on chitosan. ExperimentsPickering emulsions (O/W) formed by CS-PNIPAM were prepared. The stability and response performance of the emulsions were investigated by observing the macroscopic states, microscopic images, droplet size distributions, emulsion emulsification indices, water partition rates, etc. Molecular dynamics and dissipative particle dynamics simulations were used to reveal the distribution pattern of the emulsifiers at the water-oil interface and clarify the stabilization and pH/temperature response mechanism of the emulsions. FindingsCS-PNIPAM performs excellent emulsification in various oil phases. The addition of salt ions enhances the stability performance of the emulsion. At low pH, CS will be protonated to break the emulsion, while increasing the pH will deprotonate CS and reform the emulsion. Also, the increase of temperature to 80 °C leads to emulsion breakage due to the agglomeration of PNIPAM.

Theoretical basis and experimental verification for evaluating the distribution of engineered nanoparticles in water-oil system

The distribution of nanoparticles between aqueous and organic phases is universally considered as the starting point in predicting the fate and bioavailability of engineered nanoparticles in the environment. However, the theoretical basis for determining the distribution of nanoparticles in the immiscible water-oil system remains unclear. Here, for the first time, theoretical calculations were conducted to illustrate the underlying mechanism. It was suggested that the distribution of nanoparticles was largely controlled by the surface charge, particle size and surface hydrophobicity, and the water-oil interface was not the favorable phase for nanoparticles until a size threshold (10 nm) was met and the particle surface became amphiphilic. The theoretical results were verified by the experimental approaches of different nanoparticles distributed in the water-octanol mixture. The neutralization of a charged surface led to enhanced distribution into octanol for hydrophobic nanoparticles (e.g., aqueous C60), yet it had little effect on hydrophilic nanoparticles (e.g., fullerol). More nanoparticles were trapped at the water-oil interface when size grew larger (e.g., Ag-CIT and Au-CIT with citrate) and the surface rendered amphiphilic by polymeric coatings (e.g., Ag-PVP with polyvinylpyrrolidone), though larger hydrophobic nanoparticles like aqu-nC60 tended to stay in the octanol. The surface charge and hydrophobicity may have an important impact on the path-dependent distribution of nanoparticles in water- octanol system. The mechanistic insights based on theoretical calculations and experimental approaches will facilitate the accurate prediction of the distribution of engineered nanoparticles in biological and environmental systems.

The effect of climbing film on molybdenum disulfide nanosheets flooding in the tertiary oil recovery

With the development of nanotechnology, nanomaterials have shown good potential for enhanced oil recovery, which is of great significance for oil and gas production. Compared with nanoparticles and nanoemulsions, nanosheets have higher interfacial activity due to their two-dimensional structure, which can form a climbing film on the interface of oil-water and efficiently improve oil recovery. However, the influencing factors of the film-climbing effect and the relationship between the film-climbing effect and enhanced oil recovery are still not clear.In this paper, small-sized water-soluble nanosheets which were molybdenum disulfide (MoS2) nanosheets (30–50 nm) were synthesized using a one-step hydrothermal method, which have strong stability during the flooding test. And then, modifiers with different carbon chain lengths were used to modify the hydrophile-lipophile balance (HLB) of nanosheets.Next, the influencing factors of nanosheets' climbing film were discussed, and the two-phase height index was innovatively used to characterize the strength of the nanosheets climbing film in the oil-water system. The results show that the longer the carbon chain length of the modifier, the closer the nanosheets are to neutral wet with stronger interfacial activity. In addition, molybdenum disulfide nanosheets can produce a climbing film at the oil-water interface, which is related to salinity, concentration, and diameter of test jar. In a word, the oil displacement efficiency can be characterized by the two-phase height index, and the higher the index, the higher the oil displacement efficiency. This makes us fully realize the importance of climbing film in tertiary oil recovery, and provides a new method for the effective development of oil and gas resources.

A novel oil-water microemulsion strategy for controllable synthesis of large mesoporous carbon nanoparticles

Recently, the carbon nanoparticles with defined architecture, small particle diameter and large mesopore size, have aroused people's enormous interests on account of their laudable properties. Here, it is novel mesoporous carbon nanoparticles (MCNs) that have been successfully fabricated in a neoteric oil-water microemulsion system, which is developed to synchronously adjust the surface roughness, particle diameter, and large mesopore size through accommodating the emulsion polarity. Besides, pentanol as a cosurfactant not only significantly affects the evolution of mesopore size but also acts an vital role in the interfacial interaction between carbon precursors and soft templates, leading to the fluffy growth of particles. Interestingly, an extended swelling-penetration mechanism is subtly put forward to explain the formation and transformation of MCNs, which would provide a simple and unique ingenuity for this material species. Remarkably, to fulfill the multifunctional properties of such MCNs, MCNs-2 is further utilized as a fluorescent probe platform to detect mutated nucleic acids with high selectivity and low detection limit, as well as a medical carrier to work well in drug delivery system with high adsorption/release properties and extremely low cytotoxicity, which would empower it with luciferous prospects for the applications in biosensor and biomedical fields.

Upgrading the Properties of the Crude Oil-Water System for EOR with Simultaneous Effects of a Homologous Series of NanoGemini Surface-Active Ionic Liquids, Electrolytes, and pH.

This study investigated the simultaneous effects of electrolytes, NaCl and MgCl2 electrolytes, individually and as a mixture, and pH on a homologous series of imidazolium nano-Gemini surface-active ionic liquids (GSAILs), [C4im-C m -imC4][Br2], where m = 2, 4, and 6. These can improve the properties of the crude oil-water system and consequently enhance the oil recovery. The results precisely revealed that interfacial tension (IFT) and critical micelle concentration were initially decreased with electrolyte concentration up to 55.7 and 58.6%, respectively, in comparison to the salt-free condition, followed by a slight increase. Moreover, adjusting the pH can provide a further improvement so that 79.2% IFT reduction is attained at pH 9.5 compared to that at the natural pH and that GSAILs show high stability in the pH range of 2.5-9.5. Meanwhile, aqueous solutions of crude oil and electrolyte presented 1 day emulsification indices within 43-53%, followed by minor changes after 1 week. Interestingly, the emulsification index of 77.1% was attained at pH 9.5. Surface wettability was also favorably altered from oil-wet to water-wet with the nanoGSAILs. The findings of this study help gain a better understanding of the effects of nanosurface active materials to improve oil extraction under reservoir conditions.

Main Control Factors and Hydrocarbon Accumulation Model of Volcanic Oil Reservoirs with Complex Oil–Water Relationships: A Case Study of the Carboniferous in the Chepaizi Uplift, the Junggar Basin, China

In order to study the main control factors of volcanic reservoirs with complex oil–water relationships, the Carboniferous in the Chepaizi Uplift of the Junggar Basin was taken as an example and the lithofacies characteristics, main control factors, and hydrocarbon accumulation model of volcanic reservoirs were investigated by combining the petroleum geology with field testing (data of core analysis, well logging, formation testing, and production testing). The results show that the Carboniferous in the Chepaizi Uplift experienced three stages of volcanic activities and developed seven volcanic lithofacies bodies, distributed in a bead-string connected planar form along the Hongche fault. There is no unified oil–water interface across the whole study area and there are multiple oil–water systems within one fault block. The Carboniferous volcanic reservoir experienced two stages of hydrocarbon accumulation from two different source rocks. The distribution of faults penetrating hydrocarbon kitchens and source rocks controls the macro-scale distribution of reservoirs. The physical properties of reservoirs affect the pattern of oil and water differentiation in volcanic rock bodies, while the lithofacies body-controlled hydrocarbon accumulation mode highlighting “one rock body for one reservoir” determines the distribution of reservoirs. The matching between the paleo-structure and hydrocarbon accumulation stage controls the accumulation and adjustment of hydrocarbon distribution. The Permian source rocks in the Shawan Sag serve as the lateral hydrocarbon supply and hydrocarbons accumulate in the Carboniferous structural-lithologic traps, which are summarized as the two stages of hydrocarbon accumulation of newly generated hydrocarbons into older reservoir rocks. This study of the hydrocarbon accumulation pattern in volcanic rocks aims at guiding the development of Carboniferous reservoirs with complex oil and water relationships in this area.

Development of a new hydrophobic magnetic biochar for removing oil spills on the water surface

More technologies are urgently needed for combined use to effectively eliminate the effect of oil spills, an environmental problem of widespread concern. Among these technologies, sorption methods are available to remove residual oil and prevent the further spread on the water surface. In this study, biochars, prepared from different feedstock materials and pyrolysis temperatures, were screened and further modified to improve their application in the water environment. Among cornstalk biochar (CSBC), corncob biochar (CCBC), Sophora sawdust biochar (SSBC), and rice husk biochar (RHBC), the CSBC had excellent oil sorption capacity, especially prepared at 350℃ (CSBC350), which has a complete and full pore structure. Furthermore, magnetic and silane agent modifications of CSBC350 (OMBC) were performed to enhance the properties of the magnetic field controllability and hydrophobicity to increase oil sorption. The OMBC exhibited satisfactory oil sorption capacities to crude oil, diesel oil, and engine oil in the water-oil system of 8.77 g g−1, 4.01 g g−1, and 4.44 g g−1, respectively. The sorption process of CSBC350 and OMBC complied with the pseudo-second-order kinetics (R2 > 0.97) and the Langmuir isotherm models (R2 > 0.80) based on the highest regression coefficients. The sorption mechanisms are dominated by hydrophobic forces, pore intercepts, and hydrogen-bond interactions. The biochar adsorbent can availably cooperate with other physical methods to eliminate oil contaminants, which can be an outstanding fuel source for producing heat.Graphical

Reduced graphene aerogels as energy efficient selective oil sorbents

Graphene aerogels are widely used in the oil–water system as they possess high internal surface area and super-oleophilic properties. However, they tend to absorb water along with oil, and to overcome this problem; surface coatings are generally employed using expensive fluoro-silane compounds. It leads to an increase in production costs and environmental concerns. Herein, we report super-hydrophobic 3D graphene aerogels as selective oil sorbent for oil–water​ separation. The reduction of oxygen-containing functional groups on the surface of graphene aerogels has been studied and characterized with FTIR. The thermal treatment of up to 700 °C was carried out using an in-house flow system. The gases used to reduce graphene oxide aerogel are H2 and N2 with an optimized ratio of 5:95. The presence of H2 significantly decreased the oxygen-containing functional groups in graphene aerogel. The increase in the C/O ratio results in higher uptake capacity due to higher surface area and pore volume. The thermal reduction yields a C/O ratio of 24:1, slightly higher than most reported values.

Breakup dynamics and scaling laws of liquid metal droplets formed in a cross junction

The formation of liquid metal droplets in a microfluidic cross junction with different viscosities of the continuous phase is experimentally and theoretically investigated. The flow pattern is distinguished into squeezing and dripping by the presence of gaps. The differences in driving forces between the two patterns are analyzed theoretically and confirmed experimentally by Micro-PIV results. Roles of the squeezing force and the shear force in droplet formation are varying due to the dynamic evolutions of the gap width which reduces with time. Therefore, critical values of the initial gap width are obtained which are the outcome of the competition between neck thinning and tip growing. Compared to water–oil systems, gaps are more difficult to be formed due to the extremely high interfacial tension. Moreover, universal flow pattern maps are constructed using dimensionless parameters of Wed, Cac, and Rec, proving the important roles of both the squeezing force and the shear force. A scaling law of the droplet volume considering the influence of the viscosity ratio is proposed and a very good agreement between experimental data and theoretical predictions is obtained for different liquid systems.

Mechanism responsible altering in interfacial tension and emulsification of the crude oil-water system with nano Gemini surface active ionic liquids, salts and pH

Gemini surface active ionic liquids (GSAILs) exhibit desired activities for enhanced oil recovery (EOR). This study explores the simultaneous effects of homologous series of imidazolium nano GSAILs, [Cnim-C4-imCn][Br2], n = 4, 8, and 12 with individual and mixture of NaCl, MgCl2 salts and also with aqueous phase pH on the crude oil–water system. In the presence of the medium and long alkyl chain GSAILs, electrolytes can establish extra 93.1 and 52.6% reductions in interfacial tension (IFT) and the critical micelle concentration (CMC), compared to the salt-free system, respectively. These were while, the IFT and the CMC were initially decreased with the concentration of electrolytes and then a slight increase was corresponding with the short alkyl chain GSAIL. Results also revealed 79.2% more IFT reductions under pH 9.5 compared to the natural pH as well as high stability of GSAILs within the wide pH range of (2.5–9.5). Meanwhile, crude oil and electrolyte aqueous solutions showed one day emulsification indices within (40–85)% with little decrease after one week. Remarkably, an emulsification index of more than 90% could be achieved at pH 9.5.

Horseradish peroxidase-catalyzed synthesis of high-quality polyaniline in Good’s buffer ionic liquid-buffered H2O/AOT/isooctane bicontinuous microemulsion

Here, a functionalized organic salt composed of [Nk,k,k,k]+ (k = 1–4) and [MES]- (2-(N-morpholino)ethanesulfonate), i.e., Good’s buffer ionic liquid with self-buffering and biocompatible properties, was chosen as electrolyte as well as buffer to construct a H2O/AOT/isooctane bicontinuous microemulsion for enzymatic synthesis of polyaniline (PANI). Studies on the effects of the functionalized organic salt on the phase behavior indicate that [Nk,k,k,k][MES] can tune the phase inversion temperature of AOT-stabilized oil-water microemulsion system through changing the cationic alkyl chain length, exhibiting the properties of both inorganic salt and co-alcohol. More interestingly, the stability of horseradish peroxidase (HRP) solubilized in the H2O(0.1 M [N1,1,1,1][MES], pH = 4.5)/AOT/isooctane bicontinuous microemulsion is much better than that formulated with mixed surfactants AOT/SB-12 and inorganic salt. Studies on the HRP-catalyzed oxidative polymerization of aniline in the present bicontinuous microemulsion indicates that at low surfactant content and high oil-water ratio, the present microemulsion resulted in a PANI with better conductivity than the counterpart reported elsewhere. This work is of guiding significance for constructing a less-component and enzyme-compatible bicontinuous microemulsion for template-assisted biopolymerization.

A comprehensive study on the application of a natural plant-based surfactant as a chemical enhanced oil recovery (CEOR) agent in the presence of different ions in carbonate reservoirs

Surfactant flooding is a promising CEOR approach in carbonate reservoirs and its efficiency has been verified. Commercial surfactants may impose various health and environmental issues. Therefore, utilizing a natural biodegradable surfactant at a low cost is a valuable option for the petroleum industry. In this research, a non-ionic surfactant derived from Acanthophyllum Plant Root Extract (APRE) was used as a bio-surfactant. The EOR potential of this surfactant was evaluated through various tests. Oil-water system interfacial tension (IFT) measurement, contact angle test for carbonate rock wettability alteration assessment, emulsion stability, compatibility, and surfactant flooding test were conducted. The effect of different ions of various salts on the IFT, carbonate rock wettability and the chemical interactions were also studied. The emulsion stability created by the surfactant was assessed through observational tests. The compatibility test (at 25 °C) showed that negligible sediment below the salinity of 50,000 ppm was formed. The IFT at CMC in formation water (optimum concentration of 12000 ppm) was reduced to 1.06 mN/m from an initial value of 2.16 mN/m. The optimum IFT value at different salinities was also determined. The wettability of the carbonate rock from a strongly oil-wet state (168°) was altered to water-wet (60.3°) in the presence of surfactant and FW with a concertation of 10,000 ppm. In the core flood test, the effect of different slug sizes and soaking time was also determined. It was observed that increasing slug size results in a lower mobility ratio and consequently higher oil recovery.

Synthesis of Superhydrophobic/Superoleophilic stearic acid and Polymer-modified magnetic polyurethane for Oil-Water Separation: Effect of polymeric nature

The superhydrophobic/superoleophilic materials based on polyurethane foams have been layered with three different polymers and extensive modification with iron/magnetic nanocomposite. The general desires are to study the effect of the polymer layer and to eliminate the oil contaminant from the oil–water system which is crucial due to the development of environmental technologies. These materials were generated by facile dip-coating two-step method on the polyurethane foams (PUF) surface. PUF was directly layered with polydopamine/polypyrrole/polyaniline (PDA/PPy/PANI) and incorporated with Fe-SA (stearic acid) nanocomposites by ultrasonication and refluxing. In addition, characterization by FTIR, SEM/EDX, XRD, and TGA presented that the polymer layer and Fe-SA nanocomposites successfully covered the PUF surface caused by the chelating interaction between the carboxylates and active sites on iron particles due to intermolecular hydrogen bond interaction. Interestingly, the water contact angle (WCA) measurement of the nanocomposites displayed that the contact angle significantly improved up to 164°. After 20 cycles of oil absorption capacity, the WCA steadily remained up to 153° indicating powerful superhydrophobic properties of the materials. Furthermore, the oil absorption capacity of the materials was evaluated using typical oil–water separation methods such as reusability, separation efficiency, and oil permeate flux. The results exhibited that the modified PUFs have enhanced the absorption capacity up to 44 times the foam weight, 99 % separation efficiency, and about 8000 L.m−2.h−1 oil flux. For oil removal, the dyed oil phase was rapidly absorbed within 2 s confirming the highly used products for a wide area of oil–water separation. PDA-coated PUF nanocomposites obtained the most outstanding results due to their remarkable interfacial adhesion properties which provide larger active functional groups for hydrogen bonding interaction on PUF surface and Fe-SA nanocomposites.

Prospects for Developing Low-Cost Optical Fiber Sensors for Liquid-Liquid Interface Detection

This work examines the prospects of a low-cost retroreflection optical sensor system for detection of the interface between two immiscible liquids, for applications in oil separation tanks. The sensor in its simplest configuration comprises a bare fiber optic tip, cleaved at an angle of 90º relative to the longitudinal fiber axis. The device tested experimentally is based on a 2x2 bidirectional coupler, which connects the sensor tip to a laser and two photodetectors, one used to measure the signal and the other as a reference. From experiments conducted in a laboratory wateroil system, the measured retro-reflected signal was very small, and of the same order as the differential signal due to low optical contrast liquids. To overcome this difficulty, the detection system was designed with an amplification stage, followed by filtering of the digitally converted signal. With this strategy, an accuracy of 99.7% was reached. On the light of the performance measured by the bare fiber tip configuration, an analysis on the potential improvement in performance obtained, by applying a thin layer of gold to the tip of the sensor, was made. Simulated results indicated that, for an optimized gold film, 13 nm thick, a 13fold improvement in the sensor detection limit is obtained.

Flexible polyurethane foam with improved oleophilic and hydrophobic properties for oil spill cleaning

Three chemical compounds (A1, A2, and A3) with long alkyl chains (C5, C8, and C10) were used in this work to improve the oleophilic and hydrophobic properties of blank flexible polyurethane (FPU) cubes for oil spill clean-up. Water sorption was observed to be reduced by almost 50% when compared to blank FPU, while crude oil sorption of modified FPU cubes was raised by A1 = 37.16, A2 = 42.68, and A3 = 45.94 g/g, as well as diesel fuel sorption by A1 = 36.72, A2 = 39.80, and A3 = 41.68 g/g. In the water-oil system, the sorption capacity of FPU cubes modified with three new oleophilic organic compounds was increased by A1 = 43.47, A2 = 44.49, and A3 = 45.15 g/g for crude oil spills and by A1 = 34.07, A2 = 34.16, and A3 = 36.05 g/g for diesel fuel spills, compared to blank FPU cubes of 27.29 and 22.28. The findings suggest that the modified FPU cubes could be utilized to clean up oil spills successfully.

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.