Oil Separation Research Articles

Magnetic Separation of Oil Spills from Water Using Cobalt Ferrite Nanoparticles with Fluorocarbon Functionalization

In the present study, we synthesized fluorocarbon-coated cobalt ferrite (CoFe2O4) magnetic nanoparticles using alkoxysilanes such as trimethoxy(3,3,3-trifluoropropyl)silane (TFPTMS), trimethoxy(1H,1H,2H,2H-nonafluorohexyl)silane (NFHTMS), and triethoxy(1H,1H,2H,2H-perfluorodecyl)silane (PFDTES). The synthesized nanoparticles were characterized by various techniques, including X-ray diffractometry (XRD), transmission electron microscopy (TEM/HRTEM/EDXS), Fourier transform infrared spectroscopy (FTIR), specific surface area measurements (BET), and magnetometry (VSM). To understand their surface characteristics, contact angle (CA) measurements were carried out, providing valuable insights into their hydrophobic properties. Among the samples of CoFe2O4 coated with fluoroalkoxysilanes, those with PFDTES surface coating had the highest water contact angle of 159.2°, indicating their superhydrophobic character. The potential of the prepared fluoroalkoxysilane-coated CoFe2O4 nanoparticles for the removal of waste low-SAPS synthetic engine oil from a model aqueous solution was evaluated based on three key parameters: adsorption efficiency (%), adsorption capacity (mg/g), and desorption efficiency (%). All synthesized CoFe2O4 samples coated with fluoroalkoxysilane showed high oil adsorption efficiency, ranging from 87% to 98%. The average oil adsorption capacity for the samples was as follows: F3-SiO2@CoFe2O4 (3.1 g of oil/g of adsorbent) > F9-SiO2@CoFe2O4 (2.7 g of oil/g of adsorbent) > F17-SiO2@CoFe2O4 (1.5 g of oil/g of adsorbent) as a result of increasing oleophobicity with increasing fluorocarbon chain length. The desorption results, which showed 77–97% oil recovery, highlighted the possibility of reusing the adsorbents in multiple adsorption/desorption cycles.

OPTIMIZATION OF PID CONTROLLER PARAMETERS USING MACHINE LEARNING ALGORITHMS BASED ON OIL SEPARATION PROCESS DATA

This paper presents the investigation of the process of optimizing the parameters of a PID controller using machine learning algorithms for the oil separation process control system. The optimization of the controller parameters (Kp, Ki, Kd) is important, in order to improve control quality and reduce the number of errors in dynamic processes. To solve this issue, several innovative methods were considered, such as the cuckoo search algorithm (CSA), the firefly algorithm (FA), particle swarm optimization (PSO), and the support vector machine (SVM). All the data, including the current process values (PV), setpoints (SP) and output signals (OP) were obtained from Tengizchevroil. In addition, the metrics, such as root-mean-square error (MSE), adjustment time, overshoot, and steady-state error were used to assess the effectiveness of optimized regulators. Overall, the results of the research indicate that there was a significant improvement of the dynamic characteristics of the system due to the usage of machine learning algorithms compared to the traditional approaches. The obtained parameters of optimization achieved the target value while being faster and more stable, thus increasing the productivity of control in the technological process.

Hybrid Membranes Based on Track-Etched Membranes and Nanofiber Layer for Water–Oil Separation and Membrane Distillation of Low-Level Liquid Radioactive Wastes and Salt Solutions

In this work, hybrid membranes were fabricated by depositing polyvinyl chloride (PVC) fibers onto PET track-etched membranes (TeMs) using the electrospinning technique. The resulting structures exhibited enhanced hydrophobicity, with contact angles reaching 155°, making them suitable for applications in both water–oil mixture separation and membrane distillation processes involving low-level liquid radioactive waste (LLLRW), saline solutions, and natural water sources. The use of hybrids of TeMs and nanofiber membranes has significantly increased productivity compared to TeMs only, while maintaining a high degree of purification. Permeate obtained after MD of LLLRW and river water was analyzed by conductometry and the atomic emission spectroscopy (for Sr, Cs, Al, Mo, Co, Sb, Ca, Fe, Mg, K, and Na). The activity of radioisotopes (for 124Sb, 65Zn, 60Co, 57Co, 137Cs, and 134Cs) was evaluated by gamma-ray spectroscopy. In most cases, the degree of rejection was between 95 and 100% with a water flux of up to 17.3 kg/m2·h. These membranes were also tested in the separation of cetane–water emulsion with productivity up to 47.3 L/m2·min at vacuum pressure of 700 mbar and 15.2 L/m2·min at vacuum pressure of 900 mbar.

Consolidating the state of knowledge of surface washing agents for oil spill response decision making.

Consolidating the state of knowledge of surface washing agents for oil spill response decision making.

Dopamine-assisted Sr-MOF@Hap in-situ growth for ultrafast oil-water separation and crude oil separation

Dopamine-assisted Sr-MOF@Hap in-situ growth for ultrafast oil-water separation and crude oil separation

Research Progress of Surfactant Demulsifier

In this paper, the basic concept of surfactants as chemical additives and their diversified classification system are first expounded, laying a theoretical foundation for the subsequent study of their application in demulsification technology. Then, the specific application cases of various types of surfactants in the field of demulsification are deeply analyzed, and ways in which they achieve effective separation of emulsions through their unique physical and chemical properties are revealed. Further, the internal action mechanism of surfactant demulsifier, including how to destroy the stability of emulsion and promote the separation of oil and water phase, is systematically described. On this basis, the significant advantages of surfactant demulsifier compared with traditional methods are summarized, including high cost-effectiveness, high demulsifier efficiency, strong stability, wide adaptability, and easy operation. Finally, the development direction and challenges of surfactant demulsifier in the future are prospected.

Fabrication of all biomass-based carbonized aerogels for efficient oil separation

Fabrication of all biomass-based carbonized aerogels for efficient oil separation

Influence of particle size on the color, rheological, and textural properties of sesame paste

This study investigates the impact of particle size on the physical, rheological and textural properties of sesame paste prepared from sesame seeds by colloid milling. Four sesame paste samples (SP1–SP4) were processed with varying milling gap sizes. Particle size distribution revealed a significant reduction in particle size with smaller milling gaps, resulting in finer pastes with decreased oil separation. Finer particles enhance lightness, thereby contributing to the visual appeal of the product while also decreasing yellowness index. The finest sample exhibited the smallest D50 value. Rheological behavior was modeled using the Herschel–Bulkley model, showing that both yield stress and consistency coefficient decreased as particle size diminished. The creep test results, fitted using the four-element Burger’s model, revealed that smaller particles led to higher initial compliance (Jo), retarded compliance (J1), and retardation period (λ), indicating increased material flexibility and longer stress-relaxation period. Viscosity (η) increased significantly with reduced particle size, suggesting greater internal resistance to flow, probably because of enhanced particle interactions. The textural analysis confirmed that finer particles resulted in lower hardness and work of shear, leading to a softer and a more easily spreadable paste. In industry, optimizing particle size distribution ensures desirable product qualities, consistency, and consumer satisfaction.

Experimental investigation of CTAB modified clay on oil recovery and emulsion behavior in low salinity water flooding

Enhancing oil recovery in clay-rich sandstone reservoirs remains a critical challenge, particularly for heavy oil extraction. Although low salinity water flooding has been widely investigated, the synergistic potential of combining cationic surfactants, such as cetyltrimethylammonium bromide (CTAB), with low salinity water to improve emulsion stability and, consequently, oil recovery in such reservoirs has received limited attention. This study pioneers a novel experimental approach to investigate the simultaneous impact of CTAB and smart water flooding on heavy oil recovery in clay-rich systems. By exploring the interplay between ion-tuned water and CTAB, we uncover new insights into their combined influence on emulsion behavior, interfacial properties, and oil mobilization. In this regard, the interfacial tension (IFT) and zeta potential values for sulfate-enriched seawater containing CTAB were approximately 15.2 mN/m and 6.4 mV, respectively, lower than those of magnesium-enriched seawater. This indicates enhanced interfacial activity and clay surface modification. Emulsion stability tests revealed that reduced ion concentrations, especially in sulfate-enriched aqueous solutions, significantly enhanced emulsion stability. This was illustrated by an extended emulsion separation time of approximately 70 min under these conditions. Moreover, fourier transform infrared spectroscopy (FTIR) analysis of the separated oil phases from the emulsion revealed a notable reduction in polar components in oil exposed to cation-rich water, while non-polar components were more prevalent in oil contacted with sulfate-enriched water. The contact angle measurements indicated that sulfate-enriched seawater (SW2d.2SO4) exhibited the lowest contact angle (31°) among all brine solutions. These findings provide insights into the mechanisms of emulsion stabilization and the role of oil components, offering a transformative perspective on optimizing smart water flooding with cationic surfactants for improved heavy oil recovery in clay-rich reservoirs.

Study on Filtration Efficiency of Filter Elements for Lubricating Oil Separation

For the gas injection process in the underground natural gas storage, it is of great significance to separate lubricating oil droplets from natural gas to ensure the capacity of gas injection. However, the interaction mechanism, among various factors, is still unclear in real field conditions. In this study, the filtration performances of filter elements were investigated in a range of gas temperatures from 20 °C to 70 °C, aerosol concentrations from 400 mg/m3 to 1200 mg/m3 and flowrates from 37.2 m3/h to 74.4 m3/h. The results show that at the same flowrate, the steady-state filtration efficiency decreases with increasing temperature, resulting from a shift in the upstream aerosol towards the smaller size and an increase in the concentration for droplets within the range of 0.3 to 2 μm. The filtration efficiency only increases by 0.02% at 20 °C, while the steady-state efficiency increases by more than 0.10% at 70 °C and all the flowrates. At the same gas temperature and aerosol concentration, the steady-state filtration efficiency increases with the increase in flowrate. In practical applications, the filtration performance can be improved by lowing the gas temperature, setting up fewer filter elements in the separator, and appropriately reducing the injection amount of lubricating oil.

Comparative analysis of methods for mixture calculating during sequential pumping of oil and petroleum products taken into account the primary technological mixture impact

Relevance. Sequential pumping is the main method of transportation of large volumes of oil products, which is its main advantage, as there is no need to build separate oil product pipelines. However, this method has one serious disadvantage – the formation of a mixture of petroleum products in the zone of direct contact, which is a difficult to predict process. The volume and length of the mixture must be understood for subsequent actions on their distribution to ensure the required marketable quality of petroleum products, as this will affect their beneficial use, for example, as motor fuels. Aim. To study various domestic and foreign methods and approaches to estimate primary mixture volume, evaluate the advantages and disadvantages of this or that method, verify the accuracy of calculated mixture volumes with real data, derive empirical dependence for real data, compare the calculation results and recommendations for estimation of primary mixture volume. Methods. Mathematical modeling of mixing using different methods, comparative analysis of the obtained data, extrapolation of the function using real data from the Samara–Bryansk technological pipeline. Results. The work analyzes existing approaches and methods for estimating the volume of the resulting mixture of petroleum products, and conducts comparative mathematical modeling. To evaluate the effectiveness of various methods, a comparison was made with the real data from the Samara–Bryansk pipeline. As part of the study, a comparison was made using three models of the mixture formation: without taking into account the primary technological mixture, taking into account the primary technological mixture, taking into account the primary volume of the technological mixture through the method of equivalent lengths.

Probing the exchange rate’s asymmetric reaction to oil price changes in the new BRICS Plus group

We aim to show how any variants of a unified currency among BRICS Plus countries are challengeable, by probing the disparate influence of the positive and negative alterations in the crude oil’s international price on the real effective exchange rates. The paper applies the nonlinear autoregressive distributed lag approach to separate oil price upswings from downswings and assesses how such changes asymmetrically affect the real effective exchange rates of BRICS Plus members in the short and long runs using monthly time series variables from January 2000 until July 2023. Our findings reveal that in the short run, the asymmetric impacts of the positive and negative oil price changes on the real effective exchange rates appear in all BRICS Plus countries. In the long run, Brazil and Argentina confirmed the asymmetric impact of oil price changes on their real effective exchange rates, while the symmetric impact is confirmed in Russia, the United Arab Emirates, and Ethiopia. Our findings prove that a unified currency or a unified monetary union is a very challenging idea, as continuous appreciations or depreciations of the local currencies of BRICS Plus countries will have to be implemented to preserve their alignment with the composite currency unit. Moreover, the asymmetric responses will induce diverse policy recommendations concerning the oil pricing. Our study comes to fill a vital lacuna in the literature as it is the first study to probe the asymmetric association between the oil’s international price and the real effective exchange rate in the BRICS Plus countries.

Soluble Soybean Polysaccharide Improves Quality and Shelf Life of Peanut Butter.

Peanut butter, a plant-based spread, has gained global prominence due to the increasing consumer demand for nutritious convenience foods and the rising adoption of plant-based diets. However, oil separation during storage and transportation accelerates the oxidative rancidity and reduces the shelf life of peanut butter. Enhancing peanut butter stability by minimizing oil separation is therefore essential. This study investigates the effect of soluble soybean polysaccharides (SSPSs) on the quality and shelf life of peanut butter. Optimal processing conditions were established by adding 1.7% SSPS (w/w), heating the mixture to 85 °C for 40 min, and then cooling it to 1 °C. The addition of SSPSs significantly increased the lightness of the peanut butter without altering its red-green color characteristics. Furthermore, SSPS incorporation improved its textural properties by increasing hardness and cohesiveness. Nutritional analysis showed that SSPS supplementation elevated proximate composition parameters (moisture, ash, carbohydrates, and fiber) while slightly reducing acid and peroxide values. Scanning electron microscopy revealed that SSPSs enhanced the internal network structure of peanut butter, inhibited oil migration, and reduced centrifugal emulsification rates. First-order kinetic models based on acid and peroxide values were developed to predict the effects of SSPSs on shelf life. Both the model predictions and experimental data confirmed that SSPS addition effectively extends the shelf life of peanut butter.

3D Printability of Lysine-Modified Myofibrillar Protein Emulsions

This study explores the potential of lysine (Lys) and tilapia myofibrillar protein (MP) composite particles in the formulation of highly inwardly directed emulsions (HIPEs). Infrared spectroscopy, potentiometric analysis, and molecular docking studies revealed that the interaction between Lys and MP is primarily governed by hydrogen bonding and electrostatic forces. The incorporation of Lys significantly influenced the particle size, secondary and tertiary structures, solubility, and turbidity of MP. Lys-MP-stabilized HIPEs can form highly stable denser self-supporting gel network structures. Rheological analysis of HIPEs stabilized by MP showed a low energy storage modulus (G’ 110.66 Pa) and water–oil separation, therefore preventing 3D printing. However, HIPEs stabilized by Lys (especially 1.5 wt%) significantly improved the energy storage modulus (G’ 1002.10 Pa), increased viscoelasticity and thixotropic recovery, and reduced droplet size (10.84 μm), facilitating the use of HIPE inks for 3D printing. Furthermore, HIPEs stabilized with 1.5 wt% Lys-MP demonstrated superior print accuracy (91.36%), resolution, and clarity in 3D printing applications. Overall, these findings offer a promising strategy for developing Lys-MP composite particle-stabilized HIPEs tailored for advanced 3D printing technologies.

Modeling Oil-Separation Properties of Lubricating Greases

Base oil separation from the thickener structure of a lubricating grease, also known as “bleed,” is an essential process for grease lubrication of bearings. To get more insight in this process, a model is presented to describe the bleed behavior in terms of grease parameters such as base oil content, base oil-thickener affinity, thickener permeability and elasticity, and viscosity of the base oil. With this model the bleed rate can be calculated for a given external pressure gradient. Blotting paper is used to create this external pressure gradient as well as to measure the amount of bled oil. The model calculations are compared with experimental results of the bleed rate of grease samples with varying initial oil content and describe the overall bleeding process quite well.

Partial hydrolyzed protein as an alternative stabilizer for peanut (Arachis hypogaea) butter

Partial hydrolyzed protein as an alternative stabilizer for peanut (Arachis hypogaea) butter

Cyclone microbubble flotation for enhanced oil recovery from palm oil mill effluent

In this study, we investigate cyclone microbubble (CMB) flotation for oil recovery from palm oil mill effluent (POME) under batch and continuous operations. Designed to reduce floated waste and enhance oil separation, the process was tested on a real POME from a Malaysian palm oil mill, with high temperature, low pH, and fluctuating oil and grease (O&G), total solids (TS), and chemical oxygen demand (COD) levels. For a mill processing 1,000 tons of fresh fruit bunches (FFB) daily, the POME discharge contained 7.9 tons of O&G, 36.5 tons of TS, and 59.2 tons of COD. Batch flotation achieved ~63.8% of O&G separation with a 60-minute retention time, whereas continuous flotation (flow rate > 20 L/min) showed a lower efficiency (36 ± 9%). However, O&G was enriched 3 times in the recovery tank, demonstrating an effective oil concentration. Economic analysis confirmed that energy costs were significantly lower than the value of recovered palm oil, highlighting CMB flotation’s cost-effectiveness. The findings support CMB flotation as a scalable and sustainable POME treatment method, with a potential for further efficiency improvements.

Study on Preparation of P/POMAA Membrane for Effective Separation of Herbal Volatile Oils

ABSTRACTThe separation and purification of volatile oils—essential components in traditional Chinese medicine (TCM)—face significant technical challenges due to the persistent formation of oil–water emulsions during industrial extraction processes. We designed a PVDF/POMAA membrane using self‐synthesized amphiphilic copolymer P(ACMO‐MMA‐ADMH) (POMAA) via surface segregation and response surface methodology (RSM). The optimal formulation (3.95 wt% POMAA, 13.07 wt% PVDF, 1.89 wt% PVPK30, 81.09 wt% DMAC) underwent 35.46 h non‐solvent‐induced phase inversion (NIPS). The membrane exhibited exceptional performance: purified water flux of 2146.5 L/(m2·h) and 92.4% oil retention, surpassing commercial PVDF membranes by 43% and 19.1%, respectively. Chlorination enhanced bacteriostatic activity, while stability tests confirmed resistance to acids/bases (pH 4–12), high temperatures (50°C–90°C), ethanol (60–100 vol%), and 30‐week operation. Antimicrobial efficacy prevented bacterial contamination during separation. Molecular docking revealed strong binding affinity (254.9 kcal/mol) between components, ensuring structural integrity. This study provides a stable, efficient solution for industrial‐scale TCM volatile oil purification.

Sm-MOF decorated cotton for efficient on-demand oil-water separation and organic pollutants removal

Complex wastewater containing oil–water and contaminant mixtures is a constant threat to ecosystems and public health. However, efficient water–oil separation and water treatment are required, with a preference for simple but universal matrices for possible large-scale applications. Herein, effective oil–water separation and organic pollutant removal are simultaneously realized on cotton balls decorated with polydimethylsiloxane combined with a samarium metal–organic framework. Cotton balls containing polydimethylsiloxane (10 %) and Sm-MOF (Synthesis temperature was 110 ℃, 15 mg/L) were successfully prepared by a simple precipitation method, with a high water contact angle of 150.75 ± 1.1°. After pre-wetting with a low surface energy solution, the modified cotton was endowed with repeatable super-wetting transitions between superhydrophobic/superoleophilic and superhydrophilic/underwater superoleophobic properties. In addition to on-demand separations of immiscible oil–water mixtures at a rate of 95 %, water-in-oil emulsions could be separated by the addition of different surfactants. The mechanism of demulsification of the treated cotton ball was studied based on the type of emulsifier and the results of emulsified oil separation. Cotton balls modified with 10 % PDMS and Sm-MOF (Synthesis temperature was 140 °C; 15 mg/L) showed higher adsorption capacity compared to pure cotton balls, adsorbing about 98.7 % of Eriochrome Black T within 2 h. Cotton balls modified by PDMS and Sm-MOF are an effective, safe and green material with promising applications in the simultaneous separation of oil–water mixtures and removal of organic pollutants from water systems.

Performance of ethanol transformable microemulsions and remediation of salinized oil - contaminated soils.

Performance of ethanol transformable microemulsions and remediation of salinized oil - contaminated soils.