Oil Solubility Research Articles

Augmentation of antifungal activity of fluconazole using a clove oil nanoemulgel formulation optimized by factorial randomized D-optimal design.

In the present study, fluconazole (FLU) showed the highest solubility in clove oil and was selected as the oil phase for the FLU-loaded nanoemulsion (FLU-NE). Among the studied cosurfactants, Labrafac was better than ethanol at providing globules with acceptable sizes and a lower polydispersity index (PDI) when Tween 80 was the surfactant. This optimized FLU-NE was thermodynamically stable. Furthermore, FLU-NE stored at 40 ± 2°C and 75 ± 5% relative humidity for 6months demonstrated good stability. The FLU-NE was converted to a FLU-loaded nanoemulsion gel (FLU-NEG) using 2% w/v sodium carboxymethyl cellulose. The FLU-NEG was acceptable in terms of visual appearance and spreadability. Rheological studies revealed pseudoplastic behavior for FLU-NEG. The viscosity of FLU-NEG decreased when the applied rpm was increased. FLU-NEG showed greater drug release than that from a FLU-GEL formulation. Furthermore, the FLU release from FLU-NEG followed the Higuchi model. The results from the in vitro antifungal evaluation of FLU-NEG on Candida albicans ATCC 76615 strain confirmed the increase in the antifungal activity of FLU by clove oil. Significant differences were observed in the zones of inhibition produced by FLU-NEG compared to those produced by the blank nanoemulsion gel (B-NEG), fluconazole suspension (FLU-SUS), and nystatin samples. Thus, the increase in the antifungal activity of FLU using clove oil as the oil phase in its nanoemulsion formulation was quite evident from our results. Therefore, the developed FLU-NEG could be considered a potential candidate for further preclinical and clinical studies.

Gamma irradiation-induced degradation of hexachlorobenzene in methanol: Kinetics, mechanism and dehalogenation pathway

Hexachlorobenzene (HCB), a persistent organic pollutant (POP) and organochlorine compound (OCC), poses significant environmental and health risks due to its high stability and solubility in fats, oils, and organic solvents. This study investigates the degradation of HCB in methanol using gamma irradiation with a60Co source. A 2 × 10−4 M solution of HCB in methanol was prepared and irradiated at a dose rate of 1.74 Gy/s. The degradation process was monitored using Gas Chromatography-Mass Spectrometry (GC-MS), with optimized parameters for effective separation and analysis of byproducts.The results demonstrated a 100% degradation of HCB at an absorbed dose of approximately 51 kGy. The degradation pathway involved successive dechlorination, forming various chlorinated benzene (CB) byproducts such as pentachlorobenzene (PCB), tetrachlorobenzenes (TeCB), trichlorobenzenes (TCB), dichlorobenzenes (DCB), and ultimately benzene.Ion chromatography (IC) analysis revealed a dose-dependent increase in Cl⁻ concentrations, confirming the efficiency of dechlorination. A chlorine mass balance was performed to evaluate the distribution of chlorine during the degradation process, tracking Cl⁻ ions, CBs, and residual HCB. As the dose increases, the chlorine content in residual HCB decreases significantly, with none remaining at 50.2 kGy and beyond. At 169.5 kGy, nearly all chlorine (99.96%) is unaccounted for, suggesting that it has likely been released as gaseous byproducts, such as Cl₂ or other volatile chlorinated compounds.The formation of solvated electrons and hydrogen radicals initiated the dechlorination process, as evidenced by the identified reaction mechanisms. Kinetic analysis indicated that the degradation followed pseudo-first-order kinetics, with a rate constant of 5 × 10−4 s−1. The study also outlines a dose-dependent trend in radiation chemical yields (G values), initially increasing to a peak of 7.3 × 10−2 molecules per 100 eV at 12.6 kGy and subsequently decreasing to as low as 5.4 × 10−4 at 50.2 kGy.This study highlights the effectiveness of gamma irradiation for the complete degradation of HCB in methanol, offering a promising method for the remediation of POPs-contaminated environments. The proposed mechanism and kinetic properties provide a comprehensive understanding of the radiolytic degradation process, paving the way for further applications in environmental cleanup technologies.

Relationship between friction reduction effect and solubility in base oil of organic friction modifiers

This study explored the relationship between the solubility of additives in base oils and their friction-reduction efficacy using cetyl alcohol as a model additive. Atomic force microscope friction tests demonstrated that the friction-reduction effect of cetyl alcohol varied significantly across the base oils. The solvation free energy was computed to evaluate the solubility of cetyl alcohol. A direct proportional relationship between friction-reduction and solvation free energy was observed, indicating additives with lower solubility have better friction-reduction performance. Neutron reflectometry experiments and molecular dynamics simulations revealed that lower solubility correlates with stronger adsorption. This study quantitatively clarified the relationship between solubility, adsorption, and friction reduction, providing insights into optimizing lubricant formulations and contributing to a deeper understanding of boundary lubrication mechanisms.

Improved solubility and bioavailability of cyclolinopeptides by diacylglycerol in the β-cyclodextrin Pickering emulsions

Cyclolinopeptides (CLs) have anti-inflammatory, anti-osteoporosis, and anti-tumor effects, however, low water and oil solubility greatly limit their application. Herein, CLs-loaded β-cyclodextrin (β-CD) emulsions were prepared with different oil phases. The in vitro digestibility, cellular absorption, and anti-inflammatory effects were evaluated. Camellia oil diacylglycerol (CO DAG) showed enhanced dissolving ability for CLs due to high polarity. β-CD formed inclusion complexes with DAG through hydrogen bond and the emulsions showed smaller size and higher physical stability with 50 % (w/w) oil. The in vitro digestibility of the DAG emulsion was increased and the CLs' bioavailability was 13.6–fold higher than CLs in oil. The CLs–loaded Pickering emulsion digesta exhibited a higher nitric oxides (NO) inhibition rate (58.62 %) and Caco-2 cell penetration (3.09 × 10−6 cm/s). Therefore, emulsion formulated with β-cyclodextrin and DAG can effectively improve the solubility and bioavailability of CLs, which has significant potential for application in functional foods and pharmaceutical industry.

Микронизация в технологии минорного компонента консервирующего действия

Natural preservatives are a global trend in the food industry. As a rule, they are traditional herbs or spices. Flavonoids inhibit microbial activity. However, they are effective only when their distribution in the food matrix is uniform. This uniformity is achieved by increasing their solubility, e.g., by micronization. The research assessed the feasibility and effectiveness of micronization of a plant preservative using a purified flavonoi d fraction obtained from defatted sea-buckthorn meal. The study featured samples of purified flavonoid fraction of sea-buckthorn meal with different dispersions. Their solubility, antioxidant properties, antimicrobial activity, and fungicidal effect were assessed by standard methods. Micronization under ultrasonic conditions and cryogenic grinding increased the solubility in water, ethyl, and oil. Ultrasonic micronization proved efficient as it produced particles of 1,400 nm under rational conditions, i.e., 50 W ultrasonic vibration in a 0.5% suspension for 10 min. The sample obtained in this way increased the rate of catalase reaction by 19% relative to the control sample while maintaining a constant rate of glutathione reduction. Its antioxidant activity increased fourfold. The samples demonstrated bacteriostatic activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, as well as fungistatic activity against Candida albicans. Purified flavonoid fraction of sea-buckthorn meal micronized under ultrasonic conditions can be recommended as a natural preservative in various food systems.

Enhanced Solubility and Miscibility of CO2-Oil Mixture in the Presence of Propane under Reservoir Conditions to Improve Recovery Efficiency

The existence of propane (C3H8) in a CO2-oil mixture has great potential for increasing CO2 solubility and decreasing minimum miscibility pressure (MMP). In this study, the enhanced solubility, reduced viscosity, and lowered MMP of CO2-saturated crude oil in the presence of various amounts of C3H8 have been systematically examined at the reservoir conditions. Experimentally, a piston-equipped pressure/volume/temperature (PVT) cell is first validated by accurately reproducing the bubble-point pressures of the pure component of C3H8 at temperatures of 30, 40, and 50 °C with both continuous and stepwise depressurization methods. The validated cell is well utilized to measure the saturation pressures of the CO2-C3H8-oil systems by identifying the turning point on a P-V diagram at a given temperature. Accordingly, the gas solubilities of a CO2, C3H8, and CO2-C3H8 mixture in crude oil at pressures up to 1600 psi and a temperature range of 25–50 °C are measured. In addition, the viscosity of gas-saturated crude oil in a single liquid phase is measured using an in-line viscometer, where the pressure is maintained to be higher than its saturation pressure. Theoretically, a modified Peng–Robinson equation of state (PR EOS) is utilized as the primary thermodynamic model in this work. The crude oil is characterized as both a single and multiple pseudo-component(s). An exponential distribution function, together with a logarithm-type lumping method, is applied to characterize the crude oil. Two linear binary interaction parameters (BIP) correlations have been developed for CO2-oil binaries and C3H8-oil binaries to accurately reproduce the measured saturation pressures. Moreover, the MMPs of the CO2-oil mixture in the presence and absence of C3H8 have been determined with the assistance of the tie-line method. It has been found that the developed mathematical model can accurately calculate the saturation pressures of C3H8 and/or CO2-oil systems with an absolute average relative deviation (AARD) of 2.39% for 12 feed experiments. Compared to CO2, it is demonstrated that C3H8 is more soluble in the crude oil at the given pressure and temperature. The viscosity of gas-saturated crude oil can decrease from 9.50 cP to 1.89 cP and the averaged MMP from 1490 psi to 1160 psi at 50 °C with the addition of an average 16.02 mol% C3H8 in the CO2-oil mixture.

From Nanotechnology to Oilfields: the Potential of Microemulsions and Nanoemulsions in Preflush Fluids for a Sustainable Alternative

Objective: The objective of this study is to contextualize the advancements in the application of micro- and nanoemulsions in preflush fluids within the oil industry. Theoretical Framework: The study draws upon concepts in nanotechnology and fluid dynamics, focusing on the role of preflush fluids in wellbore cleaning and rock wettability adjustment. Method: A bibliometric analysis and review of the literature were conducted. The bibliometric analysis included 145 keywords and 382 articles related to preflush fluids in the oil industry, published between 2003 and 2023. The data were analyzed and visualized using VOSviewer. Results and Discussion: The results revealed fluctuations in the number of publications on this topic over the years. The bibliometric review highlighted the evolution of preflush fluid formulations, particularly those involving micro- and nanoemulsion systems. These fluids demonstrated high oil solubilization capacity and wettability reversal, effectively addressing formation stability issues. Research Implications: The findings underscore the significance of micro- and nanoemulsion systems in enhancing the efficiency and environmental sustainability of preflush fluids used in oil extraction operations. Originality/Value: This study contributes to the literature by offering a comprehensive analysis of the advancements in preflush fluid formulations, emphasizing the sustainable potential of micro- and nanoemulsions in the oil industry.

Self-assembly behavior of BS12 in water for combination flooding potential: Deep eutectic solvent as a component

Deep eutectic solvent (DES) as standalone or mixed with surfactant flooding has been increasingly recognized and has attracted attention in enhanced oil recovery (EOR). However, the association between self-assembly behavior and the EOR potential of zwitterionic surfactants in DES-water systems has not been profoundly studied. In this work, two choline-based DES were prepared preferentially. The self-assembly and micellar growth of dodecyl dimethyl betaine (BS12) in DES-water systems was investigated by particle size analysis, fluorescence spectroscopy, and transmission electron microscopy. In the system containing 60 wt% DES, micelles were stretched ∼100 times via complexation, hydrogen bond, and electrostatic shield. Afterward, the key parameters of EOR were evaluated. The synergy effect of DES and BS12 in water reduced the critical micelle concentration (cmc) and the oil–water interfacial tension (IFT) to below 1 mmol/L and 0.1 mN/m, respectively. DES strengthened the BS12 aqueous solution to transform the oil-wet sandstone into water-wet. Therefore, the forces on the crude oil in the pore throats may favor its removal. In the mixed system, larger micelles exhibited better crude oil solubilization performance. Compared with the surfactant-alone system, the solubilization and low IFT brought by DESs/BS12 systems increased the cumulative crude oil recovery rate to 10.74 % and 7.61 %, thus showing promising potential for EOR.

Improving the efficiency of combined displacement of ultra-viscous oil from the reservoir by carbon dioxide and coolant

Currently, in the world practice, special attention is paid to the processing of carbon dioxide in the aspect of obtaining it at the field itself, which reduces the cost of the technology of gas capture and injection into the well, because it is important for Russia due to the remoteness of the main part of oil fi elds. Realization of the gas method of oil feedstock extraction increases its efficiency several times taking into account the elimination of the ecological problem of utilization of carbon dioxide formed on a large scale industrially, with the growth of qualitative parameters of extracted commercial oil feedstock, taking into account the relatively small cost of carbon dioxide, the ability to recycle, as well as the use at any stage of fi eld operation. It is obvious that the increase of efficiency of technologies of carbon dioxide influence on the formation mass in complex with a thermal agent for super viscous oil feedstock requires an integrated approach in terms of methodical and empirical studies of regime parameters, applied technological processes and materials. On the basis of systematization of known theoretical data, results of empirical studies and their industrial approbation the authors recommend an algorithm for research of the problem. The article presents empirical substantiation of the ability to increase the effi ciency of exploitation of carbonate deposit of super viscous oil at great depth through the impact of thermal agent and carbon dioxide through the inclusion of the matrix component of the reservoir mass in more mobile development. It is shown that it is possible to incorporate the oil-saturated matrix by means of increasing the mobility of carbon dioxide when the temperature in the reservoir rises, the high degree of solubility of extra-viscous oil there and the additive drop in its dynamic viscosity. The data of empirical studies lead to the conclusion that the level of heating of the deposit and the volume of carbon dioxide supplied serve as optimizable factors, with a rational combination of which can increase the effectiveness of their influence.

Research on the Supercritical CO2 Extraction Process of Hetian Rose Essential Oil

A longstanding concern in plant essential oil extraction is how to optimize extraction efficiency with limited materials. Supercritical CO2 extraction has been proven effective in enhancing the yield and efficiency of extracting plant essential oils. However, the impact of temperature, pressure, and co-solvent content on extracting Hetian rose essential oil remains unclear. There is a lack of research on the influence of pretreatment methods. This study focuses on investigating supercritical CO2 extraction of rose essential oils from Xinjiang Hetian. The research analyzes the effects of pressure and temperature on the extraction rate and validates the efficiency by calculating the solubility of essential oils in supercritical fluid. Under conditions of 35 MPa, 40 °C, 10 L/h, and a particle size of 0.8 mm, this study evaluates the extraction efficiency using Xinjiang Hetian rose materials pretreated with salt solutions at concentrations of 5%, 10%, and 20%, as well as enzyme solutions at concentrations of 2%, 5%, and 10%. Results indicate that appropriate solution concentration can enhance the extraction effect and mass transfer process, but excessively low or high concentrations do not contribute to improved extraction reactions. The highest extraction rate (8.99%) is achieved using a salt solution concentration of 10%, while the lowest (4.21%) is obtained with a salt solution concentration of 20%.

Development of bedaquiline nanoemulsions intended for paediatric multidrug-resistant tuberculosis: excipient selection and preformulation studies.

Preformulation investigations into the development of drug formulations, encompassing considerations related to the structure of the drug, excipients, composition, and physical attributes are crucial. This phase is pivotal in ensuring the ultimate success of nanoemulsion development. The objective of this study was to evaluate and define the properties of bedaquiline (BDQ) and the necessary excipients for the formulation of self-emulsifying BDQ-loaded nanoemulsions. To determine the saturation solubility of BDQ in various oils, an in-house validated HPLC method was used. Fourier transform infrared spectroscopy was utilised to identify and evaluate the compatibility between BDQ and the selected excipients. The water titration method was used to construct phase diagrams to identify the type of structure that resulted following emulsification and to characterise the behaviour of mixtures along dilution paths. The solubility studies revealed that BDQ exhibited the highest solubility in olive oil, with a solubility of 3.45 ± 0.041 mg/ml. The design space led to the formation of emulsions categorised as Winsor products. Importantly, the FTIR data indicated the absence of any potential interactions between BDQ and the chosen excipients. The preformulation studies were successful and facilitated the selection of compatible and suitable excipients for the formulation of BDQ-loaded nanoemulsions.

Liquefied dimethyl ether as alternative extraction solvent for high γ-oryzanol rice bran oil: Systematic HSP theory and experimental evaluation

This study aimed to systematically find an alternative solvent to replace hexane for the extraction of bio-oil with high γ-oryzanol content from rice bran (RB). The selection involved predicting solubility through Hansen solubility theory, experimental validation, determination of suitable extraction conditions, and comparison of oil quality with that of conventional hexane. A wide variety of solvents: subcritical water (SCW), supercritical carbon dioxide (SCCO2), bio-based solvents (alcohols and terpenes), and liquefied dimethyl ether (LDME), were initially assessed for rice bran oil (RBO) and γ-oryzanol solubility using Hansen solubility spheres. Solvents demonstrating high solubility for both RBO and γ-oryzanol, including LDME, ethyl acetate, acetone, and others (alcohols and SCCO2) known for effective vegetable oil extraction, were selected/identified for experimental extraction comparison. Among these, LDME performed better overall, affording greater solubility and requiring less solvent, shorter duration, lower pressure, and no additional co-solvents for equivalent extractions. Optimal conditions for LDME extraction were identified as 30 °C with a solvent-to-sample ratio of 10 mL/g and an extraction time of 10 min. Oils extracted with LDME and hexane displayed similar fatty acid compositions and no adverse effects on RB protein and carbohydrate structures after LDME extraction were observed. This study demonstrates LDME as a promising alternative to replace hexane for RBO extraction to further valorize this abundant low-cost RB residue into bio-oil and its γ-oryzanol and de-oil RB co-products.

Investigation of the Inhibitory Effects of Illicium verum Essential Oil Nanoemulsion on Fusarium proliferatum via Combined Transcriptomics and Metabolomics Analysis.

Fusarium proliferatum is the main pathogen that causes Panax notoginseng root rot. The shortcomings of strong volatility and poor water solubility of Illicium verum essential oil (EO) limit its utilization. In this study, we prepared traditional emulsion (BDT) and nanoemulsion (Bneo) of I. verum EO by ultrasonic method with Tween-80 and absolute ethanol as solvents. The chemical components of EO, BDT, and Bneo were identified by gas chromatography-mass spectrometry (GC-MS) and the antifungal activity and mechanism were compared. The results show that Bneo has good stability and its particle size is 34.86nm. The contents of (-) -anethole and estragole in Bneo were significantly higher than those in BDT. The antifungal activity against F. proliferatum was 5.8-fold higher than BDT. In the presence of I. verum EO, the occurrence of P. notoginseng root rot was significantly reduced. By combining transcriptome and metabolomics analysis, I. verum EO was found to be involved in the mutual transformation of pentose and glucuronic acid, galactose metabolism, streptomycin biosynthesis, carbon metabolism, and other metabolic pathways of F. proliferatum, and it interfered with the normal growth of F. proliferatum to exert antifungal effects. This study provide a theoretical basis for expanding the practical application of Bneo.

Optimal conditions for nano-emulsified vegetable oil synthesis for the biostimulation of 1,1,2-trichloroethane and vinyl chloride contaminated groundwater in bioreactors

Contamination of groundwater with chlorinated aliphatic hydrocarbons (CAHs) has become increasingly widespread. Enhanced reductive dechlorination (ERD) by emulsified vegetable oil (EVO) is an environmentally friendly, low-carbon and sustainable technology that effectively eliminates the threat from CAHs. To improve the permeability and bioavailability of EVO in the low-permeability substratum, nano-emulsified vegetable oil (nanoEVO) can be synthesized using a modified phase inversion composition method (MPIC) by increasing the emulsification temperature that reduces the shear force required for the formation of nanodroplets and the interfacial tension between the mixed phase and water. The emulsification temperature of 60 °C, the water content of 40–70%, the droplet diameter (DD) of nanoEVO prepared by MPIC is ∼200 nm, and had good monodispersion (≤0.2). The high molecular weight and low solubility of vegetable oil, and similar size of droplet make nanoEVO remains homogeneous after storage for > one year. NanoEVO can effectively biostimulate indigenous bacteria in CAHs-contaminated groundwater to dechlorinate 1,1,2-trichloroethane (1,1,2-TCA) to ethene via vinyl chloride (VC). The maximum dihaloelimination rate of 1,1,2-TCA was ∼66.06 μM·Cl−·day−1 and the maximum hydrogenolysis rate of VC was ∼35.67 μM·Cl−·day−1. NanoEVO effectively increased the relative abundance of Dehalococcoides from <0.10 to 9.61%. The abundances of Dhc 16S rRNA gene and dehalogenase gene vcrA increased by 102 and 103, respectively. Biostimulation shaped the structure of microbial communities and promoted hydrolytic acidification and anaerobic fermentation. Moreover, the syntrophic VFA-oxidizing bacteria participated in secondary fermentation and were closely correlated with H2 consumption metabolism. By providing carbon sources and maintaining an anaerobic environment with stable pH and ORP, nanoEVO biostimulated the hydrolytic acidification led by fermentative bacteria, secondary fermentation with syntrophic VFA-oxidizing bacteria and reductive dechlorination carried out by dechlorinator, thus greatly increasing the CAH-dechlorinating ability of indigenous microbial communities.

Effectiveness of different antioxidants in suppressing the evolution of thermally induced peroxidation products in hemp seed oil

Several scientific studies have warned that the ingestion of dietary lipid oxidation products (LOPs) may initiate or exacerbate the development of several chronic non-communicable diseases in humans. Indeed, the constantly increasing consumption of culinary oils by larger global populations indicates the need for scientific techniques to suppress the evolution of LOPs in thermo-oxidised oils. This study employed a 600.13 MHz frequency NMR spectrometer in evaluating the effect of 10, 50, and 100 ppm concentrations of chemical compounds reported to have antioxidant properties in continuously-stirred and thermally stressed polyunsaturated fatty acid (PUFA)-rich hemp seed oil at a frying temperature of 180℃ for 180 min. Research data acquired showed that the antioxidants α- and γ-tocopherol, γ-oryzanol, β-carotene, eugenol, resveratrol, ascorbyl palmitate, gentisic acid, and L-ascorbic acid all played a vital role in suppressing the evolution of secondary aldehydic lipid oxidation products in hemp seed oil. However, the most ineffective LOP-suppressing agent was L-lysine, an observation which may be accountable by its poor oil solubility. Nonetheless, trends deduced for compounds acting as antioxidants were mainly unique for each class of agent tested. Conversely, the antioxidant capacity of resveratrol was consistently higher, and this effect was found to be independent of its added amounts. This report provides a direct approach in developing scientific methods for the suppression of LOPs in thermo-oxidatively susceptible PUFA-rich cooking oils.

Machine learning methods for predicting CO2 solubility in hydrocarbons

The application of carbon dioxide (CO2) in enhanced oil recovery (EOR) has increased significantly, in which CO2 solubility in oil is a key parameter in predicting CO2 flooding performance. Hydrocarbons are the major constituents of oil, thus the focus of this work lies in investigating the solubility of CO2 in hydrocarbons. However, current experimental measurements are time-consuming, and equations of state can be computationally complex. To address these challenges, we developed an artificial intelligence-based model to predict the solubility of CO2 in hydrocarbons under varying conditions of temperature, pressure, molecular weight, and density. Using experimental data from previous studies, we trained and predicted the solubility using four machine learning models: support vector regression (SVR), extreme gradient boosting (XGBoost), random forest (RF), and multilayer perceptron (MLP). Among four models, the XGBoost model has the best predictive performance, with an R2 of 0.9838. Additionally, sensitivity analysis and evaluation of the relative impacts of each input parameter indicate that the prediction of CO2 solubility in hydrocarbons is most sensitive to pressure. Furthermore, our trained model was compared with existing models, demonstrating higher accuracy and applicability of our model. The developed machine learning-based model provides a more efficient and accurate approach for predicting CO2 solubility in hydrocarbons, which may contribute to the advancement of CO2-related applications in the petroleum industry.

Effect of in-situ emulsification on CO2/N2-based cyclic solvent injection process for enhancing heavy oil recovery and CO2 storage

Surfactant-assisted CO2/N2-based CSI (SA CO2/N2-CSI) process emerges as a strategic solution to migrate the high energy consumption and carbon intensity associated with traditional thermal operations for heavy oil recovery. However, the interphase mass transfer makes the emulsification behavior in this process complex. In this study, the effect of in-situ emulsification on CO2/N2-CSI is assessed using a sandpack model and microchannel chip. Mesoscopically, SA CO2/N2-CSI outperforms conventional CO2/N2-CSI in terms of both oil recovery and CO2 storage, owing to the enhanced CO2 diffusion, oil solubilization, and foamy oil stability due to emulsification. Microscopically, the impact of emulsifier injection rate on oil removal efficiency in the dead-end pores becomes negligible when the injection rate exceeds 50 nL/min, providing insights to the emulsification mechanisms underlying the optimal pressure depletion rate (9 kPa/min) in SA CO2/N2-CSI. This study demonstrates the applicability of the SA CO2/N2-CSI in fostering sustainable heavy oil production and CO2 storage.

Synthesis of long straight‐chain alkane substituted ferrocene with ultra‐robust oil solubility as multifunctional organometallic additive

Tailoring of organometallics structure toward desirable properties continues to be both fascinating and challenging in the field of materials science. Herein, a novel ferrocene derivative with long straight‐chain alkane mono‐substituent is synthesized and used as multifunctional organometallic additive in the base oil. This ferrocene‐based organometallic compound (MFc) is synthesized via the Friedel‐Crafts acylation of ferrocene with myristyl chloride, followed by reduction with sodium borohydride. The chemical structure, crystallizability, surface morphology, and the thermal properties of the as‐synthesized compound are systematically characterized. As the iron‐containing standard substance, the MFc was preferable dissolve in lubricating oil with the iron element content as high as 2*105 ppm. Resultantly, the MFc/oil solutions exhibited excellent stability even after high‐speed centrifugal treatment, long‐term storage up to 3 months, and ultra‐low temperature treatment at −40°C for 24 h. Moreover, the MFc as a functional lubricant additive could reduce the average wear scar diameter, wear volume, and coefficient of friction with 40%, 73%, and 18%, respectively, as compared to the corresponding pure base oil. This synthetic strategy provides a novel perspective for the design of functional organometallics, and the as‐synthesized novel ferrocene derivative may find a wide range of advanced potential applications in analytical chemistry, tribology, and interfacial science.

Developing statistical and machine learning models for predicting CO2 solubility in live crude oils

CO2 solubility in crude oil primarily affects the viscosity and swelling capacity of oil and determines the displacement efficiency of CO2 flooding during the enhanced oil recovery process. Dissolution of CO2 into crude oil also ensures safe and permanent storage of CO2 in depleted formations via solubility trapping. This study employed statistical and machine learning algorithms to develop precise and stable predictive models for estimating CO2 solubility in crude oils with dissolved gas. Recognizing the limitations of existing experimental data on CO2 solubility for live oils (crude oils with dissolved gas), we introduced a novel approach employing statistical and machine learning techniques for developing accurate and robust predictive models. Our methodology combined regularization, k-fold cross-validation, and statistical significance tests to ensure the robustness of the models, practices not considered in the previous studies. A linear regression model with L2 regularization is developed as the base model and compared with a 2nd order polynomial model and an ensemble feed-forward neural network (FNN) model integrated with gradient boosting (GB). The incorporation of GB into the neural network capitalizes on the additive sequence of FNN models, thereby enhancing the accuracy and reliability of predictions. Moreover, an improved user-accessible and easily implementable correlation is proposed to estimate CO2 solubility in live crude oils at diverse operating conditions as a function of reservoir temperature, saturation pressure, bubble-point pressure, oil molecular weight, and specific gravity. The performances of the developed model and the correlation are compared against the literature models and correlations. The FNN model with an overall R2 score of 0.9978, average absolute relative deviation (AARD) of 1.54 %, and root mean squared error (RMSE) of 0.0083 outperformed the previously published models and correlations. The new correlation, while being relatively simpler than previously published correlations, showed similar predictive performance with an overall R2 score of 0.9817, AARD of 4.98 %, and RMSE of 0.0225. The model and the correlation can be used to estimate CO2 solubility in live crude oils with 0.67 to 0.97 specific gravity for reservoir temperatures and pressures in the range of 28 to 124 °C and 3.23 to 32.76 MPa, respectively.

An improved method for determining the water number for surfactants

Surfactants have a significant role in everyday life and various industries. Their amphipathic nature significantly influences their properties, functions, and applicability. The ratio of water and oil solubility is characterized by the HLB value (hydrophilic-lipophilic balance) or the closely related water number.A determination of the water number of surfactants represents the amount of water that a surfactant can incorporate into a microemulsion. The results of measuring the water number provide information about the hydrophilic properties of the surfactant in question. Understanding the water number helps determine the applicability of surfactants. From the water number of surfactants, conclusions can be drawn about the HLB value of the particular surfactant, providing further insights into its properties. Although a well-established method for determining water number has long been available, it has been revealed that many of the auxiliary substances and chemicals used in this process have severe health-damaging effects, leading to their discontinuation in routine laboratory use.Our goal was to find a solvent combination that would be suitable for the water number determination method. Additionally, we aimed to investigate solvents that are environmentally and human-biologically less harmful, easily and affordably obtainable.•The study presents a method for determining the water number of surfactants.•The method is straightforward to execute and free from harmful solvents.•By improving the method, we enhanced the reliability of the examination.