Physical, morphological and storage stability of Clove oil nanoemulsion based delivery system

Clove oil based Nanoemulsions (NE) were prepared ultrasonically using Tween 80 and soy lecithin as synthetic and natural surfactants, respectively. The developed NEs were characterized for various parameters (particle size, polydispersity index, zeta potential, morphology, viscosity, colour, turbidity and pH) and the comparative effect of both the surfactants at variable levels (oil:tween 80-1:1, 1:2, 1:3 and 1:4 and oil: soy lecithin- 1:1, 1:1.5 and 1:2) was assessed. It was found that the type of surfactant and oil to surfactant ratio significantly affected particle size and stability of NEs. The NE prepared using tween 80 @1:3 had smallest average droplet diameter (40.9 nm). The formulated NEs were stored at 25 °C and 4 °C and analyzed for turbidity, pH and phase separation up to 90 days. Results revealed that the type and concentration of the surfactant significantly influenced the particle size and stability of NEs. NEs prepared using tween 80 were found to be more viscous than those prepared with soy lecithin. The prepared clove oil NEs have important implication to be used as a natural delivery system to increase the shelf life of food products.

Low-cost production and application of lipopeptide for bioremediation and plant growth by Bacillus subtilis SNW3

At present time, every nation is absolutely concern about increasing agricultural production and bioremediation of petroleum-contaminated soil. Hence, with this intention in the current study potent natural surfactants characterized as lipopeptides were evaluated for low-cost production by Bacillus subtilis SNW3, previously isolated from the Fimkessar oil field, Chakwal Pakistan. The significant results were obtained by using substrates in combination (white beans powder (6% w/v) + waste frying oil (1.5% w/v) and (0.1% w/v) urea) with lipopeptides yield of about 1.17 g/L contributing 99% reduction in cost required for medium preparation. To the best of our knowledge, no single report is presently describing lipopeptide production by Bacillus subtilis using white beans powder as a culture medium. Additionally, produced lipopeptides display great physicochemical properties of surface tension reduction value (SFT = 28.8 mN/m), significant oil displacement activity (ODA = 4.9 cm), excessive emulsification ability (E24 = 69.8%), and attains critical micelle concentration (CMC) value at 0.58 mg/mL. Furthermore, biosurfactants produced exhibit excellent stability over an extensive range of pH (1–11), salinity (1–8%), temperature (20–121°C), and even after autoclaving. Subsequently, produced lipopeptides are proved suitable for bioremediation of crude oil (86%) and as potent plant growth-promoting agent that significantly (P < 0.05) increase seed germination and plant growth promotion of chili pepper, lettuce, tomato, and pea maximum at a concentration of (0.7 g/100 mL), showed as a potential agent for agriculture and bioremediation processes by lowering economic and environmental stress. Graphical Abstract

Technologies Involved in the Demulsification of Crude Oil

Due to the use of enhanced recovery processes that necessitate the use of a considerable amount of water, mature petroleum reservoirs generate crude oil with huge amounts of water. The majority of this water gets emulsified into crude oil during production, increasing viscosity and making flow more difficult, resulting in production, transportation, and refining operational challenges that have an influence on corporate productivity. Natural surfactants with a strong potential to create stable emulsions are naturally mixed with crude oils. Because crudes with a high amount of stable emulsion have a lower value, the stable emulsion must be adequately processed to meet industrial requirements. As a result, basic research on natural surfactants that contribute to emulsion stability is examined in order to effectively separate emulsions into oil and water. This would need a review of various emulsification methods as well as the proper formulation for effective demulsification. The petroleum industry recognizes the importance of an efficient demulsification procedure for treating emulsions. Numerous studies on the mechanisms of emulsification and demulsification have been undertaken for decades. To guarantee optimal hydrocarbon output, effective treatment is required. The present paper is to review reported works on the formation of petroleum emulsions, demulsification treatments, and characteristics of fit-for-purpose demulsifiers as well as research trends in emulsion treatment.

Preliminary evaluation of a natural surfactant extracted from Myrtus communis plant for enhancing oil recovery from carbonate oil reservoirs

Surfactants are among the materials used to improve water properties for injection into oil reservoirs, and reduce injection phase and crude oil interfacial tension (IFT). Recently, the interest in the use of natural surfactants has increased and is constantly on the rise to solve some challenges of using chemical surfactants such as incompatibility with the environment and the high cost. In this study, we have used aqueous extract of powdered leaf of Myrtus communis as an available source of natural surfactant. The extracted surfactant was characterized by TGA, 1H NMR and FTIR techniques. The surfactant efficiency was demonstrated by performing some experiments including IFT and injection of chemical slug and surfactant into carbonate plugs. The surfactant adsorption on carbonate rock was also studied. It was observed that this natural surfactant can reduce IFT to 0.861 mN/m at surfactant critical micelle concentration (CMC) of 5000 ppm. This minimum IFT was further reduced at optimum salinity and alkali. Finally, an increase of 14.3% oil recovery by surfactant flooding and 16.4% oil recovery by ASP slug injection containing NaOH alkali and partially hydrolyzed polyacrylamide (PHPA) polymer with 0.5 PV volume from carbonate plugs was achieved.

Whey Proteins as a Potential Co-Surfactant with Aesculus hippocastanum L. as a Stabilizer in Nanoemulsions Derived from Hempseed Oil

The use of natural surfactants including plant extracts, plant hydrocolloids and proteins in nanoemulsion systems has received commercial interest due to demonstrated safety of use and potential health benefits of plant products. In this study, a whey protein isolate (WPI) from a byproduct of cheese production was used to stabilize a nanoemulsion formulation that contained hempseed oil and the Aesculus hippocastanum L. extract (AHE). A Box–Behnken experimental design was used to set the formulation criteria and the optimal nanoemulsion conditions, used subsequently in follow-up experiments that measured specifically emulsion droplet size distribution, stability tests and visual quality. Regression analysis showed that the concentration of HSO and the interaction between HSO and the WPI were the most significant factors affecting the emulsion polydispersity index and droplet size (nm) (p < 0.05). Rheological tests, Fourier transform infrared spectroscopy (FTIR) analysis and L*a*b* color parameters were also taken to characterize the physicochemical properties of the emulsions. Emulsion systems with a higher concentration of the AHE had a potential metabolic activity up to 84% in a microbiological assay. It can be concluded from our results that the nanoemulsion system described herein is a safe and stable formulation with potential biological activity and health benefits that complement its use in the food industry.

Reducing THI Injection and Gas Hydrate Agglomeration by Under-Inhibition of Crude Oil Systems

Gas hydrates constitute a serious flow assurance problem. Over the last decades, industry has faced this problem by using avoidance methods (e.g. injection of thermodynamic hydrate inhibitors) and management strategies (e.g. addition of hydrate anti-agglomerants). In the former, hydrates are completely avoided by shifting the hydrate boundary towards higher pressure and lower temperatures; in the latter, hydrates are allowed to form but their tendency to agglomerate is reduced. It should be noted that some crude oils are naturally able to avoid hydrate agglomeration, this non-plugging tendency may originate from the surfactant-like behavior of fractions like asphaltenes and acids. Recent works have shown that the natural non-plugging potential of certain oils can be affected by the addition of polar molecules like alcohols. There is another strategy for managing hydrate that consist of the addition of THIs at a concentration lower that the one required to full hydrate inhibition. In this case, hydrates are under-inhibited. Studies carried out on hydrate agglomerating systems have shown that under-inhibition might prevent hydrate agglomeration only in a specific range of THI concentrations and sub-cooling; however, work on non-plugging oils is scarce. In this paper, the hydrate agglomeration of two crude oils under-inhibited with methanol and MEG was evaluated through a visual rocking cell apparatus and a high-pressure rheometer. Results showed that THIs and the crude oil's natural surfactants were capable of acting synergistically in reducing hydrate agglomeration and improving the system flowability.

Plant-Derived Saponins: A Review of Their Surfactant Properties and Applications

Increasing environmental concern and consumer demand for natural, sustainable and eco-friendly products have prompted the replacement of synthetic surfactants with their natural plant-based alternatives. Saponins are the plant based natural surfactants characterized by their foam forming properties in aqueous solution. Their natural origin makes them eco-friendly, bio-degradable and non-toxic. Further, they possess better physicochemical properties than the syn-thetic ones. They are also reported to exhibit a lot of useful biological activities such as anti-cancer, antifungal, anti-inflammatory, antimicrobial, antioxidant and cholesterol-lowering properties. Because of their excellent surface activity, biological activities and wide distribution in nature, saponin rich plants deserve deeper insight as a sustainable source of natural surfactants as they possess the potential to replace toxic synthetic surfactants abundant today. This review article is intended to provide a brief overview on the saponins with a special notion on their surface-active properties. It encourages further studies on development of commercial formulations based on saponins for the complete replacement of the synthetic counter parts, making better use of plants sources thereby contributing to global agenda of green environment.

The Oscillatory Spinning Drop Technique. An Innovative Method to Measure Dilational Interfacial Rheological Properties of Crude Oil-Brine Systems in the Presence of Asphaltenes

The oscillatory spinning drop method has been proven recently to be an accurate technique to measure dilational interfacial rheological properties. It is the only available equipment for measuring dilational moduli in low interfacial tension systems, as it is the case in applications dealing with surfactant-oil-water three-phase behavior like enhanced oil recovery, crude oil dehydration, or extreme microemulsion solubilization. Different systems can be studied, bubble-in-liquid, oil-in-water, microemulsion-in-water, oil-in-microemulsion, and systems with the presence of complex natural surfactants like asphaltene aggregates or particles. The technique allows studying the characteristics and properties of water/oil interfaces, particularly when the oil contains asphaltenes and when surfactants are present. In this work, we present a review of the measurements of crude oil-brine interfaces with the oscillating spinning drop technique. The review is divided into four sections. First, an introduction on the oscillating spinning drop technique, fundamental and applied concepts are presented. The three sections that follow are divided according to the complexity of the systems measured with the oscillating spinning drop, starting with simple surfactant-oil-water systems. Then the complexity increases, presenting interfacial rheology properties of crude oil-brine systems, and finally, more complex surfactant-crude oil-brine systems are reviewed. We have found that using the oscillating spinning drop method to measure interfacial rheology properties can help make precise measurements in a reasonable amount of time. This is of significance when systems with long equilibration times, e.g., asphaltene or high molecular weight surfactant-containing systems are measured, or with systems formulated with a demulsifier which is generally associated with low interfacial tension.