Demulsifying water-in-oil emulsions by ethyl cellulose demulsifiers studied using focused beam reflectance measurement

Aromatic poly (amino acids) as an effective low-temperature demulsifier for treating crude oil-in-water emulsions

Amphiphilic aromatic poly (amino acids) polymers were designed as biodegradability demulsifiers with higher aromaticity, stronger polarity, and side chain-like combs. The effects of demulsifier dosage, structural characteristics and emulsion properties such as pH, salinity, and oil content on the demulsification efficiency were investigated. The results show that the poly (L-glutamic-benzyl ester)-block-poly (L-phenylalanine) (PBLG15-b-PPA15) as the demulsifier can remove more than 99.97% of the oil in a 5.0 wt% oil-in-water (O/W) emulsion at room temperature within 2 min. The poly (L-tyrosine)-block-poly (L-phenylalanine) (PTyr15-b-PPA15) with environmental durability demonstrates high effectiveness, universality, and demulsification speed. It achieves a remarkable demulsification efficiency of up to 99.99% for a 20.0 wt% O/W emulsion at room temperature. The demulsification mechanism indicates that demulsifiers have sufficient interfacial activity can quickly migrate to the oil-water interface after being added to the emulsions. Additionally, when demulsifiers are present in a continuous phase in the molecular form, their "teeth" side chains are beneficial for increasing coalescence and flocculation capacities. Furthermore, according to the Density Functional Theory (DFT) calculations, enhancing the intermolecular interactions between demulsifiers and the primary native surfactants that form an oil-water interfacial film is a more efficient approach to reducing demulsification temperature and improving demulsification efficiency and rate.

Demulsification of Crude Oil Emulsions Using Versatile and Eco-Friendly Demulsifiers Based on Cellulose Decorated with Imidazolium-Bearing Triazole Moiety

Water in the crude oil forms emulsions that must be broken before refining processes. Here, the novel and versatile derivatives of imidazolium ionic liquids (ILs) containing triazole moiety [SIm-TazCn][Br] were synthesized via click chemistry and then grafted onto the cellulose (CEL) to prepare eco-friendly demulsifiers for breaking water-in-oil (W/O) emulsions. The prepared compounds with two kinds of alkyl chains named CEL[SIm-TazC6][Br] and CEL[SIm-TazC10][Br] were characterized and employed for demulsifying W/O (30:70 and 50:50 vol %) emulsions. Also, the effect of the type and concentration of each demulsifier on the phase separation and dehydration efficiency (DE) were investigated through the bottle test. According to the bottle test results, the CEL[SIm-TazC6][Br] derivative at 4000 ppm showed a good DE of 79% after 5 min, which increased to 82% after 24 h. The interfacial tension (IFT) of derivatives at different concentrations was measured. The minimum IFT value of 16.3 mN/m was obtained for CEL[SIm-TazC6][Br] with a shorter alkyl chain at 4000 ppm after 24 h. The green and efficient CEL-based surfactants significantly demulsified the W/O emulsions because of the collaboration between imidazolium and triazole moieties.

Process Analytical Technology for the Production of Parenteral Lipid Emulsions According to Good Manufacturing Practices

The good manufacturing practices (GMP) and process analytical technology (PAT) initiatives of the US Food and Drug Administration, in conjunction with International Council for Harmonisation (ICH) quality guidelines Q8, Q9, and Q10, ensure that manufacturing processes for parenteral formulations meet the requirements of increasingly strict regulations. This involves the selection of suitable process analytics for process integration and aseptic processing. In this article, we discuss the PAT requirements for the GMP-compliant manufacturing of parenteral lipid emulsions, which can be used for clinical nutrition or for the delivery of lipophilic active ingredients. There are risks associated with the manufacturing processes, including the potential for unstable emulsions and the formation of large droplets that can induce embolisms in the patient. Parenteral emulsions are currently monitored offline using a statistical approach. Inline analytics, supplemented by measurements of zeta potential, could minimize the above risks. Laser scanning technology, ultrasound attenuation spectroscopy, and photo-optical sensors combined with image analysis may prove to be useful PAT methods. In the future, these technologies could lead to better process understanding and control, thus improving production efficiency.

Demulsification of Heavy Oil-in-Water Emulsion by a Novel Janus Graphene Oxide Nanosheet: Experiments and Molecular Dynamic Simulations

Various nanoparticles have been applied as chemical demulsifiers to separate the crude-oil-in-water emulsion in the petroleum industry, including graphene oxide (GO). In this study, the Janus amphiphilic graphene oxide (JGO) was prepared by asymmetrical chemical modification on one side of the GO surface with n-octylamine. The JGO structure was verified by Fourier-transform infrared spectra (FTIR), transmission electron microscopy (TEM), and contact angle measurements. Compared with GO, JGO showed a superior ability to break the heavy oil-in-water emulsion with a demulsification efficiency reaching up to 98.25% at the optimal concentration (40 mg/L). The effects of pH and temperature on the JGO’s demulsification efficiency were also investigated. Based on the results of interfacial dilatational rheology measurement and molecular dynamic simulation, it was speculated that the intensive interaction between JGO and asphaltenes should be responsible for the excellent demulsification performance of JGO. This work not only provided a potential high-performance demulsifier for the separation of crude-oil-in-water emulsion, but also proposed novel insights to the mechanism of GO-based demulsifiers.

Laser-structured superhydrophobic/superoleophilic aluminum surfaces for efficient oil/water separation

The current demand for oil/water separation with an efficient, cost-effective, and environmentally friendly method is increasing. A laser-structured superhydrophobic/superoleophilic aluminum was prepared by using a nanosecond laser. The aluminum plate was used for oil/water separation without external force, which can replace the traditional porous materials. The effect of hole diameter and spacing on the effectiveness of oil/water separation is discussed. The results show that the aluminum plate with a hole size of 0.5 mm can be considered a more appropriate choice for the oil/water mixtures with large water content. In addition, complete separation of oil and water can be achieved in the hole spacing range of 1.0-3.0 mm. The oil separation speed can be increased without changing the water permeability by reducing the hole spacing, which is positively related to the hole spacing. Separation efficiencies were tested with various oil/water mixtures. The aluminum plate with a hole size of 0.5 mm can quickly separate the different oil mixtures with less than 50% oil content while achieving an oil separation efficiency of up to 99%. Due to the difference in dynamic viscosity of various oil phases, the separation efficiencies of the petrol, kerosene, and diesel are slightly different but can still be maintained above 99%. The laser-processed aluminum plate has several advantages of high porosity, high surface of superhydrophobic properties, and easy tunable structures. In practical applications, the hole size and the spacing should be appropriately adjusted according to specific conditions, such as different oils, the mixing ratios, etc., to obtain the best separation efficiency and speed.

Smart systems for determination of drug's solubility

The solubility of drugs is a crucial physicochemical property in the drug discovery or development process and for improving the bioavailability of drugs. There are various methods for evaluating the solubility of drugs including manual measurement methods, mathematical methods, and smart methods. Manual measurement and mathematical methods have some defects which make the smart systems more reliable and important in this field. In this review, various instruments used for the solubility determination, along with the smart systems, have been discussed. Mechanism and applications of each method have been elaborated in detail. Moreover, unique characteristics as well as some limitations of discussed methods are also described.

Flocculating and dewatering performance of hydrophobic and hydrophilic solids using a thermal-sensitive copolymer

Thermal-sensitive polymers have been tested on settling, compacting or dewatering of clays or oil sand tailings. However, not much attention has been paid to explore the effect of temperature on flocculating performance using thermal-sensitive polymers. In this study, poly(NIPAM-co-DMAPMA) was synthesized and employed to investigate the flocculating and re-flocculating performance of hydrophilic and hydrophobic particles at two specific temperatures; meanwhile settling and dewatering behaviors were also investigated. The results demonstrated that good flocculating performances were achieved at both room temperature (∼23 °C) and lower critical solution temperature (45 °C). Furthermore, larger flocs were formed at 45 °C as the copolymer was added. Floc strength and re-flocculating ability of the flocs were also intensified prominently at 45 °C. Additionally, settling and dewatering rates of suspensions were improved, and the moisture of filtered cakes was reduced when suspensions were at 45 °C. The phenomena could be justified by the phase transition of the copolymer from hydrophilicity to hydrophobicity as the temperature increased. There were much stronger adhesion forces between particles and higher adsorption amount of the copolymer onto solid surfaces at 45 °C. Therefore, the copolymer may be promising in solid-liquid separation to improve the floc size, floc strength, and settling and dewatering rate to achieve much lower moisture filtered cake.

Effect of pH on the flocculation behaviors of kaolin using a pH-sensitive copolymer

pH-sensitive copolymers have been widely introduced to achieve rapid dewatering and consolidation of solids in mining and oil sands processing wastes. But no more attention has been given to the flocculation efficiency of solid suspensions as a function of pH using pH-sensitive copolymer. In this study, a pH-sensitive copolymer was synthesized and employed to investigate the flocculation behaviors of kaolin by focused beam reflectance measurement (FBRM). A titration test was introduced to characterize the copolymer conformation transition. The results demonstrated that at pH ranging from 3 to 6, with the pH increase, the zeta potential magnitude of kaolin particles increased, resulting in the repulsive forces between particles increasing. However, the hydrophobicity of kaolin increased as the pH increased. Thus, the hydrophobic forces could neutralize a part of the repulsive forces between particles and result in good and similar flocculation performances. At the pH greater than 6, the zeta potential magnitude of kaolin particles and copolymer molecules increased significantly, and the repulsive force between kaolin particles increased after copolymer addition due to the kaolin particles being more negatively charged, which resulted in poor flocculation efficiency and cloudy supernatant. It was concluded that the pH-sensitive copolymer could achieve both perfect flocculation efficiency and low moisture of filter cake at the isoelectric point of copolymer.