Demulsification Efficiency of Some New Demulsifiers Based on 1,3,5-Triethanolhexahydro-1,3,5-triazine

This study mainly concentrates on the synthesis of three novel demulsifiers and the investigation of their demulsification efficiency. The demulsifiers were derived from 1,3,5-triethanolhexahydro-1,3,5-triazine, which was prepared by the reaction of monoethanol amine with formaldehyde. The 1,3,5-triethanolhexahydro-1,3,5-triazine was ethoxylated by introducing 20 units of ethylene oxide and then esterified at different molar ratios with oleic acid (1, 2, and 3) to give three demulsifiers, namely, E₂₀TO, E₂₀TO₂, and E₂₀TO₃. The chemical structures of the prepared demulsifiers were confirmed by ¹H NMR and FTIR spectrum. The demulsification efficiency of these demulsifiers was tested on the natural water-in-oil (w/o) emulsions (50% water content). From the obtained results, it has been found that the investigated demulsifiers have a great potential to break the w/o emulsions. The trioleat ester (E₂₀TO₃) exhibited the maximum demulsification efficiency (96%) after 120 minutes at 55°C.     

Surface Active and Thermodynamic Properties in Relation to the Demulsification Efficiency for Some Ethoxylated Derivatives of Alkyldiamines and Polyalkylenepolyamines

In this work, nine monostearic esters of ethoxylated dialkyle-amine (group I) and ethoxylated polyalkylenepolyamine (group II) nonionic surfactants were prepared and characterized by FTIR spectroscopy and nitrogen content. The 1,4-diaminobutane (DAB), 1,6 diamino hexane (DAH), 1,8-diamino-octane (DAO), diethylenetriamine (DETA), triethylenetetramine (TETA), and tetraethylenepentamine (TEPA) were ethoxylated at 50, 100, 150 ethylene oxide units individually. The ethoxylated products of (group I) reacted with stearic acid to give the monostearate products. The surface tension of the prepared compounds were measured at 25°C and 60°C. The thermodynamic parameters of micellization and adsorption were also calculated. The surface active properties, such as critical micelle concentration (CMC), maximum surface excess concentration (Γ_max), effectiveness of surface tension reduction (π_cmc), and minimum area per molecule at the aqueous solution-air interface (A_min), have been calculated. The surface active and thermodynamic properties of the prepared compounds were correlated to their chemical structure. It was found that CMC decreases when increasing the molecular weight of polyethylene oxide units. Furthermore, the data show that the synthesized surfactants favor adsorption than micellization, so that they can be used as demulsifiers for waxy crude oil emulsion (BSW 18%). In this respect, the demulsification test was carried out and the results of demulsification efficiency were correlated to the chemical composition of the investigated compounds. Some factors that affect the demulsification efficiency were also considered such HLB, concentration and time. The maximum demulsification efficiency (100%) was obtained by DAOE_150-M and TEPAE₁₅₀ at 60 and 45 minutes (300 ppm), respectively.     

Investigation of the Demulsification Efficiency of Some Ethoxylated Polyalkylphenol Formaldehydes Based on Locally Obtained Materials to Resolve Water-in-Oil Emulsions

Fourteen ethoxylated polyalkylphenol formaldehyde surfactants were prepared from locally sourced raw materials. These surfactants were used as demulsifiers to resolve asphltenic crude oil emulsions. Different factors affecting demulsification efficiency such as water:oil ratios, surfactant concentration, surfactant molecular weight, ethylene oxide content, alkyl chain length, and asphaltene content were investigated. From the data obtained it was found that the demulsification efficiency increases by increasing the concentration, alkyl chain length and water content in the emulsion. Also it was found that the increase of asphaltene content in the crude oil impeded the demulsification efficiency. The effect of molecular weight was studied and it was found that the demulsification efficiency was controlled by an optimum range of molecular weight between 3640 to 3810 for the family of demulsifiers studied. Regarding the effect of ethylene oxide content in the demulsifier structure, it was found that the maximum demulsification efficiency was obtaind at 40 units ethylene oxide. The maximum demulsification efficiency was obtained by TND5 (m.wt. = 3800, eo = 40 units). With this demulsifier 100% water separation was exhibited after 35 minutes at 150 ppm demulsifier concentration and 50% w/o emulsion. The surface, interfacial tension, and hydrophilic lipophilic balance (HLB) of the invistigated demulsifers were studied. The obtained results justified that they are strongly related to the demulsification effeciency.     

磁性可回收氟化石墨烯破乳材料的制备及乳液分离性能

以氟化石墨烯(FG)为原料, 首先制备了水合肼还原的具有一定亲水性的氟化石墨烯(HFG), 然后采用溶剂热法制备了可磁性分离的四氧化三铁负载的氟化石墨烯复合破乳材料(HFG-Fe₃O₄). 分别利用透射电子显微镜(TEM)、 扫描电子显微镜(SEM)、 傅里叶变换红外光谱仪(FTIR)、 X射线粉末衍射仪(XRD)和X射线光电子能谱仪(XPS)对HFG-Fe₃O₄的形貌、 结构和化学性质进行了表征. 最后研究了HFG-Fe₃O₄对含油废水的破乳性能, 探讨了影响其破乳性能的主要因素, 并对其破乳机理进行了分析. 结果表明: HFG-Fe₃O₄是一种表面负载有Fe₃O₄纳米颗粒的二维片状材料, 在最佳剂量为600 mg/L时对酸性和中性含油废水具有良好的破乳效果. 在酸性和中性条件下, 主要是利用HFG-Fe₃O₄与含油废水之间的静电吸引力以及HFG-Fe₃O₄与沥青质之间的π-π相互作用实现油-水分离. 但是, 在碱性条件下, HFG-Fe₃O₄与油滴之间的静电斥力将急剧增大, 最终导致破乳效率降低. 此外, 将磁性回收的HFG-Fe₃O₄循环利用4次后其乳液分离效率并没有明显下降, 表现出优异的循环稳定性.     

Demulsification and Interfacial Properties of Crosslinking Phenol-Amine Resin Block Polyether Demulsifiers

Six novel crosslinking phenol-amine resin block polyether demulsifiers were synthesized for demulsification of surfactant-polymer flooding emulsion. The demulsification performances of these demulsifiers were investigated by conventional graduated bottle test. Their interfacial behaviors at water-oil interface were explored by dynamic interfacial tension and interfacial dilational viscoelasticity measurements. The results show that the demulsification efficiency is dependant on the hydrophilic-hydrophobic balance (HLB) value of these demulsifiers. It was also correlated to the interfacial activity and the dilational elasticity at the water-oil interface. The higher the HLB value of demulsifiers, the better the demulsification efficiency is.     

Demulsification of water-in-oil emulsion by wetting coalescence materials in stirred- and packed-columns

Demulsification of emulsified water-in-oil droplets was developed using wetting coalescence materials. Demulsification tests were carried out using conventional stirred- and packed-columns. Of the four kinds of natural fibers and two kinds of inorganic materials tested, natural fiber A, selected from shaves of a wood showed the best performance in demulsification. The demulsification efficiency can exceed 97% when demulsification conditions are optimized. The packed-column showed much better performance both in terms of demulsification efficiency and repeated use of the recovered oil phase for extracting cadmium in a simulated wastewater. Operating variables that govern the demulsification efficiency were investigated.     

Synthesis and Evaluation of New Demulsifiers Incorporating Linear Alkyl Benzene Moiety for Treating Water-in-Oil Emulsion

In the present study, five types of water soluble demulsifiers based on linear alkyl benzene were prepared. The chemical structures of the prepared demulsifiers were elucidated using Fourier transform-infrared (FTIR) and ¹H NMR spectra. Different factors affecting demulsification efficiency such as; water content, demulsifier concentration, hydrophilic lipophilic balance (HLB), and ethylene oxide unit were investigated. Also, the rheological properties in relation to demulsification efficiency were studied. The surface and thermodynamic parameters of the prepared demulsifiers were determined at 25°C including, surface tension (γ) and effectiveness, maximum surface excess (Γ_max), and minimum surface area (A_min). From the obtained data, it was found that the demulsification efficiency increases with increasing the water content and concentration of the demulsifiers. Primarily evaluation study of demulsification performance of the new demulsifiers showed that as the ethylene oxide unit in the demulsifiers increase (10–40 ethylene oxide units), the performance of the demulsifiers increasing, however, it decrease in case of demulsifiers with (80 ethylene oxide unit).     

Polymeric Surfactants and Emerging Alternatives used in the Demulsification of Produced Water: A Review

Stable emulsions are frequently encountered in oil production and cause a series of environmental and operational issues. Chemical demulsification is widely used for the separation of oil from water or removal of water from oil. The chemicals used in the demulsification process have a strong affinity to the oil-water interface. This review presents the various types of chemical demulsifiers used for the demulsification of water-in-oil and oil-in-water emulsions. The review covers the relevant properties of polymeric surfactants such as polyether, dendrimers, and natural biodegradable polymeric surfactants. In addition, emerging alternatives like nanoparticles-based demulsifiers and ionic liquids are also reviewed. The factors affecting the demulsification efficiency of these demulsifiers and structure-property relationships are discussed. Copolymers with high hydrophilic content and molecular weight are more efficient demulsifiers. Similarly, the position isomerism (same carbon skeleton and functional groups but a different location of functional groups) strongly affects the HLB and demulsification performance. Generally, dendrimers show better performance compared to linear polymeric surfactants due to their relatively higher interfacial activity, better penetrability, and a larger number of reactive terminal groups. Techniques used to evaluate the performance of demulsifiers are also covered. The review also highlights the current developments and future prospects of chemical demulsifiers.     

改性超支化破乳剂的合成及其破乳性能评价

采用新癸酰氯(C₁₀H₁₉CIO)对超支化聚乙烯亚胺(HPEI)进行改性,合成了双亲性超支化破乳剂HPEI-C₁₀,并对其化学组分、热稳定性及润湿性进行了表征。考察了破乳剂的质量浓度、破乳温度、沉降时间以及pH对HPEI和HPEI-C₁₀的破乳效率的影响,并借助偏光显微镜观察破乳过程。结果表明：在质量浓度为50 mg·L^-1、破乳温度为20℃、沉降时间为30 min以及pH为6的条件下,HPEI-C₁₀破乳效率可达91.95%。HPEI-C₁₀在破乳温度为20～60℃时的破乳效率均大于90.00%。与HPEI相比,HPEI-C₁₀具有添加量少、适用温度范围广和沉降时间短等优势,为HPEI-C₁₀的广泛应用提供了数据支撑。     

功能化磁性纳米粒子在乳状液制备及破乳中的应用及作用机制

功能化磁性纳米粒子因其独特的理化性质,在乳状液制备与破乳领域的应用受到广泛关注。本文归纳了功能化磁性纳米粒子的制备方法、合成结构与特征性质,阐述了其在乳状液制备及破乳中的应用过程,重点分析了磁性纳米粒子在溶液中良好分散、稳定吸附于油水界面排布为膜结构的作用行为,尤其是磁性纳米粒子的磁响应特征对乳状液中界面性质、液滴形貌及运动状态的影响,并进一步总结出其表面性质及作用行为对稳定乳状液或使乳状液破乳的规律。针对磁性纳米粒子对乳状液稳定性影响规律的探究可为其在应用领域提供理论支持。最后本文就功能化磁性纳米粒子研究中亟待解决的新问题作出展望。     

支状嵌段聚醚的界面聚集行为及对原油乳状液的破乳作用

合成了三种不同聚氧丙烯/聚氧乙烯(PPO/PEO)比例的含苯环支状嵌段聚醚, 通过界面张力、界面流变、表面压以及对原油乳状液的破乳脱水效果的测定, 考察了其界面聚集行为和破乳作用对PEO含量和分子量的依赖性, 并且对比研究了三种支状聚醚分子交联前后的破乳性能. 结果表明, PEO含量高且分子量大者,其单分子界面占据面积大, 在油/水界面达到吸附平衡的时间短, 其油/水界面扩张模量及扩张弹性均高于PEO含量较少者. 但是对原油乳状液的破乳脱水效果则是PEO含量居中的聚醚最好. 温度影响和交联与否的研究表明, 交联并不能提高分子量较大的聚醚对原油乳状液的破乳效果, 温度对聚醚分子交联前后的破乳效果有不同的影响规律. 本研究可为原油集输过程中化学品的选择与应用提供一定的依据.     

无机盐对支状嵌段聚醚破乳作用的影响

通过阴离子聚合反应合成了一种七支状聚氧丙烯/聚氧乙烯(PPO/PEO)三嵌段聚醚;考察了不同无机盐存在时对原油乳状液的破乳效果的影响;通过界面张力、浊点和界面膨胀流变性的测定探讨了其界面聚集行为和破乳作用对无机盐的依赖性.结果表明,盐溶型无机离子存在时,能提高聚醚的破乳效果,而盐析型无机离子存在时,不利于聚醚的破乳作用;温度升高破乳速度加快,但45℃时脱出的水质最清.     

Screening and Demulsification Mechanism of Fluorinated Demulsifier Based on Molecular Dynamics Simulation

In order to solve the problem of demulsification difficulties in Liaohe Oilfield, 24 kinds of demulsifiers were screened by using the interface generation energy (IFE) module in the molecular dynamics simulation software Materials Studio to determine the ability of demulsifier molecules to reduce the total energy of the oil–water interface after entering the oil–water interface. Neural network analysis (NNA) and genetic function approximation (GFA) were used as technical means to predict the demulsification effect of the Liaohe crude oil demulsifier. The simulation results show that the SDJ9927 demulsifier with ethylene oxide (EO) and propylene oxide (PO) values of 21 (EO) and 44 (PO) reduced the total energy and interfacial tension of the oil–water interface to the greatest extent, and the interfacial formation energy reached −640.48 Kcal/mol. NNA predicted that the water removal amount of the SDJ9927 demulsifier was 7.21 mL, with an overall error of less than 1.83. GFA predicted that the water removal amount of the SDJ9927 demulsifier was 7.41mL, with an overall error of less than 0.9. The predicted results are consistent with the experimental screening results. SDJ9927 had the highest water removal rate and the best demulsification effect. NNA and GFA had high correlation coefficients, and their R²s were 0.802 and 0.861, respectively. The higher R² was, the more accurate the prediction accuracy was. Finally, the demulsification mechanism of the interfacial film breaking due to the collision of fluorinated polyether demulsifiers was studied. It was found that the carbon–fluorine chain had high surface activity and high stability, which could protect the carbon–carbon bond in the demulsifier molecules to ensure that there was no re-emulsion due to the stirring external force.     

Synthesis of LDHs and Rheological Properties of Laponite／LDHs Dispersions

The chemical composition, morphology of the particles of positively charged layered double hydroxides (LDHs) were studied by ICP, Mastersizer, TEM. The preliminary results indicated that with adding LDHs to 1% laponite dispersion the yield stress of laponite/LDHs mixed dispersions increased at first, then decreased dramatically to a minimum, and the yield stress rose again when LDHs increased further.     

Synthesis and Evaluation of Surface Activity of Gemini Borate Surfactants Based on Glucose Moiety

A series of Gemini borate surfactants were synthesized based on glucose molecule. Their chemical structures were confirmed using ¹H-NMR,¹³C nuclear magnetic resonance (NMR), and mass spectroscopy. The surface activities of these Gemini amphiphiles were measured, including surface tension (γ), critical micelle concentration (CMC), effectiveness (II_cmc), efficiency (pC₂₀), maximum surface excess (Γ_max), and minimum surface area (A_min) at different temperatures 25, 35, and 45°C either in pure water or in water–ethanol mixture (10%). Also, thermodynamic data including free energy, entropy, and enthalpy changes (ΔS, TΔS, ΔH) for adsorption at the air–water interface and also for micellization in surfactant solutions were calculated.     

Synthesis and characterization of lower generation broom molecules

Dendritic molecules with dodecyl groups as the hyperbranchs were synthesized in methanol by Michael addition with dodecylamine and methyl acrylate as raw materials. This new-type dendritic molecules were called vividly ＂broom molecules＂ in this report. The surface tension of the aqueous solution of broom molecule terminated amino group was measured by using the dropvolume method. The demulsification performance of the broom molecules for the oil/water （O/W） simulated crude oil emulsion was examined. The experimental results revealed that, as a new-type of surfactants, the broom molecules terminated amino groups showed demulsification for the O/W simulated crude oil emulsion. 2007 Jun Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.     

Synthesis and properties of room-temperature self-healing polyurethane elastomers

Two kinds of polyurethane elastomers were synthesized. One containing acylhydrazone bonds was named TPIA. The other containing both acylhydrazone and disulfide bonds was named TPID. Self-repairable ability and reprocessability of these two elastomers were studied. The results show that: The polyurethane elastomer TPIA can automatically repair damage to it under acidic conditions. After self-healing for 24 h, the strength and the elongation value at break recovered to 32% and 55% of the originality, respectively. The polyurethane elastomer TPID can automatically repair damage to it under visible light at room temperature. After 24 h of self-healing time, 75% of the original strength and 100% of the original elongation values at break were obtained. These two polyurethane elastomers can be reprocessed in their cured state by just applying temperature and pressure.     

Heterogemini Surfactants Based on Fatty Acid Synthesis and Interfacial Properties

A series of novel nonionic surfactants based on fatty acids, each with two hydrophilic and two hydrophobic groups in the molecule (so-called Gemini surfactants), have been synthesized. The hydrophobic part of the surfactant, made from oleylnitrile, has a double bond in the middle of the chain to which the hydrophilic part is attached. One of the hydrophilic groups is a methyl-capped polyoxyethylene chain with 11 or 16 oxyethylene units, whereas the other is a secondary hydroxyl group. The reason for using the nitrile derivative of the fatty acid instead of a more conventional derivative such as an ester or amide is to achieve good hydrolytic stability, which is often demanded for cleaning applications. The cmc values of the surfactants were determined to be 0.2 and 0.4 mM for NIHG550 and NIHG750, respectively, using tensiometry and fluorescence. Pulsed-field gradient spin-echo NMR measurements gave similar but slightly higher values. The micelle size of NIHG750 was estimated to be on the order of 40 ?, as calculated from the self-diffusion coefficient. The dynamic surface tension, gamma(t), was measured in the range 1 ms-1 s using a maximum bubble pressure instrument and analyzed in terms of asymptotic solutions to the Ward and Tordai equation. The results suggest that at the beginning the adsorption is essentially diffusion-controlled. However, close to equilibrium, the DST decays are not consistent with a diffusion-controlled adsorption mechanism. One important result from the present work is that the heterogeminis seem to align better than conventional surfactants at the air-liquid and solid-liquid interfaces. Copyright 2001 Academic Press.     

Influence of Asphaltene Concentration on the Interfacial Properties of Two Typical Demulsifiers

Oil-in-water emulsion is an innovate manner by which heavy crude oil can be transported from producing sites to transforming sites through pipelines. The effect of emulsifier on the interfacial properties and demulsification performance of demulsifier for heavy crude oil–in-water emulsion has been studied by many researchers. However, the influence of asphaltene in heavy crude oil on the interfacial properties of demulsifier has not been investigated yet. In this article, the influence of asphaltene concentration of two typical demulsifiers (straight-chained SP-1 and branch-chained AE-1) was systematically studied in terms of absorption thermodynamics, absorption kinetics, and coalescence kinetics. The results revealed that the demulsifier adsorption was a ΔS controlled spontaneous process. The absolute value of ΔG of SP-1 adsorption was found to decrease with asphaltene concentration, whilst the asphaltene concentration had no significant influence on that of AE-1. With the increase of asphaltene concentration, the demulsifiers’ adsorption rates increased, but the reorganization rates on the interface decreased. Coalescence speed of asphaltene droplet decreased with asphaltene concentration in spite of demulsifier type. Additionally, AE-1 had higher absolute value of ΔG, adsorption speed, and coalescence speed than that of SP-1 at the same condition.     

Preliminary Study on the Dynamic Properties of PMVS Filled with Surface-treated Silica

Dynamic properties of polymethylvinylsiloxane (PMVS) filled with surface-treatedsilica (SiO2) were studied using an advanced rheometric expansion system (ARES). The results revealed that the coupling agent, bis (3-triethoxysilylpropyl) tetrasulfane (TESPT) exerted a pronounced effect on the storage modulus (G‘), and the effect of TESPT involved a frequency-dependent relation.