Demulsification Behavior, Characteristics, and Performance of Surfactant Stabilized Oil-in-Water Emulsion under Bidirectional Pulsed Electric Field

As a novel electric demulsification method,bidirectional pulsed electric field(BPEF)was employed to demulsify the surfactant stabilized oil-in-water(SSO/W)emulsion for oil/water separation in this work.The demulsification behavior,characteristics,and stages under BPEF were explored.It was discovered that BPEF drove SSO/W emulsion to move and form vortexes,during which the oil droplets aggregated and accumulated to generate an oil droplet layer(ODL).ODL subsequently transformed into a continuous oil layer(COL)leading to the demulsification and separation of SSO/W emulsion.The conversion rate of ODL to COL was defined and used to evaluate the demulsification process and reflect the coalescence ability and transformation efficiency of dispersed oil droplets into COL.Furthermore,the effects of BPEF voltage,frequency,duty cycle,ratio of pulse output time,and surfactant type and content on the demulsification performance were examined.The optimal values of BPEF parameters for demulsification operation were 400 V,25 Hz,50%,and 4:1.O/W emulsion containing anionic surfactant was apt to be demulsified by BPEF,nonionic surfactant took the second place and cationic surfactant was the most difficult.A high surfactant content was not conducive to the BPEF demulsification.This work is anticipated to provide useful guidance for oil/water separation and oil recovery from actual emulsified oily wastewater by BPEF.

Study on an improved rotating microchannel separator in the intensification for demulsification and separation process

An improved rotating microchannel(IRM) separator was further explored in the intensification for demulsification and separation process. Oil-in-water(O/W) emulsion system of 2-ethylhexyl phosphoric acid-2-ethylhexyl ester(P507)–water without emulsifier was employed to evaluate the performance of the new equipment. In this experiment, the influence on demulsification separation process was explored by changing the geometrical structure and channel height of the microchannel and combining the liquid–liquid two-phase flow pattern, and the correlation general graph between demulsification efficiency and dimensionless parameters was established. The total demulsification effect of the IRM and the separation capacity of the clear organic phase recovered from demulsification are significantly improved. In addition, the liquid–liquid two-phase flow pattern of the clear organic phase after demulsification and the remaining emulsion in the IRM are observed and recorded by high-speed photography. The separation ability of organic phase from the upper outlet can be significantly improved when the total demulsification rate of IRM is up to 90%. There are 3 types and 6 kinds of flow patterns observed. The results demonstrated that the suitable demulsification performance is obtained when the liquid–liquid two-phase inside the IRM is in a parallel pattern. Finally, the relation map between total demulsification efficiency and the universal flow is drawn, which provides a basis for the accurate control of the IRM device.

Preparation and electro-catalytic activity of nanoporous palladium by dealloying rapidly-quenched Al_(70)Pd_(17)Fe_(13) quasicrystalline alloy

The formation of nanoporous Pd was studied by electro-chemical dealloying a rapidly-quenched Al70Pd17Fe13 quasicrystal alloy in dilute NaCl aqueous solution,and the electro-catalytic activity of the nanoporous Pd towards methanol electro-oxidation was evaluated by cyclic voltammetry in 1 mol/L KOH solution.XRD and TEM analyses revealed that nano-decomposition of quasicrystal grains occurred in the initial stage of dealloying,and the fully dealloyed sample was composed of FCC-Pd phase.Scanning electron microscopy observation indicated that a maze-like nanoporous pattern was formed in the dealloyed sample,consisting of percolated pores of 5.20 nm in diameter in a skeleton of randomly-orientated Pd nano-ligaments with a uniform thickness of^5 nm.A retention of^12 at.%Al in the Pd nano-ligments was determined by energy dispersive X-ray spectroscopy(EDS).The nanoporous Pd demonstrated obvious electro-catalytic activity towards methanol electro-oxidation in alkaline environment.

Demulsification of Emulsion Liquid Membrane by Wetting Coalescence Materials

Demulsification of emulsified water-in-oil droplets was worked out with the employment of wetting coalescence materials. Demulsification is carried out in conventional stirred-column and packed-column. Among the four kinds of natural fibers and two kinds of inorganic materials tested, natural fiber A, originated from wood shavings was found to give the best performance of demulsification. The demulsification efficiency can exceed 96.5% 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 simulated wastewater. Operating variables governing the demulsification efficiency were investigated.

Demulsification of Water in oil Emulsion by Using Porous Glass Membrane

The hydrophilic porous glass membranes were used to demulsify water in oil emulsion, liquid membrane and demulsification efficiency can reach more than 96 percent. Effects of pore size of the membrane, transmembrane pressure and volumetric ratio of oil phase to internal aqueous phase in the emulsion on demulsification were investigated. Correspondingly, effect of transmembrane pressure on permeation flux of the droplets was also studied.

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry,linear polarization and chronoamperometry.The graphene nanopowder modified electrode was prepared using the drop coating method,which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH=7.0.Linear responses for dopamine and uric acid were obtained in the ranges of3.3μmol/L to 249.1μmol/L and 6.7μmol/L to 386.3μmol/L with detection limits of 1.5μmol/L and 2.7μmol/L(S/N=3),respectively.The response time was less than 2 s in case of dopamine and 3 s in case of uric acid,respectively.The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.

Mechanism of Coalescence Demulsification with Microfiltra- tion Membrane

A study on the membrane coalescence demulsification was carried out with four working systems of water/n-butyl alcohol, water/n-octanol, water/30% TBP(in kerosene) and water/kerosene. The membranes made of polytetrafluoroethylene (PTFE) with 1.0μm pore size were used. The results indicated that the excellent demulsification efficiency for emulsions with various oil contents was obtained. A conductivity probe was used to study the demulsification mechanism. An electrode probe was designed and used to determine the oil content near the membrane surface. The obtained data showed that the oil content in the permeated stream was much higher than that in the feed emulsion. A physical mechanism to explain the membrane demulsification was put forward.

松籽油水酶法提取及酶法破乳工艺研究

以压榨松籽饼粕为原料,利用水酶法提取松籽油,通过单因素及响应曲面试验研究松籽油提取工艺,并对提油过程中产生的乳状液进行破乳研究分析。结果表明,碱性蛋白酶酶解效果最佳,最优工艺为酶解时间2.5 h,温度56℃,pH值11.3,加酶量5045 U·g^(-1),此条件松籽油提油率为71.73%。经比较碱性蛋白酶添加量为3000 U·g^(-1)时破乳效果最好,破乳率为87.68%,在酶法破乳后进行酸化处理,通过调节pH值至5时破乳率提高至92.18%,此条件下松籽油得油率为70.36%。

微波—离子液体协同破乳的参数优化研究

针对稠油O/W型乳状液难以破乳的问题,本文采用响应面方法对微波辐射功率、微波辐射时间和离子液体浓度等参数进行优化,在此基础上,进一步确定搅拌速率、搅拌时间、破乳温度的最佳参数。实验结果表明,微波和离子液体协同作用可以显著提高稠油乳状液的破乳效果,当微波辐射功率为400 W、微波辐射时间为40 s、离子液体[C_(16)MIM]Br浓度为1.337 mmol/L、搅拌速率为1200 r/min、搅拌时间为5 min、破乳温度为75℃时,稠油O/W型乳状液破乳效率达到最高值99.10%。该研究为微波-离子液体破乳技术在现场的应用提供了理论支撑。

一种净水型破乳剂在孤岛油田的应用

文章探讨了孤岛油田聚合物驱原油的乳化状态,发现胶质和沥青质是影响原油破乳的主要因素,导致孤岛油田原油难以破乳并且污水含有较高的油分。为解决这一问题,实验室中通过对聚头与环氧乙烷(EO)、环氧丙烷(PO)进行聚合反应成功地制备出净水型破乳剂,并经过多次试验选定破乳剂5050作为效果最佳的配方。同时,确定了5050最佳的反应物料质量(聚头、EO、PO)比为1∶149∶149,并找到了EO和PO各自最优的聚合反应温度分别为125℃和140℃。

超纤革水性含浸工艺的改进

针对现有水性聚氨酯含浸超纤革工艺的缺点,从基布改性和传统工艺优化二方面改进了超纤革的水性含浸工艺,研究了水性聚氨酯固含量、浆料黏度、整理及烘干方式对含浸超纤革性能的影响。结果表明:当水性聚氨酯固含量为25%、浆料黏度为2000~3000 mPa·s时,采用等离子体改性基布,含浸后盐溶液破乳,红外照射预烘后再高温热风烘干,制备的含浸超纤革符合QB/T 2888—2007中B类绒面合成革的产品标准。

CO_(2)响应型β-环糊精材料用于稠油降黏

制备了一种环境友好型马来酸酐改性β-环糊精(MAH-β-CD),温和条件下将其与聚醚胺(JD230)通过静电作用合成了具有CO_(2)响应性的表面活性剂(MJD230)。MJD230能与稠油形成稳定的水包油乳液,进而有效降低溶液的表面张力。在CO_(2)调控下,MJD230可重复用于稠油的乳化降黏和破乳。利用FTIR对MJD230结构进行了表征。通过观察降黏率和乳液粒径优化MJD230的合成条件,同时对降黏效果和乳液的稳定性进行了考察。将在反应温度为60℃,反应时间为60min,MAH-β-CD与JD230物质的量比为2∶1条件下制备的MJD230配成质量分数为0.5%的MJD230水溶液,其与稠油按照体积比为3∶7乳化后,稠油降黏率可达99.19%。反应体系pH和电导率的可逆变化证明了MJD230溶液对CO_(2)的响应性,这为表面活性剂驱油和CO_(2)捕集相结合提高稠油采收率提供了可行的途径。

影响油泥超声波除油效果的因素与机理

油泥超声波除油技术绿色环保,但目前除油效率不高、机理不明,在工业中未得到广泛应用。针对南方某油田高含油钻屑油泥的特性,设计了一套油泥超声除油试验装置,考察了超声频率、超声功率、超声温度等7个主要因素对除油效果的影响。结果表明:超声频率、超声功率、超声作用时间、固液比(油基钻屑与水质量比)和pH对油泥除油效果影响较大,而超声温度和超声处理次数对除油效果影响较小。在最佳工艺条件下,除油率达到57.18%;当超声空化作用产生的剪切力大于油与固体颗粒之间的相互作用力时,附着在固体颗粒表面的油分脱附,且随温度升高和固液比降低,油泥的黏度降低,超声空化作用增强;弱碱环境下HSiO3-占据油泥颗粒吸附位点,可阻止油的再吸附,除油效率较高。

LP油田沉降罐过渡带原油破乳脱水实验研究

LP油田沉降罐过渡带原油中含有起乳化作用的胶态FeS等成分,导致原油脱水困难,不能满足原油进后续电脱水器的要求;分析了过渡带原油物性、原油组分及采出水组成,对FeS脱除剂及破乳剂的筛选进行优化实验,重点研究了FeS脱除剂与破乳剂联合破乳效果及适应性。结果表明,筛选出的FeS脱除剂BLJ-01对FeS有很好的溶解效果,体积分数3%的FeS脱除剂BLJ-01和质量浓度800 mg/L的破乳剂X-75联合使用,55℃下可有效去除沉降罐过渡带原油中FeS,沉降罐过渡带原油脱水率达85.78%;BLJ-01与X-75配合使用适应性较强,对含水率超过40%的P2联合站沉降罐过渡带原油脱水率均可达80%以上,且在弱酸或弱碱性条件下都可以表现出优良的破乳效果,也适用于SJ站沉降罐过渡带原油的破乳脱水,并能显著降低破乳剂使用量。

以废弃PET塑料为原料制备离子液体破乳剂

传统以环氧乙烷和环氧丙烷为原料的聚醚类破乳剂需要危险复杂的生产过程,而且破乳性能仍然难以满足实际生产的要求。利用废弃聚对苯二甲酸乙二醇酯(PET)塑料为主要原料,合成了一种用于油包水(W/O)原油乳液脱水的离子液体破乳剂BADT-IL,采用傅里叶变换红外光谱仪(FT-IR)和核磁共振氢谱仪(^(1)H-NMR)分析了BADT-IL的化学结构,考察了BADT-IL浓度、沉降时间、破乳温度、盐度和pH值对原油乳液破乳效率的影响,并通过测试界面张力(IFT)、Zeta电位、三相接触角(CA)、聚结时间和显微观察等多种手段对BADT-IL在原油乳液中的破乳机理进行了探讨。研究结果表明,在含水率为70%的原油乳液中加入250 mg/L的BADT-IL,60℃条件下静置180 min后破乳效率高达95.23%;同样的条件下,对含水率为30%的原油乳液的破乳效率达到99.22%,且分离后水相清澈、油水界面整齐。BADT-IL具有良好的耐盐性,而且增大盐度能提升破乳效率,在50 g/L的条件下,含水率为70%的原油乳液的破乳效率为96.33%。随着破乳温度的升高,破乳速率显著加快,且破乳效率也随之提高。此外,与常用的商业破乳剂对比,BADT-IL表现出优异的破乳性能。BADT-IL在破乳过程中能够有效降低油水界面的IFT,并取代界面处的乳化剂,形成不稳定的复合界面膜从而促进水滴的聚结,最终实现有效的油水分离。

多功能稠油破乳解堵剂的研究与应用

针对稠油开采过程中,沥青质在井筒及近井地带沉积和稠油乳化堵塞等导致油井产量低的问题,合成了5种不同PO/EO比例的双酚A酚胺二嵌段聚醚,并优选出破乳效果最好的DE-02,通过将破乳剂DE-02与优选出的溶剂TC-03进行复配,得到多功能稠油破乳解堵剂。对该体系进行了室内评价和现场试验,研究结果表明,多功能稠油破乳解堵剂溶解沥青质速率为5.7 mg/(mL·min),溶解石蜡速率为5.5 mg/(mL·min),在30 min时破乳率达到80%。该试剂在渤海某稠油井使用后,使该井产油量较措施前提高2倍,取得了较好的现场应用效果。

偏远井场油水分离与原油降凝技术研究

为解决延长油田部分偏远井场含水原油在井场脱水困难,冬季原油凝固流动性差外运难的问题,开展破乳剂类型、温度、浓度影响的破乳特性实验、微观形貌采集以及降凝流变特性实验,寻求高效脱水与降凝方案,通过实验结果制定生产改造方案实现高效脱水与降凝。研究表明井场破乳脱水与降凝的关键在于药剂与产液的充分融合,同时破乳剂的加入使活性水的界面张力明显下降,浓度为100ppm时,活性水的界面张力达到了最低值。通过微观形貌观察,随着破乳剂浓度的增加,油滴的粒径先增大后减小,油滴分布先稀疏后密集,在浓度为100ppm时油滴的粒径达到最大,此时界面张力最低,活性较高,破乳剂能够快速取代天然表面活性物质,导致原油破乳,破乳率达到97%以上。当破乳后未加降凝剂时原油最优热处理温度在60至70℃之间,添加浓度为150ppm的J2降凝剂,加热至50℃,凝点降低至-2~4℃。

水酶法提油关键技术研究进展

水酶法作为一种高效、节能、绿色、环保的新型油脂提取技术,具有良好的应用前景。但是,不同研究中所使用的水酶法提油工艺存在较大差异,使得后期研究人员无法从已有研究中获取提高出油率的关键技术要点和参数,导致实际应用效果不佳。因此,该文查阅了近年来国内外有关水酶法提油的最新研究成果,并从原料预处理、酶解和破乳3个层面对水酶法提油的关键技术进行分析和总结,以便后续研究人员了解水酶法及水酶法提油的关键技术要点,并为其在实际应用时选择合适的粉碎粒径、原料预处理方法、酶种类、酶解时间和温度及破乳方法等提供参考和建议。

超亲氮化碳-硅藻土复合滤层油包水乳液快速破乳

目的实现高黏度油品油包水乳液的快速高效破乳。方法以三聚氰胺为原料,通过热聚法制备超亲水材料氮化碳,采用制备的氮化碳混合硅藻土制备复合滤饼,通过抽滤实现高黏度油包水乳液快速破乳。结果含质量分数为1.5%氮化碳的0.5 cm氮化碳-硅藻土滤饼可实现水含量在6%(w)以内,乳滴粒径在2.32μm及以上,油包水乳液完全破乳,20 kPa真空度的破乳速率可达3.57 L/min,破乳效率为97.36%,油回收率为99.72%以上;增大破乳用滤饼厚度,可用于更高含水量乳液的破乳;破乳基于超亲氮化碳对水的强吸引力和硅藻土微孔破碎共同作用。结论氮化碳-硅藻土滤饼可实现油包水乳液快速高效破乳,具工业实用前景。