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1.
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.  相似文献   

2.
微波干法催化醛酮与胺的缩合反应   总被引:3,自引:1,他引:2  
利用微波辐射和固体中性Al2 O3 载体催化醛酮与胺的缩合反应的方法合成了十六种亚胺 ,研究了微波功率、作用时间、产物提取方式等因素对反应的影响 ;与无微波作用的一般合成方法相比 ,该法明显地提高反应速度及产率 ;文中用低极性熔点递变物质灌装毛细管的方法观测微波作用下反应温度 ,探讨微波作用化学反应的机理 ,其机理除与微波加热作用有关外还与分子间氢键及分子的缔合性有关。  相似文献   

3.
高效原油破乳剂GE-189的制备与应用研究   总被引:8,自引:0,他引:8  
以分子量大、活泼氢多、具有分支结构的瓜胶作起始剂,与环氧乙烷、环氧丙烷加成,首次合成出具有分支结构的瓜胶类原油破乳剂GE-189,并把这种破乳剂及其与常规破乳剂F3111的复配体系应用于不同油田原油乳状液的室内破乳脱水试验。结果表明,破乳剂复配体系在脱水速率、脱水效果等方面均优于各现场剂,把这种破乳剂与生物表面活性剂复配,于巴西海上油田原油乳状液的破乳脱水,能够显著提高原油乳状液的破乳脱水速率和脱水体积,两者之间表现出明显的协同作用。  相似文献   

4.
新型高效原油破乳剂PNT-05的研制与应用   总被引:10,自引:0,他引:10  
针对中原油田采油六厂二区原油破乳脱水过程中存在的脱水速度慢,乳化中间层厚等问题,通过分子结构设计手段,在非离子型破乳剂基础上,经酯化,在破乳剂分子中引入阳离子基团,合成出季胺盐阳离子型破乳剂PNT-05,利用季胺盐阳离子型破乳剂与助剂复配的方法室内解决了中原油田二区原油破乳脱水过程中顾在的问题,与油田现场用破乳剂相比,新的破乳剂体系脱水速度快,脱水效率高,使乳化中间层变薄或消失,同时探讨了季胺盐阳离子型破乳剂PNT-05的作用机制。  相似文献   

5.
微波辐射下L-氨基酸的快速消旋方法   总被引:4,自引:0,他引:4  
微波辐射作用下的L-氨基酸消旋反应是一种新的氨基酸消旋方法,具有对环境友好的优点。本文报道了在微波辐射下,以1.Omol/L氢氧化钠水溶液替代有机酸作为反应溶剂,水杨醛为催化剂,水杨醛与L-氨基酸的摩尔比为0.1,L-氨基酸可以快速消旋;消旋反应随微波辐射功率的提高而加快,在600W时已接近最大反应速率。同时也讨论了微波作用下L-氨基酸的消旋反应机理。  相似文献   

6.
在离子液体和氟化钾反应体系中,研究了卤代哒嗪化合物的氟代反应,讨论了微波辐射条件下由卤代哒嗪化合物合成氟代哒嗪化合物的方法。用离子液体作为反应介质替代了传统的分子溶剂,提高了产物收率,简化了操作。用微波反应不仅获得了较好的收率,也缩短了反应时间。利用离子液体和微波辐射条件进行氟代反应是一种绿色化学方法。  相似文献   

7.
李晓如  黄湘川  杨辉 《合成化学》2004,12(5):502-504,507
在微波辐射和相转移催化剂存在的条件下,利用Henry反应,快速合成了β-甲基-β-硝基对羟基苯乙烯。考察了微波辐射功率、辐射时间、不同种类的相转移催化剂、反应物摩尔比等因素对收率的影响。结果表明:对羟基苯甲醛50mmol,n(对羟基苯甲醛):n(硝基乙烷)=1:2,微波辐射功率195W,辐射时间5min,PEG-800 2.5mmol(对羟基苯甲醛的5mol%),以冰乙酸/醋酸铵为缩合剂,收率70.5%。  相似文献   

8.
植物纤维微波辐射预处理的研究进展   总被引:1,自引:0,他引:1  
综述了微波辐射预处理技术在植物纤维发酵、纸浆生产、木材加工三个化学加工中的应用研究进展。结果表明,微波辐射预处理能有效地提高植物纤维的化学反应和加工性能,而且预处理作用深度大,具有缩短反应时间,提高生产效率,降低生产能耗等优点。并且指出了微波辐射预处理植物纤维的不足:应用范围有限,其工业化研究处于探索阶段;升温快,反应过程不易控制。最后提出未来研究的重点:微波辐射预处理植物纤维加速反应机理、温度的控制和检测方法等方面。  相似文献   

9.
介绍了一种适用于微波化学反应器的防爆喷缓冲装置的结构、工作原理和使用方法。并通过水射流缓冲试验,以及在频率为2450MHz,微波功率为525W下,与常规方法作对比试验。探讨了该装置的防爆喷效果和防溶剂耗散效果,为微波辐射加热减少有害气体的挥发和溶液的爆喷,提供了一种安全的试验装置。  相似文献   

10.
纳米结构羟基磷灰石的微波固相合成新方法   总被引:9,自引:0,他引:9  
本文报道了一种简单的室温下微波辅助合成羟基磷灰石(HAP)的新方法。与常规方法相比,该方法具有反应条件温和、反应时间极短的优点。合成中,以Ca(NO3)2·4H2O和Na3PO4·12H2O为原料,经过研磨和微波加热得到了HAP纳米粒子和纳米棒。用XRD、FTIR,BET和SEM等对产物进行了表征。在反应过程中,微波辐射作为一种加热处理手段对HAP的形成起到非常重要作用。同时  相似文献   

11.
Two case studies are presented that shows the effects of chemical demulsifiers used under conventional heating and in combination with microwave radiation on efficiency of demulsification and light transmittance of the water separated from the emulsions. The data shows that the chemical demulsifiers coupling with microwave radiation does a better job at demulsifying the water-in-crude-oil emulsions than when the chemical demulsifiers are used under conventional heating. The demulsification efficiency of AE-121 could reach 100% under microwave irradiation (300 W) for 50 seconds.  相似文献   

12.
Stability and demulsification of emulsions stabilized by asphaltenes or resins   总被引:11,自引:0,他引:11  
Experimental data are presented to show the influence of asphaltenes and resins on the stability and demulsification of emulsions. It was found that emulsion stability was related to the concentrations of the asphaltene and resin in the crude oil, and the state of dispersion of the asphaltenes and resins (molecular vs colloidal) was critical to the strength or rigidity of interfacial films and hence to the stability of the emulsions. Based on this research, a possible emulsion minimization approach in refineries, which can be implemented utilizing microwave radiation, is also suggested. Comparing with conventional heating, microwave radiation can enhance the demulsification rate by an order of magnitude. The demulsification efficiency reaches 100% in a very short time under microwave radiation.  相似文献   

13.
Experimental data are presented to show the influence of solid particles on demulsification. It was found that the solid particles could effectively resist demulsification. Compared with conventional heating, microwave radiation can enhance the demulsification rate by an order of magnitude and increase the demulsification effectiveness. The demulsification effectiveness of the emulsions stabilized by graphite powder can reach 82%–89% in a very short time under microwave radiation, whilst that of the emulsions stabilized by barium sulfate can attain 100% under similar conditions.  相似文献   

14.
微波用于破乳的研究   总被引:8,自引:0,他引:8  
原油自井下开采出来要穿过窄隙,与水和气混在一起。油中含有沥青质、石油环烷酸;水中含有各种矿物质,都是天然的乳化剂。因此,大量原油将以乳状液的形式被开采出来,大多数为油包水型(W/O),开发到中后期还会出现油包水、水又包油(O/W/O)型。这种原油无法进一步加工,于是,原油脱水成为采油和集输中一个普遍关注的问题。原油脱水国外较多使用化学破乳法,我国各油田多使用电—化学破乳。电—化学脱水法对高含水原油的适应性差,还需增设预脱水工序。而纯化学脱水,试剂昂贵,生产费用较高。因而,近年来人们开始探索将超声技术、微波技术用于破乳。本文考察了微波破乳效果及其机制,并与常规法进行比较。  相似文献   

15.
It is known that hydrophobic microfiltration membranes can be used for demulsification of oil-in-water (o/w) emulsion due to coalescence of oil droplets in membrane pores. This study demonstrates that a hydrophilic polymer membrane can be used for the demulsification of surfactant-stabilized water-in-oil (w/o) emulsions. The success of demulsification is dependent on the type of emulsions and membrane used. Membrane pore size and transmembrane pressure were found to affect demulsification efficiency (DM), while other factors, such as membrane thickness and initial water content have slight or almost no effect. A coalescence mechanism of the demulsification phenomenon is also discussed. The separation process is not based on sieving effects due to a difference in membrane pore size, but is determined by droplet interactions with membrane surface.  相似文献   

16.
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.  相似文献   

17.
In the present work, three polymeric surfactants were prepared and used as demulsifiers; polyalkyl phenol formaldehyde monoethanol amine ethoxylate, eo, 136(D1), polyalkyl phenol formaldehyde diethanol amine ethoxylate, eo, 37(D2) and polyalkyl phenol formaldehyde triethanol amine ethoxylate, eo, 21.5(D3). Their demulsification potency in breaking water‐in‐crude oil emulsions was investigated. In this respect, two naturally occurring Egyptian water‐in‐oil (w/o) emulsions, one of them was waxy and the other was asphaltenic, were used in order to study the demulsification power of these compounds. The data revealed that, the resolution of water from waxy crude emulsion was easier than asphaltenic crude emulsion. The demulsification efficiency increases with increasing demulsifier concentration, contact time and temperature. The interfacial tension (IFT) at the crude oil–water interface was measured, it was found that the concentration of demulsifiers required to cause a minimum IFT are always less than these indicating a maximum demulsification efficiency. All the results were discussed in relation to emulsifier chemical structure and crude oil composition. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

18.
Recently, there has been an increasing interest in the breakage of water-in-oil (W/O) emulsions by the freeze/thaw method. Most of the previous works focused on the phase transition of the water droplet phase. This paper emphasizes the effect of continuous oil phase transition. A series of oils with different freezing points were used as oil phases to produce model emulsions, which were then frozen and thawed. The emulsion whose oil phase froze before the water droplet phase did (OFBW) on cooling was readily demulsified with a dewatering ratio as high as over 80%, but the emulsion whose oil phase did not freeze when the water droplet phase did (NOFBW) was relatively hard to break. The difference in demulsification performance between them resulted from the distinction between their demulsification mechanisms via the analyses of the emulsion stability, emulsion crystallization/melting behaviors, oil phase physical properties, and wettability of the frozen oil phase, etc. For the OFBW emulsion, the first-frozen oil phase was ruptured by the volume expansion of the subsequently frozen droplet phase, and meanwhile, some liquid droplet phase was drawn into the fine gaps/crevices of the frozen oil phase to bridge droplets, which were considered to be essential to the emulsion breakage, whereas for the NOFBW emulsion, the demulsification was attributed to the collision mechanism proposed in our previous work. The findings may provide some criteria for selecting a proper oil phase in the emulsion liquid membrane (ELM) process and then offer an alternative approach to recycle the oil phase for continuous operation. This work may also be useful for emulsion stability against temperature cycling.  相似文献   

19.
About one third petroleum production of every oil field is in the form of water in oil emulsions which are normally stabilized by the nickel and vanadium porphyrins from asphaltene portion of crude. The petroleum emulsions of Assam oil fields which have been taken for the present work, are stabilized by the organometallic compounds of iron and high molecular weight compounds from asphaltenes. There is least possibility of any change on these natural petroleum emulsions. The Assam oil field emulsions have been tried to be broken by polyoxyethylene alkyl phenols, their sulphonates and sodium sulphonates in different combinations. The nonyl and octyl phenols with 30 and 40 molecules of ethylene oxide are found most suitable demulsifiers for Lakwa, Rudrasagar and Galeki (Assam) oil fields emulsions. The effect of polyoxyethylene alkyl phenols followed by the treatment of polyvalent cations had been studied for the first time in the field of demulsification of natural petroleum emulsions. This new combination has shown the best results as this broke even the most stable petroleum emulsions which could not be broken by polyoxyethylene alkyl phenols alone. In the present paper a simple method for calculating the chemical demulsification efficiency and a factor H/S paralleled to HLB & H/L for evaluating the emulsification property of surface active agents, have been introduced.  相似文献   

20.
The kinetic of coalescence of water in Furrial crude oil emulsions (W/O) during the initial stage of demulsification process is showed through of high‐resolution image micrographics by using a confocal microscope. Furrial crude oil from Monagas state is a crude oil extra heavy with severe flocculation/aggregation problems. The kinetic of the initial stage in the coalescence process is critical and of great importance in the definition of the foreword behavior. This information allowed us to characterize the demulsification rate process in a Furrial crude oil. Total W/O emulsion separation was achieved about of 2 hours at 80ºC. The initial fast coalescence is characterized by a short binary coalescence time, which is followed by a large binary coalescence time. Our results demonstrate that the initial coalescence rate determinate the time necessary to achieve a total separation.  相似文献   

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