共查询到18条相似文献,搜索用时 98 毫秒
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乙烯-乙酸乙烯酯共聚物(EVA)是原油常用的降凝剂(PPDs),但其分子结构相对比较单一,对部分油品降凝效果不佳。 为了提高EVA的降凝效果,使用硬脂酰氯与羟基化的EVA直接反应的方法制备烷基长链接枝改性EVA,并与带有烷基长链的倍半硅氧烷(SS)纳米粒子进行复配。 研究了改性EVA和SS复配降凝剂对蜡油的降凝效果和降凝机理。 结果表明:复配降凝剂为蜡提供晶核,使蜡晶变小并降低蜡的沉淀量,导致蜡油中形成的蜡晶难以搭接在一起,形成了松散的结构,当复配质量比m(EVA-g)∶m(SS-L)=1∶2时,在蜡油中的质量分数为0.1%时,蜡油倾点降低了25 ℃。 相似文献
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采用红外光谱法、凝胶色谱法、超导核磁共振波谱法、皂化滴定法以及气相色谱-质谱法等对国内外10种常用柴油降凝剂进行了成分分析,以寻找其成分对降凝剂性能的影响。结果表明:10种柴油降凝剂均属乙烯-乙酸乙烯酯聚合型降凝剂,样品聚合物部分相对分子质量较低,乙酸乙烯酯聚合物的质量分数一般在27%~37%之间,样品溶剂为重芳烃、以C10为主的烷烃或者它们的混合物。其中,国外产品的相对分子质量较高(Mr>3 700),乙酸乙烯酯聚合物质量分数大于30%,且溶剂添加了少量含氮类分散剂。 相似文献
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在合成聚丙烯酸十八酯(POA)梳状均聚物和聚丙烯酸十八酯-乙酸乙烯酯(POA-VA)系列梳状二元共聚物的基础上,通过凝点测量、流变实验、差示扫描量热(DSC)分析及偏光显微镜观察等手段研究了POA与POA-VA对长庆含蜡原油结晶特性与流变性的影响.实验结果表明VA基团的引入调控了POA降凝剂对含蜡原油的作用效果.当OA与VA单体摩尔比为3∶1时,POA-VA对含蜡原油的流变改善效果最好,在降凝剂400 mg/kg剂量下可以降低凝点22℃,平均降黏率为51.45%;而单体摩尔比升高或降低均会使POA-VA对含蜡原油的流变改善效果变差.另外,从POA-VA分子的结晶放热特性和蜡晶微观形貌分析角度,探讨了VA含量对POA-VA作用性能的影响规律和机理. 相似文献
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降凝剂对蜡油中蜡析出与溶解影响的物理化学研究 总被引:4,自引:1,他引:3
用DSC热分析仪研究了合成蜡油的加热与冷却过程,测定了蜡油在不同蜡浓度下,添加降凝剂前后的平衡蜡溶点和析蜡点以及溶解度和饱和度,并进行了热力学分析.结果表明,含蜡油的平衡蜡溶点高于平衡析蜡点,降凝剂使平衡蜡溶点进一步升高,析蜡点进一步降低,导致含蜡油凝点较大幅度降低.在实验浓度和温度范围内,该过程符合Van′tHoff方程,降凝剂使蜡的溶解焓和溶解熵增大,析出焓和析出熵减少.降凝剂提高了蜡晶析出的临界半径,增大了成核位垒,使蜡晶析出困难. 相似文献
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基于费谢尔判别法的原油、燃料油鉴别技术研究 总被引:2,自引:0,他引:2
对原油、燃料油的鉴别方法进行了研究.以来自不同国家和地区的30个原油样品以及不同产地、不同种类的24个燃料油样品中的正构烷烃(n-C7~30)、植烷(Ph)、姥鲛烷(Pr)的含量构成训练集.借助SPSS 16.0进行费谢尔(Fisher)判别分析,建立Fisher判别函数.将判别变量值代入后,得到样本的空间位置,再计算样本至各组重心的距离,据此判断分类情况.结果表明,Fisher判别法可以很好地用于原油和燃料油的鉴别,具有快速、准确等特点. 相似文献
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原油加剂降凝的研究 总被引:2,自引:0,他引:2
采用高温气相色谱分析了越南、阿曼和大庆原油中蜡的碳数及分布组成,采用偏光显微镜观察了不同蜡含量原油的蜡晶形态变化时,分析了蜡结晶过程中的结构、分布状态和生长规律与不同原油组成的关系,得出了蜡结晶过程与原油组成之间的变化规律。结合采用X射线衍射仪和DSC差示扫描量热仪对自制聚合物(MOA)的结晶度和热性能的分析测试,表明原油中蜡晶结构与聚合物的结晶度密切相关,结晶度变化时,蜡晶分散效果有所区别,两者匹配状态时分散效果最佳,体系的粘温特性研究也证明了这一点。同时,降凝剂使得系统的热性能——溶解焓和溶解熵均发生了改变,原油中石蜡的熔程变长,相变能变大。 相似文献
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Mohammed Shahid Akhlaq Dagobert Kessel Wolfgang Dornow 《Journal of colloid and interface science》1996,180(2):309
To improve the understanding of wettability, especially the influence of colloidal stability and composition of crude oil, wetting experiments on quartz sand were performed with an asphaltene-rich oil, a resin-rich oil, and with model oils containing different colloid compositions. A two-step procedure was developed to investigate the wetting behavior. In the first step those crude oil components were extracted, which preferentially wet solid surfaces. The extracted crude oil components were characterized in the second step. The amount of adsorbed oil components correlates with the stability of the crude oil colloids: low colloidal stability of crude oil leads to larger amounts of adsorbed components than does high colloidal stability. The addition of resins and/or low molecular weight asphaltenes to the crude oil stabilizes the crude oil colloids; i.e., a lower amount of wetting components are isolated by extraction in such systems. To find out, which fraction of the adsorbed oil components determines the wetting behavior of a crude oil, the wetting properties of the toluene solutions of these fractions were compared to those of the toluene solutions of the precipitated crude oil colloids. The fractions extracted with the solvent systems chloroform and methanol/chloroform showed nearly the same wetting behavior as the crude oil colloids. These fractions are characterized by the highest molecular weights, higher sulfur compositions, and the lowest H/C ratios. On the other hand, the nitrogen compounds predominate in the acetone fraction. 相似文献
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Serkan Keleşoğlu Paul Meakin Johan Sjöblom 《Journal of Dispersion Science and Technology》2013,34(11):1682-1691
The time dependence of the interfacial tension between water–acidic crude oil and water–synthetic oil was investigated for aqueous phase pHs ranging from 2 to 9 using the du Noüy ring method at 20°C. Myristic acid in dodecane was selected as a model (synthetic oil) for acidic crude oil containing indigenous surfactants, and the similarities and differences between the dynamic interfacial tension behaviours of the natural and synthetic crude oil systems were compared. The initial interfacial tension and the relaxation of the interfacial tension are sensitive to the aqueous phase pH for both systems. The adsorption kinetics of the indigenous surfactants and myristic acid could be well fitted with the monoexponential model, and the time constants obtained in this manner indicates that reorganization of the indigenous surfactants and myristic acid at the w/o interface are pH dependent. The experimental results also indicate that indigenous surfactants in acidic crude oil and myristic acid in dodecane have similar film formation behaviours at the w/o interface for the range of pHs investigated. 相似文献
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生物标记烃类在生油岩母质类型与成熟度判定中的应用 总被引:1,自引:0,他引:1
甾烷、萜烷这些天然有机化合物在石油和富含有机质的沉积岩中存在十分广泛[1],它们的热稳定性及抵抗微生物侵蚀的能力强于正烷烃,能较稳定地存在于地质体中,并且它们在由生物体转化到地质体的过程中始终保持着特定的物型和分布[2],具有良好的“遗传”性质,可以... 相似文献
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Julie M GuidrozJoseph Sneddon 《Microchemical Journal》2002,73(3):363-366
The use of nitrous oxide-acetylene flame atomic absorption spectrometry for the determination of vanadium in burned and unburned Venezuelan crude oil was demonstrated. Results from laboratory controlled experiments suggest that if the temperature typically obtained in the burning of oil as a form of re-mediation (∼1000 °C), then vanadium will not be removed from burning crude oil. This was found to be the case in an open container, on the surface of water, and on the surface of a fixed size sandy soil. 相似文献
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Today’s changeable market and resultant disturbance of crude oil supply require agile and flexible scheduling of crude oil operation. The objective of flexible scheduling is to keep stable crude oil op-eration and satisfy production demands under the circumstances of supply disturbance. In this paper, a new mixed integer non-linear programming (MINLP) formulation is set up for crude oil scheduling firstly, and then some heuristic rules worked out by some experts are proposed to linearize bilinear terms and ... 相似文献