一种纳米原油降凝剂的合成及应用研究

制备了丙烯酸十八酯-马来酸酐共聚物降凝剂,并将其与改性蒙脱土复合制备出纳米复合降凝剂,最后将两种降凝剂应用于克拉玛依原油。对两种降凝剂进行降凝黏粘应用效果表征,对降凝剂和加剂前后原油进行FTIR和DSC表征以确定其合成效果和降凝机理。结果显示,当降凝剂加入量为600mg/kg时,两种降凝剂可分别使原油凝点降低15℃和20℃,黏度降低30%和50%,且降凝剂的加入,在显著提高原油的析蜡温度和析蜡速率的同时使得原油热蜡焓降低,即降凝剂影响了原油中石蜡的析出过程和析出后蜡晶形态,使得原油体系更加稳定,最终改善原油低温流动性。     

复配型降凝剂对大庆原油降凝效果的研究

含蜡原油在低温下会析出蜡晶,使原油失去流动性,给原油的开采和运输带来困难。本文通过几种不同的单体进行聚合反应,得到了一种三元聚合物AMS,并和EVA进行复配。考察了复配型降凝剂在不同温度、不同复配比例、以及不同加剂量下对大庆原油的降凝效果。实验结果表明:在加剂温度为60℃时,AMS-EVA复配降凝剂的最佳加剂量为0.5%,可使大庆原油凝点降低10℃。这种复配型降凝剂可以降低大庆原油的黏度,改善其低温流动性。     

BEM/PMSQ杂化降凝剂对青海含蜡原油作用效果及其机理

基于聚甲基硅倍半氧烷（PMSQ）微球良好的有机相容性与规则的微观球形形貌,将PMSQ微球与BEM降凝剂通过熔融共混制备了BEM/PMSQ杂化降凝剂。以青海含蜡原油为研究对象,通过流变实验评价了BEM/PMSQ杂化降凝剂对原油的凝点、黏弹性、黏度与屈服值的影响,利用偏光显微镜观察了加剂前后原油蜡晶形貌的变化,并与单独添加BEM降凝剂的油样进行了对比。结果表明：不加剂原油凝点27.0℃;在相同的降凝剂加量下（100 μg·g^-1）,降凝效果最好的是BEM/PMSQ 2%杂化降凝剂,可降低原油凝点19.0℃,相较于添加BEM降凝剂,进一步降凝6.0℃,降低胶凝点4.3℃,10℃时平均降黏率39.0%,G'值降低了62.0%。PMSQ微球与BEM/PMSQ杂化降凝剂在十二烷中的分散状态照片表明PMSQ微球表面吸附了BEM降凝剂,从而在原油中作为蜡晶的成核模版存在,使所形成的蜡晶结构更为紧凑,包覆更少的液态油,从而改善原油的宏观流变性。     

BEM/PMSQ杂化降凝剂对青海含蜡原油作用效果及其机理

基于聚甲基硅倍半氧烷(PMSQ)微球良好的有机相容性与规则的微观球形形貌,将PMSQ微球与BEM降凝剂通过熔融共混制备了BEM/PMSQ杂化降凝剂。以青海含蜡原油为研究对象,通过流变实验评价了BEM/PMSQ杂化降凝剂对原油的凝点、黏弹性、黏度与屈服值的影响,利用偏光显微镜观察了加剂前后原油蜡晶形貌的变化,并与单独添加BEM降凝剂的油样进行了对比。结果表明:不加剂原油凝点27.0℃;在相同的降凝剂加量下(100μg·g~(-1)),降凝效果最好的是BEM/PMSQ 2%杂化降凝剂,可降低原油凝点19.0℃,相较于添加BEM降凝剂,进一步降凝6.0℃,降低胶凝点4.3℃,10℃时平均降黏率39.0%,G′值降低了62.0%。PMSQ微球与BEM/PMSQ杂化降凝剂在十二烷中的分散状态照片表明PMSQ微球表面吸附了BEM降凝剂,从而在原油中作为蜡晶的成核模版存在,使所形成的蜡晶结构更为紧凑,包覆更少的液态油,从而改善原油的宏观流变性。     

含氮原油降凝剂的合成及评价

以马来酸酐(MA)和丙烯酸十八酯(OA)为单体进行聚合,并用十二胺接枝改性,合成了丙烯酸十八酯-马来酸双十二烷基酰胺梳型共聚物(POMN)。用红外光谱对聚合物进行了表征,并考察了该降凝剂对长庆含蜡原油的降凝减黏效果。结果表明,当n(MA):n(OA)=1:4,加剂量为300μg/g,加剂温度为60℃时,降凝效果较好,原油凝点降低13℃,原油低温黏度也大大降低。为了进一步扩大降凝效果,进行了复配实验。结果表明,POMN与乙烯-醋酸乙烯酯(EVA)按质量比为1:1复配,效果最佳,降凝幅度可达17℃,大大改善了含蜡原油的低温流动性能。     

EVA/改性SiO_2纳米复合降凝剂的制备及对含蜡模拟油降凝降黏的效果研究

利用纳米二氧化硅(SiO_2)表面带有羟基的性质,使用硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550)和硬脂酸对其改性,得到有机纳米二氧化硅(YSiO_2)。采用溶液共混法制备了YSiO_2与乙烯醋酸乙烯共聚物(EVA)降凝剂的复合产物EVA/YSiO_2,以蜡质量分数20%的模拟油为研究对象,通过凝点和流变试验,从宏观上评价EVA/YSiO_2对不同含蜡量模拟油的作用效果,并与EVA、EVA/未改性SiO_2纳米复合降凝剂进行对比,利用偏光显微镜考察加剂前后不同模拟油蜡晶形貌的变化。结果表明:采用加剂量为500×10-6的EVA/YSiO_2纳米复合降凝剂,可使含蜡质量分数20%的模拟油凝点从33℃降至0℃,并大幅降低油样黏度。偏光显微试验结果表明:添加EVA/YSiO_2能有效降低蜡晶尺寸,并促进蜡晶分散。     

柴油低温流动改进剂的合成及性能评价

介绍了在甲苯溶液中将甲基丙烯酸酯-马来酸酐二元共聚物用高级脂肪醇、聚乙二醇酯化,得到一系列新聚合物,通过对长庆石化分公司混合柴油的冷滤点的测试,改性后的二元共聚物可降低混合柴油的冷滤点3-4℃;利用多种低温流动改进剂的协同作用,探讨了合成主剂与不同的降凝剂和蜡晶分散剂复配效果;用差示扫描量热法（DSC）对加剂柴油和空白柴油在降温过程中的相变情况进行了研究,实验结果表明加剂后延缓了柴油中石蜡的结晶速度,使石蜡结晶温度降低,改善了柴油的低温流动性。     

高蜡原油降凝剂的合成与评价

通过自由基聚合合成了降凝剂丙烯酸十八酯-马来酸酐二元共聚物,正交试验表明聚合物中极性和非极性基团比例适当、侧链上长短链并存,其降凝效果较好。偏光显微镜观察加剂后原油中蜡晶状态变化,降凝机理主要是共晶作用,降凝剂改变了蜡晶在不同方向上的生长速度,阻止三维网状结构的形成。流变实验显示,降凝剂的加入扩大了原油牛顿流体的范围,降低了原油在较低温度下的粘度,并使原油由塑性流体转变为假塑性流体,改善了原油的低温流动性。     

哈拉哈塘油田高含蜡原油降凝剂合成及性能研究

哈拉哈塘油田南部区块原油含蜡量高,生产过程中井筒频繁堵塞,严重影响正常生产。分析了井筒堵塞物成分,主要以微晶蜡堵塞为主;合成了15种共聚物,评价了合成物的降凝和降黏效果,优选出效果较好的SDA-1降凝剂,使原油凝点降低28℃,0℃时原油降黏率为80%;偏光显微结果表明,加剂后原油蜡晶明显变小,SDA-1抑制了蜡晶生长;高温高压井筒模拟研究结果表明,加入1 000 mg/L SDA-1降凝剂后,井筒举升压差由1.37 kPa降低至0.67 kPa,有效抑制了蜡晶析出,SDA-1具有良好应用前景。     

降凝剂对彩南原油流变性的影响

通过最佳加剂条件的筛选,彩南原油在5512热处理温度下,添加100ppm降凝剂EvA＋AA,不仅降低了彩南原油的凝点和反常点,使原油的牛顿流体温度范围边宽,并使非牛顿流体温度下的粘度减小：当重复加热温度低于55℃时,重复加热会恶化降凝剂的改性效果;在原油反常点以上,高速剪切对降凝剂的改性效果影响不大,在原油的析蜡高峰区内高速剪切会使降凝荆的效果变差;静态稳定性实验表明该降凝剂稳定性较好。     

集输工艺对高蜡原油中降凝剂作用的影响分析

高蜡原油的集输工艺对降凝剂的降凝降黏作用有较大影响。使用降凝剂AE对吉林木南原油降凝处理,考察了集输过程中降凝剂加量和加剂温度、泵的高速剪切、原油的重复加热和输送过程中冷却速率等工艺条件对降凝剂作用效果的影响。结果表明,降凝剂最佳加剂量0.7%,最佳加剂温度70℃,高速剪切温度应在析蜡点10℃以上,重复加热温度应不低于60℃,在55～40℃的析蜡高峰区应使原油温度缓慢降低。     

Effect of wax inhibitors on pour point and rheological properties of Iranian waxy crude oil

A variety of techniques have been employed in order to reduce problems caused by the crystallization of paraffin during the production and/or transportation of waxy crude oil. Flow improvers are used extensively to increase the mobility of crude oil. In this study, the influence of the ethylene-vinyl acetate copolymer (EVA), as flow improver, with different ranges of molecular weight on the viscosity and pour point of five Iranian waxy crude oils was evaluated. Five types of Iranian waxy crude oil were selected based on their similar wax (> 10%) but different asphaltene contents. Also, the effect of asphaltene content on the performance of this flow improver was studied. The rheological behavior of these crude oils, with middle range API gravity, in the absence/presence of flow improver was studied. The rheological data cover the temperature range of 5 to 40 °C. The results indicated that the performance of flow improver was dependent on the molecular weight and the asphaltene content. For crude oil with low asphaltene, higher molecular weight flow improvers are the best additive and lower molecular weight flow improvers showed good efficiency for crude oil with high asphaltene content. Addition of small quantities of asphaltene solvents such as xylene (1 wt.%), alone or in combination with flow improver, can improve viscosity of crude oil with high asphaltene content.     

Effects of polyglycerol esters of fatty acids and ethylene‐vinyl acetate co‐polymer on crystallization behavior of biodiesel

Biodiesel fuels (BDF) have many problems in the cold due to their crystallization properties. In particular, precipitation of large crystals of high‐melting fractions in BDF at low temperatures remarkably changes cold flow property of BDF and, thereby, it increases the values of cold filter plugging point. In this study, we evaluated polyglycerol esters of fatty acids (PGE) and ethylene‐vinyl acetate co‐polymer (EVA) as chemical additives to improve the cold flow property of palm oil‐based FAME (PFME). The results of solid fat content measurement indicate that the simultaneous addition of PGE and EVA showed synergistic effects on suppression of crystallization of PFME, however such effect was not observed when EVA was used alone. DSC thermograms indicated that the PGE additives not only decreased the crystallization temperature but also kinetically suppressed the crystal growth. Polarized light microscopy showed that the simultaneous addition of PGE and EVA led to the formation of considerably small and fine‐dispersed crystals of PFME. These results indicate that combined effects of PGE and EVA caused the formation of fine‐dispersed PFME crystals, which could improve the viscous properties of palm oil‐based BDF at relatively cold temperatures.     

Crystallization kinetics of organogels prepared by rice bran wax and vegetable oils

Rice bran wax (RBX) obtained during rice bran oil purification can form organogels in edible oils. The kinetics of crystallization and the viscous properties of RBX organogels were studied using differential scanning calorimetry (DSC), viscosity changes with varying temperature, hardness measurements by penetrometry, and synchrotron radiation X-ray diffraction (SR-XRD). The organogels were prepared by RBX in concentrations of 1%, 3%, 6%, and 10% on a weight basis in salad oil, olive oil, and camellia oil. The liquid oil type had no significant effect on the melting and crystallization temperatures of the RBX. However, the viscosity and the texture of the organogels differed with liquid oil type, temperature, and RBX concentration. Changes in the viscosity of the RBX organogels were monitored during cooling from 80°C to 20°C. Drastic viscosity changes occurred in accordance with the onset of crystallization in DSC thermographs obtained at a rate of 5°C/min. RBX in the olive oil and camellia oil mixtures had higher viscosity than RBX in the salad oil mixture, which correlates with the hardness obtained in texture measurements at 20°C. SR-XRD was used to clarify the crystal structures of the building blocks of the RBX organogels in salad oil. It was found that the RBX formed crystals with a long spacing of 7.3 ± 1 nm and short spacings of 0.41 ± 1 nm and 0.37 ± 1 nm. The intensity of the long-spacing pattern was remarkably weaker than that of the short-spacing patterns, which demonstrated strong anisotropy in the crystal growth of RBX crystal particles.     

原油降凝剂的合成及性能研究

针对我国原油含蜡量较高的特点,采用在原油中加入化学降凝剂的方法,对原油降凝。以高活性聚异丁烯为主要原料,先与苯进行烷基化反应得到聚异丁烯烷基苯,再以浓硫酸为磺化剂进行磺化反应,制得的烷基苯磺酸经中和反应制得烷基苯磺酸盐原油降凝剂。红外光谱分析表明,产物为预期产物。用偏光显微镜研究了加剂前后晶体形态,并探讨了降凝机理。通过对产物与大庆原油进行的降凝效果的测定,证实合成的产物在大庆原油中加入量为0.6%时降凝效果最好,降凝幅度为8℃。     

Viscoelastic and adhesion properties of EVA/tackifier/wax ternary blend systems as hot-melt adhesives

Two types of wax were added to a ethylene vinyl acetate (EVA) copolymer/aromatic hydrocarbon resin (tackifier) blend in the molten state and the miscibility, viscoelastic and adhesion properties of ternary blends as hot-melt adhesives (HMAs) were investigated. Miscibility and viscoelastic properties were studied using differential scanning calorimetry (DSC), Brookfield viscometry and dynamic mechanical thermal analysis (DMTA), and their adhesion strength was determined in terms of single lap shear strength. DSC thermograms of both types of waxes showed their melting peaks in a similar region to that of EVA/tackfier blend. It was difficult to evaluate the miscibility of ternary blends using DSC because the melting peaks of the waxes overlapped with those of the EVA/tackifier blend, although the glass transition temperature (T _g) of the ternary blend systems slightly increased with increasing wax concentration. However, their storage modulus (E′) increased slightly and loss tangent (tan δ) showed different peaks when two types of wax were added to the EVA/tackifier blend. Therefore, the miscibility of EVA/tackifier blend altered with addition of waxes. In addition, their melt viscosity decreased with increasing wax concentration. Furthermore, the adhesion strength of the ternary blends decreased with increasing wax concentration, despite the increment of storage modulus. These results suggested that the ternary blends of EVA/tackifier/wax were heterogeneous.     

不同加热温度和降温速率对含蜡原油析蜡点的影响

利用差示扫描量热法(DSC)对原油的析蜡特性进行分析,并得到了析蜡过程的热谱图和dh/d T-T曲线。以大庆原油为研究对象,对dh/d T-T曲线进行分析,探讨了加热理温度、温降速率对析蜡点的影响。结果表明:加热温度高于溶蜡点温度时,析蜡点随温变化小;加热温度低于溶蜡点温度,析蜡点随温度的降低先增大后减小。温降速率越大,析蜡点越低。     

低温控温结晶法分离提纯1,8-桉叶油素的工艺

采用全结晶工艺对原料桉叶油[w(cineole)=63.24%]进行分离提纯,在无晶种添加下,降温速率4℃/h、结晶终温-30℃、发汗速率5℃/h、发汗终温-19℃时,可将原料油提纯至77.52%。添加晶种后,可有效提高操作温度,缩小结晶温度的操作范围,提高产品的纯度,在降温速率4℃/h、结晶终温-25℃、发汗速率4℃/h、发汗终温-6℃的操作条件下,将原料油提纯至89.63%。实验得到了低温控温添加晶种结晶法分离提纯1,8-桉叶油素的适宜工艺流程和操作参数,该方法相对其他分离方法具有较为明显的优势。