柴油中正构烷烃的高温气相色谱分析

利用高温气相色谱法对柴油中正构烷烃的碳数分布及含量进行了分析。同时根据所得数据计算出正构烷烃的平均相对分子质量及平均碳原子数。试验表明，气相色谱的最佳测定条件为：柱初温60℃，柱终温330℃，升温速率6℃／min，汽化室温度350℃。分析出吐哈两种柴油中C11～C19的正构烷烃均占分析总量的75％以上，吐哈0^#与-10^#柴油正构烷烃的平均相对分子质量、平均碳原子数分别为214．57、15．18和203．34、14．38。所得数据为设计研究针对吐哈原油有效降凝剂提供了参考数据。     

国内外常用降凝剂成分分析及性能表征

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（M_r>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。     

富马酸十六醇酯-苯乙烯二元共聚物柴油低温流动改进剂的合成、表征及性能评价(英文)

以富马酸和十六醇为原料、对甲苯磺酸为催化剂、对苯二酚为阻聚剂、甲苯为溶剂,采用直接酯化法制备了富马酸十六醇酯单体（DHF）;以富马酸十六醇酯和苯乙烯为聚合单体、过氧化苯甲酰为引发剂,通过自由基聚合制备了富马酸十六醇酯-苯乙烯二元共聚物（FOS）。用IR、¹H-NMR对DHF单体及FOS共聚物进行了表征,分析了张家港0# 柴油和胜利海科5# 柴油的正构烷烃分布,考察了共聚物的降滤效果,讨论了降滤作用机理。结果表明,当添加剂量为0.1%时,FOS能使张家港0# 柴油冷滤点降低6℃,胜利海科柴油5# 柴油冷滤点降低3℃;FOS对不同柴油表现出了不同的感受性;与2种商业降凝剂复配后,表现出良好的协同效应,作为商业降凝剂的优良助剂,FOS具有一定的应用前景。     

应用溶解度参数理论筛选柴油萃取脱蜡的溶剂

采用基团贡献法分别计算了酮类、氯代烃类、酯类、醇类和醚类溶剂的色散溶解度参数(δd)、极性溶解度参数(δp)和氢键溶解度参数（δh）,并分析了柴油组分中正构烷烃和芳烃的三维溶解度参数的特点。研究了溶剂溶解度参数与其萃取柴油脱蜡效果的关系。结果表明,除了醇类溶剂之外,在参数贡献图中距离正构烷烃距离越远的溶剂,正构烷烃得率越大,萃取效果越好;色散力贡献比大于2/3的溶剂萃取时蜡膏的含油量明显低于色散力贡献比小于2/3的溶剂。     

大豆油生物柴油低温流动性能影响的研究

以大豆油为原料采用碱催化酯交换法合成生物柴油，测定了其酸值、游离甘油、总甘油、灰分、黏度和磷含量等指标。实验表明,共存的甲醇、水分和甘油酯对生物柴油的低温流动性能影响极少，饱和脂肪酸甲酯的同时析出对生物柴油低温流动性能起关键作用。考察了5种柴油降凝剂、0号和20号柴油以及乙醇对生物柴油低温流动性能的影响。0号柴油有效地改善生物柴油黏度，但对其低温流动性能影响不大。20号柴油和乙醇能显著降低生物柴油的凝点、倾点、冷滤点和黏度。其中3种降凝剂有效降低生物柴油的凝点和倾点，1种降凝剂能小幅度改善冷滤点，5种降凝剂都能使生物柴油的黏度小幅上升。     

改性聚丙烯酸高级酯的合成及其降凝效果的考察

用酯化和热聚合同时进行的方法合成了聚丙烯酸高级醇酯（PAE），并对其进行改性，得到改性聚丙烯酸高级酯（MPAE），在实验室评价了MPAE对几种0#柴油的低温流动性能的改进效果。结果表明，该工艺路线产品的收率几乎达到100％，成本低。并且，改性后的聚丙烯酸高级酯在较宽的分子量范围内具有较好的降凝效果；相比之下，改性之前聚丙烯酯高级酯只在很窄的分子量范围内具有降凝效果。与其它柴油降凝剂相比，MPAE对柴油具有良好的感受性，一般能降低柴油冷滤点3℃－6℃，凝固点降幅在10℃－12℃左右，具备了工业化价值。     

柴油对流动改进剂感受性差异的原因表征与分析

柴油对低温流动改进剂具有较高的选择性。流动改进剂对不同的炼油厂、不同原油以及不同的加工工艺炼制的柴油的感受性和降冷滤效果截然不同。主要是由柴油的化学组成决定。一般认为，柴油中正构烷烃的摩尔分数和分布是影响其低温流动改进剂使用效果的主要因素。正构烷烃摩尔分数越低，碳数分布越广，添加低温流动改进剂效果越好；此外，柴油中所含的单环芳烃是高碳数烷烃的优良溶剂，其摩尔分数越高，柴油低温蜡析出量越少，加低温流动改进剂效果越好。     

加速溶剂萃取法提取海洋沉积物中正构烷烃的方法研究

采用加速溶剂萃取法(ASE)提取了海洋沉积物中的正构烷烃,并对ASE的萃取剂比例、萃取温度、静态萃取时间以及循环次数等实验条件进行优化。结果表明,当样品长碳链正构烷烃含量较高或需要检测长碳链正构烷烃含量时,可使用甲醇-二氯甲烷(1∶3)作为萃取剂;而甲醇-二氯甲烷(1∶9)适用于短碳链正构烷烃含量较高或需要检测短碳链正构烷烃含量的样品。加速溶剂萃取提取沉积物中正构烷烃的最佳条件为:萃取温度150℃,静态提取时间15 min,循环3次。在优化条件下,测定沉积物样品中正构烷烃的精密度除C15为20%外,其余为3%~14%,替代物回收率为84%~114%。相比于传统的索氏提取法,该方法的工作效率高、回收率高、精密度良好,适用于沉积物样品中正构烷烃的定量分析。     

差分气液色谱法直接测定煤油和柴油中的正构烷烃

正构烷烃(nニ烷烃)是石油中的重要组分,对其在石油馏份中的含量和分布已进行了大量工作。1972年Folmer提出了差分色谱法,Stuckey也在这方面进行了一些工作。我们应用程序升温差分色谱法分析了自制煤油和柴油标样以及煤油和柴油馏份油中的n-烷烃,结果较为满意。方法速度快,信号解释简单。实验部分 1.仪器设备:捷克41型气相色谱仪,在其中一个放大器微调线路中附加了一个可调电     

Pt/SAPO-11催化剂上柴油馏分临氢异构化改质反应研究

以SAPO-11为载体制备了Pt/SAPO-11柴油异构降凝催化剂．采用微反评价选取n-C12烷烃为柴油模型分子进行临氢异构化反应研究，结果显示异构化产物以单甲基异构体为主，在多支链的异构体中以双甲基异构体为主．同时，采用固定床加氢装置考察了催化剂对不同性质柴油原料的异构化性能．实验结果表明，处理直馏柴油和焦化柴油时，在实现柴油深度降凝的同时柴油收率达到95％以上，且十六烷值有所提高，生产的-20^#、-35^#清洁柴油性能可达到国家优质低凝柴油指标，该催化剂具有较高的实际应用潜力．     

柴油低温流动性改进剂的研制及性能评价 Ⅰ. 低温流动性改进剂对柴油的感受性

在分析胜利石化总厂 0 #柴油和齐鲁石化 0 #柴油的烃族组成、蜡碳分布的基础上 ,进行分子设计 ,研制出一种柴油低温流动性改进剂。它主要由具有一定粘度的三元共聚物组成。实验结果表明 ,这种柴油低温流动性改进剂能十分有效地提高胜利石化总厂 0 #柴油的低温使用性能 ,而胜利石化 0 #柴油对目前国内外其它低温流动性改进剂的感受性较差。     

Submicron carbon-based hybrid nano-pour-point depressant with outstanding pour point depressant and excellent viscosity depressant

We have investigated the effective utilization potential of carbon nanomaterials in the field of pour point depressants, and reported three kind of carbon-based hybrid nano-pour-point depressants with different dimensions. In this paper, poly-α-olefins-acrylate high-carbon ester pour point depressant (PAA-18) was prepared by esterification and polymerization as the basic pour point depressant. Then, the basic pour point depressant PAA18 was modified by solvothermal method with graphene oxide (GO), carbon nanospheres (Cna) and carbon nanotubes (OCNTs). The morphology and structure of the composites were analyzed by SEM, FTIR and XRD. The results showed that PAA18 was successfully in situ polymerized on GO, Cna and OCNTs. We took the simulated oil as the experimental object, and evaluated its pour point, rheological properties and wax crystal morphology, and achieved excellent results. In the three carbon-based hybrid nano-pour-point depressants with different carbon contents, the oxidation carbon nanotubes composite pour point depressant (PAA18-1 % OCNTs) with carbon content of 1 % had the best pour point and viscosity reduction effect when the dosage was 1250 ppm, which could make the pour point of the simulated oil containing wax decrease by 16 °C. PAA18-1 % OCNTs reduced the pour point by 5 °C more than PAA18. This paper provides reference for the application of carbon nanomaterials in the field of pour point depressant.     

倍半硅氧烷/改性乙烯-乙酸乙烯酯共聚物复配降凝剂对蜡油倾点的影响

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 ℃。     

Polymers-Copolymer as Flow Improvers for Fuel Oils and Their Electrical Conductivity

In order to find efficient cold flow improvers for fuel oil, polymethylmethacrylate (PMMA), polystyrene (PS), and a copolymer [styrene (S)–methylmethacrylate (MMA) were prepared. The structure of these polymers and the copolymer were characterized by infrared spectral analysis and their molecular weights were measured. These polymers-copolymer were used as additives for fuel oils in order to lower their pour point. Accordingly, they were evaluated as flow improvers for fuel oil. The results indicated that PMMA possesses less performance as pour point depressant. While the addition of PS and the copolymer (S–MMA) yield excellent pour point depressants for fuel oil. Upon studying the prepared additives and their properties, it was found that the electrical properties of the copolymer were changed due to the presence of polar ion in MMA effect on the electrical properties. The highest electrical conductivity was found when styrene:MMA molar ratio was 1:1.     

Utilization of α-olefins obtained by pyrolysis of waste high density polyethylene to synthesize α-olefin-succinic-anhydride based cold flow improvers

A new route of utilization of α-olefin rich hydrocarbon fractions obtained by waste polymer pyrolysis was investigated. α-olefin-succinic-anhydride intermediate-based pour point depressant additives for diesel fuel were synthesized, in which reactions needed α-olefins were obtained by pyrolysis of waste high-density polyethylene (HDPE). Fraction of α-olefins was produced by the de-polymerization of plastic waste in a tube reactor at 500℃ in the absence of catalysts and air. C17～22 range of mixtures of olefins and paraffins were separated for synthesis and then, these hydrocarbons were reacted with maleic-anhydride (MA) for formation of α-olefin-succinic-anhydride intermediates. The olefin-rich hydrocarbon fraction contained approximately 60% of olefins, including 90%～95% α-olefins. Other intermediates were produced in the same way by using commercial C20 α-olefin instead of C17～22 olefin mixture. The two different experimental intermediates with number average molecular weights of 1850g/mol and 1760g/mol were reacted with different alcohols: 1-butanol, 1-hexanol, 1-octanol, i-butanol, and c-hexanol to produce their ester derivatives. The synthesized ten experimental pour point depressants were added in different concentrations to conventional diesel fuel, which had no other additive content before. The structure and efficiency of experimental additives were followed by different standardized and non-standardized methods. Results showed that the experimental additives on the basis of the product of waste pyrolysis were able to decrease not only the pour but also the cloud point and cold filter plugging point (CFPP) of diesel fuel, whose effects could be observed even if the concentration of additives was low. Furthermore, all additives had anti-wear and anti-friction effects in diesel fuel.     

Effect of gemini surfactant additives on pour point depressant of crude oil

Efficiencies of cationic gemini surfactant additives in improving the pour point depressant of crude oil were investigated. The length of alkyl chain is a major factor affecting the improvement of the pour point depression. The adsorption behavior of these gemini surfactants at air/solution and oil/solution interfaces were investigated by measuring the surface tension and interfacial tension as functions of concentration. It is found that there is a good relation between surface properties especially interfacial tension of the gemini surfactants and their efficiency in depressing the pour point. Also, the surface parameters and free energies of micellization and adsorption confirm the decreasing and improving of pour point depression. Crystallization study in crude oil revealed the relationship between the structure and activity of gemini surfactant additives. It is found that the x-ray diffraction patterns of waxes with additives are remarkably different from those without additives. The mechanism of the depressants action has been suggested according the adsorption of each additive. Adsorption of the additive on the surface of the wax particles inhibits their growth and alters the crystal habits through micelle core. Pretreatment of the crude oil with pour point depressants has received the greatest acceptance due to its simplicity and economy.     

Poly-Acrylic Acid Derivatives as Diesel Flow Improver for Paraffin-Based Daqing Diesel

Since the diesel products from paraffin-based Daqing crude oil showed low sensitivity to certain commercial diesel pour point depressant (PPDs) that resulted from the high content of paraffin, certain poly-acrylic acid derivatives (PADE) with -COOR, -COOH, -CONHR, and -COO-NH3 R groups by molecular design on the mechanics of diesel; PPDs were synthesized and evaluated as cold flow improver for Daqing 0# diesel in this paper. The pure PADE was superior to the commercial PPDs and displayed a substantial ability of wax crystals dispersion. There was a synergistic effect among the PADE and T1804 and secondary amine. The synergism clearly improved the low temperature performance of Daqing diesel products and could reduce the cold filter plugging point of 0# diesel by 6-7℃.     

Advances in the research of polymeric pour point depressant for waxy crude oil

In the pipeline transportation of waxy crude oil when the temperature of the waxy crude oil drops lower than the wax appearance temperature (WAT), wax precipitates continuously from oil phase, which brings a series of negative impacts on pipeline performance and even causes complete blockage under severe conditions in recent decades, polymeric pour point depressants have a very important practical application in depressing the pour point and improving the fluidity of waxy crude oil, thus reducing the cost of waxy crude oil pipeline transportation. The most commonly used types of the polymeric pour point depressants include ethylene-vinyl acetate (EVA) copolymers, comb copolymers, and nano-hybrid pour point depressants. In this paper, the structural character, interactive types, and the action mechanism of the polymeric pour point depressants are reviewed with their application and research progress introduced.     

降凝剂对蜡油中蜡析出与溶解影响的物理化学研究

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.     

Preparation and Evaluation of Some Terpolymers as Lube Oil Additives

In the present work, some polymeric additives were prepared to use as viscosity index improvers and pour point depressants for lube oil via copolymerization of hexadecylacrylate and dodecylacrylate with styrene. Structure of the prepared compounds was confirmed by infrared spectroscopy and nuclear magnetic resonance. The molecular weights of the prepared copolymers were determined by using gel permeation chromatograph. The efficiency of the prepared terpolymers as viscosity index improvers and pour point depressants for lube oil was investigation. It was found that all the prepared terpolymers are effective as viscosity index improvers and pour point depressants. The viscosity index of the prepared terpolymers increases with increasing the concentration of the additives and increases by increasing the percentage of hexadecylacrylate until 70%. The best result for viscosity index of the prepared terpolymers is when the percentage of styrene is 10%. The pour point of the prepared compound decreases with decreasing concentration of additive used.