石油精细化学品在原油预处理过程中的应用研究

【作者】 刘桂玲；

【导师】 高晋生； 徐心茹；

【作者基本信息】 华东理工大学 ， 化学工艺， 2004， 博士

【摘要】 随着国内外原油的劣质化、重质化,原油的预处理过程越来越受到重视。本论文为实现原油预处理的多效化,合成了针对性强的系列石油精细化学品,研究了电脱盐破乳剂与含沥青质、含蜡原油性质的关系,同时开展了原油脱盐脱铁与脱盐脱硫的研究。探讨了原油脱盐机理,提出了相应的盐分传质模型。原油中沥青质的存在导致油相粘度升高,并且沥青质缔合胶粒的存在不利于盐分由油相到水相的传质。油溶性的酚醛树脂系列破乳剂适合沥青质含量较高的原油脱盐,多元醇系列破乳剂的脱水效果好,多元醇5#破乳剂与酚醛树脂6#破乳剂复配后对沥青质含量为5.4%的5#原油的脱盐率为78%,脱水率达到100%。实验结果表明,石蜡的存在不利于原油电脱盐脱水。通过对含蜡原油的表观粘度研究可知,原油的表观粘度随蜡含量增加而增加。原油中石蜡的增加造成原油的粘度升高导致原油不能有效的脱水,从而影响了脱盐。在不同系列破乳剂中,多乙烯多胺系列破乳剂适合于含蜡原油脱盐,二胺系列破乳剂适合于含蜡原油脱水。三段式结构多元醇系列破乳剂优于二段式结构。以多乙烯多胺为起始剂的3#破乳剂对含蜡量为25.9%的8#原油的脱盐率达到89%,脱水率达到87%。在胜利原油、罗凯利亚原油及鲁宁管输原油中48~75%的铁以有机酸盐形式存在,络合铁约占6~40%。在破乳剂存在下,脱盐过程并不能有效地脱除原油中大部分金属铁。合成了系列脱铁剂,并探讨了脱铁机理。三种原油中加入脱铁剂后都有一定的脱铁效果,其中聚胺羧酸盐类脱铁剂的脱铁效果要优于有机膦酸盐。在原油中加入脱铁剂TE-4,在脱盐的同时,能有效地脱除金属Fe、Ca、Na、Mg,并能部分脱除Ni、V。对三种原油脱铁剂TE-4的加入量都存在最佳脱铁值,在最佳投入量下三种原油的脱后铁含量分别降到2.5ug/g、12.44ug/g及2.9ug/g,对应的脱铁率分别为74.25%、66.85%及94.54%。对伊朗、沙特原油合成不同的脱硫剂进行静态脱硫实验,其中TS-2适合于伊朗原油,TS-1适合于沙特原油。在最佳工艺条件下,这两种脱硫剂与破乳剂共同作用分别使伊朗原油的脱硫率、脱盐率和脱水率分别达到26.5%、74%和85%;沙特原油的脱硫、脱盐率和脱水率分别达到16.1%、59%和88%。本论文选择了脂肪酸、胺等作为疏水基、亲水基物料合成具有羧基并且含有氮原子的SA、SB、SC及SD系列破乳剂并研究了合成机理,合成的破乳剂中,SC-14适合于胜利原油的脱盐脱水,在最佳工艺条件下,其脱水率和脱盐率分别为76.3%和79.5%。在合成中破乳剂SC-14无需接聚环氧丙烷和环氧乙烷,具有合成路线简单、安全的优点;SD-12适合于奥里乳化原油的脱盐脱水,在最佳工艺条件下,能达到显著的脱盐脱水效果;在合成中破乳剂SD-12在分子中引入氧乙烯基增加破乳剂的亲水性,从而实现该乳化原油有效的破乳。对SC、SD系列原油破乳剂,通过加入盐转移剂实现该系列部分破乳剂的深度脱盐,能将胜利、奥里乳化原油的脱盐率从60%左右提高到70%以上。根据对乳化原油脱盐传质过程的深入分析,建立了一种空心球壳传质模型用于胜利原油减压蒸馏400~450℃馏分与20%水混合形成W/O型乳化液的脱盐脱水过程,通过检验,该模型与实验值基本吻合,该模型表明脱盐脱水过程与温度、原油性质、破乳剂性质、乳化液制备条件及油水两相的体积等因素相关,说明考虑界面膜破裂因素的空心球壳模型对电脱盐过程具有一定的实际指导意义。更多还原

【Abstract】 Along with the inferiority and heavilization of worldwide crude oils, more and more attentions are paid to its pretreatment. The desertation focusing on multifunctions of pretreatment for crude oils synthesizes a series of fine chemicals for petroleum, with which the contents studied the relationship between the electric desalting demulsifiers and asphaltic, paraffinic crude oil, deferrization, desulfurization, desalting mechanism for crude oil and model of salt transfer.Asphaltene in crude oil causes raising of crude viscosity and its micelles interferes with the salt transfer from oil to aqueous phase. The oil-soluble phenolic resin series are compatible with asphaltic crude oil for desalting, whereas the polyhydric alcohol series are more efficient in dewatering efficiency. After the recombination of phenolic resin demulsifier 5# with polyhydric alcohol 6# desalting dewatering efficiency (DDE) for asphaltic crude oil can reach 78% and 100%. Experimental results indicate that paraffin in crude oil exerts a great influence on DDE and dynamic viscosity of crude oil increases with the increase of paraffinic content in crude oil by testing dynamic viscosity. Because higher viscosity for paraffinic crude oil leads to inefficient dewatering, and hence decreases the desalting efficiency. Among different kinds of demulsifiers series, the polyamine series are more compatible with paraffinic crude oil for desalting and diamine series are compatible for dewatering. The triblock copolymer structure of PO-EO-PO for polyhydric alcohol is more effective with this type of crude oil than the diblock of PO-EO. DDE of Polyamine demulsifier 3# for crude oil 5# which paraffinic content is 25.9% are 89% and 87%.It is found that 48~75% iron exists in Shengli, Rocalya and Luning crude oils as organacid salt and 6~40% as iron complex. Most irons can not be efficient removed from crude oils using only demulsifier in the desalting process. Four deferric agents are synthesized and the mechanism of deferrization is discussed. The deferric agents can get a better result of deferrization for three crude oils, in which the polyanine-carboxylate types have a better deferrization rate than the organophosphate ones. Deferric agent TE-4 can effectively remove Fe, Ca, Na and Mg from crude oils as well as part of Ni and V. There exists an optimal dosage for deferric agent TE-4 and at the optimal dosage, iron content after deferrization for three crude oils is 2.5μg/g, 12.44μg/g and 2.9μg/g, corresponding to deferric rate of 74.25%, 66.85% and 94.54% respectively.Some desulfurizers are synthesized for Iran and Saudi crude oils, among which TS-2 is efficient for Iran crude oil and TS-1 for Saudi crude oil. At the optimal conditions, desulfurizing, desalting and dewatering efficiencies of TS-2 for Iran crude oil reach 26.3%, 74% and 85% and TS-1 for Saudi crude oil are 16.1%, 59% and 88% respectively.Demulsifers of SA, SB, SC and SD series containing carboxyl and nitrogen are synthesized with fatty acids as hydrophobic group and amines as hydrophilic group and synthetic mechanism is also discussed. SC-14 polymerized without PO and EO is efficient for Shengli crude oil in DDE and hence its synthesis process is simple, convenient and safe. At the optimal conditions, DDE of SC-14 for Shengli crude oil are 76.3% and 79.5%. Whereas SD-12 containing oxyethylene group is compatible with Oli crude oil and thus effectively demulsifies for such oil-water emulsion. At the optimal conditions, DDE of SD-12 for Oli crude oil also get a better result..Desalting efficiencies for SC and SD series can be improved by the salt transfer agent, that is, desalting efficiency of such agent recombinated with demulsifier for Shengli and Oli crude oils can raise from 60% to over 70%. After studied the salt transfer process further, a model of hollow spherical shell is used for W/O emulsion formed by mixing 400~450℃distillate of Shengli vacuum distillation with 20% water. The model approximately coincides with the test result after verified. Such model manifests that desalting and dewatering process has relation to temperature, crude oil and demulsifier properties, emulsive conditions, volume of oil and water phase etc. As a result, concerning rupture of interfacial membrane, it is helpful for pretreatment process of crude oil.更多还原