原油中环烷酸催化酯化前后的高分辨质谱分析

原油中的环烷酸可通过酯化反应转化为环烷酸酯,从而降低原油酸值。本文利用Zn-Al水滑石作为酯化反应催化剂,乙二醇作为反应物。对催化酯化前后的原油采用ESI FT-ICR MS进行分析,从中鉴定出了O2、O1、N1、N2、N1O1及N1O2六种类型的杂原子非烃化合物,其中O2的丰度最高。酯化前原油中O2的丰度远高于其它组分,酯化后O2的丰度显著降低。酯化前后的原油样品中,丰度较高的环烷酸的DBE值均为5,碳数均基本分布在C30-C34。研究结果表明,原油中的环烷酸可被有效酯化从而显著降低原油酸值,酯化前后环烷酸的碳数和DBE值分布均基本接近,这主要是由于酯化过程中各类环烷酸的酯化效率基本相同。     

实沸点蒸馏对2种高酸原油腐蚀性的影响及表征

高酸原油经实沸点蒸馏后酸值会发生较大程度的损失,哪些类型的石油酸发生了损失及高酸原油腐蚀性是否同等降低却不得而知。针对这一问题,对2种典型高酸原油实沸点蒸馏前后的酸值和腐蚀性进行了考察,并对蒸馏前后高酸原油中的石油酸进行了质谱表征。结果表明：2种高酸原油实沸点蒸馏后液相腐蚀速率减小,而气相腐蚀速率明显增大,说明大分子石油酸分解成了沸点较低的小分子石油酸;2种高酸原油的气、液总腐蚀速率降低都远小于酸值的损失,说明分解生成的小分子石油酸的腐蚀性更强;2种高酸原油实沸点蒸馏前后石油酸的类型变化不大,但碳数分布变化明显,碳数越高的大分子石油酸分解越多。高酸原油的腐蚀性与酸值并非线性关系,石油酸的类型即脂肪酸和一环环烷酸含量可能是影响高酸原油腐蚀性的重要因素。     

反应条件对渣油加氢产物中碱性氮化物的影响

利用间歇式固定床反应器对大连混合渣油进行催化加氢反应,研究氢分压和剂油比对加氢液体产物中碱性氮化物分布及类型的影响;利用电喷雾傅里叶变换离子回旋共振质谱（ESI FT-ICR MS）对原料油及产物中的碱性氮化物进行表征。结果表明：反应前后渣油中N1（含1个N原子）类的碱性化合物占绝大比例,N1S1（含1个N、1个S原子）和O1（含1个O原子）类化合物的比例次之,其它类型的相对丰度均较低;随氢分压的增大,产物中大部分碱性氮化物类别的丰度有所下降,同时发生了加氢断侧链致使N1类化合物分子的碳数减少,分子尺寸变小;随剂油质量比的增大,杂原子的相对丰度减弱,分子饱和度减小,N1类化合物的等效双键数（DBE）分布没有显著变化（DBE为9~18）;但加氢反应的断链使得分子碳数明显变小为C20~C34;反应后产物中杂原子明显减少。     

含酸原油加工中石油酸的分布及传递

为了考察含酸原油中的石油酸在各装置的分布情况,对某炼油厂常减压蒸馏、催化裂化、焦化、加氢、重整装置进行了全面的采样分析,不仅得到了装置各部位的酸值分布及传递,还对重点装置原料和产品中的石油酸变化进行了分子水平表征。结果表明：常减压蒸馏装置常二线、常三线、减一线、减二线及减压渣油易发生高温酸腐蚀;实沸点蒸馏与常减压蒸馏酸分布存在明显差异;与催化裂化原料相比,催化裂化柴油和油浆中各碳数的石油酸含量都很低,3种物料中含量最高的石油酸都是二环环烷酸;焦化柴油和焦化蜡油中各碳数的石油酸含量都很低,其中一环环烷酸相对含量较高,分解较少。本研究结果对含酸原油加工、装置防腐及产品质量控制都具有指导意义。     

克拉玛依九区原油中石油酸分子的表征北大核心CSCD

采用高效液相色谱-飞行时间质谱联用法(HPLC-TOF MS)技术分析了含酸原油中的石油酸,对质谱直接进样法和HPLC-TOF MS法分析石油酸组成进行了比较,优化了溶剂、流动相等条件,并对九区原油中的石油酸组分进行了定性及半定量分析。实验结果表明,采用HPLC-TOF MS技术,结合负离子电喷雾电离方式,可将烷基苯酸与饱和脂肪酸、环烷酸分离,有助于获得最接近真实分布的石油酸组成,使不同类型石油酸化合物的定量分析结果更加准确。九区原油的石油酸主要由环烷酸构成,且二环环烷酸含量最高;另含有少量饱和脂肪酸、烷基苯酸、羧酸二聚体,以及低含量含有O2S和O3S的酸性化合物。     

蓬莱和苏丹高酸原油中的石油酸结构组成研究

采用醇碱水溶液萃取蓬莱和苏丹高酸原油中的石油酸。通过红外光谱、核磁共振和负离子电喷雾质谱三种表征技术鉴定了原油中的石油酸结构和组成。结果表明,这两种原油中的石油酸结构基本一致,分别为脂肪酸、环烷酸和芳香酸,不同的是对于同一种类的石油酸,碳数范围不同,所占的质量百分数不同。     

环烷酸催化脱羧机理的研究

为深入认识环烷酸催化脱羧的反应机理,选取具有代表性的带有较长侧链的9 环己基壬酸为模型化合物,采用基于密度泛函理论的量子化学从头计算方法研究了该分子的电荷分布和前线轨道分布,发现分子中的羰基O原子更易受到B酸和L酸进攻。在此基础上,进一步分析了该分子与B酸和L酸作用前后的键长、键级等变化,推演出了羧基β位碳碳键发生断裂生成小分子的石油酸和直接脱羧生成CO2 2条反应路径。比较2条反应路径的反应能垒后,提出了在B酸作用下,9 环己基壬酸分子更容易发生的是生成小分子石油酸的反应,而在L酸作用下,9 环己基壬酸分子更容易发生直接脱羧生成CO2反应的观点。     

胜利高酸原油馏分油中石油酸的腐蚀性研究

对胜利高酸原油200~350 ℃和350~450 ℃馏分油中的石油酸用醇碱抽提、纯化后,采用元素分析法、蒸气压渗透法、红外光谱法和氢核磁共振波谱法对石油酸结构组成进行了分析,并考察了A20碳钢在两个馏分油中的腐蚀速率随温度的变化。结果表明：胜利原油200~350 ℃和350~450 ℃馏分油中石油酸的平均分子式分别为C15.86H27.51O2.06和C32.86H54.77O2.29;石油酸腐蚀不仅与酸含量有关,更与其结构密切相关,随着馏分变重,石油酸的烃支化度由0.197升至0.292,烃支化程度增大,石油酸与羧基相连基团的吸电子能力降低,石油酸酸性减弱,对碳钢腐蚀能力降低,同时,石油酸在与碳钢接触反应时,所受空间位阻增大,减缓了石油酸对碳钢的腐蚀;石油酸的腐蚀性随温度升高而增大,小分子石油酸的腐蚀能力强。     

原油中的石油酸组分全二维气相色谱/飞行时间质谱分析

通过分析原油酸性组分衍生化样品，初次尝试了利用全二维气相色谱/飞行时间质谱技术（GC×GC-TOFMS）鉴定原油有机酸性化合物组成。研究结果表明:检测的原油中含有脂肪酸和环烷酸2类酸性化合物，其中脂肪酸类化合物主要由正构一元脂肪酸、类异戊二烯酸、2-乙基链烷酸和正构二元脂肪酸构成；环烷酸类化合物主要由单环长链脂肪酸、1，4-二甲氧基蒽、脱氢松香酸和甾烷酸等化合物构成。全二维气相色谱飞行时间质谱为石油酸组分的精细地球化学剖析提供了新的分析手段。      

高酸原油的腐蚀研究

苏丹脱酸原油和蓬莱原油相比，酸值接近，但腐蚀性远小于蓬莱原油，这主要归因于碳数较小的石油酸的强腐蚀性。苏丹高酸原油脱酸后，石油酸总量减少，碳数较小腐蚀性强的石油酸被脱除，故而腐蚀性大大降低。通过分析苏丹高酸原油腐蚀前后的石油酸分布，进一步验证了碳数较小的石油酸是造成腐蚀的主要原因。     

苏丹Dar原油及其馏分油石油酸组成分析

The Dar crude oil produced in Sudan was distilled into several fractions. The heteroatom class species in crude and its fractions were characterized by the negative-ion ESI FT-ICR MS. The major emphasis was put upon the study on the O2 class species (petroleum carboxylic acids). The test results revealed that aliphatic acids and monocyclic naphthenic acids accounted for a large proportion in petroleum carboxylic acids of the Dar crude. The relative abundance of aliphatic acids and monocyclic naphthenic acids decreased with an increasing boiling point of fractions. Meanwhile, the relative abundance of bicyclic and tricyclic naphthenic acids increased at first and then decreased, whereas the relative abundance of petroleum carboxylic acids with higher double-bond equivalence (DBE) values increased. The high abundance of aliphatic acids in the Dar crude and its fractions covered the carbon numbers in a range of 16 to 18 which had important geochemical signifi- cance. The O2 class species were distributed in a broad range of DBE values and carbon numbers with increasing boiling points of fractions.     

Tracking Catalytic Esterification of Naphthenic Acids in Crude Oil by ESI FT-ICR MS

The catalytic esterification reaction was used to decrease total acid number(TAN) of crude oil by converting naphthenic acids to naphthenic acid esters in the presence of Zn-Al hydrotalcite used as the catalyst and glycol used as the reactant. The crude oil and its corresponding esterified oil were characterized by the negative-ion electrospray ionization(ESI) Fourier transform ion cyclotron resonance mass spectrometry(FT-ICR MS). Six acidic class species, O_2, O_1, N_1, N_2, N_1O_1 and N_1O_2 were assigned in the negative-ion spectrum both in the crude oil and its esterified oil. Among the identified acidic compounds, the O2 class was dominant. The relative abundance of O_2 class species was much higher than other acidic class species in crude oil, while it was significantly decreased after esterification. The most abundant O_2 class species had a carbon number of 30-34 and a double-bond equivalence(DBE) value of 5 before and after esterification. It could be concluded that the naphthenic acids in crude oil can be esterified to lower its TAN value, and each of them seems to exhibit identical esterification efficiency approximately due to the similar DBE versus the-carbon number distribution before and after esterification.     

超高酸原油中环烷酸类型及分布规律研究

通过对国内某原油进行实沸点切割和环烷酸分离,采用电位滴定仪、红外光谱仪及质谱仪等研究原油、馏分油中环烷酸分布及类型.研究结果表明:原油酸值为13.18 mg(KOH)/g,属于超高酸原油,其环烷酸主要集中为400～425℃,425～450℃和>450℃馏分,分别占原油总酸质量的4.68％,5.34％和54.44％;超高...     

A New Method for Determination of Naphthenic Acids in Crude Oil

The petroleum acids in crude oil were separated by extraction with column chromatogram and anion exchange resin. The separation effect and the related composition and structure of petroleum acids were obtained by using IR (Infra-Red) spectra techniques. The separated petroleum acids can under special conditions react with methanol to form corresponding esters, which can be analyzed by CI (chemical ionization)-MS (mass spectrometry). The characteristic ion peaks m/z (M 15)^ of naphthenic acid esterscombined with z-series formula CnH2n zO2 of naphthenic acids can be used to classify naphthenic acids into fatty acids, mono-cyclic, bi-cyclic, tri-cyclic, and higher polycyclic acids. The analytical results can give the molecular weight and the carbon number distribution of petroleum acids contained in crude oil. The results of study indicate that this method is simple, rapid and easy in operation.     

减压渣油中钙赋存状态的研究

利用酸解的方法将低凝稠油减压渣油和超稠油减压渣油中的石油酸钙变为有机酸,采用醇碱溶液抽提的方法将石油酸抽提出来,通过红外光谱表征,证明是支化度较高、侧链较短的环烷酸。根据抽提物的模拟蒸馏数据对2种原油脱钙后柴油馏分和润滑油馏分酸值的增加情况进行了估算。     

风城稠油中石油酸组成结构分析

由氢氧化钾-乙醇水溶液分离风城稠油中的石油酸,结合元素分析、红外光谱(FT-IR)、核磁共振(NMR)、电喷雾质谱(ESI-MS)、紫外光谱(UV-Vis)和荧光色谱等方法分析其结构组成。结果表明:风城稠油所含石油酸主要是一元羧酸二聚体,平均相对分子质量为665,平均分子式为C43.51H78.47O3.78,氢碳原子比为1.80;各类酸分布范围较广,其中,环烷酸含量最高,占79.84%,脂肪酸次之,占20.16%;环烷酸中一环环烷酸、二环环烷酸、三环环烷酸、四环环烷酸/芳环羧酸、五环环烷酸/芳环并一环羧酸和六环环烷酸/芳环并二环羧酸的含量相当,均在11.00%~18.88%之间。此外,还检测到微量3~4环的芳香结构物质。     

实沸点蒸馏前后高酸重质原油的石油酸分布表征

The molecular transformations of carboxylic acids in heavy acidic SL crude before and after true boiling point distillation were examined by ultra-high resolution negative-ion electrospray ionization （ESI） Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR MS）. The acid class （heteroatom number）, type （z numbers） and carbon number distributions were positively characterized. It was found out that the total acid number （TAN） of SL crude decreased after true boiling point distillation, and the abundance of O2 class in mass spectra was also found to be reduced from 67.6% to 34.5% in SL TBP mixed crude as measured by MS spectra, indicating to a potential carboxylic acid decomposition. However, it was interesting that the carboxylic acids type distribution in both oils was almost the same although their relative abundance in SL TBP mixed crude turned to be much lower, suggesting that various petroleum carboxylic acid types have the similar thermal decomposition reaction behavior. Furthermore, for each O2 type of acids in SL TBP mixed crude, the abundance of carboxylic acids with carbon number higher than 35 was reduced greatly, especially for those with carbon number higher than 60, the mass peaks of which were nearly totally removed, indicating that the large carboxylic acid molecules in heavy fractions decomposedmore significantly because of longer heating time during the true boiling point distillation process. As a result, the reduction ofTAN may be caused by the thermal decomposition of carboxylic acids especially those with high carbon number, suggesting that quick distillation or much lower pressure is required to avoid the thermal decomposition.     

炼油厂含盐废水中环烷酸的鉴定与分析

分别用快速化学定性法、GC-MS法、电喷雾(ESI)-MS法和FTIR法研究了加工高酸原油含盐废水及其处理过程废水中环烷酸的快速鉴定、来源、分子识别及含量。实验结果表明,利用在酸性和碱性条件下均产生沉淀的现象可快速鉴定炼油厂含盐废水中的环烷酸;GC-MS法可确定环烷酸主要来自含酸原油电脱盐过程,是影响含酸原油加工废水达标排放的主要组分;ESI-MS法能有效鉴定废水中环烷酸的类型及相对分子质量分布,某炼油厂含盐废水生化处理出水中检出碳数为5～41、相对分子质量为102～596、环数为0～6的环烷酸,其中C18环烷酸的含量最高;FTIR法测定某炼油厂气浮和生化处理后,环烷酸的总去除率为93.3%。