Composition of petroleum heavy ends. 2. Characterization of compound types in petroleum >675 °C residues

The characterization of polar compound types in petroleum residues of b.p. >675 °C are described. The fractions of acids, bases, and neutral nitrogen compounds prepared by the method described in Part 1 (Fuel 1981, 60, 14) were further separated and analysed. Major compound types identified in the acid fraction are carboxylic acids, phenols, pyrrolic nitrogen compounds, and amides. Quantitative estimates of the compound types were made by two infrared methods. Major compound types identified in the bases were pyridine benzologs, amides, and pyrrolic nitrogen compounds; types found in the neutral nitrogen fraction were amides and pyrrolic nitrogen compounds. The average molecular weight of the >675 °C residues was estimated to be 900 after being determined by four different methods.     

Nitrogen compound distribution in middle distillate fuels derived from petroleum,oil shale,and tar sand sources

Nitrogen compounds present in crude sources constitute serious problems both for producers and consumers. For producers, these compounds are responsible for poisoning catalysts during the refining processes. For consumers, these compounds are responsible for the degradation observed in fuels during storage and handling. The quality of petroleum, as measured by °API gravity, continues to decrease in quality. This, coupled with the inevitable use of other crude sources, if used in quantity will further decrease the stability of middle distillate fuels. In this article we present our method for the separation and quantitation of the slate of nitrogen compounds present in middle distillate fuels derived from petroleum, oil shale and tar sand sources. Results from our laboratory indicate that of all of the nitrogen compounds present in middle distillate fuels, the indole type structure is the most deleterious.     

Coal tar nitrogen bases

A method involving acid extraction, fractionation, derivatization and g.c.-m.s. analysis was used to characterize the basic nitrogen compounds in coal tar. It was found that these compounds fall into ten compound types belonging to eighteen homologous series. Separation of aza-arenes from amines by derivatization is recommended as a better procedure.     

炼油工艺过程氮分布

在石油炼制及加工过程中,原料中的氮化物会对生产操作和产品质量造成许多负面影响。研究不同工艺过程的氮分布规律,可以用于开发炼油工艺过程的氮分布模型,指导炼油企业优化原油配置和生产方案。     

A new technique for the acid/base separation of petroleum and coal-derived fractions

A new method for the acid/base fractionation of asphaltenes and other petroleum and coal-derived materials has been developed. This technique, which employs a strong, solid acid, has been shown to separate on the basis of acidity or basicity and to fractionate in a fashion similar to hydrogen chloride precipitation. In addition, the yields of fractions were shown to depend on the acidity of the separating medium.Basic and non-basic fractions were characterized by elemental analysis, e.s.r., n.m.r., interfacial tension, mass spectrometry, molecular weight, u.v.-visible spectrophotometry, and silylation. These data provide detailed information on the elemental distributions, functional group types, carbon and hydrogen types, and vanadium environments in the two fractions. The findings indicate that basic nitrogen is concentrated in the basic fraction while non-basic nitrogen and hydroxyl are mainly in the non-basic fraction. Although total nitrogen was concentrated in the basic fraction from coal asphaltenes, this was not the case for petroleum asphaltenes.     

焦化苯加氢精制工艺研究

介绍一种焦化苯加氢精制脱除杂质的工艺方法。该技术采用加氢精制,精制后的产品噻吩脱除率99.99%以上、总硫脱除率〉99%、碱性氮脱除率100%、总氮脱除率〉99%、液收〉99%,精制苯中总硫质量分数〈1×10^-6,检测不出总氮。精制后的产品符合石油苯国家标准的质量要求,可用于有机化工合成。     

Comprehensive two-dimensional gas chromatography for basic and neutral nitrogen speciation in middle distillates

The molecular knowledge of nitrogen compounds in diesel feedstocks has become a key issue in the development of hydrotreatment processes, especially for ultra-low sulfur diesel production. Indeed, nitrogen species have a strong impact on the hydrodesulfurization (HDS) pathway, since basic nitrogen is known to poison acidic sites of HDS catalysts.Since conventional methods only allow a poor degree of information, the increased separation power of comprehensive two-dimensional gas chromatography (GC × GC-NCD) was used in this study to obtain a detailed overview of nitrogen compounds by type (basic/neutral), by family and by carbon breakdown in diesel and liquefied coal samples. Partially hydrogenated compounds such as tetrahydrocarbazole and tetrahydroquinoline derivatives could even be detected in liquefied coal samples as well as diesel from ebullated bed conversion units. Comparison of GC-NCD with GC × GC-NCD for quantitative determination of nitrogen compounds by family was achieved in a first step. These results demonstrate the superiority of GC × GC to allow for a comprehensive characterization of nitrogen compounds in diesel and related samples in one injection. Furthermore, nitrogen speciation by GC × GC-NCD technique allows identifying most nitrogen species in conventional diesel or liquefied coal samples, with no use of mass spectrometry.GC × GC-NCD was also applied to a wide range of diesel feedstocks obtained from distillation, cokefaction, FCC, ebullated bed hydroconversion units to correlate nitrogen species to the origin of the feedstocks or distillation end points, giving interesting indications on reaction mechanisms involved in the processes.     

Separation of Nitrogenous-Type Compounds from Synthetic Crudes

Abstract

This study describes the use of model compounds combined with gas chromatography analysis as a simple method to characterize complex adsorption systems and to obtain information on the adsorption mechanism. The possibility of using adsorbents for the selective removal of nitrogenous compounds from petroleum fractions is demonstrated. The adsorbent chosen in this study is ilmenite treated with bromide. The extent of removal is high for basic nitrogenous compounds but low for acidic/neutral nitrogenous compounds.     

The correlation between nitrogen species in coke and NOx formation during regeneration☆

Nitrogen oxides(NO x)emission during the regeneration of coked fluid catalytic cracking(FCC)catalysts is an environmental issue.In order to identify the correlations between nitrogen species in coke and different nitrogencontaining products in tail gas,three coked catalysts with multilayer structural coke molecules were prepared in a fixed bed with model compounds(o-xylene and quinoline)at first.A series of characterization methods were used to analyze coke,including elemental analysis,FT-IR,XPS,and TG–MS.XPS characterization indicates all coked catalysts present two types of nitrogen species and the type with a higher binding energy is related with the inner part nitrogen atoms interacting with acid sites.Due to the stronger adsorption ability on acid sites for basic nitrogen compounds,the multilayer structural coke has unbalanced distribution of carbon and nitrogen atoms between the inner part and the outer edge,which strongly affects gas product formation.At the early stage of regeneration,oxidation starts from the outer edge and the product NO can be reduced to N_2 in high CO concentration.At the later stage,the inner part rich in nitrogen begins to be exposed to O_2.At this period,the formation of CO decreases due to lack of carbon atoms,which is not bene ficial to the reduction of NO.Therefore,nitrogen species in the inner part of multilayer structural coke contributes more to NO X formation.Based on the multilayer structure model of coke molecule and its oxidation behavior,a possible strategy to control NO X emission was discussed merely from concept.     

Möglichkeiten zum Nachweis semicyclischer Amidinendgruppen in Polycaprolactam durch Abspaltung des Amidinheterocyclus. Untersuchungen an niedermolekularen Modellamidinen und an peramidiniertem Polycaprolactam

In search of new identification methods for terminal semicyclic amidine groups in polyamide 6, a study was made with model compounds to investigate whether the amidine heterocycle could be transformed with CH-acid methylene compounds and primary nitrogen bases in an identifiable form. It was found, that high concentrated hydrazine hydrat changes semicyclic amildines, the type of which is formed in polyamide 6, quantitatively into 2-hydrazino-l-aza-eyelohepten-(I). By the hydrazinolysis of polyamide 6, all amino groups of which were converted into amidine groups, after deamination a rapid decrease of the residual basicity was noted, which could be related to the separation of the amidine heterocycle by intermediate formation of 2-hydrazino-l-aza-cyclohepten-(1). However, this product due to its very small concentration and insufficient stability could not be identified. With CH-acid methylene compounds and ammonia the reaction is only possible when the exocyclic amidine nitrogen is dialkylated. Concluding, from the results obtained, the hydrazinolysis could be the best way for a direct identification and a quantitative determination of terminal semicyclic amidine groups in poly-amide 6.     

Nitrogen compounds characterization in atmospheric gas oil and light cycle oil from a blend of Mexican crudes

The distribution of basic and non-basic nitrogen compounds along the distillation curves of the middle distillates atmospheric gas oil (AGO) and light cycle oil (LCO), used as feedstocks for diesel fuel production, is presented in this paper. For this purpose, the total and basic nitrogen content of true boiling point distillation fractions of AGO and LCO were obtained, followed by nitrogen compounds identification by a GC-MS technique. The ratio of quinoline, indole and carbazole derivatives was determined as 1/0.75/2.5 in AGO. In LCO, a 1/2.3/12.2 ratio of aniline, indole and carbazole derivatives was found. A complete physical and chemical characterization of both AGO and LCO is also presented.     

Composition of petroleum heavy ends 1. Separation of petroleum >675 °C residues

Residues from four crude oils have been separated into fractions of acids, bases, neutral nitrogen compounds, saturate hydrocarbons, and aromatic hydrocarbons. The separation scheme is a modification of a separation scheme originally developed for high-boiling petroleum distillates. The gross compositions of the four residues are compared.     

Electrochemical oxidation mechanisms of different type 1,4-dihydropyridine derivatives in acetonitrile

A series of 32 substituted dihydropyridines of essentially two types (PyH and PyR) was electrochemically oxidized at a platinum electrode in acetonitrile. Based upon voltammetric experiments in anhydrous, acid, basic and neutral, partially aqueous media, on cp. coulometric results and on preparative electrolyses, side reactions were detected within the framework of the investigated electro-oxidation mechanism; these reactions elucidate some as yet non-investigated aspects in the behaviour of these compounds. With the PyH type a one-electron EC mechanism was also discovered in addition to the dominating ECE mechanism; moreover a pronounced protonation of the reactant was observed. With the PyR type compounds relatively stable radical cations homogeneously catalyse the oxidation of acetonitrile giving rise to proton splitting off on account of the oxidation proper. On the basis of the above results, overall mechanisms of the electro-oxidation of both 1,4-dihydropyridine types in acetonitrile were suggested or supplemented.     

Nitrogen compound distributions in hydrotreated shale oil products from commercial-scale refining

The distributions of nitrogen compounds in crude and hydrotreated shale oil products have been determined. About 11600 m³ (73000 bbl) of Paraho retorted shale oil were hydrotreated by The Standard Oil Company of Ohio at their Toledo refinery. A hydrotreated whole product, a jet fuel, a diesel fuel, and a residuum were produced and individually separated into compound-type fractions by adsorption chromatography. The nitrogen compound types in these fractions were characterized by i.r. spectroscopy, differential potentiometric titration, and high-resolution m.s. The distributions of nitrogen compound types and nitrogen base types in the hydrotreated products are compared with those in the Paraho retorted shale oil feedstock used in the hydroprocessing. The nitrogen compound types that were readily hydrodenitrogenated during commercial-scale refining are similar to nitrogen compound types removed during one-pass, bench-scale hydroprocessing.     

石油产品溶剂脱氮研究进展

石油产品中的氮化物对其安定性有较大的影响,在石油加工过程中极微量氮化物就会导致催化剂中毒,含氮燃料燃烧后产生的氮氧化物对大气污染严重。石油脱氮技术主要有酸洗脱氮法、吸附脱氮法和加氢脱氮法。综述了石油产品脱氮研究进展,提出了催化裂化柴油络合萃取脱氮的途径。     

Removal of nitrogen compounds from lubricating base stocks with complexing of oxalic acid

A new method to remove the nitrogen compounds from lubricating base stocks was revealed by using the complexing and crystallization of oxalic acid and nitrogen compounds in this paper. The data indicated that the reaction and filtration temperatures obviously influence the nitrogen removal efficiency. The suitable reaction temperature was 100–130 °C and the reaction time is more than 20 min. The crystal water in oxalic acid can lower the removal efficiency, which can be improved when inert gas is introduced to take out the crystal water in oxalic acid. When clay was used in the reaction system, the nitrogen removal efficiency was improved and the filtration temperature was also elevated. Oxalic acid can remove more than 98% of basic nitrogen compounds and more than 70% of nonbasic nitrogen compounds from the lubricating base stocks. The removal of basic nitrogen showed a linear relationship with the removal of nonbasic nitrogen.     

二氧化碳酸性水溶液洗涤脱除碱性氮化合物研究

介绍碱性氮化合物对油品质量和加工过程影响，加氢精制脱碱性氮效率和存在问题，研制开发出二氧化碳酸性水溶液洗涤脱除碱性氮新技术，可将油品中碱性氮化合物分离出来，洗涤柴油脱碱氮率平均达65%以上，提高了油品安全性，本技术可以脱除碱性氮后再进行加氢精制是劣质油加工的一个新途径。此方法工艺简单，投资少，成本低。     

重质烷基苯磺酸盐的合成及其性能研究

以发烟硫酸作为磺化剂,选用C9催化重整烷基化重质产物为原料,在不同反应条件下合成一种石油三采用的表面活性剂重质烷基苯磺酸盐,确定了磺化反应的最佳条件。对产品进行红外谱图分析,结果表明磺酸根存在;通过石油醚萃取法测定未磺化油含量,从而计算磺化率;测定乙醇不溶物含量确定无机盐含量。通过中和滴定测定磺酸的中和值,从而得出反应产生的废酸量与磺化剂用量有关。此外,配制一系列浓度重质烷基苯磺酸盐溶液,测量了其表面张力,得到表面张力与产品溶液浓度之间的关系,并且得出其临界胶束浓度、饱和吸附量以及极限分子面积;采用两相滴定法测定重质烷基苯磺酸盐的平均相对分子质量,并确定其活性物含量。     

抚顺页岩油碱性氮化物的脱除

用LCH-28脱氮剂脱除抚顺页岩油中的碱性氮化物.LCH-28脱氮剂主要由Bronsted酸和Lewis酸(占脱氮剂总重量的0.1％～10％)组成.当剂油质量比为1∶10、反应时间为10 min、反应温度为80～90℃、保温沉降时间为180 min时,碱性氮化物的脱除率达到85.2％,相应的页岩油损失率为18.3％,探...     

Second row transition metal sulfides for the hydrotreatment of coal derived naphtha III. Removal of individual nitrogen compounds

The disappearance of individual nitrogen compounds is followed during the hydrotreatment of a coal-derived naphtha containing a mixture of nitrogen-, sulfur- and oxygen-containing heteroatom compounds over bulk second row transition metal sulfides. The naphtha contains mainly three types of nitrogen compounds: pyridines, anilines and quinolines. While quinoline is the least reactive of the three simplest compounds in these compound classes, substituted anilines are the compounds most difficult to remove from the naphtha. The presence or absence of an alkyl substituent exerts a strong influence on the reactivity of individual compounds and can over-shadow the differences between compound types. The reactivity patterns of the methyl-substituted pyridines indicate a steric hindrance about the nitrogen atom. The order of reactivity between alkyl-substituted anilines is different over the various sulfides with steric hindrance about the nitrogen atom indicated for only the higher activity catalysts. Except for molybdenum sulfide, the reactivity of quinoline is less than or equal to that of methyl-substituted quinolines. The individual nitrogen compounds do not disappear according to a first order rate expression but indicate strong product inhibition of the reaction rate. The overall removal of nitrogen does not follow simple first, zero or second order kinetics and shows similar kinetic behavior as for the disappearance of individual nitrogen compounds.