沉积有机质的加氢热解及其地球化学信息研究

用加氢热解(hydropyrolysis)释放高演化源岩干酪根和沥青分子网络中共价键结合的生物标志物,在恢复原始有机地球化学信息方面具有重要的意义,可应用于源岩有机质生源确定、成熟度确定、古沉积环境判识以及油/源对比等.实验表明,样品沥青“A“与加氢热解产物中生物标志物的组成存在一定的差异,加氢热解产物中含有丰富的地球化学信息.加氢热解具有产物收率高、结构重排少、生物特征保持完整等特点,能够合理地释放出沉积有机质分子骨架中具有原生性的组分,保持完整的原始生物标志物结构和立体化学特征.加氢热解技术为油气地球化学研究开辟了新途径.     

神木煤显微组分加氢热解的TG/MS研究

在TG-151热天平上考察了神木煤显微组分加氢热解的热重特性；用质谱对加氢热解气体进行了在线检测分析。结果表明，镜质组比惰质组有较高的挥发分收率和最大失重速率；较低的起始热解温度和热解峰温。镜质组有较高的C1～C4轻质烃类和C6～C8芳香烃类收率，原煤居中，惰质组最少；镜质组比惰质组有较高的水生成， 加氢热解过程中各种烃类和水的逸出都高于相应热解下的。     

Studies of Athabasca asphaltene Langmuir films at air-water interface

Asphaltenes are present in heavy oils and bitumen. They are a mixture of hydrocarbons having complex structures of polyaromatic rings and short side chains. In general, the high-molecular-weight asphaltene is the most aromatic fraction with the highest number of side chains and the low-molecular-weight asphaltene contains the lowest number of side chains, while the number of side chains of the whole asphaltene fraction lies in between. In this study, asphaltenes were extracted and/or fractionated from Athabasca oil sand bitumen. Subfractions of high and low molecular weight and the whole asphaltenes were characterized using a Langmuir trough and complementary techniques such as VPO, FTIR, AFM, and contact angle measurements. At an air-water interface, amphiphilic asphaltene molecules can form a monolayer. Various fractions (high, low, and whole) of the asphaltene molecules behave similarly at the air-water interface, characterized by close resemblance of their surface pressure-area, hysteresis, and relaxation isotherms. The high-molecular-weight asphaltene is the most expanded fraction, while the low-molecular-weight asphaltene fraction is the most condensed, with the whole asphaltene lying in between. At the air-water interface a monolayer of the low-molecular-weight asphaltene relaxes at a faster rate than one of the high-molecular-weight asphaltene.     

生物降解原油研究的新方法

利用沥青质包裹烃和沥青质钌离子催化氧化（RICO）产物中的生标对生物降解原油进行了研究。研究表明，虽然原油中的生标受到了严重破坏，但利用这两种方法在沥青质中均可以获得较为完整的生标系列。与其它方法相比，这两种方法简单方便，结果较为可靠、准确，可能是生物降解原油研究的发展方向。     

Comparative study of crude oils from the Machete area in the Eastern Venezuelan Basin by pyrolysis of asphaltenes

This work is an analysis of crude oil samples from the two most recent producing wells in the Machete area (Orinoco Tar Belt, Venezuela). The aim is to determine the type of environment in which the precursor organic materials were deposited. In spite of the fact that the degree of maturity and the biodegradation of the two crude oils are similar, their characterization leads us to conclude that they have very distinctive and different origins. The comparative study was performed by separating their main fractions, pyrolysis of asphaltenes, and further identification of several indicators (aromatic, polar and sulfur compounds, linear aliphatic hydrocarbons, and cadalene). Moreover, several biomarkers (terpanes, hopanoids and steranes) present in the saturated fractions obtained from the two crude oils were analyzed by using gas chromatography combined with mass spectrometry (GC–MS). The statistical study of geochemical indicator values and relative proportions of lipid and lipid-like biomarkers present in products from asphaltene pyrolysis shows a high probability of there being two distinct crude oil families from the Machete area.     

Disjoining pressure isotherms of water-in-bitumen emulsion films

In the oil sands industry, undesirable water-in-oil emulsions are often formed during the bitumen recovery process where water is used to liberate bitumen from sand grains. Nearly all of the water is removed except for a small percentage (approximately 1 to 2%), which remains in the solvent-diluted bitumen as micrometer-sized droplets. Knowledge of the colloidal forces that stabilized these water droplets would help to increase our understanding of how these emulsions are stabilized. In this study, the thin liquid film-pressure balance technique has been used to measure isotherms of disjoining pressure in water/toluene-diluted bitumen/water films at five different toluene-bitumen mass ratios. Even though a broad range of mass ratios was studied, only two isotherms are obtained, indicating a possible change in the molecular orientation of surfactant molecules at the bitumen/water interfaces. At low toluene-bitumen mass ratios, the film stability appears to be due to a strong, short-range steric repulsion created by a surfactant bilayer. Similar isotherms were obtained for water/toluene-diluted asphaltene/water films, indicating that the surface active material at the interface probably originated from the asphaltene fraction of the bitumen. However, unlike the bitumen films, films of toluene-diluted asphaltenes often formed very rigid interfaces similar to the "protective skin" described by other researcher.     

Isolation of neutral and acidic lipid biomarker classes for compound-specific-carbon isotope analysis by means of solvent extraction and normal-phase high-performance liquid chromatography

An analytical method for the quantitative determination of neutral and acidic lipid biomarkers in particulate and sediment samples has been developed. The method involves a first step with solvent extraction to isolate the neutral from the acidic compounds and a second step using normal-phase HPLC on a Nucleosil silica column to separate four different classes of neutral compounds: (1) aliphatic hydrocarbons, (2) aromatic hydrocarbons, (3) ketone compounds and (4) sterol and alcohol compounds. Recoveries of the individual spiked lipid biomarkers for the whole analytical procedure ranged from 88 to 106% for fatty acids, from 50 to 60% for aliphatic hydrocarbons (> or = n-C17), from 50 to 60% for polycyclic aromatic hydrocarbons (PAHs) (> or = 3 rings), 83% for friedelin and 60-80% for the sterol and alcohol compounds. The isolated compound classes were analysed by gas chromatography-combustion-isotope ratio mass spectrometry to measure the stable carbon isotope ratios in the individual compounds. The method enables the isolation of compound classes without fractionation for compound-specific carbon isotope analysis (delta13C). This analytical protocol has been applied, and proved suitable, for the determination of lipid biomarkers (sterols, fatty alcohols and fatty acids) in marine particulate material and for the determination of PAHs in sediment samples.     

催化加氢热解/气相色谱-质谱研究沉积物中生物标志物

针对地质体中高演化沉积有机质，应用催化加氢热解/气相色谱-质谱方法测定了干酪根中以共价键结合的生物标志物。结果表明，实验样品的催化加氢热解产物收率明显高于二氯甲烷（DCM）索氏抽提，产物色谱图中饱和烃的峰形、保留时间和质谱特征与索氏抽提峰形基本一致；对比两种方法产物中饱和烃主要指标甾烷m/z 217和藿烷m/z 191表明，经过加氢还原，干酪根分子网络中共价键结合着两种生物标志物分子骨架得到印证，为催化加氢热解提取沉积物中生物标志物的方法可靠性提供了依据。催化加氢热解/气相色谱-质谱技术是一种对研究高演化沉积有机质中生物标志化合物有独特作用的有效分析手段。     

生物质催化热解制取轻质芳烃

以轻质芳烃苯、甲苯、二甲苯和萘(BTXN)为目的产物,采用双颗粒流化床反应器对3种木材生物质进行了热解实验. 结果表明,木材生物质的初次热解终止温度低,有利于低温催化转化. 生物质中92%的挥发分在673 K时已释放完全,且生物质在初期热解得到的焦油经过二次分解反应可以转化为其它产物,通过有效控制生物质热解二次气相反应,能够改变其产物的分布,从而获得不同的目的产物. 生物质的催化加氢热解实验结果表明,催化剂种类和热解温度对加氢热解产物收率及其分布均有影响, BTXN是热解或加氢热解过程中二次气相反应的中间产物. 为了获得高产率的BTXN, 必须选择加氢活性适度的催化剂. 当CoMo-S/Al2O3催化剂作为流化介质进行加氢热解时,在863 K时, BTXN的收率可达6 3%(干燥无灰质量基准), 而NiMo/Al2O3催化剂表现出了很强的加氢活性, CH4的收率高达99 5%.     

原油非烃化合物结构与含量的馏分分离及联用色谱信息获取通用方法

用正己烷将沥青质从油样中分离,再根据类组分之间极性差别,用中性氧化铝-硅胶双层析柱将原油样其余部分分成脂肪烃、芳香烃和7个非烃馏分。各馏分回收完全。用色-质联用技术,将非烃馏分再分离并获取实验数据,为原油非烃结构和含量测定奠定有关的信息基础。不同油井样品研究和重复实验表明,方法对各种原油非烃化合物分离和信息测定有很好的重现性。     

自由落下床中生物质与煤共热解的协同效应对焦油组成的影响

利用溶剂萃取-柱层析方法,将自由落下床中豆秸与大雁褐煤共热解以及单种原料热解的液体产品分为沥青烯、酚类、脂肪烃类、芳香烃类和极性物等组分。结果表明,共热解的沥青烯产率为11.4%,低于根据煤和生物质单独热解的质量加权平均计算值19.0%,且芳香性增大;与计算值相比,低分子量的酚类、甲基苯酚、二甲基苯酚及其衍生物的含量提高了5%;而且长侧链的脂肪烃含量减少。共热解焦油的芳香类组分中十氢萘的质量分数是43.37%,但其在单一原料热解焦油中并没有被检测到。热解油分析结果表明,自由落下床生物质与煤快速共热解过程中存在协同效应,其主要原因是,发生氢解和加氢反应。煤与生物质共热解有利于产生低分子量的化合物,改善油品的质量。     

Catalytic dechlorination of aromatic chloride with supported palladium catalysts in alkaline 2-propanol: influence of hydrocarbon solvents

Summary Catalytic dechlorination of p-chloroanisole (p-chloromethoxybenzene) was carried out in a solution of NaOH in 2-propanol in the presence of Pd/Al₂O₃ or Pd/C at 40°C. When aromatic hydrocarbons such as toluene or benzene were added to the solution, the dechlorination rates were strongly suppressed. However, aliphatic hydrocarbons such as n-hexane or cyclohexane hardly affected the dechlorination rates.     

煤中有机硫形态结构和热解过程硫变迁特性的研究

利用热解 质谱并结合固定床热解反应装置，对煤中有机硫的形态主其对加氢热解过程 变迁特性的影响，进行了较系统的研究。结果表明，煤中有机硫的形态结构在褐煤中主要以脂肪族、芳香族硫化物为主，而在 煤中则主要以各种不同芳构化程度的噻吩结构为主，初步表明煤中有机硫形态结构随煤变质程度的变迁呈较强的连续递变性。煤热解过程中硫在呼产物中的变迁和分布与煤中有机硫的形态结构特点密切相关。较高芳构化噻吩结构不完全的氧     

Surface microstructure of bitumen characterized by atomic force microscopy

Bitumen, also called asphalt binder, plays important roles in many industrial applications. It is used as the primary binding agent in asphalt concrete, as a key component in damping systems such as rubber, and as an indispensable additive in paint and ink. Consisting of a large number of hydrocarbons of different sizes and polarities, together with heteroatoms and traces of metals, bitumen displays rich surface microstructures that affect its rheological properties. This paper reviews the current understanding of bitumen's surface microstructures characterized by Atomic Force Microscopy (AFM). Microstructures of bitumen develop to different forms depending on crude oil source, thermal history, and sample preparation method. While some bitumens display surface microstructures with fine domains, flake-like domains, and dendrite structuring, ‘bee-structures’ with wavy patterns several micrometers in diameter and tens of nanometers in height are commonly seen in other binders. Controversy exists regarding the chemical origin of the ‘bee-structures’, which has been related to the asphaltene fraction, the metal content, or the crystallizing waxes in bitumen. The rich chemistry of bitumen can result in complicated intermolecular associations such as coprecipitation of wax and metalloporphyrins in asphaltenes. Therefore, it is the molecular interactions among the different chemical components in bitumen, rather than a single chemical fraction, that are responsible for the evolution of bitumen's diverse microstructures, including the ‘bee-structures’. Mechanisms such as curvature elasticity and surface wrinkling that explain the rippled structures observed in polymer crystals might be responsible for the formation of ‘bee-structures’ in bitumen. Despite the progress made on morphological characterization of bitumen using AFM, the fundamental question whether the microstructures observed on bitumen surfaces represent its bulk structure remains to be addressed. In addition, critical technical challenges associated with AFM characterization of bitumen surface structures are discussed, with possible solutions recommended. For future work, combining AFM with other chemical analysis tools that can generate comparable high resolution to AFM would provide an avenue to linking bitumen's chemistry to its microscopic morphological and mechanical properties and consequently benefit the efforts of developing structure-related models for bituminous materials across the different length scales.     

Composition of the black crusts from the Saint Denis Basilica, France, as revealed by gas chromatography-mass spectrometry

The organic fraction of black crusts from Saint Denis Basilica, France, is composed of a complex mixture of aliphatic and aromatic compounds. These compounds were studied by two different analytical approaches: tetramethyl ammonium hydroxide (TMAH) thermochemolysis in combination with gas chromatography-mass spectrometry (GC-MS), and solvent extraction, fractionation by silica column, and identification of the fraction components by GC-MS. The first approach, feasible at the microscale level, is able to supply fairly general information on a wide range of compounds. Using the second approach, we were able to separate the complex mixture of compounds into four fractions, enabling a better identification of the extractable compounds. These compounds belong to different classes: aliphatic hydrocarbons (nalkanes, n-alkenes), aliphatic and aromatic carboxylic acids (n-fatty acids, alpha,omega-dicarboxylic acids, and benzenecarboxylic acids), polycyclic aromatic hydrocarbons (PAH), and molecular biomarkers (isoprenoid hydrocarbons, diterpenoids, and triterpenoids). With each approach, similar classes of compounds were identified, although TMAH thermochemolysis failed to identify compounds present at low concentrations in black crusts. The two proposed methodological approaches are complementary, particularly in the study of polar fractions.     

New approach to study of spilled crude oils using high resolution GC-MS (SIM) and metastable reaction monitoring GC-MS-MS

Polycyclic aromatic hydrocarbons (PAHs) and geochemical biomarkers are good environmental markers to study the origin and evolution of an oil spill. To have access to the greatest number of molecular ratios, no fractionation of oil into aliphatic and aromatic compounds is made. Three analytical MS approaches are tested to analyze markers in this total hydrocarbon fraction: classical quadrupole GC-MS, high resolution GC-MS (HR GC-MS) and metastable reaction monitoring GC-MS-MS (MRM GC-MS-MS). This analytical approach is used to follow the evolution of PAHs in petroleum polluted mangrove soils over 8 years by using molecular ratios between polycyclic aromatic hydrocarbons and tri- and tetracyclic terpanes.     

Comparison of microprobe two-step laser desorption/laser ionization mass spectrometry and gas chromatography/ mass spectrometry studies of polycyclic aromatic hydrocarbons in ancient terrestrial rocks

Microprobe two-step laser desorption/laser ionization mass spectrometry (μL²MS) and gas chromatography/mass spectrometry (GC/MS) were used to analyze polycyclic aromatic hydrocarbons (PAHs) in ancient terrestrial rocks. μL²MS provides an in situ analysis of very small samples, records the PAHs with no isomer information, and gives quantitative data on the degree of alkylation of a given PAH series over the complete mass range. GC/MS provides isomer separation and quantitation of PAHs in bitumen but not kerogen, and is limited by sample size. Combination of these techniques allows analysis of very small samples by μL²MS with GC/MS confirmation of isomer distributions of the solvent extractable components (bitumen). It was found that the concentration of bitumen within the rock samples affects the PAH alkylation signal for μL²MS. At low bitumen concentrations μL²MS can produce pyrolysis products from kerogen that is present; however, as bitumen concentrations increase, the PAH distribution from bitumen dominates the signal.     

Catalytic air oxidation of ambient temperature hydrocarbons

Catalytic air oxidation of the aliphatic hydrocarbons n-decane, hexanes, gasoline and diesel fuel was conducted at ambient temperature with novel iron catalysts. The concentration of n-decane in water was reduced from 1.42 g in 100 ml to 0.07 g in 100 ml in 5 h at room temperature forming carbon monoxide and water by means of intermediate aldehydes. Results of FT–IR and GC–MS analyses demonstrated formation of aldehydes and unsaturated alcohols. Carbon monoxide was detected on catalyst residues and in the vapor phase. The indicated catalytic reaction mechanisms are discussed.     

An optimized extraction and gas chromatography analysis method for the quantification of diluent hydrocarbons in froth treatment tailings

Froth treatment tailings are one type of waste stream generated during the extraction of surface-mined oil sands bitumen. To remove water and solids from bitumen froth recovered during the water-based extraction process, hydrocarbon diluent is added, and settling and/or centrifugation are applied to the diluted bitumen froth, producing diluted bitumen and froth treatment tailings. While recovery processes are in place to remove and recycle the diluent from froth treatment tailings, some residual diluent can remain. Since tailings are stored in outdoor ponds, the residual diluent can have implications for methanogenic microbial processes and resulting greenhouse gas emissions. This work presents a methodology to accurately extract and quantify diluent hydrocarbons from froth treatment tailings using gas chromatography. A cold-start temperature program is used to separate diluent hydrocarbons from any residual bitumen in the sample, and diluent is quantified using commercial standards as well as unprocessed diluent. A series of extraction parameters were tested and results from multiple conditions are shown with a rationale for the selected optimized parameters. Quantification of diluent in tailings samples is demonstrated from 60 to 5329 μg/g, and results from quality control standards show an average diluent recovery of 100 ± 10%.