Planar chromatographic separation of petroleum residues and coal-derived liquids

Vacuum distillation residues from two petroleum crudes, a coal liquefaction extract and a coal tar pitch have been fractionated by planar chromatography (PC) using two solvent sequences: pyridine–acetonitrile and tetrahydrofuran (THF)–toluene. Fractions recovered from PC were examined by UV-fluorescence spectroscopy (UV-F), size-exclusion chromatography (SEC). UV-F and SEC of the whole samples showed differences in aromatic cluster size and molecular mass (MM) ranges which could be related to the different origins of the samples. The MM ranges indicated by SEC were greater for the vacuum residues than for coal-derived materials. However, the UV-F spectra of the fractions indicated that the petroleum residue fractions contained similar aromatic types, whereas the fractions from coal liquids contained significantly different aromatic types. SEC profiles of the fractions indicated a separation of coal-derived samples by increasing molecular size with increasing immobility in PC, whereas for petroleum fractions, the same trend was not apparent. MALDI-mass spectra of the set of original samples showed broadly similar ranges of MM distributions but additional work is necessary to identify appropriate matrices and procedures in order to improve the MALDI spectra.     

Isolation and Characterization of Sulfur-Containing Polycyclic Aromatic Compounds (Thia-Arenes) from Complex Environmental Mixtures

Abstract

A multi-dimensional chromatographic method was developed and applied to the separation of thia-arenes and polycyclic aromatic hydrocarbons (PAH) derived from coal tar. A thia-arene-rich fraction, prepared using a combination of alumina chromatography and palladium chloride/silica gel chromatography, was further separated using normal phase HPLC to isolate fractions containing thia-arenes with molecular masses ranging from 184 amu to 284 amu. These fractions were analysed using gas chromatography-mass spectrometry; approximately one-half of the thia-arenes in a coal tar extract were retained and separated by the palladium chloride-silica gel step. This methodology has been successfully applied to coal tar, air particulate material, sediments and biological samples.     

天祝煤MRF工艺热解焦油的组成分析

本文对天祝煤ＭＲＦ（ＭｕｔｉｓｔａｇｅＲｏｔａｒｙＦｕｒｎａｃｅ）热解焦油进行了常规及元素分析，了解其基本特性；用毛细管色谱分别对焦油各馏分进行了分析，共定性定量了１０３种化合物，酚类化合物以低级酚（苯酚、甲酚）为主，中性化合物为多烷基芳烃衍生物、脂肪族链状烷烃和烯烃。上述分析结果为从焦油中提取酚类化工原料或将其加工成各种燃料油的可行性提供了依据。     

催化裂化生物质焦油构成变化

利用层析法对生物质焦油进行分析,比较了不同来源、不同裂化工况处理后焦油族分构成的差异,并对催化裂化过程机理进行探讨。生物质原料组成的不同导致热解焦油构成的差异,木屑焦油中芳香类和极性物的质量分数高于稻杆和稻壳焦油,热解温度越高产生的焦油芳香性越大。催化裂化后,芳香类族分在焦油中的质量分数增长近1倍,其他族分的质量分数出现不同幅度的下降,裂化温度950℃以上时,芳香类的质量分数已达50％。芳香类的转化速度较小,还存在其他族分向芳香类的转化,引起裂化后焦油芳香化程度增大,且这种趋势随焦油转化程度的增大而更为明显。     

New ways to increase the depth of crude oil refining

Experimental data on thermal oxidative degradation of petroleum tar and mazut (distillation residue) are presented. Experiments were performed in a pilot installation with a continuous 1.5-L reactor at temperatures of 430–460°С and pressures of 2–6 atm with feeding air into the reactor in an amount of 30–80 L kg^–1. Under these conditions, the yield of light fractions considerably increases (to 36% for tar and to 57% for mazut) as compared to thermal cracking. As in the case of thermal cracking, the cracking residue can be used as boiler fuel or asphalt. Based on the yield of hydrocarbon fractions obtained at different process parameters, the general scheme of thermal oxidative transformations of the feed was suggested, and a mathematical model describing all the experimental data obtained was constructed.     

Compositional studies of high-temperature coal tar by GC/FTIR analysis of light oil fractions

Summary A method for determination of the composition of the light oil fractions in high-temperature coal tar by means of distillation, followed by gas chromatography on a crosslinked fused-silica, capillary column coated with optimum amount of stationary phase and identification by capillary gas chromatography/Fourier transform infrared spectrometry combined with GC retention indices (GC/FTIR-RI) is described. This method was effectively used to identify complex mixture such as coal tar without any standard samples, especially, adapted for isomeric compounds. More than 60 and 50 compounds were also separated and identified respectively in light oil fractions. This shows the capability of the capillary GC/FTIR combined with GC retention indices to identify isomers not accomplished by GC/MS.     

Molecular characterisation of birch bark tar by headspace solid-phase microextraction gas chromatography-mass spectrometry: a new way for identifying archaeological glues

To develop an analytical methodology, as non-destructive as possible, suitable for the identification of natural substances from archaeological origin, we studied the potentiality of solid-phase microextraction (SPME) for analysing birch bark tar, an adhesive commonly used during ancient times. First of all, birch bark tars were produced by a controlled heating of birch bark. The two kinds of samples obtained using different processes of fabrication, one at liquid state, the second one at solid state, were then analysed by headspace HS-SPME-GC-MS. Different conditions of sample treatment were tested (two different fibre coatings, various times and temperatures of extraction) in order to suggest optimal conditions for the analysis of birch bark tar. Both samples were shown to be rich in volatile organic components. Two main groups of constituents, namely phenolic compounds issued from lignin or tannin known to be present in bark and sesquiterpenoid hydrocarbons, secondary metabolites largely distributed in the plant kingdom, were detected for the first time in birch bark tar. HS-SPME-GC-MS appears thus to be a very efficient method for investigating the volatiles emitted by plant tars and could be further used for the study of birch bark tar samples issued from archaeological context.     

氧气对秸秆热解氮迁移与转化的影响

以秸秆为原料,在两段式固定床反应器上模拟层燃工况进行热解实验,研究了氧气对热解过程中燃料氮迁移与转化的影响。通过对焦油中含氮化合物种类与含量的GC-MS分析,提出了热解过程中燃料氮转化的反应路径,并分析了氧气的影响。与惰性气氛下相比,氧气的引入降低了焦油与焦炭的产率,从而降低了焦油与焦炭中氮的分配比,增加了气体组分中氮的分配比。以蛋白质和氨基酸作为燃料氮的禀赋形态,其在热解过程中发生一系列一次反应,生成酰胺、胺类等初级焦油产物。初级焦油发生二次反应,进一步生成腈类及含氮杂环化合物等二级焦油产物。有氧条件下,焦油中酰胺、胺类等初级焦油成分的含量显著降低,腈类及含氮杂环化合物等二级焦油成分的含量升高。     

外加铁矿石对哈密低阶煤热解特性影响

为探讨铁矿石对哈密低阶煤热解特性影响,采用热重分析仪(thermal gravity analysis/differential thermal gravity,TG/DTG)和实验室固定床反应器(fixed bed)对哈密低阶煤进行热解实验,研究了两种铁矿石对哈密煤热解反应性、热解气和焦油分布规律的影响。利用傅里叶红外光谱(FT-IR)和色谱-质谱分析仪(GC-MS)对焦油中官能团的变化以及焦油中物质组成进行了分析对比。结果表明,当热解温度从室温升高至150℃时,原煤中添加铁矿石的煤样失重速率峰逐渐向高温阶段推移;当热解温度高于450℃时,不同铁矿石对原煤热解的催化作用差异更加明显,且镜铁矿原生矿物质赤铁矿;当两种铁矿石添加量分别为20%时,热解焦油和热解气都能得到较高的收率;对于煤样HM-JT来说,此时焦油产率为7.88%,热解气相产物H_2、CO_2、CH_4、CO产率与未添加镜铁矿的原煤煤样相比分别提高了4.27%、3.76%、4.39%、3.61%。对于煤样HM-CT来说,焦油催化裂解效果一直受到铁矿石添加量的影响。在镜铁矿和赤铁矿添加量分别增加到20%的过程中,煤样热解生成焦油的产率逐渐下降,而轻质焦油产率和轻质焦油分数逐渐增大到6.37%、58.48%、5.34%、56.22%,焦油中氧脱除率分别达到43.16%、36.89%。随着铁矿石的加入,焦油中二甲苯相对含量由4.32%分别降低至3.78%、3.93%,而甲苯相对含量由1.11%升高至1.32%、1.45%;焦油中邻甲酚和二甲酚中分子中的甲基取代基被脱除生成苯酚或甲酚,且镜铁矿对焦油中苯系物和酚类化合物的脱甲基作用强于赤铁矿。     

Sampling of benzene in tar matrices from biomass gasification using two different solid-phase sorbents

Biomass tar mainly consists of stable aromatic compounds such as benzene and polyaromatic hydrocarbons, benzene being the biggest tar component in real biomass gasification gas. For the analysis of individual tar compounds, the solid-phase adsorption method was chosen. According to this method, tar samples are collected on a column with an amino-phase sorbent. With a high benzene concentration in biomass tar, some of the benzene will not be collected on the amino-phase sorbent. To get over this situation, we have installed another column with activated charcoal which is intended for collection of volatile organic compounds, including benzene, after the column with the amino-phase sorbent. The study of maximal adsorption amounts of various compounds on both adsorbents while testing different sampling volumes led to the conclusion that benzene is a limiting compound. The research proved that the use of two sorbents (500 mg + 100 mg) connected in series allows for assessment of tar in synthesis gas with a tar concentration up to 30-40 g m(-3), which corresponds to the requirements of most gasifiers.     

Organic residue analysis of Neolithic pottery from North Greece

Organic residues associated with Neolithic pottery from two Late Neolithic sites, Paliambela and Makriyalos (Northern Greece), were analyzed by gas chromatography-mass spectrometry. The study aimed at identifying the origin of the tar used for waterproofing and gluing broken pots. Reference tars were prepared in laboratory conditions by pyrolysis of the bark from three tree species, namely from Betula pendula (silver birch), Ostrya carpinifolia (hop hornbeam) and Carpinus orientalis (Eastern hornbeam). The results suggest that mostly birch bark tar was used as glue for fixing broken pieces of the pots as well as for waterproofing close-shaped vessels. None of the archaeological tars derived from the two hornbeams. The analysis shows certain variability in the composition of birch bark tar, which is related to the production technique and to the re-use of tar. Of particular interest is the presence of characteristic diterpenoid biomarkers in several samples, which indicates that pine pitch was used for gluing and pine resin for waterproofing vessels for liquids. Correspondence: Sophia Mitkidou, Department of Science, School of Technological Applications, Technological Institute of Kavala, Greece     

水热处理对白石湖煤热解过程中钠钙迁移行为的影响

采用高压釜对富镜质组白石湖煤进行了水热处理,通过傅里叶红外光谱(FT-IR)分峰拟合方法分析了煤中含氧官能团变化。在固定床中开展分离废液和未分离废液水热处理煤样的热解实验,利用原子吸收分光光度计(AAS)测定了热解产物中钠钙含量。结果表明,白石湖煤经水热处理后水分、挥发分、氧含量以及Cl、Na和Ca等无机元素含量明显降低。水热处理过程中芳香醚水解和羧酸盐发生离子交换反应使得氢含量和H/C原子比增加,促进固定床热解焦油产率升高。300℃下水热处理脱除了部分有机形式Ca后随水废液被分离;废液中钠钙等无机元素的催化作用导致未分离废液较分离废液的样品具有更高热解气产率和更低焦油产率。白石湖原煤及其水热处理样品热解产物中Na含量和分布由高到低顺序均为:热解焦热解水焦油热解气,Ca含量和分布顺序为:热解焦焦油热解水热解气。水热处理温度越高,热解过程钠和钙释放率越低,释放的Na主要进入热解水,其次焦油;而释放的Ca则主要分布于焦油中,其次热解水。     

Stress Relaxation in Polymer-Modified Bitumens

The efficiency of BNK-40/180 bitumen modification with a blended thermoelastoplast and its components is studied by measuring the kinetics of the stress relaxation in melts. Asphaltene agglomerates are disclosed to be the main kinetic units of the stress relaxation in bitumens and bitumen–polymer compositions. The efficiency of bitumen modification with polymers is mainly affected by the solubility of the latter in the malthene fraction and their adsorption on asphaltenes. The experiments performed made it possible to estimate the behavior of modified bitumens at low shear rates corresponding to the extreme conditions of their use.     

神华煤液化油窄馏分的临界性质

引入Aspen Plus软件,用COAL LIQ模块计算得到神华煤液化油300℃以前8个窄馏分的临界温度、临界压力、临界体积。同时利用MXXC基团贡献法,以GC MS数据为基准对8个馏分的临界性质进行验证计算。结果表明,计算结果与利用化学结构法测定的基本一致。随馏出温度的提高,馏分临界温度逐渐升高,临界压力先升高再降低,临界体积先减小后增大,转折点出现在180℃~200℃馏分段。通过对化合物的结构分析表明,馏分中大量极性化合物的富集是造成计算数据点转折及跳跃的原因。为验证两种计算方法的一致性,引入斯米尔切诺夫统计检验法进行分析。结果表明,两种方法计算结果的总体分布函数在95%的置信区间内一致,表明对于计算临界性质,Aspen Plus计算方法可以代替基团贡献法估算法。此外,Aspen软件计算简便,其结果可为煤液化反应器的放大及过程优化直接引用。     

The analysis of seasonal air pollution pattern with application of neural networks

Air pollution monitoring includes measuring the concentrations of air contaminants such as nitrogen dioxide, sulfur dioxide, some polycyclic aromatic hydrocarbons(PAHs), suspended particulate matter (PM) and tar substances. The purpose of this study was to determine the possibility of using artificial neural networks for identification of any patterns occurring during heating and nonheating seasons. The samples included in the study were collected over a period of 5 years (1997–2001) in the area of the city of Gdansk and the levels of pollutants measured in the samples collected were used as inputs to two different types of neural networks: multilayer perceptron (MLP) and self-organizing map (SOM). The MLP was used as a tool to predict in what heating season a certain sample was collected, and the SOM was applied for mapping all samples to recognize any similarities between them. This study also presents the comparison between two projection methods—linear (principal component analysis, PCA) and nonlinear (SOM)—in extracting valuable information from multidimensional environmental data. In the research the MLP model with 13-12-1 topology was developed and successfully trained for classification of air samples from different seasons. The sensitivity analysis on the inputs to the MLP indicated benz[α]anthracene, benzo[α]pyrene, PM₁, SO₂, tar substances and PM₁₀ as the most distinctive variables, while PCA pointed to PAHs and PM₁.     

Estimation of the molecular mass range of the tar from pyrolysis of casein by gas chromatography-mass spectrometry, probe mass spectrometry and size exclusion chromatography with 1-methyl-2-pyrrolidinone as eluent

Casein has been pyrolysed to obtain a biochar (28.3% yield), with mostly meso- and macro-pore structure, and a liquid tar product of high yield (37.5%) with the balance as gas (20.9%) and water (13.3%). The elemental composition of the casein tar was: C 66.7%, H 8.3%, N 12.1% and O 12.9% (by difference). The tar sample has been characterised by mass spectrometry, gas chromatography (GC)/MS and heated-probe MS, to give molecular mass distributions for comparison with molecular mass ranges indicated by analytical-scale size-exclusion chromatography (SEC). The tar appeared to be completely soluble in 1-methyl-2-pyrrolidinone (NMP), the solvent used for SEC. It appeared to consist mostly of lower molecular mass fractions with elution times at 18-26 min. GC/MS analysis showed the presence of both aliphatic and aromatic nitrogen-containing components. Neither GC/MS nor heated-probe MS were able to detect more than about half the tar components.     

A macro analytic method for coal tar derived from pyrolysis at different temperatures

There is considerable interest in experimental and computational investigations of how tar is affected by the conditions employed for coal pyrolysis. Although a multitude of analysis methods for coal tar have been developed and tested, few have focused on the dynamics of tar formation on a macro level. In this work, an experimental device was designed to analyze the dynamic characteristics of the tar release process at different temperatures. The tar yield was continuously recorded during the process of coal pyrolysis; then the release proportion of coal tar, which was similar to weightless conversion in thermogravimetric analysis, was defined. Based on the macroscopic phenomena of tar release, dynamic equations were deduced to establish a hybrid dynamic model for tar generation. The fitting result illustrates that the established hybrid dynamic model is effective for predicting the tar yield. Furthermore, the shrinking core model, a multi‐particle first‐order reaction, and the Anti–Jander diffusion equation were built to elucidate the macro release mechanisms of coal tar.     

Characterization of spilled oils by measuring fluorescence emission spectra of fractions separated by high-speed gel-permeation chromatography

Summary Fluorescence emission spectra of oil fractions separated by high-speed gel-permeation chromatography (GPC) were measured to characterize the oils spilled into the environment. Crude oils, weathered crude oils, and tar balls were analysed. In GPC, polystyrene gel and tetrahydrofuran were used as a stationary phase and a mobile phase, respectively; the eluate was separated into five equi-volume fractions. Fluorescence emission spectra of the fractions were obtained at an excitation wavelength of 340 nm. Maximum emission wavelength, relative emission intensity at 386 nm, and emission intensity ratio (440 nm/386 nm) on the spectra of fractions were studied as identification parameters. The change of the identification parameters with weathering the crude oil (Murban) was small. The proposed method was applied to the characterization of tar balls sampled in the sea near Japan.

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Charakterisierung von Ölverschmutzungen durch Auswertung der Fluorescenz-Emissionsspektren von Fraktionen, die durch Hochgeschwindigkeits-Gelpermeations-Chromatographie getrennt wurden

Zusammenfassung Rohöle, verwitterte Rohöle sowie Teerballen wurden untersucht. Bei der Chromatographie wurde Polystyrolgel als stationäre und Tetrahydrofuran als mobile Phase verwendet. Das Eluat wurde in fünf Fraktionen gleichen Volumens getrennt. Für die Fluorescenzmessung wurde eine Anregungswellenlänge von 340 nm benutzt. Als Identifizierungsparameter dienten die maximale Emissionswellenlänge, die relative Emissionsintensität bei 386 nm sowie das Verhältnis der Emissionsintensitäten bei 440/386 nm. Die Veränderung der Parameter bei der Verwitterung (Murban-Öl) war nur gering. Die Methode wurde zur Charakterisierung von Teerballen angewendet, die aus dem Meer in der Nähe Japans entnommen worden waren.

     

Production of High-Density Jet and Diesel Fuels by Hydrogenation of Highly Aromatic Fractions

Physicochemical characteristics and hydrocarbon composition of highly aromatic wastes (light gas oil from catalytic cracking, pyrolysis tar, coal tar, coal gasification tar) as a feedstock for producing high-density jet fuels are considered. The hydrogenation reactions of polycyclic aromatic hydrocarbons, including mixtures of hydrocarbons with different numbers of rings, are described. Catalysts for hydrogenation of highly aromatic waste to obtain fuel fractions are considered. Particular attention is paid to catalyst deactivation in the course of processing of this feedstock. A separate section deals with the choice and implementation of procedures for processing highly aromatic feedstock to obtain jet and diesel fuels.