STRUCTURAL CHARACTERIZATION OF AROMATIC FRACTIONS OF SOME TYPICAL SOLVENT REFINED COALS USING MASS SPECTROMETRIC TECHNIQUES

Three aromatic fractions from two typical Chinese solvent-refined coals (one, FS2, derived from bituminous-sapropelitic cannel coal, and the other two, DT2A and DT2B, derived from a bituminous, weakly caking coal) were characterized for their chemical composition and molecular weight distribution using field ionization (FI) and field desorption (FD) mass spectrometric techniques. Some characteristic components derived from the chemical ionization technique were subjected to further fragmentation analyses using tandem mass spectrometry.

The FS2 fraction is composed of 3-5 ring condensed aromatics of cata configuration with abundant naphthenic groups fused with an aromatic cluster. The most abundant component -- cyclopentachrysene -- is resolved at M/Z 268, which may possibly be the product of aroir.atization of hopanes existing in the source material during dia- and catagenesis. Sample DT2A contains polycyclic aromatic hydrocarbons with a higher degree of aromatic condensation and 3-5 ring clusters. The concentration of C-4 substituted phenanthrene was especially high, indicating the probable presence of retene derived from triterpanic acid in the land plantresins during geological conversion of coal. The second aromatic fraction, DT2B, is differentiated from DT2A mainly by the aromatic ring number (6-9 rings for DT2B) and degree of aromatic condensation (mainly cata configuration). The suitability for producing advanced carbon materials of the three samples studied is discussed.     

SOLVENT EXTRACTION OF PAKISTAN COALS (III) EXTRACTION AND CHARACTERIZATION OF THE EXTRACTS BY SPECTROSCOPIC TECHNIQUES

The Makerwal coal of Pakistan gives higher extractibi1ity with Tetrahydrofuran ( THF ) as compared to Sharigh, Sor-Range and Lakhra coals. The structural characterization of Pakistan coal extracts by FT-IR spectroscopy indicates that all the extracts contained less condensed aromatic rings in comparision to their original coal.     

SOLVENT EXTRACTION OF PAKISTAN COALS (III) EXTRACTION AND CHARACTERIZATION OF THE EXTRACTS BY SPECTROSCOPIC TECHNIQUES

Abstract

The Makerwal coal of Pakistan gives higher extractibi1ity with Tetrahydrofuran ( THF ) as compared to Sharigh, Sor-Range and Lakhra coals. The structural characterization of Pakistan coal extracts by FT-IR spectroscopy indicates that all the extracts contained less condensed aromatic rings in comparision to their original coal.     

SPECTROSCOPIC CHARACTERIZATION OF SOLVENT SOLUBLE FRACTIONS OF PETROLEUM VACUUM RESIDUES

ABSTRACT

NMR and FTIR spectroscopic techniques were used to investigate the effect of different solvent extraction schemes on the composition and chemical nature of species of vacuum residues of two Indian crude oils (namely Jodhpur and Heera) extractable into polar (ethyl acetate) and non-polar (n-pentane and n-heptane) solvents. The obtained soluble fractions were found to consist of mainly simple aliphatic and naphthenic ring structures, while insoluble fractions consisted primarily aromatic compounds. The results were used to draw inferences on the relative utility of different extraction schemes to upgrade vacuum residues as feedstocks for secondary conversion processes in petroleum industry.     

SPECTROSCOPIC CHARACTERIZATION OF SOLVENT SOLUBLE FRACTIONS OF PETROLEUM VACUUM RESIDUES

NMR and FTIR spectroscopic techniques were used to investigate the effect of different solvent extraction schemes on the composition and chemical nature of species of vacuum residues of two Indian crude oils (namely Jodhpur and Heera) extractable into polar (ethyl acetate) and non-polar (n-pentane and n-heptane) solvents. The obtained soluble fractions were found to consist of mainly simple aliphatic and naphthenic ring structures, while insoluble fractions consisted primarily aromatic compounds. The results were used to draw inferences on the relative utility of different extraction schemes to upgrade vacuum residues as feedstocks for secondary conversion processes in petroleum industry.     

催化裂化柴油溶剂抽提降芳烃工艺技术研究

针对中国石化长岭分公司催化裂化柴油芳烃含量高、十六烷值低的问题,采用溶剂抽提降芳烃技术改善柴油质量,同时对抽出的芳烃进行分离和利用。实验结果表明：在130～150 ℃、剂油体积比1.5～6.0的条件下进行溶剂抽提,抽余油的芳烃质量分数降至38.4%～63.3%,十六烷值大于45,较原料提高了20个单位以上;所抽出的芳烃混合组分中单环芳烃（烷基苯）含量高,可以作为芳烃溶剂油。     

离子淌度-飞行时间质谱测定减压蜡油芳香分及胶质中的碱性氮化物

采用柱层析法将减压蜡油（VGO）分离为饱和分、芳香分和胶质,然后用电喷雾电离源（ESI）离子淌度-飞行时间质谱（IMS-TOF MS）对其芳香分与胶质中的碱性氮化物进行了表征,对不同来源的VGO中碱性氮化物的结构差异进行了分析。结果表明：对于不同来源的VGO样品,即使碱性氮化物不饱和程度接近,其芳环的连接方式也存在明显差异;而对于同一样品的芳香分和胶质,则存在碳数相近,但胶质中等效双键数稍低的现象。以核磁共振波谱仪异核单量子相干试验和加氢脱氮反应评价作为辅证,进一步推测了VGO中碱性氮化物的芳环侧链长度与其脱除难度之间的关联。将柱层析分离技术与ESI IMS-TOF MS联用,可以解决高蜡含量样品难以溶解的问题,并减弱强极性组分的离子化抑制作用,得到比直接进样更为全面的质谱信息。     

苝的质谱鉴定及其有机地球化学意义

我们曾用柱色谱结合薄层色谱分离、紫外吸收光谱和荧光光谱测定各种岩样的苝。但样品中的苝是否是一种单一结构?除分子量为252的结构外,是否还有分子量较大的各种烷基衍生物?我们已觉察到上述手段对苝骨架周围的基团反映是不很灵敏的。因此,我们决定对苝进行毛细管气相色谱-质谱-计算机联用鉴定研究,还想对苝的地球化学意义再作一次较深入的探讨。     

SOLVENT EXTRACTION OF PAKISTANI COALS (ii): EXTRACTION AND CHARACTERIZATION OF METHANOL-BENZENE EXTRACTS

Structural characterization of the solvent extracts from four different Pakistani lignitic coals has been carried out by their proximate, elemental analysis and FT-Infrared and ¹H n.m.r. spectra. The yield of each extracts was greater with 1:1 benzene-methanol mixture in comparison to the total yield obtained by separate extractions with benzene and methanol. The extracts contained significantly less amount of ash and fixed carbon along with an increase in the percentage of volatile matter. The FTIR and ¹H n.m.r. spectra indicated that basically all the extracts contained less condensed aromatic rings in comparison to the coal. The FTIR spectra showed sharp well resolved peaks which have been assigned to various functional groups.

The ¹H n.m.r. spectra were used to obtain average structural parameters for all the extracts. A detailed analysis of the FTIR and n.m.r. spectra of the coal and their extracts provided an important in-sight into the differences between various extracts and also between various coals and their corresponding extracts.     

SOLVENT EXTRACTION OF PAKISTANI COALS (ii): EXTRACTION AND CHARACTERIZATION OF METHANOL-BENZENE EXTRACTS

ABSTRACT

Structural characterization of the solvent extracts from four different Pakistani lignitic coals has been carried out by their proximate, elemental analysis and FT-Infrared and ¹H n.m.r. spectra. The yield of each extracts was greater with 1:1 benzene-methanol mixture in comparison to the total yield obtained by separate extractions with benzene and methanol. The extracts contained significantly less amount of ash and fixed carbon along with an increase in the percentage of volatile matter. The FTIR and ¹H n.m.r. spectra indicated that basically all the extracts contained less condensed aromatic rings in comparison to the coal. The FTIR spectra showed sharp well resolved peaks which have been assigned to various functional groups.

The ¹H n.m.r. spectra were used to obtain average structural parameters for all the extracts. A detailed analysis of the FTIR and n.m.r. spectra of the coal and their extracts provided an important in-sight into the differences between various extracts and also between various coals and their corresponding extracts.     

CHEMICAL CHARACTERIZATION OF ASPHALT USING THERMAL CHROMATOGRAPHY WITH MASS SPECTROMETRY

ABSTRACT

We have delineated similarities and differences in chemical composition among neat asphalt samples obtained from the Strategic Highway Research Program (SHRP) Materials Reference Library in Austin, TX, and oxidized materials prepared by SHRP contractors using thermal chromatography (TC). This unique method for disassembling complex materials for analysis using precise temperature programming in a controlled and well characterized environment was combined with flamie ionization detection (FID) and with gas chromatographic (GC) separation and mass spectral (MS) detection. Our TC/FID analyses provided thermal profiles of materials under study-quantity of evolved species as a function of temperature--, while our TC/MS studies allowed structures to be assigned to the various components evolved from the asphalt matrix. Distinct differences among neat samples and between neat samples and their oxidized counterparts were easily discerned, both in comparisons of thermal profiles and of compound-specific identifications of components     

液相色谱法及质谱法测定柴油芳烃适用性研究

基于SH/T 0806—2008和SH/T 0606—2005方法,对比采用高效液相色谱示差折光检测器（HPLC）和气相色谱-质谱联用（GC-MS）测定柴油中芳烃含量的分析结果、加标回收率及掺兑测定的准确性,讨论两种方法分析结果的差异性和适用性,并在此基础上对8个国VI车用柴油样品的芳烃含量进行测定。结果表明,两种方法均具有较好的掺兑准确性,但由于柴油分子组成的复杂性,存在大量与模型化合物结构不同的化合物,HPLC法的加标回收率会受到示差折光检测器响应特性差异的影响而产生偏差,也使得由HPLC法得到的多环芳烃和总芳烃含量存在一定的偏差。     

CLEAN FUELS FROM LOW GRADE COALS FOR THERMAL POWER STATIONS THROUGH BATCH AND SEMICONTINUOUS SOLVENT REFINING TECHNIQUE USING COAL DERIVED SOLVENTS UNDER AMBIENT PRESSURE CONDITIONS AND COMBUSTION (FIRING) CHARACTERISTICS OF SOLVENT REFINED COAL AND OF RESIDUAL COAL

Availability of good quality coals is declining. Firing of low grade coals with frequent variation of quality in thermal power stations is problematic and involves environmental pollution hazards. Low grade coals can be refined through solvent extraction. Solvent refined coal obtained through solvent extraction is a clean and high calorific value coal with a uniform quality. This has good flammability characteristics because of its high volatile matter contents and low ash contents. Batch extraction of low grade coal earn Dies obtained from two different thermal cower stations in new Delhi, in anthracene oil (a coal derived solvent) has been reported. Semi-continuous extraction of these coals by successive extraction techniques using anthracene oil (AO) followed by liquid paraffin (LP) solvents haB also been carried out and reported. Kinetic studies of the extraction of coal in AO has been performed. About 35% coal was rendered extractable through semicoatinuous extraction. The residual coals obtained after solvent refining were found to be free flawing and contained sufficient volatile matter for making these suitable for firing in fluidized bed combuators for integrated combined cycle power generation.     

CLEAN FUELS FROM LOW GRADE COALS FOR THERMAL POWER STATIONS THROUGH BATCH AND SEMICONTINUOUS SOLVENT REFINING TECHNIQUE USING COAL DERIVED SOLVENTS UNDER AMBIENT PRESSURE CONDITIONS AND COMBUSTION (FIRING) CHARACTERISTICS OF SOLVENT REFINED COAL AND OF RESIDUAL COAL

ABSTRACT

Availability of good quality coals is declining. Firing of low grade coals with frequent variation of quality in thermal power stations is problematic and involves environmental pollution hazards. Low grade coals can be refined through solvent extraction. Solvent refined coal obtained through solvent extraction is a clean and high calorific value coal with a uniform quality. This has good flammability characteristics because of its high volatile matter contents and low ash contents. Batch extraction of low grade coal earn Dies obtained from two different thermal cower stations in new Delhi, in anthracene oil (a coal derived solvent) has been reported. Semi-continuous extraction of these coals by successive extraction techniques using anthracene oil (AO) followed by liquid paraffin (LP) solvents haB also been carried out and reported. Kinetic studies of the extraction of coal in AO has been performed. About 35% coal was rendered extractable through semicoatinuous extraction. The residual coals obtained after solvent refining were found to be free flawing and contained sufficient volatile matter for making these suitable for firing in fluidized bed combuators for integrated combined cycle power generation.     

傅里叶变换离子回旋共振质谱仪表征VGO馏分油中噻吩类含硫化合物

在平均质量分辨率为220000,m/z检测范围150～1200的条件下,采用大气压光致电离源(APPI)的9.4 T傅里叶变换离子回旋共振质谱仪(FTICR MS),建立了VGO馏分油中噻吩类硫化物的表征方法。在所研究的VGO中,主要包括2种(含1个硫原子S₁和含2个硫原子S₂),共计29类噻吩类硫化物,碳数分布范围为15～50。对VGO依沸点分布的窄馏分进行含硫化合物种类分布考察结果表明,在4个窄馏分中,均,通以S₁硫化物为主, S₂硫化物含量较少,而且随着馏分沸点的增加,其中的烷基取代基的碳数增加,多环芳烃含硫化合物含量增加,S₂硫化物含量增加。     

全二维气相色谱-飞行时间质谱法分析表征重馏分油中多环芳烃化合物

建立全二维气相色谱-飞行时间质谱分析方法,利用该方法对重馏分油中多环芳烃进行详细表征,通过标准化合物的保留时间、质谱图和NIST谱库定性和半定量分析重馏分油中的多环芳烃和烷基取代多环芳烃,并研究结构和烷基取代基对多环芳烃加氢转化的影响。结果表明,不同结构、不同烷基取代位置和不同烷基取代数量的多环芳烃的加氢转化率有很大区别。全二维气相色谱-飞行时间质谱具有高分辨能力和高灵敏度,是分析表征复杂样品中目标化合物的强有力工具,将在石油的分子水平表征领域发挥重要的作用     

CHARACTERIZATION OF THE STRUCTURAL FEATURES OF OXIDIZED BEYPAZARI LIGNITE USING DECONVOLUTED SOLID STATE 13C NMR SPECTRA

ABSTRACT

The solid state ¹³C NMR method have been used to investigate the structural changes occurred in Beypazari lignite while oxidizing at 150°C in a dynamic air atmosphere. Least squares curve fitting techniques have been used to resolve the overlapping bands in the 0-220 ppm region of the 13_c NMR spectra. Measurements of the relative intensities of the functional groups observed in the oxidized coals were used to follow the progress of air oxidation. Oxidation reactions seemed to decrease the total intensities of both aliphatics and aromatics, though the reduction in aliphatics was more pronounced. The relative intensities of the total aliphatics decreased from 1.0 to 0.9 and 0.6 in the original and lignites oxidized for 12 and 312 hours, respectively. The relative intensities of Ar-C-C in the 130-148 ppm region for the same set of samples were 1.0, 0.9 and 0.8. The least-squares bands resolved in the carbonyl region were at 175 ppm and 190 ppm in the original lignite; at 180 ppm (carboxylic acids), 195 ppm (meta substituted ketones) 210 ppm (di orto substituted ketones) in the lignite oxidized for 12 hours and at 170 ppm (esters), 180 ppm, 200 ppm (aldehydes) and 210 ppm in the lignite oxidized for 312 hr. Carbonyl intensity increased from 1.0 in the original lignite to 2.3 and 3.3 in the oxidized lignites. The intensity of aromatic ethers increased from 1.0 in the original lignite to 1.9 and 1.6 for the oxidized samples. The mechanism of oxidation ether. Aldehydes are easily oxidized to carboxylic acids in the presence of air by the free radical formation of a peroxy acid. The carboxylic acid formed by disproportionation reactions between the peroxy acid and aldehydes might combine with phenols to produce esters as it was observed in the present work. The presence of high free radical concentration in the oxidation atmosphere probably caused to abstract hydrogen atoms from the aromatic structures thus degrading aromatics to produce hydroperoxides which acted later as it was described above. The gradual degradation of aromatic structures observed in the present study indicated that the oxidation reactions of the aromatic rings should less probable when compared to the oxidation of aliphatic structures.     

CHARACTERIZATION OF THE STRUCTURAL FEATURES OF OXIDIZED BEYPAZARI LIGNITE USING DECONVOLUTED SOLID STATE 13C NMR SPECTRA

The solid state ¹³C NMR method have been used to investigate the structural changes occurred in Beypazari lignite while oxidizing at 150°C in a dynamic air atmosphere. Least squares curve fitting techniques have been used to resolve the overlapping bands in the 0-220 ppm region of the 13_c NMR spectra. Measurements of the relative intensities of the functional groups observed in the oxidized coals were used to follow the progress of air oxidation. Oxidation reactions seemed to decrease the total intensities of both aliphatics and aromatics, though the reduction in aliphatics was more pronounced. The relative intensities of the total aliphatics decreased from 1.0 to 0.9 and 0.6 in the original and lignites oxidized for 12 and 312 hours, respectively. The relative intensities of Ar-C-C in the 130-148 ppm region for the same set of samples were 1.0, 0.9 and 0.8. The least-squares bands resolved in the carbonyl region were at 175 ppm and 190 ppm in the original lignite; at 180 ppm (carboxylic acids), 195 ppm (meta substituted ketones) 210 ppm (di orto substituted ketones) in the lignite oxidized for 12 hours and at 170 ppm (esters), 180 ppm, 200 ppm (aldehydes) and 210 ppm in the lignite oxidized for 312 hr. Carbonyl intensity increased from 1.0 in the original lignite to 2.3 and 3.3 in the oxidized lignites. The intensity of aromatic ethers increased from 1.0 in the original lignite to 1.9 and 1.6 for the oxidized samples. The mechanism of oxidation ether. Aldehydes are easily oxidized to carboxylic acids in the presence of air by the free radical formation of a peroxy acid. The carboxylic acid formed by disproportionation reactions between the peroxy acid and aldehydes might combine with phenols to produce esters as it was observed in the present work. The presence of high free radical concentration in the oxidation atmosphere probably caused to abstract hydrogen atoms from the aromatic structures thus degrading aromatics to produce hydroperoxides which acted later as it was described above. The gradual degradation of aromatic structures observed in the present study indicated that the oxidation reactions of the aromatic rings should less probable when compared to the oxidation of aliphatic structures.     

CHARACTERIZATION OF THE MACROMOLECULAR STRUCTURE OF PINGSHUO COAL MACERALS USING 13C-NMR, XPS, FTIR AND XRD TECHNIQUES

The macromolecular strucutures of the three major macerals, vitrinite, exinite and fusinite, separated from a unique Pingshuo bituminous coal are probed and characterized using advanced analytical techniques including ¹³C-NMR, XPS, FTIR and XRD. Structural parameters of the individual macerals, for instance, aromaticity, carbon and hydrogen distribution, existing form of heteroatoms and functional groups are measured and investigated. The microcrystallite parameters are also calculated from XRD analysis. The results indicate that the differences in macromolecular structure of the three macerals are obvious and can be distinguished from each other.     

CHARACTERIZATION OF THE MACROMOLECULAR STRUCTURE OF PINGSHUO COAL MACERALS USING 13C-NMR,XPS, FTIR AND XRD TECHNIQUES

Abstract

The macromolecular strucutures of the three major macerals, vitrinite, exinite and fusinite, separated from a unique Pingshuo bituminous coal are probed and characterized using advanced analytical techniques including ¹³C-NMR, XPS, FTIR and XRD. Structural parameters of the individual macerals, for instance, aromaticity, carbon and hydrogen distribution, existing form of heteroatoms and functional groups are measured and investigated. The microcrystallite parameters are also calculated from XRD analysis. The results indicate that the differences in macromolecular structure of the three macerals are obvious and can be distinguished from each other.