CHARACTERIZATION OF DESULFURESATION EXTRACTS FROM MIDWESTERN U.S. COALS

Coals from Midwestern States were extracted using two different processes, viz., a supercritical extraction process and a perchloroethylene coal refining process. The objectives of these processes are the selective removal of sulfur and nitrogen compounds from high-sulfur coals. The solvent extracts were analyzed using gas chromatography/mass spectrometry as well as wet chemical analysis. The extracted organosulfur compounds varied, depending upon the extraction process, extraction conditions, type of solvent, type of coal, and degree of weathering. The experimental results are compared among the types of coal as well as among the different processes, from viewpoints of chemical and molecular interaction.     

A COMPARISON OF ALCOHOL- WATER BLENDS IN THEIR SUPERCRITICAL DESULFURIZATION EFFICIENCY OF MIDWESTERN U.S. BITUMINOUS COALS

Binary mixtures of methanol- water and ethanol-water at their supercritical conditions have been investigated for their ability to desulfurize Midwestern bituminous coals.The reduction of pyritic, sulfatic, and organic sulfur have been as high as 60%, 97 percnt;, and 28 percnt; respectively (based on a Btu basis). The experiments have been carried out utilizing statistical experimental designs and response surface methodology. The discerning characteristics as well as optimal process conditions have been identified. Critical comparisons with respect to the coal desulfurization efficiency between the alcohol blends have been made from a process engineering point of view. It was found that methanol-water supercritical mixture is effective in desulfurization of all forms of sulfur in coal, while the enthanol-water supercritical mixture is efficient for removing only inorganic forms of sulfur from coal.     

CHARACTERIZATION OF POLAR EXTRACTS FROM TWO PETROLEUM-DERIVED FUELS

Abstract

Petroleum fuels of marginal stability have been used as a source of nitrogen-rich polar extracts. Polar compounds were isolated by mild acid extraction followed by silica gel adsorption. The extracts were characterized and identified by combined capillary column GC/MS. Both fuels were studied by two methods under accelerated storage conditions, bottle tests and oxygen overpressure. Bottle tests were conducted at 80°C for 14 days and the oxygen overpressure at both 65 and 43°C for 6 days and 4 weeks respectively. Filterable insolubles and adherent gum were measured for both methods. Peroxide numbers were determined by ASTM D3703-85 for both stressed and original fuel samples.     

CHARACTERIZATION OF POLAR EXTRACTS FROM TWO PETROLEUM-DERIVED FUELS

Petroleum fuels of marginal stability have been used as a source of nitrogen-rich polar extracts. Polar compounds were isolated by mild acid extraction followed by silica gel adsorption. The extracts were characterized and identified by combined capillary column GC/MS. Both fuels were studied by two methods under accelerated storage conditions, bottle tests and oxygen overpressure. Bottle tests were conducted at 80°C for 14 days and the oxygen overpressure at both 65 and 43°C for 6 days and 4 weeks respectively. Filterable insolubles and adherent gum were measured for both methods. Peroxide numbers were determined by ASTM D3703-85 for both stressed and original fuel samples.     

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.     

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 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.     

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.     

CHARACTERIZATION AND STABILITY PROPERTIES OF POLAR EXTRACTS DERIVED FROM A RECENT SHALE LIQUID

A shale fuel of marginal stability has been used as a source of nitrogen-rich polar extracts. Polar compounds were isolated by mild acid extraction followed by silica gel adsorption and were identified by GC/HS. Alkyl substituted pyridines were the prevalent class of compounds present in most extracts. The effects of adding these shale derived fractions as dopants to a stable shale diesel fuel (0-11) were examined in terms of sediment formation and peroxide number under accelerated storage stability test conditions. The activities of the extracts in inducing fuel instability were correlated with their composition.     

CHARACTERIZATION AND STABILITY PROPERTIES OF POLAR EXTRACTS DERIVED FROM A RECENT SHALE LIQUID

ABSTRACT

A shale fuel of marginal stability has been used as a source of nitrogen-rich polar extracts. Polar compounds were isolated by mild acid extraction followed by silica gel adsorption and were identified by GC/HS. Alkyl substituted pyridines were the prevalent class of compounds present in most extracts. The effects of adding these shale derived fractions as dopants to a stable shale diesel fuel (0-11) were examined in terms of sediment formation and peroxide number under accelerated storage stability test conditions. The activities of the extracts in inducing fuel instability were correlated with their composition.     

COMPARISON OF REFLECTANCE DATA FROM VARIOUS MACERALS FROM SUB-BITUMINOUS COALS

Reflectance values were determined for selected huminite (eu-ulminite, eugelinite and phlobaphinite) and liptinite (cutinite and resinite) samples from a 560—m thick unit of lignitic-sub-bituminous coals in the Hat Creek coal deposit of British Columbia.
The objective of this study was to determine: (a) the reflectance differences between macerals, especially those of the humocollinite subgroup, and to determine the possibility of the use of the reflectance of the humocollinite maceral as an indicator of rank; (b) the trend of reflectance of humocollinite macerals (kerogen Type III) with depth; and (c) comparison of the reflectance trends of resinite and cutinite (kerogen Type II) with that of the humocollinite macerals (kerogen Type III).
Two types of corpohuminite were found in the same coal: Type 1 phlobaphinite with reflectance lower than eu-ulminite, and Type 2 phlobaphinite with reflectance higher than eu-ulminite. Reflectance of eugelinite was higher than corpohuminite and eu-ulminite.
Kerogen Type III (huminite) in these coals consists of: a) low-reflecting hydrogen-rich phlobaphinite Type 1; b) phlobaphinite Type 2 and eu-ulminite B. with intermediate reflectance and hydrogen content; c) relatively high-reflecting and perhaps hydrogen-poor eugelinite. The reflectance of all these macerals increased with depth.     

微量元素在煤成烃研究中的应用

通过对吐哈盆地不同类型烃源岩有机质及原油中微量元素的研究，并在与世界及我国其它地区原油对比的基础上，探讨了煤成烃中和微量元素的分布规律，运用微量元素进行了油源对比的尝试。     

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.     

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

ABSTRACT

ABSTRACT

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.     

CHARACTERIZATION OF SYNCRUDES FROM THE H-COAL PROCESS

A detailed comparison of the physical properties and chemical composition of two syncrudes obtained from the H-Coal liquefaction process are presented. The syncrudes were obtained while processing an Illinois #6 bituminous coal and a Western Kentucky #9 bituminous coal.     

SEPARATION OF MACERALS FROM SUBBITUMINOUS COALS AND THEIR RESPONSE TO LIQUEFACTION

Separation of macerals from three Alberta subbituminous coals was investigated using float-and-sink method with dense liquids followed by the density gradient technique proposed by Dyrkacz and co-workers at Argonne National Laboratory, U.S.A. Resolutions of 90 percent or greater purity were obtained in some fractions in quantities sufficient to study their response to liquefaction. The ease of liquefaction of macerals isolated from subbituminous coals was, in descending order, liptinite, vitrinite, inertinite. Liquefaction of inertinite occurred at somewhat higher temperatures compared to that of vitrinite macerals which initiated between 350^° and 400^°C.

Analysis of the chemical makeup of macerals from a subbituminous coal indicated that liptinite was relatively rich in hydrogen, whereas vitrinite and inertinite were relatively rich in oxygen and carbon respectively. The average densities were 1.285, 1.345 and 1.458 g/cc for liptinite, vitrinite, and inertinite respectively. X-ray diffraction and NMR spectra of the three macerals were also investigated which will be the subject of a future detailed report.     

SEPARATION OF MACERALS FROM SUBBITUMINOUS COALS AND THEIR RESPONSE TO LIQUEFACTION

ABSTRACT

Separation of macerals from three Alberta subbituminous coals was investigated using float-and-sink method with dense liquids followed by the density gradient technique proposed by Dyrkacz and co-workers at Argonne National Laboratory, U.S.A. Resolutions of 90 percent or greater purity were obtained in some fractions in quantities sufficient to study their response to liquefaction. The ease of liquefaction of macerals isolated from subbituminous coals was, in descending order, liptinite, vitrinite, inertinite. Liquefaction of inertinite occurred at somewhat higher temperatures compared to that of vitrinite macerals which initiated between 350^° and 400^°C.

Analysis of the chemical makeup of macerals from a subbituminous coal indicated that liptinite was relatively rich in hydrogen, whereas vitrinite and inertinite were relatively rich in oxygen and carbon respectively. The average densities were 1.285, 1.345 and 1.458 g/cc for liptinite, vitrinite, and inertinite respectively. X-ray diffraction and NMR spectra of the three macerals were also investigated which will be the subject of a future detailed report.     

CHEMICAL CHARACTERISTICS OF SUPERCRITICAL TOLUENE EXTRACTS FROM TWO TURKISH LIGNITES

Samples from two major deposits of Turkish lignites were subjected to supercritical toluene extraction at 325°C and 14.1 MPa in an autoclave. The resultant extracts were separated into pre-asphaltene, asphaltene, saturates, aromatics and resin fractions by column chromatography. The fractions were characterized by ¹H-NMR, ¹³C-NMR, IR. and elemental analysis in order to compare the chemical composition of extracis from the two coal samples. The results show that the extracts from the Tungbiiek (T-coal) deposits contain aliphatic constituent which is composed of mostly long chain unbranched alkyl compounds while the extracts from the Soma Mcrkeg (S-coal) deposits contain a significant amount of branched paraffinic compounds. The resin fractions from both samples were found to contain a significant amount of single ring aromatic compounds.     

CHEMICAL CHARACTERISTICS OF SUPERCRITICAL TOLUENE EXTRACTS FROM TWO TURKISH LIGNITES

ABSTRACT

Samples from two major deposits of Turkish lignites were subjected to supercritical toluene extraction at 325°C and 14.1 MPa in an autoclave. The resultant extracts were separated into pre-asphaltene, asphaltene, saturates, aromatics and resin fractions by column chromatography. The fractions were characterized by ¹H-NMR, ¹³C-NMR, IR. and elemental analysis in order to compare the chemical composition of extracis from the two coal samples. The results show that the extracts from the Tungbiiek (T-coal) deposits contain aliphatic constituent which is composed of mostly long chain unbranched alkyl compounds while the extracts from the Soma Mcrkeg (S-coal) deposits contain a significant amount of branched paraffinic compounds. The resin fractions from both samples were found to contain a significant amount of single ring aromatic compounds.     

CHARACTERIZATION OF VARIOUS BITUMEN SAMPLES FROM TAR SANDS

We have investigated twenty three bitumen samples obtained using different separation methods such as: ultracentrifugation, Dean-Stark extraction, solvent extraction employing vigorous agitation, hot water separation and the Solvent Extraction Spherical Agglomeration technique. These samples were extracted from oil sand feedstocks of different grades, Suncor sludge pond tailings and mineral agglomerates obtained from the Solvent Extraction Spherical Agglomeration process. All of the bitumen samples were examined on a comparative basis using various analytical techniques. These included: fractionation into asphaltenes and maltenes; elemental analyses; molecular weight determination using vapour pressure osmometry and gel permeation chromatography, infrared, proton and 13C nuclear magnetic resonance spectroscopy. Proton and ¹³C n.m.r. spectroscopic data were used to determine the distribution of various types of hydrogens and carbons in the samples. These data were also used to derive various molecular parameters in order to investigate average molecular structures of different bitumen samples and some of their asphaltene fractions.