Carlson, RE
1992
High-Resolution Chromatographic Characterization of Depolymerized Coals of Different Rank: Aliphatic and Aromatic Hydrocarbons
Carlson, R.E.; Critchfield, S.; Vorkink, W.P.; Dong, J.-Z.; Pugmire, R.J.; Bartle, K.D.; Lee, M.L.; Zhang, Y. and Shabtai, J.S.
Fuel, 71(1):1-29, 1992. Funded by US Department of Energy, Gas Research Institute and ACERC.
A selective, low temperature depolymerization procedure has been applied to four Argonne coals of different rank to produce products that are representative of the original coal macromolecular structure, and that are amenable to chromatographic analysis. The products of this depolymerization procedure retained most of the original aromatic and functional group structures of the original coals. A comparison of liquid C-13 NMR spectra of the products and solid-state C-13 NMR spectra of the original coals showed only minor changes in the aromaticities of two of the coals, and some loss of the carbonyl carbons in all of the coals.
Tetrahydrofuran pre-extracts of the four coals and their depolymerized products were separated into chemical classes by adsorption chromatography. Two of these fractions, which contained aliphatic hydrocarbons and polycyclic aromatic hydrocarbons were analyzed using gas chromatography/mass spectrometry. Structural identifications were based on a combination of chromatographic retention and mass spectral fragmentation data. For the lower rank coals, the compositions of the pre-extracts were quite different from the corresponding depolymerized products, and they contained an abundance of molecular biological markers. The compositions of the pre-extracts became more similar to the depolymerized products as rank increased.
1991
Analysis of Depolymerization Products of Various Rank Coals Using High Resolution Chromatographic Techniques
Carlson, R.E.; Vorkink, W.P.; Lee, M.L.; Zhang, Y. and Shabtai, J.S.
1991 Pittsburgh Coal Conference and Exposition on Analytical Chemistry and Applied Spectroscopy, Chicago, IL, March 1991. Funded by ACERC.
Elucidation of the organic structure of coal is vital to designing and optimizing processes for direct coal usage (e.g., combustion or coal conversion), and the efficient utilization of this abundant natural resource. Due to the extremely complex macromolecular structure of coal, present structural information is sparse. The analysis of coal and coal derived materials has been approached by numerous analytical and chemical techniques. However, many of those methods fail to yield specific information concerning the macromolecular network, or they significantly alter the network. Solvent extracts have provided valuable information concerning the "easily" extractable portion of the coal matrix, again leaving the macromolecular skeleton virtually unexplored. Structural investigations of coal carried out at high temperatures (>300ºC) lead to free radical rearrangement, crosslinking and thermal cracking of the sample.
A mild depolymerization method has been developed which yields a tetrahydrofuran (THF) soluble product that represents 50 to >70% of the original material, depending on coal rank. Detailed analysis of these products was performed using high-resolution gas chromatography and gas chromatography/mass spectrometry. The qualitative and quantitative results of four depolymerized Argonne coals (Beulah Zap, Illinois No. 6, Utah Blind Canyon, Pocahontas No.3) will be discussed and compared to room temperature solvent extracts (THF) of the same coals.
1990
High Resolution Chromatographic Characterization of Depolymerized Coals of Different Rank: Aliphatic and Aromatic Hydrocarbons
Carlson, R.E.; Critchfield, S.; Vorkink, W.P.; Dong, J.-Z.; Pugmire, R.J.; Bartle, K.D. and Lee, M.L.
Fuel, 1990 (In Press). Funded by US Department of Energy, Gas Research Institute and ACERC.
A selective, low temperature depolymerization procedure has been applied to four Argonne coals of different rank to produce products that are representative of the original coal macromolecular structure, and that are amenable to chromatographic analysis. The products of this depolymerization procedure retained most of the original aromatic and functional group structures of the original coals. A comparison of liquid C-13 NMR spectra of the products and solid-state C-13 NMR spectra of the original coals showed only minor changes in the aromaticities of two of the coals, and some loss of the carbonyl carbons in all of the coals.
Tetrahydrofuran pre-extracts of the four coals and their depolymerized products were separated into chemical classes by adsorption chromatography. Two of these fractions, which contained aliphatic hydrocarbons and polycyclic aromatic hydrocarbons were analyzed using gas chromatography/mass spectrometry. Structural identifications were based on a combination of chromatographic retention and mass spectral fragmentation data. For the lower rank coals, the compositions of the pre-extracts were quite different from the corresponding depolymerized products, and they contained an abundance of molecular biological markers. The compositions of the pre-extracts became more similar to the depolymerized products as rank increased.
Carlson, RE
1992
High-Resolution Chromatographic Characterization of Depolymerized Coals of Different Rank: Aliphatic and Aromatic Hydrocarbons
Carlson, R.E.; Critchfield, S.; Vorkink, W.P.; Dong, J.-Z.; Pugmire, R.J.; Bartle, K.D.; Lee, M.L.; Zhang, Y. and Shabtai, J.S.
Fuel, 71(1):1-29, 1992. Funded by US Department of Energy, Gas Research Institute and ACERC.
A selective, low temperature depolymerization procedure has been applied to four Argonne coals of different rank to produce products that are representative of the original coal macromolecular structure, and that are amenable to chromatographic analysis. The products of this depolymerization procedure retained most of the original aromatic and functional group structures of the original coals. A comparison of liquid C-13 NMR spectra of the products and solid-state C-13 NMR spectra of the original coals showed only minor changes in the aromaticities of two of the coals, and some loss of the carbonyl carbons in all of the coals.
Tetrahydrofuran pre-extracts of the four coals and their depolymerized products were separated into chemical classes by adsorption chromatography. Two of these fractions, which contained aliphatic hydrocarbons and polycyclic aromatic hydrocarbons were analyzed using gas chromatography/mass spectrometry. Structural identifications were based on a combination of chromatographic retention and mass spectral fragmentation data. For the lower rank coals, the compositions of the pre-extracts were quite different from the corresponding depolymerized products, and they contained an abundance of molecular biological markers. The compositions of the pre-extracts became more similar to the depolymerized products as rank increased.
1991
Analysis of Depolymerization Products of Various Rank Coals Using High Resolution Chromatographic Techniques
Carlson, R.E.; Vorkink, W.P.; Lee, M.L.; Zhang, Y. and Shabtai, J.S.
1991 Pittsburgh Coal Conference and Exposition on Analytical Chemistry and Applied Spectroscopy, Chicago, IL, March 1991. Funded by ACERC.
Elucidation of the organic structure of coal is vital to designing and optimizing processes for direct coal usage (e.g., combustion or coal conversion), and the efficient utilization of this abundant natural resource. Due to the extremely complex macromolecular structure of coal, present structural information is sparse. The analysis of coal and coal derived materials has been approached by numerous analytical and chemical techniques. However, many of those methods fail to yield specific information concerning the macromolecular network, or they significantly alter the network. Solvent extracts have provided valuable information concerning the "easily" extractable portion of the coal matrix, again leaving the macromolecular skeleton virtually unexplored. Structural investigations of coal carried out at high temperatures (>300ºC) lead to free radical rearrangement, crosslinking and thermal cracking of the sample.
A mild depolymerization method has been developed which yields a tetrahydrofuran (THF) soluble product that represents 50 to >70% of the original material, depending on coal rank. Detailed analysis of these products was performed using high-resolution gas chromatography and gas chromatography/mass spectrometry. The qualitative and quantitative results of four depolymerized Argonne coals (Beulah Zap, Illinois No. 6, Utah Blind Canyon, Pocahontas No.3) will be discussed and compared to room temperature solvent extracts (THF) of the same coals.
1990
High Resolution Chromatographic Characterization of Depolymerized Coals of Different Rank: Aliphatic and Aromatic Hydrocarbons
Carlson, R.E.; Critchfield, S.; Vorkink, W.P.; Dong, J.-Z.; Pugmire, R.J.; Bartle, K.D. and Lee, M.L.
Fuel, 1990 (In Press). Funded by US Department of Energy, Gas Research Institute and ACERC.
A selective, low temperature depolymerization procedure has been applied to four Argonne coals of different rank to produce products that are representative of the original coal macromolecular structure, and that are amenable to chromatographic analysis. The products of this depolymerization procedure retained most of the original aromatic and functional group structures of the original coals. A comparison of liquid C-13 NMR spectra of the products and solid-state C-13 NMR spectra of the original coals showed only minor changes in the aromaticities of two of the coals, and some loss of the carbonyl carbons in all of the coals.
Tetrahydrofuran pre-extracts of the four coals and their depolymerized products were separated into chemical classes by adsorption chromatography. Two of these fractions, which contained aliphatic hydrocarbons and polycyclic aromatic hydrocarbons were analyzed using gas chromatography/mass spectrometry. Structural identifications were based on a combination of chromatographic retention and mass spectral fragmentation data. For the lower rank coals, the compositions of the pre-extracts were quite different from the corresponding depolymerized products, and they contained an abundance of molecular biological markers. The compositions of the pre-extracts became more similar to the depolymerized products as rank increased.