MoS2 was used as an efficient catalyst for hydropyrolysis （Hypy） of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction （SE）, it was found that MoS2 ca...MoS2 was used as an efficient catalyst for hydropyrolysis （Hypy） of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction （SE）, it was found that MoS2 catalytic Hypy can remarkably promote the yields of total chloroform extracts, saturates, aromatics, hopanes and steranes. In addition, the difference of biomarker parameters indicated that isomerization of covalently-bound biomarkers is much more difficult than their free counterparts. Meanwhile, the high conversion of total organic carbon （TOC） in MoS2 catalytic Hypy of organic matter proved that the presence of dispersed molybdenum sulfide accelerated the breaking of C-C bonds and the release of hydrocarbons. To address the catalytic mechanism, a series of control experiments based on free Hypy and catalytic Hypy were conducted. The results showed that the calculated atomic ratio of carbon conversion/hydrogen conversion for catalytic Hypy was much larger than the presumed value of 1/2, indicating that intensive hydrogenation took place and significantly influenced the distribution of liquid products. Analysis of stable hydrogen isotope data, infrared spectra and m/z 83 ion chromatograph of the saturate fraction further confirmed this hypothesis. The difference of S content changing （AS） between catalyst-free Hypy and catalytic Hypy, and the thermal characteristics of the catalyst, indicated that active H2S was definitely generated and it probably initiated free radical reactions in the early stage of hydropyrolysis of organic matter.展开更多
The Shibantan Member（Dengying Formation, South China） represents one of only two carbonate settings with Ediacara-type organisms and offers a rare opportunity to study the biogeochemistry of these ecosystems. To eva...The Shibantan Member（Dengying Formation, South China） represents one of only two carbonate settings with Ediacara-type organisms and offers a rare opportunity to study the biogeochemistry of these ecosystems. To evaluate possibilities and limitations for future biomarker studies on fossil-bearing outcrop samples of the Shibantan Member, we analysed the spatial distribution of hydrocarbons in extractable organic matter（i.e. bitumen） on a millimetre scale. Our study demonstrates that the sample and most likely also other rocks from the same setting are contaminated with petroleum-derived compounds that bear the potential for erroneous interpretations in palaeo-reconstructions. The contamination was revealed by distribution patterns and amounts of extractable n-alkanes and acyclic isoprenoids. The contamination is linked to the external weathering surfaces but also to cracks within the rock, and the extent most likely depends on concentration gradients between these contamination sources. Here we show that contamination can successfully be distinguished from syngenetic signals obtained from non-extractable organic matter（i.e. kerogen） using catalytic hydropyrolysis（Hy Py）. However, we observed that decalcification is necessary to achieve sufficient yields of kerogen-bound hydrocarbons and to avoid artificial alteration of the biomarker signals due to matrix effects.展开更多
There are abundant bitumens and oil seepages stored in vugs in a Lower-Triassic Daye formation(T_1d)marlite in Ni'erguan village in the Southern Guizhou Depression. However, the source of those oil seepages has no...There are abundant bitumens and oil seepages stored in vugs in a Lower-Triassic Daye formation(T_1d)marlite in Ni'erguan village in the Southern Guizhou Depression. However, the source of those oil seepages has not been determined to date. Multiple suites of source rocks of different ages exist in the depression. Both the oil seepages and potential source rocks have undergone complicated secondary alterations, which have added to the difficulty of an oil-source correlation. For example, the main source rock, a Lower-Cambrian Niutitang Formation"(∈_1n) mudstone, is over mature, and other potential source rocks, both from the Permian and the Triassic, are still in the oil window. In addition, the T_1d oil seepages underwent a large amount of biodegradation. To minimize the influence of biodegradation and thermal maturation, special methods were employed in this oil-source correlation study. These methods included catalytic hydropyrolysis, to release covalently bound biomarkers from the over mature"kerogen of ∈_1n mudstone, sequential extraction, to obtain chloroform bitumen A and chloroform bitumen C from the T_1d marlite, and anhydrous pyrolysis, to release pyrolysates from the kerogen of T_1d marlite. Using the methods above, the biomarkers and n-alkanes releasedfrom the oil samples and source rocks were analysed by GC–MS and GC-C-IRMS. The oil-source correlation indicated that the T_1d oil seepage primarily originated from"the ∈_1n mudstone and was partially mixed with oil generated from the T_1d marlite. Furthermore, the seepage also demonstrated that the above methods were effective for the complicated oil-source correlation in the Southern Guizhou Depression.展开更多
Hydro-catalytic pyrolysis on Yunnan lignite were studied in a fixed bed to determine their effects on high-value raw materials, such as BTX, PCX and lower naphthalene, in liquid products. Ni and Mo were chosen as acti...Hydro-catalytic pyrolysis on Yunnan lignite were studied in a fixed bed to determine their effects on high-value raw materials, such as BTX, PCX and lower naphthalene, in liquid products. Ni and Mo were chosen as active pyrolysis centers through thermogravimetry, after which their catalytic effects were analyzed in a fixed bed. The results showed that different concentrations of impregnated Ni and Mo solution can significantly increase the yield of high-value products and enable catalyst separating and recycling with this method of online catalytic pyrolysis.展开更多
基金supported by the Science and Technology Major roject (2008A-0600) from CNPC
文摘MoS2 was used as an efficient catalyst for hydropyrolysis （Hypy） of three samples of sedimentary organic matter with different maturities. Through comparison with Soxhlet extraction （SE）, it was found that MoS2 catalytic Hypy can remarkably promote the yields of total chloroform extracts, saturates, aromatics, hopanes and steranes. In addition, the difference of biomarker parameters indicated that isomerization of covalently-bound biomarkers is much more difficult than their free counterparts. Meanwhile, the high conversion of total organic carbon （TOC） in MoS2 catalytic Hypy of organic matter proved that the presence of dispersed molybdenum sulfide accelerated the breaking of C-C bonds and the release of hydrocarbons. To address the catalytic mechanism, a series of control experiments based on free Hypy and catalytic Hypy were conducted. The results showed that the calculated atomic ratio of carbon conversion/hydrogen conversion for catalytic Hypy was much larger than the presumed value of 1/2, indicating that intensive hydrogenation took place and significantly influenced the distribution of liquid products. Analysis of stable hydrogen isotope data, infrared spectra and m/z 83 ion chromatograph of the saturate fraction further confirmed this hypothesis. The difference of S content changing （AS） between catalyst-free Hypy and catalytic Hypy, and the thermal characteristics of the catalyst, indicated that active H2S was definitely generated and it probably initiated free radical reactions in the early stage of hydropyrolysis of organic matter.
基金supported by the Deutsche Forschungsgemeinschaft (grant BL971/1-3)the National Basic Research Program of China (2013CB835006)+2 种基金the National Natural Science Foundation of Chinathe Courant Research Centre of the University Gttingenthe German Academic Exchange Service
文摘The Shibantan Member（Dengying Formation, South China） represents one of only two carbonate settings with Ediacara-type organisms and offers a rare opportunity to study the biogeochemistry of these ecosystems. To evaluate possibilities and limitations for future biomarker studies on fossil-bearing outcrop samples of the Shibantan Member, we analysed the spatial distribution of hydrocarbons in extractable organic matter（i.e. bitumen） on a millimetre scale. Our study demonstrates that the sample and most likely also other rocks from the same setting are contaminated with petroleum-derived compounds that bear the potential for erroneous interpretations in palaeo-reconstructions. The contamination was revealed by distribution patterns and amounts of extractable n-alkanes and acyclic isoprenoids. The contamination is linked to the external weathering surfaces but also to cracks within the rock, and the extent most likely depends on concentration gradients between these contamination sources. Here we show that contamination can successfully be distinguished from syngenetic signals obtained from non-extractable organic matter（i.e. kerogen） using catalytic hydropyrolysis（Hy Py）. However, we observed that decalcification is necessary to achieve sufficient yields of kerogen-bound hydrocarbons and to avoid artificial alteration of the biomarker signals due to matrix effects.
基金supported jointly by the National Science and Technology Major Project of China (Grant Nos: 2011ZX05008002 and 2011ZX05005-001)
文摘There are abundant bitumens and oil seepages stored in vugs in a Lower-Triassic Daye formation(T_1d)marlite in Ni'erguan village in the Southern Guizhou Depression. However, the source of those oil seepages has not been determined to date. Multiple suites of source rocks of different ages exist in the depression. Both the oil seepages and potential source rocks have undergone complicated secondary alterations, which have added to the difficulty of an oil-source correlation. For example, the main source rock, a Lower-Cambrian Niutitang Formation"(∈_1n) mudstone, is over mature, and other potential source rocks, both from the Permian and the Triassic, are still in the oil window. In addition, the T_1d oil seepages underwent a large amount of biodegradation. To minimize the influence of biodegradation and thermal maturation, special methods were employed in this oil-source correlation study. These methods included catalytic hydropyrolysis, to release covalently bound biomarkers from the over mature"kerogen of ∈_1n mudstone, sequential extraction, to obtain chloroform bitumen A and chloroform bitumen C from the T_1d marlite, and anhydrous pyrolysis, to release pyrolysates from the kerogen of T_1d marlite. Using the methods above, the biomarkers and n-alkanes releasedfrom the oil samples and source rocks were analysed by GC–MS and GC-C-IRMS. The oil-source correlation indicated that the T_1d oil seepage primarily originated from"the ∈_1n mudstone and was partially mixed with oil generated from the T_1d marlite. Furthermore, the seepage also demonstrated that the above methods were effective for the complicated oil-source correlation in the Southern Guizhou Depression.
文摘Hydro-catalytic pyrolysis on Yunnan lignite were studied in a fixed bed to determine their effects on high-value raw materials, such as BTX, PCX and lower naphthalene, in liquid products. Ni and Mo were chosen as active pyrolysis centers through thermogravimetry, after which their catalytic effects were analyzed in a fixed bed. The results showed that different concentrations of impregnated Ni and Mo solution can significantly increase the yield of high-value products and enable catalyst separating and recycling with this method of online catalytic pyrolysis.
