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Maria Mastalerz - One of the best experts on this subject based on the ideXlab platform.
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petrographic characterization and Maceral controls on porosity in overmature marine shales examples from ordovician silurian shales in china and the u s
Geofluids, 2021Co-Authors: Lin Wei, Shasha Sun, Dazhong Dong, Zhensheng Shi, Jia Yin, Shudi Zhang, Maria MastalerzAbstract:The pore structure characterization and its controlling factors in overmature shales are keys to understand the shale gas accumulation mechanism. Organic matter in source rocks is a mixture of various Macerals that have their own specific evolutionary pathways during thermal maturation. Pores within Macerals also evolve following their own path. This study focused on petrographic characterization and Maceral controls on porosity in overmature marine shales in China and the United States. Shale from Ordos Basin in China was also selected as an example of overmature transitional shale for Maceral comparison. Organic petrology techniques were used to identify Maceral types and describe morphological features in detail; scanning electron microscopy techniques were then used to document the abundance and development of pores within Macerals. Helium measurement, mercury intrusion capillary pressure, and CO2 adsorption were especially applied to quantify the pore structure of Wufeng-Longmaxi shale from Sichuan Basin in China. The vitrinite reflectance equivalent of the studied overmature samples is ~2.4%. The Macerals within the studied marine shales are composed mainly of pyrobitumen and zooclasts. At this maturity, pyrobitumen develops abundant gas-related pores, and their volume positively correlates to gas content. Three types of pyrobitumen and its related pore structure are characterized in Wufeng-Longmaxi shales. Zooclasts contribute to total organic carbon (TOC) content but little to porosity. When the TOC content is above 1.51% in Wufeng-Longmaxi samples, the TOC content positively correlates to quartz content. Organic matter strongly controls micropore development. Pores of provide a significant amount of micropore volume. Clay mineral and quartz contents control micro- and macropore increments in organic-lean shales. MICP results indicate that pores within 3-12 nm and 900-2500 nm account for a major contribution to pore volume obtained. Determining the proportions of pyrobitumen to zooclasts within the total organic matter in pre-Devonian organic-rich marine shales is important in predicting porosity and gas storage capacity in high-maturity shales.
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Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S.
'Hindawi Limited', 2021Co-Authors: Lin Wei, Maria Mastalerz, Shasha Sun, Dazhong Dong, Zhensheng Shi, Jia Yin, Shudi Zhang, Xiong ChengAbstract:The pore structure characterization and its controlling factors in overmature shales are keys to understand the shale gas accumulation mechanism. Organic matter in source rocks is a mixture of various Macerals that have their own specific evolutionary pathways during thermal maturation. Pores within Macerals also evolve following their own path. This study focused on petrographic characterization and Maceral controls on porosity in overmature marine shales in China and the United States. Shale from Ordos Basin in China was also selected as an example of overmature transitional shale for Maceral comparison. Organic petrology techniques were used to identify Maceral types and describe morphological features in detail; scanning electron microscopy techniques were then used to document the abundance and development of pores within Macerals. Helium measurement, mercury intrusion capillary pressure, and CO2 adsorption were especially applied to quantify the pore structure of Wufeng-Longmaxi shale from Sichuan Basin in China. The vitrinite reflectance equivalent of the studied overmature samples is ~2.4%. The Macerals within the studied marine shales are composed mainly of pyrobitumen and zooclasts. At this maturity, pyrobitumen develops abundant gas-related pores, and their volume positively correlates to gas content. Three types of pyrobitumen and its related pore structure are characterized in Wufeng-Longmaxi shales. Zooclasts contribute to total organic carbon (TOC) content but little to porosity. When the TOC content is above 1.51% in Wufeng-Longmaxi samples, the TOC content positively correlates to quartz content. Organic matter strongly controls micropore development. Pores of diameter~0.5 nm provide a significant amount of micropore volume. Clay mineral and quartz contents control micro- and macropore increments in organic-lean shales. MICP results indicate that pores within 3-12 nm and 900-2500 nm account for a major contribution to pore volume obtained. Determining the proportions of pyrobitumen to zooclasts within the total organic matter in pre-Devonian organic-rich marine shales is important in predicting porosity and gas storage capacity in high-maturity shales
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Meso- and microporosity of the subbituminous kM2 coal seam (Soma, Turkey) and its relationship with coal characteristics
International Journal of Coal Geology, 2017Co-Authors: Ali Ihsan Karayigit, Maria Mastalerz, R. Görkem Oskay, Xavier Querol, Nir Roy LiebermanAbstract:Abstract This study focuses on meso- and microporosity of the subbituminous kM2 coal seam and its relation to coal characteristics. The coal seam is being mined in an underground coal mine at the Eynez sector in the Soma Basin (Western Turkey). The analysed coal samples are characterized by low moisture (avg. 8.2%, on air-dry basis) and total S content (avg. 1.5%, on dry basis), and moderate ash yield (avg. 26.1%, on dry basis). The predominant Maceral group is huminite, in which telohuminite is the dominant Maceral subgroup (up to 57.1 vol.%, on whole-coal basis), whereas liptinite and inertinite Maceral groups occur in low but variable proportions. Mineralogically, the samples are composed of quartz, clay minerals (kaolinite and illite), carbonates, pyrite, and rarely feldspars and gypsum. Statistical and SEM-EDX analyses indicate that the majority of elements have inorganic affinity, particularly the aluminosilicate minerals. The specific surface area and volume of mesopores, and average mesopore size determined by low pressure N2 adsorption, range widely throughout the studied seam section. Micropore characteristics, analysed by low-pressure CO2 adsorption, demonstrate that micropores are abundant, and specific surface area and volume of micropores vary widely. Surface area and volume of mesopores are slightly higher in the lower part of the seam, whereas the opposite was observed for surface area and volume of microspores. These trends may imply that hydrostatic pressure has little impact upon mesopore characteristics, although increased ash yields in the lower part of the seam suggest that minerals are the major contributor of coal mesopores. Furthermore, total C contents and huminite Macerals, particularly telohuminite, display positive correlations with micropore characteristics. Thus, the variations in the microporosity are mainly correlated with the proportion of organic matter (Macerals) in the analysed samples. The contents of aluminosilicate-affiliated elements display moderate to strong positive correlations with surface area and volume of mesopores, and total S and B contents display weak positive correlations with surface area and volume of micropores. The element B likely precipitated from porewater or intra-seam solutions during coalification and was absorbed by Macerals having abundant microporosity. The abundance of micropores along with frequent disseminated pyrite crystals within the reactive Macerals (telohuminite group) and higher total S contents in the upper parts of the seam could increase the risk of self-heating. Therefore, care should be taken to use caution when mining the upper part of the seam.
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comparative optical properties of Macerals and statistical evaluation of mis identification of vitrinite and solid bitumen from early mature middle devonian lower mississippian new albany shale implications for thermal maturity assessment
International Journal of Coal Geology, 2016Co-Authors: Yinzhi Wang, Lin Wei, Maria MastalerzAbstract:Abstract Vitrinite reflectance (VRo in %) is used routinely to quantify thermal maturity in sedimentary basins. Reflectance and fluorescence of other Macerals such as solid bitumen and amorphous organic matter (AOM) can provide an independent means to assess thermal maturity and hydrocarbon generation potential. However, similarity in petrographic characteristics of these Macerals, solid bitumen and vitrinite in particular, often causes difficulties with their identification and, consequently, reflectance can be measured on misidentified particles, making reported VRo values unreliable. The purpose of this study is to compare reflectance values of various Macerals in early mature shales and to evaluate the implications of misidentifying solid bitumen and vitrinite for assessing thermal maturity. To address this issue, 15 organic-matter-rich samples from the Middle Devonian/Lower Mississippian New Albany Shale from a corehole in Daviess County, Indiana, were selected. These samples were chosen because they had distinct and easily identified AOM, solid bitumen, vitrinite, and inertinite particles, allowing for statistically relevant comparisons. VRo values (0.57 to 0.65%) of the studied sample suite cover the early mature stage, and expressed no trend with depth. In comparison, reflectance values of solid bitumen (BRo) and AOM (AOMRo) from the same samples are lower, and range from 0.44 to 0.52% and 0.27 to 0.31%, respectively. These differences are accompanied by corresponding differences in chemistry of Macerals as demonstrated by the micro-FTIR technique. Specifically, compared to vitrinite and inertinite, solid bitumen shows lower aromaticity, and compared to AOM and alginite, it exhibits shorter aliphatic chains. Reflectance was observed to vary systematically; samples having higher VRo also feature elevated solid bitumen and AOM reflectance values. The relationship between vitrinite and solid bitumen can be expressed by the following equation: vitrinite reflectance equivalent (VRoE in %) = (0.83 × BRo) + 0.22, whereas for vitrinite and AOM, VRoE = (0.84 × AOMRo) + 0.38. Statistical evaluation of the differences in reflectance values caused by Maceral misidentification indicates that in extreme cases, when a petrographer cannot distinguish between vitrinite and solid bitumen, the reflectance can be shifted by 0.06–0.09%. For this set of samples, such a difference could shift maturity assessment from early mature to immature. In more common cases, when the analyst can distinguish between the Macerals but has difficulties with their overlapping reflectance interval, the reflectance difference that results from misidentification is only within a 0.0–0.02% range. Therefore, if the level of uncertainty in Maceral identification can be determined, the calculation of VRoE values from measured BRo, can reduce inaccuracy in VRo values for interpreting the thermal histories of sedimentary basins, which, in turn, is essential for the assessment of oil and gas resources and for building a successful exploration model.
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coal Macerals chemistry and its implications for selectivity in coal floatability
International Journal of Coal Preparation and Utilization, 2015Co-Authors: Maria Holuszko, Maria MastalerzAbstract:Macerals are the smallest components of coal recognizable on the microscopic scale and, even when optically homogeneous, they may have variable elemental and molecular chemistry not only across different coal ranks but also in iso-rank coals. These variations in Maceral chemistry may have significant impact on the behavior of the coal during processing and may also complicate predictions of this behavior. Flotation is one of the processes that is impacted by interMaceral variations. Flotation is used as a main process to upgrade the fines of higher rank coals. It depends on the surface properties of coal particles, hence their chemical composition. Most of the minerals associated with coal, with the exception of a few (elemental sulfur or some pyrites), are hydrophilic and can easily be separated if liberated from coal by flotation. The organic matter (Macerals) possesses different degrees of hydrophobicity, and its response to flotation can vary depending on the surface properties that result from chemic...
Lin Wei - One of the best experts on this subject based on the ideXlab platform.
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petrographic characterization and Maceral controls on porosity in overmature marine shales examples from ordovician silurian shales in china and the u s
Geofluids, 2021Co-Authors: Lin Wei, Shasha Sun, Dazhong Dong, Zhensheng Shi, Jia Yin, Shudi Zhang, Maria MastalerzAbstract:The pore structure characterization and its controlling factors in overmature shales are keys to understand the shale gas accumulation mechanism. Organic matter in source rocks is a mixture of various Macerals that have their own specific evolutionary pathways during thermal maturation. Pores within Macerals also evolve following their own path. This study focused on petrographic characterization and Maceral controls on porosity in overmature marine shales in China and the United States. Shale from Ordos Basin in China was also selected as an example of overmature transitional shale for Maceral comparison. Organic petrology techniques were used to identify Maceral types and describe morphological features in detail; scanning electron microscopy techniques were then used to document the abundance and development of pores within Macerals. Helium measurement, mercury intrusion capillary pressure, and CO2 adsorption were especially applied to quantify the pore structure of Wufeng-Longmaxi shale from Sichuan Basin in China. The vitrinite reflectance equivalent of the studied overmature samples is ~2.4%. The Macerals within the studied marine shales are composed mainly of pyrobitumen and zooclasts. At this maturity, pyrobitumen develops abundant gas-related pores, and their volume positively correlates to gas content. Three types of pyrobitumen and its related pore structure are characterized in Wufeng-Longmaxi shales. Zooclasts contribute to total organic carbon (TOC) content but little to porosity. When the TOC content is above 1.51% in Wufeng-Longmaxi samples, the TOC content positively correlates to quartz content. Organic matter strongly controls micropore development. Pores of provide a significant amount of micropore volume. Clay mineral and quartz contents control micro- and macropore increments in organic-lean shales. MICP results indicate that pores within 3-12 nm and 900-2500 nm account for a major contribution to pore volume obtained. Determining the proportions of pyrobitumen to zooclasts within the total organic matter in pre-Devonian organic-rich marine shales is important in predicting porosity and gas storage capacity in high-maturity shales.
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Petrographic Characterization and Maceral Controls on Porosity in Overmature Marine Shales: Examples from Ordovician-Silurian Shales in China and the U.S.
'Hindawi Limited', 2021Co-Authors: Lin Wei, Maria Mastalerz, Shasha Sun, Dazhong Dong, Zhensheng Shi, Jia Yin, Shudi Zhang, Xiong ChengAbstract:The pore structure characterization and its controlling factors in overmature shales are keys to understand the shale gas accumulation mechanism. Organic matter in source rocks is a mixture of various Macerals that have their own specific evolutionary pathways during thermal maturation. Pores within Macerals also evolve following their own path. This study focused on petrographic characterization and Maceral controls on porosity in overmature marine shales in China and the United States. Shale from Ordos Basin in China was also selected as an example of overmature transitional shale for Maceral comparison. Organic petrology techniques were used to identify Maceral types and describe morphological features in detail; scanning electron microscopy techniques were then used to document the abundance and development of pores within Macerals. Helium measurement, mercury intrusion capillary pressure, and CO2 adsorption were especially applied to quantify the pore structure of Wufeng-Longmaxi shale from Sichuan Basin in China. The vitrinite reflectance equivalent of the studied overmature samples is ~2.4%. The Macerals within the studied marine shales are composed mainly of pyrobitumen and zooclasts. At this maturity, pyrobitumen develops abundant gas-related pores, and their volume positively correlates to gas content. Three types of pyrobitumen and its related pore structure are characterized in Wufeng-Longmaxi shales. Zooclasts contribute to total organic carbon (TOC) content but little to porosity. When the TOC content is above 1.51% in Wufeng-Longmaxi samples, the TOC content positively correlates to quartz content. Organic matter strongly controls micropore development. Pores of diameter~0.5 nm provide a significant amount of micropore volume. Clay mineral and quartz contents control micro- and macropore increments in organic-lean shales. MICP results indicate that pores within 3-12 nm and 900-2500 nm account for a major contribution to pore volume obtained. Determining the proportions of pyrobitumen to zooclasts within the total organic matter in pre-Devonian organic-rich marine shales is important in predicting porosity and gas storage capacity in high-maturity shales
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comparative optical properties of Macerals and statistical evaluation of mis identification of vitrinite and solid bitumen from early mature middle devonian lower mississippian new albany shale implications for thermal maturity assessment
International Journal of Coal Geology, 2016Co-Authors: Yinzhi Wang, Lin Wei, Maria MastalerzAbstract:Abstract Vitrinite reflectance (VRo in %) is used routinely to quantify thermal maturity in sedimentary basins. Reflectance and fluorescence of other Macerals such as solid bitumen and amorphous organic matter (AOM) can provide an independent means to assess thermal maturity and hydrocarbon generation potential. However, similarity in petrographic characteristics of these Macerals, solid bitumen and vitrinite in particular, often causes difficulties with their identification and, consequently, reflectance can be measured on misidentified particles, making reported VRo values unreliable. The purpose of this study is to compare reflectance values of various Macerals in early mature shales and to evaluate the implications of misidentifying solid bitumen and vitrinite for assessing thermal maturity. To address this issue, 15 organic-matter-rich samples from the Middle Devonian/Lower Mississippian New Albany Shale from a corehole in Daviess County, Indiana, were selected. These samples were chosen because they had distinct and easily identified AOM, solid bitumen, vitrinite, and inertinite particles, allowing for statistically relevant comparisons. VRo values (0.57 to 0.65%) of the studied sample suite cover the early mature stage, and expressed no trend with depth. In comparison, reflectance values of solid bitumen (BRo) and AOM (AOMRo) from the same samples are lower, and range from 0.44 to 0.52% and 0.27 to 0.31%, respectively. These differences are accompanied by corresponding differences in chemistry of Macerals as demonstrated by the micro-FTIR technique. Specifically, compared to vitrinite and inertinite, solid bitumen shows lower aromaticity, and compared to AOM and alginite, it exhibits shorter aliphatic chains. Reflectance was observed to vary systematically; samples having higher VRo also feature elevated solid bitumen and AOM reflectance values. The relationship between vitrinite and solid bitumen can be expressed by the following equation: vitrinite reflectance equivalent (VRoE in %) = (0.83 × BRo) + 0.22, whereas for vitrinite and AOM, VRoE = (0.84 × AOMRo) + 0.38. Statistical evaluation of the differences in reflectance values caused by Maceral misidentification indicates that in extreme cases, when a petrographer cannot distinguish between vitrinite and solid bitumen, the reflectance can be shifted by 0.06–0.09%. For this set of samples, such a difference could shift maturity assessment from early mature to immature. In more common cases, when the analyst can distinguish between the Macerals but has difficulties with their overlapping reflectance interval, the reflectance difference that results from misidentification is only within a 0.0–0.02% range. Therefore, if the level of uncertainty in Maceral identification can be determined, the calculation of VRoE values from measured BRo, can reduce inaccuracy in VRo values for interpreting the thermal histories of sedimentary basins, which, in turn, is essential for the assessment of oil and gas resources and for building a successful exploration model.
C G Thomas - One of the best experts on this subject based on the ideXlab platform.
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the behaviour of inertinite Macerals under pulverised fuel pf combustion conditions
Organic Geochemistry, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, D Phontanant, Michio ShibaokaAbstract:Abstract The usefulness of the current system of classification of the inertinite group of Macerals for understanding the pulverised fuel (pf) combustion process is discussed and questioned. Results to date on the combustibility of inertinite Macerals are indecisive, especially as inertinite is mosltly regarded as a single entity. Simulated pf combustion experiments with a laser microreactor revealed that the inertinite Macerals yielded a wide diversity of char morphologies. With one-to-one correlations between Maceral and char, it was possible to determine which Maceral was fusible or infusible (commonly called reactive and inert respectively). The microreactor is being developed to measure the burning parameters of individual Maceral particles. For example, the data will show which Macerals are slow burning (and by how much) and whether fusibility has any relevance to the speed of char burning.
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reactive fusible inertinite in pulverized fuel combustion 1 a laser microreactor technique
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Lee F Brunckhorst, Dheera PhonganantAbstract:Abstract The adoption of the concept of reactive (fusible) and inert (infusible) Macerals in pulverized fuel (p.f.) combustion is examined together with the need to determine these constituents under realistic conditions. A laser microreactor method is described in which 100 μm monoMaceral particles are heated at 105 − 106 K s −1 to ~1600 °C in air. Two applications are described. First, the particles are heated for ~40 ms, the pyrolysis converting the Maceral into a char particle with individual morphology; in particular, whether the Maceral fuses or melts (termed reactive) or not (termed inert) is determined by optical microscopy. Second, high-speed cinephotomicroscopy of the combusting particle is possible using longer irradiation periods, revealing in great detail the morphology of swelling and combustion. The validity of the method is substantiated by comparing char morphologies with those from a drop-tube furnace. Other features of the laser microreactor technique are discussed and it is shown that the equipment simulates the p.f. combustion process properly for these applications.
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Reactive (fusible) inertinite in pulverized fuel combustion: 2. Determination of reactive (fusible) inertinite
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Dheera Phong-anantAbstract:Abstract A laser microreactor was used to study six coals to determine the proportion of their inertinite Macerals that fused or melted under p.f. combustion conditions, i.e. their percentage of reactive (fusible) inertinite. The method pyrolyses individual monoMaceral particles, giving one-to-one correlation between the Maceral and the char formed. Photomicrographs of Macerals and their chars revealed the wide diversity of char types that derive from inertinite. Classifying these into fused and unfused chars showed that the inertinite divided into fusible and infusible Macerals at a particular reflectance value for each coal. Calculations using the whole coal reflectogram gave the percentage of the inertinite that was reactive. This averaged 75% for four Australian coals and 51% for two Laurasian coals, both much larger than previous methods had indicated. Predictions from earlier methods indicated that either the heating rate or the reaction temperature, or both, affect the fusible-infusible boundary and hence the proportion of the inertinite that exhibits reactive (fusible) behaviour.
Michio Shibaoka - One of the best experts on this subject based on the ideXlab platform.
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the behaviour of inertinite Macerals under pulverised fuel pf combustion conditions
Organic Geochemistry, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, D Phontanant, Michio ShibaokaAbstract:Abstract The usefulness of the current system of classification of the inertinite group of Macerals for understanding the pulverised fuel (pf) combustion process is discussed and questioned. Results to date on the combustibility of inertinite Macerals are indecisive, especially as inertinite is mosltly regarded as a single entity. Simulated pf combustion experiments with a laser microreactor revealed that the inertinite Macerals yielded a wide diversity of char morphologies. With one-to-one correlations between Maceral and char, it was possible to determine which Maceral was fusible or infusible (commonly called reactive and inert respectively). The microreactor is being developed to measure the burning parameters of individual Maceral particles. For example, the data will show which Macerals are slow burning (and by how much) and whether fusibility has any relevance to the speed of char burning.
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reactive fusible inertinite in pulverized fuel combustion 1 a laser microreactor technique
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Lee F Brunckhorst, Dheera PhonganantAbstract:Abstract The adoption of the concept of reactive (fusible) and inert (infusible) Macerals in pulverized fuel (p.f.) combustion is examined together with the need to determine these constituents under realistic conditions. A laser microreactor method is described in which 100 μm monoMaceral particles are heated at 105 − 106 K s −1 to ~1600 °C in air. Two applications are described. First, the particles are heated for ~40 ms, the pyrolysis converting the Maceral into a char particle with individual morphology; in particular, whether the Maceral fuses or melts (termed reactive) or not (termed inert) is determined by optical microscopy. Second, high-speed cinephotomicroscopy of the combusting particle is possible using longer irradiation periods, revealing in great detail the morphology of swelling and combustion. The validity of the method is substantiated by comparing char morphologies with those from a drop-tube furnace. Other features of the laser microreactor technique are discussed and it is shown that the equipment simulates the p.f. combustion process properly for these applications.
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Reactive (fusible) inertinite in pulverized fuel combustion: 2. Determination of reactive (fusible) inertinite
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Dheera Phong-anantAbstract:Abstract A laser microreactor was used to study six coals to determine the proportion of their inertinite Macerals that fused or melted under p.f. combustion conditions, i.e. their percentage of reactive (fusible) inertinite. The method pyrolyses individual monoMaceral particles, giving one-to-one correlation between the Maceral and the char formed. Photomicrographs of Macerals and their chars revealed the wide diversity of char types that derive from inertinite. Classifying these into fused and unfused chars showed that the inertinite divided into fusible and infusible Macerals at a particular reflectance value for each coal. Calculations using the whole coal reflectogram gave the percentage of the inertinite that was reactive. This averaged 75% for four Australian coals and 51% for two Laurasian coals, both much larger than previous methods had indicated. Predictions from earlier methods indicated that either the heating rate or the reaction temperature, or both, affect the fusible-infusible boundary and hence the proportion of the inertinite that exhibits reactive (fusible) behaviour.
Martin E. Gosnell - One of the best experts on this subject based on the ideXlab platform.
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the behaviour of inertinite Macerals under pulverised fuel pf combustion conditions
Organic Geochemistry, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, D Phontanant, Michio ShibaokaAbstract:Abstract The usefulness of the current system of classification of the inertinite group of Macerals for understanding the pulverised fuel (pf) combustion process is discussed and questioned. Results to date on the combustibility of inertinite Macerals are indecisive, especially as inertinite is mosltly regarded as a single entity. Simulated pf combustion experiments with a laser microreactor revealed that the inertinite Macerals yielded a wide diversity of char morphologies. With one-to-one correlations between Maceral and char, it was possible to determine which Maceral was fusible or infusible (commonly called reactive and inert respectively). The microreactor is being developed to measure the burning parameters of individual Maceral particles. For example, the data will show which Macerals are slow burning (and by how much) and whether fusibility has any relevance to the speed of char burning.
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reactive fusible inertinite in pulverized fuel combustion 1 a laser microreactor technique
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Lee F Brunckhorst, Dheera PhonganantAbstract:Abstract The adoption of the concept of reactive (fusible) and inert (infusible) Macerals in pulverized fuel (p.f.) combustion is examined together with the need to determine these constituents under realistic conditions. A laser microreactor method is described in which 100 μm monoMaceral particles are heated at 105 − 106 K s −1 to ~1600 °C in air. Two applications are described. First, the particles are heated for ~40 ms, the pyrolysis converting the Maceral into a char particle with individual morphology; in particular, whether the Maceral fuses or melts (termed reactive) or not (termed inert) is determined by optical microscopy. Second, high-speed cinephotomicroscopy of the combusting particle is possible using longer irradiation periods, revealing in great detail the morphology of swelling and combustion. The validity of the method is substantiated by comparing char morphologies with those from a drop-tube furnace. Other features of the laser microreactor technique are discussed and it is shown that the equipment simulates the p.f. combustion process properly for these applications.
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Reactive (fusible) inertinite in pulverized fuel combustion: 2. Determination of reactive (fusible) inertinite
Fuel, 1993Co-Authors: C G Thomas, Martin E. Gosnell, E Gawronski, Michio Shibaoka, Dheera Phong-anantAbstract:Abstract A laser microreactor was used to study six coals to determine the proportion of their inertinite Macerals that fused or melted under p.f. combustion conditions, i.e. their percentage of reactive (fusible) inertinite. The method pyrolyses individual monoMaceral particles, giving one-to-one correlation between the Maceral and the char formed. Photomicrographs of Macerals and their chars revealed the wide diversity of char types that derive from inertinite. Classifying these into fused and unfused chars showed that the inertinite divided into fusible and infusible Macerals at a particular reflectance value for each coal. Calculations using the whole coal reflectogram gave the percentage of the inertinite that was reactive. This averaged 75% for four Australian coals and 51% for two Laurasian coals, both much larger than previous methods had indicated. Predictions from earlier methods indicated that either the heating rate or the reaction temperature, or both, affect the fusible-infusible boundary and hence the proportion of the inertinite that exhibits reactive (fusible) behaviour.
