The Experts below are selected from a list of 123 Experts worldwide ranked by ideXlab platform
Loic Courtois - One of the best experts on this subject based on the ideXlab platform.
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novel 3d centimetre to nano scale quantification of an organic rich mudstone the carboniferous bowland shale northern england
Marine and Petroleum Geology, 2016Co-Authors: Kevin G Taylor, P D Lee, Katherine J Dobson, Patrick J Dowey, Loic CourtoisAbstract:X-ray computed tomography and serial block face scanning electron microscopy imaging techniques were used to produce 3D images with a resolution spanning three orders of magnitude from ∼7.7 μm to 7 nm for one typical Bowland Shale sample from Northern England, identified as the largest potential shale gas reservoir in the UK. These images were used to quantitatively assess the size, geometry and connectivity of pores and organic matter. The data revealed four types of Porosity: intra-organic pores, organic interface pores, intra- and inter-mineral pores. Pore sizes are bimodal, with peaks at 0.2 μm and 0.04 μm corresponding to pores located at organic–mineral interfaces and within organic matter, respectively. These pore-size distributions were validated by nitrogen adsorption data. The multi-scale imaging of the four pore types shows that there is no connected visible Porosity at these scales with equivalent diameter of 20 nm or larger in this sample. However, organic matter and clay minerals are connected and so the Meso Porosity (<20 nm) within these phases provides possible diffusion transport pathways for gas. This work confirms multi-scale 3D imaging as a powerful quantification method for shale reservoir characterisation allowing the representative volumes of pores, organic and mineral phases to be defined to model shale systems. The absence of connected Porosity at scales greater than 20 nm indicates the likely importance of the organic matter network, and associated smaller-scale pores, in controlling hydrocarbon transport. . The application of these techniques to shale gas plays more widely should lead to a greater understanding of properties in the low permeability systems.
Mohammad Mahdi Labani - One of the best experts on this subject based on the ideXlab platform.
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comparisons of pore size distribution a case from the western australian gas shale formations
Journal of Unconventional Oil and Gas Resources, 2014Co-Authors: Adnan Al Hinai, Reza M Rezaee, Lionel Esteban, Mohammad Mahdi LabaniAbstract:Abstract Pore structure of shale samples from Triassic Kockatea and Permian Carynginia formations in the Northern Perth Basin, Western Australia is characterized. Transport properties of a porous media are regulated by the topology and geometry of inter-connected pore spaces. Comparisons of three laboratory experiments are conducted on the same source of samples to assess such micro-, Meso- and macro-Porosity: Mercury Injection Capillary Pressure (MICP), low field Nuclear Magnetic Resonance (NMR) and nitrogen adsorption (N2). High resolution FIB/SEM image analysis is used to further support the experimental pore structure interpretations at sub-micron scale. A dominating pore throat radius is found to be around 6 nm within a Mesopore range based on MICP, with a common Porosity around 3%. This relatively fast experiment offers the advantage to be reliable on well chips or cuttings up the pore throat sizes >2 nm. However, nitrogen adsorption method is capable to record pore sizes below 2 nm through the determination of the total pore volume from the quantity of vapour adsorbed at relative pressure. But the macro-Porosity and part of the Meso-Porosity is damaged or even destroyed during the sample preparation. BET specific surface area results usually show a narrow range of values from 5 to 10 m2/g. Inconsistency was found in the pore size classification between MICP and N2 measurements mostly due to their individual lower- and upper-end pore size resolution limits. The water filled pores disclosed from NMR T2 relaxation time were on average 30% larger than MICP tests. Evidence of artificial cracks generated from the water interactions with clays after re-saturation experiments could explain such Porosity over-estimation. The computed pore body to pore throat ratio extracted from the Timur–Coates NMR model, calibrated against gas permeability experiments, revealed that such pore geometry directly control the permeability while the Porosity and pore size distribution remain similar between different shale gas formations and/or within the same formation. The combination of pore size distribution obtained from MICP, N2 and NMR seems appropriate to fully cover the range of pore size from shale gas and overcome the individual method limits.
Ntouma Magda - One of the best experts on this subject based on the ideXlab platform.
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The effect of mineralogy and microstructure on sinter solid-state reduction
2020Co-Authors: Ntouma MagdaAbstract:Ironmaking in the blast furnace is a rather complex process, governed by the generation of multi-phases and fluid-flow conditions. It includes the reduction of iron ore pellet or sinter material towards producing metallic iron. The metallurgical behaviour of sinter and its reduction rate are controlled by its initial physical and chemical properties, as well as the blast furnace gaseous conditions. To improve and optimize the metallurgical performance of sinter for ironmaking, it is necessary to understand the fundamental mechanisms of phase equilibria, microstructural transformations and reaction kinetics as relevant to different sinters in the upper shaft down to the reserve zone of the blast furnace. The objective of the present MSc research is to study the sinter solid state reduction reactions that take place in terms of thermodynamics and metallurgical kinetics when varying the initial material composition under certain temperature and gas atmosphere conditions. Six pilot scale sinter materials with strongly variable bulkmineralogical and chemical composition were sized down to fractions of 250-500μm,being a grain range adequately fine to isolate microstructural effects, whileexcluding the impact of Meso-Porosity and mechanical fractures (>1 mm), as practically aspossible. A industrial sinter sample, obtained from the production lineof Tata Steel Ijmuiden was included in order to verify potential differences inreduction. The starting materials were characterized with XRD, XRF, sizedistribution and BET measurements. Thirty six (36) isothermal reduction experiments were performed in the TGA and GERO furnace under two set of conditions; i) T=750oC/XCO=0.55/N2=0.5, ii) T=950oC/XCO=0.65/N2=0.5 simulating point-conditions of the BRASS test, as relevant to the stability field of Wüstite and solid state reduction. The reduction experiments were interrupted at different reduction times. The 36 reduced samples were further analysed with XRD for phase quantification to then be placed in polished sections for microscopical analysis. The materials were examined under Reflected Light Optical (LOM) and Scanning Electron (SEM) microscopes in order to verify microstructural changes, visualize phase transitions and identify existing stable and meta-stable phases. In total 396 microscopical images were produced. The results of the experiments were compared with thermodynamic models, which show which phases and reduction degree are theoretically expected at equilibrium. Hereby,based on research results, the study attempted to give answers to the initialreseach questions in order to confirm or deny the research hypothesis. The mainfindings of the study were mostly qualitative, referring to the mineralogicalchanges observed during reduction and their impact on reduction kinetics.Results verified that starting composition and mineralogy influencesreducibility kinetics, while the way minerals impact reducibility is dependedon the imposed conditions. It was observed that at T= 950oC/XCO=0.65/N2=0.5, the differences between the reduction rates of low and high basicitysamples become smaller, due to enhancement of the relative reduction progressof minerals like precipitated Magnetite. At T=750oC/XCO=0.55/N2=0.5,the transition of Magnetite to Wüstite occurred in different stages ofreduction progress, amongst samples. In addition, the effect of mineralogy and microstructure could not be distinguished ofthat of open particle Porosity. Findings obtained from the XRD analysis andmicroscopy verified that Hematite is the most pronemineral to reduction followed by SFCA, while Magnetite stays stable for longer.Even within the samemicrostructure, Hematite is clearly reduced to a greater distance from theparticle exterior than the Ca-ferrites surrounding it, and its normalizeddecrease in the XRD analyses from its initial concentration is clearly fasterthan that for any of the Ca-ferrites (SFCA, CF2). Moreover, the relative reduction of Hematite and SFCA differsbetween the two sets of conditions; More reducing conditions converge thereduction progress of the two phases, due to SFCA’s greater reduction. The reduction fronts of Hematite and SFCA converge in a single sinter particlewith higher temperature conditions.Two types of unreacted SFCA wereidentified under the microscope, one Fe-rich SFCA and one Ca-Al-rich SFCA. SFCA1 starts reducing into a multiphase intergrowth, comprised by an Fe-rich pathand a Ca-Si-Al -rich path, while the high Ca type SFCA demonstrates one -to-onephase transition.The reduction experiments inthe GERO showed that longer-time experiments always give the same samplesequence based on reduction progress; WCS108 is the most reduced, followed byWCS90, WCS86, the industrial sinter MH1785, WCS62 and WCS94, whilst noparticular differences were observed in reduction behavior of the industrialsinter MH1785/21 compared to pilot-pot sinter samples. In addition, the comparisons between the reductionexperiments and the thermodynamic predictions showed that there is mostly qualitative agreement, but results differ quantitatively. Finally, based on the findings of the research work conducted, the study hypothesis was confirmed; Sinter microstructure and mineralogy influences sinter solid statereduction. Civil Engineering | Geo-Engineerin
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The effect of mineralogy and microstructure on sinter solid-state reduction
2020Co-Authors: Ntouma MagdaAbstract:Ironmaking in the blast furnace is a rather complex process, governed by the generation of multi-phases and fluid-flow conditions. It includes the reduction of iron ore pellet or sinter material towards producing metallic iron. The metallurgical behaviour of sinter and its reduction rate are controlled by its initial physical and chemical properties, as well as the blast furnace gaseous conditions. To improve and optimize the metallurgical performance of sinter for ironmaking, it is necessary to understand the fundamental mechanisms of phase equilibria, microstructural transformations and reaction kinetics as relevant to different sinters in the upper shaft down to the reserve zone of the blast furnace. The objective of the present MSc research is to study the sinter solid state reduction reactions that take place in terms of thermodynamics and metallurgical kinetics when varying the initial material composition under certain temperature and gas atmosphere conditions. Six pilot scale sinter materials with strongly variable bulkmineralogical and chemical composition were sized down to fractions of 250-500μm,being a grain range adequately fine to isolate microstructural effects, whileexcluding the impact of Meso-Porosity and mechanical fractures (>1 mm), as practically aspossible. A industrial sinter sample, obtained from the production lineof Tata Steel Ijmuiden was included in order to verify potential differences inreduction. The starting materials were characterized with XRD, XRF, sizedistribution and BET measurements. Thirty six (36) isothermal reduction experiments were performed in the TGA and GERO furnace under two set of conditions; i) T=750oC/XCO=0.55/N2=0.5, ii) T=950oC/XCO=0.65/N2=0.5 simulating point-conditions of the BRASS test, as relevant to the stability field of Wüstite and solid state reduction. The reduction experiments were interrupted at different reduction times. The 36 reduced samples were further analysed with XRD for phase quantification to then be placed in polished sections for microscopical analysis. The materials were examined under Reflected Light Optical (LOM) and Scanning Electron (SEM) microscopes in order to verify microstructural changes, visualize phase transitions and identify existing stable and meta-stable phases. In total 396 microscopical images were produced. The results of the experiments were compared with thermodynamic models, which show which phases and reduction degree are theoretically expected at equilibrium. Hereby,based on research results, the study attempted to give answers to the initialreseach questions in order to confirm or deny the research hypothesis. The mainfindings of the study were mostly qualitative, referring to the mineralogicalchanges observed during reduction and their impact on reduction kinetics.Results verified that starting composition and mineralogy influencesreducibility kinetics, while the way minerals impact reducibility is dependedon the imposed conditions. It was observed that at T= 950oC/XCO=0.65/N2=0.5, the differences between the reduction rates of low and high basicitysamples become smaller, due to enhancement of the relative reduction progressof minerals like precipitated Magnetite. At T=750oC/XCO=0.55/N2=0.5,the transition of Magnetite to Wüstite occurred in different stages ofreduction progress, amongst samples. In addition, the effect of mineralogy and microstructure could not be distinguished ofthat of open particle Porosity. Findings obtained from the XRD analysis andmicroscopy verified that Hematite is the most pronemineral to reduction followed by SFCA, while Magnetite stays stable for longer.Even within the samemicrostructure, Hematite is clearly reduced to a greater distance from theparticle exterior than the Ca-ferrites surrounding it, and its normalizeddecrease in the XRD analyses from its initial concentration is clearly fasterthan that for any of the Ca-ferrites (SFCA, CF2). Moreover, the relative reduction of Hematite and SFCA differsbetween the two sets of conditions; More reducing conditions converge thereduction progress of the two phases, due to SFCA’s greater reduction. The reduction fronts of Hematite and SFCA converge in a single sinter particlewith higher temperature conditions.Two types of unreacted SFCA wereidentified under the microscope, one Fe-rich SFCA and one Ca-Al-rich SFCA. SFCA1 starts reducing into a multiphase intergrowth, comprised by an Fe-rich pathand a Ca-Si-Al -rich path, while the high Ca type SFCA demonstrates one -to-onephase transition.The reduction experiments inthe GERO showed that longer-time experiments always give the same samplesequence based on reduction progress; WCS108 is the most reduced, followed byWCS90, WCS86, the industrial sinter MH1785, WCS62 and WCS94, whilst noparticular differences were observed in reduction behavior of the industrialsinter MH1785/21 compared to pilot-pot sinter samples. In addition, the comparisons between the reductionexperiments and the thermodynamic predictions showed that there is mostly qualitative agreement, but results differ quantitatively. Finally, based on the findings of the research work conducted, the study hypothesis was confirmed; Sinter microstructure and mineralogy influences sinter solid statereduction. Geo-Engineerin
Mario L Occelli - One of the best experts on this subject based on the ideXlab platform.
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determination of pore size distribution surface area and acidity in fluid cracking catalysts fccs from nonlocal density functional theoretical models of adsorption and from microcalorimetry methods
Journal of Physical Chemistry B, 2003Co-Authors: Mario L Occelli, James P Olivier, And Alice Petre, A AurouxAbstract:A method based on nonlocal density functional theory (NLDFT) has been used to interpret the data for the adsorption of nitrogen at 77 K within the pores of three different commercial fluid cracking catalysts (FCCs) before and after their use in a refinery catalytic cracking unit. The integral equation of adsorption was inverted by a regularization method to yield the micropore and Mesopore size distribution over a wide range of pore widths. The results obtained are compared with the results of more traditional data treatments and indicate that the NLDFT model can provide a realistic pore volume and surface area estimation in commercial FCCs irrespective of their chemical composition and pore width distribution. Both BET and Langmuir methods grossly underestimate the FCCs surface area, and only the NLDFT method yields reliable surface area and pore volume measurements over the entire micro−Meso Porosity range present in the cataysts under study. Adsorption microcalorimetry results using ammonia as a probe ...
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surface area and microPorosity of pillared rectorite catalysts from a hybrid density functional theory method
Microporous and Mesoporous Materials, 2003Co-Authors: James P Olivier, Mario L OccelliAbstract:Abstract A hybrid density functional theory (DFT) method, using models previously developed for expanded montmorillonites, has been used to interpret the data for the adsorption of nitrogen at 77 K within the pores of a similarly expanded rectorite. Using these models and experimental isotherm data, the integral equation of adsorption was inverted by a regularization method to yield the micropore and Mesopore size distribution over a wide range of pore widths. The results obtained are compared with the results of more traditional data treatments and indicate that this hybrid DFT method can provide realistic pore volume and surface area data in layered expanded silicates over the entire micro–Meso Porosity range.
A Auroux - One of the best experts on this subject based on the ideXlab platform.
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determination of pore size distribution surface area and acidity in fluid cracking catalysts fccs from nonlocal density functional theoretical models of adsorption and from microcalorimetry methods
Journal of Physical Chemistry B, 2003Co-Authors: Mario L Occelli, James P Olivier, And Alice Petre, A AurouxAbstract:A method based on nonlocal density functional theory (NLDFT) has been used to interpret the data for the adsorption of nitrogen at 77 K within the pores of three different commercial fluid cracking catalysts (FCCs) before and after their use in a refinery catalytic cracking unit. The integral equation of adsorption was inverted by a regularization method to yield the micropore and Mesopore size distribution over a wide range of pore widths. The results obtained are compared with the results of more traditional data treatments and indicate that the NLDFT model can provide a realistic pore volume and surface area estimation in commercial FCCs irrespective of their chemical composition and pore width distribution. Both BET and Langmuir methods grossly underestimate the FCCs surface area, and only the NLDFT method yields reliable surface area and pore volume measurements over the entire micro−Meso Porosity range present in the cataysts under study. Adsorption microcalorimetry results using ammonia as a probe ...
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the location and effects of coke deposition in fluid cracking catalysts during gas oil cracking at microactivity test conditions
Journal of Catalysis, 2002Co-Authors: M L Occelli, James P Olivier, A AurouxAbstract:Abstract Nitrogen porosimetry, atomic force microscopy (AFM), and microcalorimetry together with microactivity testing have been used to characterize some of the effects of coke deposition on a fluid cracking catalyst (FCC) during gas oil cracking. Contact mode AFM images have revealed that coke forms raised surface features consisting of molecules and chain of molecules; evidence of pore blockage by coke deposits could not be obtained in the images generated. Nitrogen porosimetry results indicate that during gas oil cracking, coke is deposited inside (68%) as well as outside (32%) the catalyst porous structure. About 60% of the total coke in the porous structure is uniformly deposited within its microspace, decreasing the micropore volume and causing a shift of its pore size distribution profile toward smaller pore width values. The rest of the coke (40%) is located in Mesopores without closing any part of the internal Porosity to nitrogen sorption and therefore to catalysis. There is a moderate decrease in acid site strength and acid site density in the coked FCC. Both BET and Langmuir methods grossly underestimate the FCC surface area and only the density functional theory method yields reliable surface area and pore volume measurements over the entire micro–Meso Porosity range.