The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
S. K. Sharma - One of the best experts on this subject based on the ideXlab platform.
-
Dynamic Liquid Saturation in a Trickle Bed Reactor Involving Newtonian/non-Newtonian Liquid Phase
Industrial & Engineering Chemistry Research, 2009Co-Authors: Ajay Bansal, R K Wanchoo, S. K. SharmaAbstract:Dynamic Liquid Saturation is an important hydrodynamic parameter that affects the performance of a trickle bed reactor. The parameters that affect the dynamic Liquid Saturation, by using Newtonian Liquid phase, include gas and Liquid flow rates, surface tension and viscosity of the Liquid phase, and bed configurations. Additional rheological parameters affecting dynamic Liquid Saturation, in case of non-Newtonian viscoinelastic Liquids, are observed to be flow consistency index K and flow behavior index n. The effect of viscoelasticity, in case of non-Newtonian viscoelastic fluids, was investigated in terms of Weissenberg number. A set of 20 correlations were selected from the literature to see the applicability of these correlations under varied conditions of bed configurations and Liquid-phase properties as studied in the present investigation. It was observed that the correlations are valid only for a restricted range of parameters and none of the correlations seem to be applicable over the entire rang...
-
dynamic Liquid Saturation in a trickle bed reactor involving newtonian non newtonian Liquid phase
Industrial & Engineering Chemistry Research, 2009Co-Authors: Ajay Bansal, R K Wanchoo, S. K. SharmaAbstract:Dynamic Liquid Saturation is an important hydrodynamic parameter that affects the performance of a trickle bed reactor. The parameters that affect the dynamic Liquid Saturation, by using Newtonian Liquid phase, include gas and Liquid flow rates, surface tension and viscosity of the Liquid phase, and bed configurations. Additional rheological parameters affecting dynamic Liquid Saturation, in case of non-Newtonian viscoinelastic Liquids, are observed to be flow consistency index K and flow behavior index n. The effect of viscoelasticity, in case of non-Newtonian viscoelastic fluids, was investigated in terms of Weissenberg number. A set of 20 correlations were selected from the literature to see the applicability of these correlations under varied conditions of bed configurations and Liquid-phase properties as studied in the present investigation. It was observed that the correlations are valid only for a restricted range of parameters and none of the correlations seem to be applicable over the entire rang...
-
Modeling of trickle bed reactors involving beds of different configurations under low and high interaction regimes
Industrial and Engineering Chemistry Research, 2007Co-Authors: Ajay Bansal, Ravinder K. Wanchoo, S. K. SharmaAbstract:The Lockhart-Martinelli type model originally proposed for two-phase pressure drop estimation in the high interaction regime by Pinna et al. [AIChE J. 2001, 47,19-30] is modified and extended to high as well as low interaction regimes. The proposed modified model contains an adaptive parameter, Rm. The two-phase pressure drop is related to the Lockhart-Martinelli parameter and Liquid Saturation. The experimental data corresponding to the two-phase pressure drop and dynamic Liquid Saturation, for an air-water system on different packings are used to determine the values of Rm for each packing under low and high interaction regimes. It is observed that with decrease in particle sphericity the adaptive parameter, Rm, increases for the same hydrodynamic regime. The variation of adaptive parameter, Rm, for a particular packing with respect to adaptive parameter, Rsph, for spherical packing is found to be a function of particle sphericity.
John S Selker - One of the best experts on this subject based on the ideXlab platform.
-
Relationships between gas-Liquid interfacial surface area, Liquid Saturation, and light transmission in variably saturated porous media
Water Resources Research, 2002Co-Authors: Michael R Niemet, Mark L Rockhold, Noam Weisbrod, John S SelkerAbstract:This is the publisher’s final pdf. The published article is copyrighted by American Geophysical Union and can be found at: http://sites.agu.org/.Liquid Saturation and gas-Liquid interfacial area are important parameters for evaluating the transport and fate of contaminants in unsaturated subsurface environments. Recent findings indicate that interfacial surface area controls the relative degree of transmitted light in laboratory systems containing translucent porous media. Equations are derived to estimate the specific gas-Liquid interfacial area from the area under the primary-drainage branch of the S[subscript eff]-h characteristic curve as parameterized using common water retention functions. The total area under the curve provides the maximum available specific gas-Liquid interfacial area available at residual Saturation, which can be incorporated into the relationship to determine the gas-Liquid interfacial area at intermediate degrees of Saturation via light transmission. Experimental results, and analysis of external data sets, support these findings. Closed-form relationships are presented as enhancements to a recent method for determination of Liquid Saturations above residual using light transmission. A physically based model is developed and tested for the quantification of Liquid contents below residual Saturation
-
relationships between gas Liquid interfacial surface area Liquid Saturation and light transmission in variably saturated porous media
Water Resources Research, 2002Co-Authors: Michael R Niemet, Mark L Rockhold, Noam Weisbrod, John S SelkerAbstract:[1] Liquid Saturation and gas-Liquid interfacial area are important parameters for evaluating the transport and fate of contaminants in unsaturated subsurface environments. Recent findings indicate that interfacial surface area controls the relative degree of transmitted light in laboratory systems containing translucent porous media. Equations are derived to estimate the specific gas-Liquid interfacial area from the area under the primarydrainage branch of the Seff-h characteristic curve as parameterized using common water retention functions. The total area under the curve provides the maximum available specific gas-Liquid interfacial area available at residual Saturation, which can be incorporated into the relationship to determine the gas-Liquid interfacial area at intermediate degrees of Saturation via light transmission. Experimental results, and analysis of external data sets, support these findings. Closed-form relationships are presented as enhancements to a recent method for determination of Liquid Saturations above residual using light transmission. A physically based model is developed and tested for the quantification of Liquid contents below residual Saturation. INDEX TERMS: 1829 Hydrology: Groundwater hydrology; 1866 Hydrology: Soil moisture; 1875 Hydrology: Unsaturated zone; 1894 Hydrology: Instruments and techniques; KEYWORDS: light transmission, gas-Liquid interfacial surface area, Liquid Saturation, residual Saturation, unsaturated porous media, characteristic curve
-
a new method for quantification of Liquid Saturation in 2d translucent porous media systems using light transmission
Advances in Water Resources, 2001Co-Authors: Michael R Niemet, John S SelkerAbstract:Abstract Five physically based models for predicting Liquid Saturation from light transmission in 2D laboratory systems containing translucent porous media were developed and tested (Models A–E). The models were based upon various simplifying assumptions concerning pore geometry, wettability, and drainage. Models A–D assumed uniform-sized pores, and Liquid Saturation was an explicit function of light transmission. Model E considered a distribution of pore sizes whose drainage characteristics were inferred from the Laplace equation. Mass balances were calculated using data from drainage and infiltration experiments, in four textures of silica sand with water as the fluid. Model E performed the best overall, with systematic errors of less than 2.3% Saturation. Model E represents a robust easily applied new method for the determination of Liquid Saturation by light transmission. The other four models are presented, and compared, for reasons of historical interest and to investigate the impact of the various simplifying assumptions.
Ajay Bansal - One of the best experts on this subject based on the ideXlab platform.
-
Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids
Bulletin of Chemical Reaction Engineering & Catalysis, 2011Co-Authors: Renu Gupta, Ajay BansalAbstract:Hydrodynamic studies of trickle bed reactors (TBRs) are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic Liquid Saturation are greatly affected by the physical properties of the Liquids. In the present study experiments have been carried out in a concurrent downflow air - Liquid trickle bed reactor to investigate the dynamic Liquid Saturation and pressure drop for the water (non-foaming) and 3% polyethylene glycol and 4% polyethylene glycol foaming Liquids in the gas continuous regime (GCF) and foaming pulsing regime (FP). In the GCF regime the dynamic Liquid Saturation was found to increase with increase in Liquid flow rate for non-foaming and foaming Liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP) regime. The decrease in dynamic Liquid Saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic Liquid Saturation was observed. The pressure drop for foaming Liquids is observed to be manifolds higher compared to non-foaming Liquid in the GCF regime. ©2010 BCREC UNDIP. All rights reserved(Received: 16th January 2010, Revised: 10th February 2010, Accepted: 21st Feberuary 2010)[How to Cite: R. Gupta, A. Bansal. (2010). Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids. Bulletin of Chemical Reaction Engineering & Catalysis, 5 (1): 31-37. doi:10.9767/bcrec.5.1.775.31-37][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.5.1.775.31-37 ][Cited by: Scopus 1 | ]
-
Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids
Bulletin of Chemical Reaction Engineering & Catalysis, 2010Co-Authors: Renu Gupta, Ajay BansalAbstract:Hydrodynamic studies of trickle bed reactors (TBRs) are essential for the design and prediction of their performance. The hydrodynamic characteristics involving pressure drop and dynamic Liquid Saturation are greatly affected by the physical properties of the Liquids. In the present study experiments have been carried out in a concurrent downflow air - Liquid trickle bed reactor to investigate the dynamic Liquid Saturation and pressure drop for the water (non-foaming) and 3% polyethylene glycol and 4% polyethylene glycol foaming Liquids in the gas continuous regime (GCF) and foaming pulsing regime (FP). In the GCF regime the dynamic Liquid Saturation was found to increase with increase in Liquid flow rate for non-foaming and foaming Liquids. While for 3% and 4% polyethylene glycol solutions the severe foaming was observed in the high interaction regime and the regime is referred to as foaming pulsing (FP) regime. The decrease in dynamic Liquid Saturation followed by a sharp rise in the pressure drop was observed during transition from gas GCF to FP regime. However in the FP regime, a dip in the dynamic Liquid Saturation was observed. The pressure drop for foaming Liquids is observed to be manifolds higher compared to non-foaming Liquid in the GCF regime. ©2010 BCREC UNDIP. All rights reserved ( Received: 16th January 2010, Revised: 10th February 2010, Accepted: 21st Feberuary 2010 ) [How to Cite : R. Gupta, A. Bansal. (2010). Hydrodynamic Studies on a Trickle Bed Reactor for Foaming Liquids. Bulletin of Chemical Reaction Engineering & Catalysis , 5 (1): 31-37. doi:10.9767/bcrec.5.1.7127.31-37 ] [How to Link / DOI : http://dx.doi.org/10.9767/bcrec.5.1.7127.31-37 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/7127 ] [ Cited by : Scopus 1 | ]
-
Dynamic Liquid Saturation in a Trickle Bed Reactor Involving Newtonian/non-Newtonian Liquid Phase
Industrial & Engineering Chemistry Research, 2009Co-Authors: Ajay Bansal, R K Wanchoo, S. K. SharmaAbstract:Dynamic Liquid Saturation is an important hydrodynamic parameter that affects the performance of a trickle bed reactor. The parameters that affect the dynamic Liquid Saturation, by using Newtonian Liquid phase, include gas and Liquid flow rates, surface tension and viscosity of the Liquid phase, and bed configurations. Additional rheological parameters affecting dynamic Liquid Saturation, in case of non-Newtonian viscoinelastic Liquids, are observed to be flow consistency index K and flow behavior index n. The effect of viscoelasticity, in case of non-Newtonian viscoelastic fluids, was investigated in terms of Weissenberg number. A set of 20 correlations were selected from the literature to see the applicability of these correlations under varied conditions of bed configurations and Liquid-phase properties as studied in the present investigation. It was observed that the correlations are valid only for a restricted range of parameters and none of the correlations seem to be applicable over the entire rang...
-
dynamic Liquid Saturation in a trickle bed reactor involving newtonian non newtonian Liquid phase
Industrial & Engineering Chemistry Research, 2009Co-Authors: Ajay Bansal, R K Wanchoo, S. K. SharmaAbstract:Dynamic Liquid Saturation is an important hydrodynamic parameter that affects the performance of a trickle bed reactor. The parameters that affect the dynamic Liquid Saturation, by using Newtonian Liquid phase, include gas and Liquid flow rates, surface tension and viscosity of the Liquid phase, and bed configurations. Additional rheological parameters affecting dynamic Liquid Saturation, in case of non-Newtonian viscoinelastic Liquids, are observed to be flow consistency index K and flow behavior index n. The effect of viscoelasticity, in case of non-Newtonian viscoelastic fluids, was investigated in terms of Weissenberg number. A set of 20 correlations were selected from the literature to see the applicability of these correlations under varied conditions of bed configurations and Liquid-phase properties as studied in the present investigation. It was observed that the correlations are valid only for a restricted range of parameters and none of the correlations seem to be applicable over the entire rang...
-
Modeling of trickle bed reactors involving beds of different configurations under low and high interaction regimes
Industrial and Engineering Chemistry Research, 2007Co-Authors: Ajay Bansal, Ravinder K. Wanchoo, S. K. SharmaAbstract:The Lockhart-Martinelli type model originally proposed for two-phase pressure drop estimation in the high interaction regime by Pinna et al. [AIChE J. 2001, 47,19-30] is modified and extended to high as well as low interaction regimes. The proposed modified model contains an adaptive parameter, Rm. The two-phase pressure drop is related to the Lockhart-Martinelli parameter and Liquid Saturation. The experimental data corresponding to the two-phase pressure drop and dynamic Liquid Saturation, for an air-water system on different packings are used to determine the values of Rm for each packing under low and high interaction regimes. It is observed that with decrease in particle sphericity the adaptive parameter, Rm, increases for the same hydrodynamic regime. The variation of adaptive parameter, Rm, for a particular packing with respect to adaptive parameter, Rsph, for spherical packing is found to be a function of particle sphericity.
Michael R Niemet - One of the best experts on this subject based on the ideXlab platform.
-
Relationships between gas-Liquid interfacial surface area, Liquid Saturation, and light transmission in variably saturated porous media
Water Resources Research, 2002Co-Authors: Michael R Niemet, Mark L Rockhold, Noam Weisbrod, John S SelkerAbstract:This is the publisher’s final pdf. The published article is copyrighted by American Geophysical Union and can be found at: http://sites.agu.org/.Liquid Saturation and gas-Liquid interfacial area are important parameters for evaluating the transport and fate of contaminants in unsaturated subsurface environments. Recent findings indicate that interfacial surface area controls the relative degree of transmitted light in laboratory systems containing translucent porous media. Equations are derived to estimate the specific gas-Liquid interfacial area from the area under the primary-drainage branch of the S[subscript eff]-h characteristic curve as parameterized using common water retention functions. The total area under the curve provides the maximum available specific gas-Liquid interfacial area available at residual Saturation, which can be incorporated into the relationship to determine the gas-Liquid interfacial area at intermediate degrees of Saturation via light transmission. Experimental results, and analysis of external data sets, support these findings. Closed-form relationships are presented as enhancements to a recent method for determination of Liquid Saturations above residual using light transmission. A physically based model is developed and tested for the quantification of Liquid contents below residual Saturation
-
relationships between gas Liquid interfacial surface area Liquid Saturation and light transmission in variably saturated porous media
Water Resources Research, 2002Co-Authors: Michael R Niemet, Mark L Rockhold, Noam Weisbrod, John S SelkerAbstract:[1] Liquid Saturation and gas-Liquid interfacial area are important parameters for evaluating the transport and fate of contaminants in unsaturated subsurface environments. Recent findings indicate that interfacial surface area controls the relative degree of transmitted light in laboratory systems containing translucent porous media. Equations are derived to estimate the specific gas-Liquid interfacial area from the area under the primarydrainage branch of the Seff-h characteristic curve as parameterized using common water retention functions. The total area under the curve provides the maximum available specific gas-Liquid interfacial area available at residual Saturation, which can be incorporated into the relationship to determine the gas-Liquid interfacial area at intermediate degrees of Saturation via light transmission. Experimental results, and analysis of external data sets, support these findings. Closed-form relationships are presented as enhancements to a recent method for determination of Liquid Saturations above residual using light transmission. A physically based model is developed and tested for the quantification of Liquid contents below residual Saturation. INDEX TERMS: 1829 Hydrology: Groundwater hydrology; 1866 Hydrology: Soil moisture; 1875 Hydrology: Unsaturated zone; 1894 Hydrology: Instruments and techniques; KEYWORDS: light transmission, gas-Liquid interfacial surface area, Liquid Saturation, residual Saturation, unsaturated porous media, characteristic curve
-
a new method for quantification of Liquid Saturation in 2d translucent porous media systems using light transmission
Advances in Water Resources, 2001Co-Authors: Michael R Niemet, John S SelkerAbstract:Abstract Five physically based models for predicting Liquid Saturation from light transmission in 2D laboratory systems containing translucent porous media were developed and tested (Models A–E). The models were based upon various simplifying assumptions concerning pore geometry, wettability, and drainage. Models A–D assumed uniform-sized pores, and Liquid Saturation was an explicit function of light transmission. Model E considered a distribution of pore sizes whose drainage characteristics were inferred from the Laplace equation. Mass balances were calculated using data from drainage and infiltration experiments, in four textures of silica sand with water as the fluid. Model E performed the best overall, with systematic errors of less than 2.3% Saturation. Model E represents a robust easily applied new method for the determination of Liquid Saturation by light transmission. The other four models are presented, and compared, for reasons of historical interest and to investigate the impact of the various simplifying assumptions.
Faical Larachi - One of the best experts on this subject based on the ideXlab platform.
-
Dynamics of carbon dioxide uptake in chrysotile mining residues – Effect of mineralogy and Liquid Saturation
International Journal of Greenhouse Gas Control, 2020Co-Authors: Gnouyaro P Assima, Faical Larachi, Georges Beaudoin, John MolsonAbstract:Abstract Carbonation of chrysotile mining residues (CMR) was studied to expose the role of residue size and mineralogy, gas composition, Liquid Saturation and watering schemes in Saturation-controlled porous beds. CO 2 uptake dynamics and evolution of carbonating residue were monitored in situ in terms of gaseous CO 2 absorbed and relative humidity, bed Liquid Saturation, electrical conductivity, pore-water pH, and pressure drop. CO 2 uptake was contributed both by facile carbonation of chrysotile fines and “domestic” brucite, and slow-paced carbonation of coarser magnesium silicate particles. Chrysotile carbonation was a function of fiber length while inhibited lizardite carbonation was indirectly observed. A CO 2 -lean carbonation regime was identified where CO 2 uptake increased linearly with the CO 2 fraction. This enabled extrapolating at very low CO 2 gas contents to assess CMR carbonation under natural atmospheric conditions. Reduction of Saturation and backmixing in the Liquid proved effective for the proliferation of Mg-supersaturated zones to enhance carbonation. Maintaining low Liquid Saturation via periodic Liquid additions translated into improved carbonation because of inhibition of silanol-polymerization passivation. Partial pore Saturation proved effective in stimulating carbonation, both in flow-through and in diffusive modes, especially at lower CO 2 fractions thus foreseeing implementation of useful optimization strategies to enhance ambient carbonation of CMR heaps.
-
Offshore Floating Packed‐Bed Reactors: Key Challenges and Potential Solutions
Chemical Engineering & Technology, 2017Co-Authors: Amir Motamed Dashliborun, Faical Larachi, Markus SchubertAbstract:The influence of floating vessel motions on the hydrodynamic behavior of multiphase flows in porous media was studied using a hexapod ship motion emulator with an embarked packed column. The response of gas-Liquid distribution, pressure drop, Liquid Saturation, and flow regime transition to column inclinations and roll motions was compared to those of the corresponding static vertical and inclined configurations. Two-phase flow patterns in terms of local Liquid Saturation distribution were visualized online by means of a capacitance wire-mesh sensor positioned firmly on the floating packed bed. The hydrodynamic performance of packed beds under roll motion deviates strongly from that of the static beds, indicating that the known characteristics of the conventional land-based trickle-bed reactors cannot be transposed on a one-to-one basis for design and scale-up of the floating reactor configurations.
-
Pore-network modeling of trickle bed reactors: Pressure drop analysis
Chemical Engineering Journal, 2015Co-Authors: Rachid Hannaoui, Faical Larachi, Pierre Horgue, Yacine Haroun, Frederic Augier, Michel Quintard, Marc PratAbstract:A pore network model (PNM) has been developed to simulate gas–Liquid trickle flows inside fixed beds of spherical particles. The geometry has been previously built from X-ray micro-tomography experiments, and the flow in the throats between pores is modeled as a pure viscous Poiseuille two-phase flow. The flow distribution between pores and throats is obtained by solving mass and momentum balance equations. As a first application of this simple but powerful meso-scale model, a focus is proposed on the ability of PNM to estimate pressure drop and Liquid Saturation in co-current gas–Liquid flows. PNM results arecompared to the classical 1D pressure drop models of Attou et al. (1999), Holub et al. (1992) and Larachi et al. (1991). Agreement and discrepancies are discussed, and, finally, it has been found that the actual PNM approach produces realistic pressure drops as far as inertial contributions to friction are negligible. Concerning Liquid Saturation, the PNM only estimates its value in the throats between pores. As a consequence, Liquid Saturations are overestimated, but they can be easily corrected by an ad hoc empirical model.
-
Hydrodynamics of an inclined gas–Liquid cocurrent upflow packed bed
Chemical Engineering Science, 2013Co-Authors: Hana Bouteldja, Mohsen Hamidipour, Faical LarachiAbstract:The effects of inclination on the hydrodynamic behavior of a packed bed operating under gas–Liquid cocurrent upflow were experimentally investigated in terms of Liquid Saturation, bed overall pressure drop and gas–Liquid segregation. The non-invasive electrical capacitance tomography (ECT) imaging technique was applied to scrutinize local and axial phase distribution pattern and cross-sectionally averaged Liquid Saturation. The results indicate that bed inclination creates short circuits for the gas phase along the upper wall where it can flow in a segregated manner. Inception of transition from bubble to segregated flow regime was identified through monitoring a defined uniformity factor for ECT images. Phase segregation developed along the bed with minimum impact in the region close to the entrance. The removed bubbles were replaced by Liquid phase resulting in higher Liquid Saturation values as complete segregation state was approached. The effect of operating conditions on axial profile of Liquid Saturation was examined.
-
dynamics of carbon dioxide uptake in chrysotile mining residues effect of mineralogy and Liquid Saturation
International Journal of Greenhouse Gas Control, 2013Co-Authors: Gnouyaro P Assima, Faical Larachi, Georges Beaudoin, John MolsonAbstract:Abstract Carbonation of chrysotile mining residues (CMR) was studied to expose the role of residue size and mineralogy, gas composition, Liquid Saturation and watering schemes in Saturation-controlled porous beds. CO 2 uptake dynamics and evolution of carbonating residue were monitored in situ in terms of gaseous CO 2 absorbed and relative humidity, bed Liquid Saturation, electrical conductivity, pore-water pH, and pressure drop. CO 2 uptake was contributed both by facile carbonation of chrysotile fines and “domestic” brucite, and slow-paced carbonation of coarser magnesium silicate particles. Chrysotile carbonation was a function of fiber length while inhibited lizardite carbonation was indirectly observed. A CO 2 -lean carbonation regime was identified where CO 2 uptake increased linearly with the CO 2 fraction. This enabled extrapolating at very low CO 2 gas contents to assess CMR carbonation under natural atmospheric conditions. Reduction of Saturation and backmixing in the Liquid proved effective for the proliferation of Mg-supersaturated zones to enhance carbonation. Maintaining low Liquid Saturation via periodic Liquid additions translated into improved carbonation because of inhibition of silanol-polymerization passivation. Partial pore Saturation proved effective in stimulating carbonation, both in flow-through and in diffusive modes, especially at lower CO 2 fractions thus foreseeing implementation of useful optimization strategies to enhance ambient carbonation of CMR heaps.