This document summarizes a study on using a triphasic segmented flow millireactor for rapid nanoparticle-catalyzed gas-liquid reactions with facile catalyst recovery. Key points:
- The millireactor creates a pseudo-biphasic gas-liquid segmented flow using an aqueous catalyst phase and an organic substrate/product phase, allowing order-of-magnitude faster reactions than a batch reactor.
- For the hydrogenation of 1-hexene catalyzed by Rh nanoparticles, the millireactor achieves 80% conversion in 1 minute versus 30 minutes for a batch reactor.
- Faster mass transfer in the millireactor is achieved by reducing the diffusion distance for reactants through thinner organic segments at
The document summarizes laboratory experiments on Surfactant Alternate Gas (SAG) injection as an enhanced oil recovery technique for the Limbodara oil field in India. Core flood experiments showed that single cycle SAG injection achieved an incremental oil recovery of 27.79% over waterflooding, while two cycle SAG injection achieved 29.01% incremental recovery. The SAG process improved sweep efficiency through factors like mobility control and contact of unswept zones. The study demonstrated the feasibility of additional oil recovery through immiscible SAG injection in parts of the field experiencing early water breakthrough.
A trickle-bed reactor uses the downward movement of a liquid and upward or downward movement of gas over a packed bed of catalyst particles to facilitate catalytic reactions. There are three basic types - conventional trickle beds with randomly packed catalyst, semi-structured beds with structured or monolithic catalyst, and micro-trickle beds with catalyst in microchannels. In operation, the liquid trickles down while the gas flows concurrently up or down, with various flow regimes depending on flow rates and properties. Examples of uses include liquid-phase hydrogenation in refineries, oxidation of compounds in wastewater, and wastewater treatment using biofilm on the packed bed surface.
Bubble column reactors allow gas and liquid to contact by dispersing gas into the liquid in the form of bubbles. The document discusses bubble column fundamentals, types of bubble columns, gas sparging methods, bubble flow dynamics, CFD modeling techniques, and comparisons of experiments and simulations. It provides details on gas holdup, interphase forces, flow regimes, and strategies for verifying CFD models of bubble columns with experimental data.
Slurry reactor Presentation Chemical Engineering CL311gptshubham
This document describes a slurry reactor. A slurry reactor is a multiphase reactor where a gas is bubbled through a liquid containing suspended solid catalyst particles. The document defines slurry reactors, provides examples of their applications, and discusses modeling and design considerations. Equations are presented for determining the rate of gas absorption, transport to the catalyst surface, diffusion and reaction within catalyst pellets, and identifying the limiting step. Advantages and disadvantages of slurry reactors are also summarized.
This experiment studied the effect of step change input on the concentration in a continuous stirred tank reactor (CSTR) system consisting of three reactors in series. Sodium chloride solution was introduced to the first reactor and deionized water was pumped through the system. Conductivity readings were taken from each reactor every 3 minutes. The results showed that the conductivity increased over time as the salt solution spread through the reactors. After 84 minutes, the conductivity values equalized across the three reactors, indicating the input had achieved steady state distribution. Issues with data recording affected the smoothness of the plotted results graph.
The document summarizes the design of a new water treatment plant to treat up to 12 million gallons of water per day from the Big River in Croc, Louisiana. The proposed design uses multiple treatment processes in sequence, including ozone disinfection, coagulation, flocculation, sedimentation, biologically active carbon filtration, and clearwell storage before distribution. Process designs were provided for each treatment step, along with expected performance results meeting regulatory requirements for contaminant removal and disinfection credits. Chemical dosing needs and equipment were also specified.
Bourbiaux, b. et al. 2016. experimental and numerical assessment of chemical ...DavidMoedano
This document summarizes an experimental study on chemical enhanced oil recovery (EOR) in oil-wet fractured carbonate reservoirs. Small-scale experiments were conducted using limestone plugs and mini-plugs to quantify the kinetics of spontaneous imbibition of chemical solutions using CT scanning and NMR measurements. A second set of experiments imposed viscous drive conditions on a larger plug to account for the contribution of fractures to oil recovery. The recovery kinetics and flow behavior are interpreted to understand how a wettability modifier alters rock wettability and reduces interfacial tension to enhance oil recovery from the matrix blocks. The results indicate that modeling is needed to specify optimal chemical additives and processes to maximize recovery rates.
The document describes a study investigating the kinetics of the hydration of n-butene to secondary butanol (SBA) catalyzed by a sulfonic acid ion exchange resin in a multiphase reactor system. A laboratory plant was designed with a reactor that allows visualization of the separate liquid phases and precise control of reaction conditions. Kinetic experiments were performed under conditions where the surface reaction was found to be the rate-limiting step. The experimental results matched well with a four-parameter kinetic model based on a Langmuir-Hinshelwood rate expression.
The document summarizes laboratory experiments on Surfactant Alternate Gas (SAG) injection as an enhanced oil recovery technique for the Limbodara oil field in India. Core flood experiments showed that single cycle SAG injection achieved an incremental oil recovery of 27.79% over waterflooding, while two cycle SAG injection achieved 29.01% incremental recovery. The SAG process improved sweep efficiency through factors like mobility control and contact of unswept zones. The study demonstrated the feasibility of additional oil recovery through immiscible SAG injection in parts of the field experiencing early water breakthrough.
A trickle-bed reactor uses the downward movement of a liquid and upward or downward movement of gas over a packed bed of catalyst particles to facilitate catalytic reactions. There are three basic types - conventional trickle beds with randomly packed catalyst, semi-structured beds with structured or monolithic catalyst, and micro-trickle beds with catalyst in microchannels. In operation, the liquid trickles down while the gas flows concurrently up or down, with various flow regimes depending on flow rates and properties. Examples of uses include liquid-phase hydrogenation in refineries, oxidation of compounds in wastewater, and wastewater treatment using biofilm on the packed bed surface.
Bubble column reactors allow gas and liquid to contact by dispersing gas into the liquid in the form of bubbles. The document discusses bubble column fundamentals, types of bubble columns, gas sparging methods, bubble flow dynamics, CFD modeling techniques, and comparisons of experiments and simulations. It provides details on gas holdup, interphase forces, flow regimes, and strategies for verifying CFD models of bubble columns with experimental data.
Slurry reactor Presentation Chemical Engineering CL311gptshubham
This document describes a slurry reactor. A slurry reactor is a multiphase reactor where a gas is bubbled through a liquid containing suspended solid catalyst particles. The document defines slurry reactors, provides examples of their applications, and discusses modeling and design considerations. Equations are presented for determining the rate of gas absorption, transport to the catalyst surface, diffusion and reaction within catalyst pellets, and identifying the limiting step. Advantages and disadvantages of slurry reactors are also summarized.
This experiment studied the effect of step change input on the concentration in a continuous stirred tank reactor (CSTR) system consisting of three reactors in series. Sodium chloride solution was introduced to the first reactor and deionized water was pumped through the system. Conductivity readings were taken from each reactor every 3 minutes. The results showed that the conductivity increased over time as the salt solution spread through the reactors. After 84 minutes, the conductivity values equalized across the three reactors, indicating the input had achieved steady state distribution. Issues with data recording affected the smoothness of the plotted results graph.
The document summarizes the design of a new water treatment plant to treat up to 12 million gallons of water per day from the Big River in Croc, Louisiana. The proposed design uses multiple treatment processes in sequence, including ozone disinfection, coagulation, flocculation, sedimentation, biologically active carbon filtration, and clearwell storage before distribution. Process designs were provided for each treatment step, along with expected performance results meeting regulatory requirements for contaminant removal and disinfection credits. Chemical dosing needs and equipment were also specified.
Bourbiaux, b. et al. 2016. experimental and numerical assessment of chemical ...DavidMoedano
This document summarizes an experimental study on chemical enhanced oil recovery (EOR) in oil-wet fractured carbonate reservoirs. Small-scale experiments were conducted using limestone plugs and mini-plugs to quantify the kinetics of spontaneous imbibition of chemical solutions using CT scanning and NMR measurements. A second set of experiments imposed viscous drive conditions on a larger plug to account for the contribution of fractures to oil recovery. The recovery kinetics and flow behavior are interpreted to understand how a wettability modifier alters rock wettability and reduces interfacial tension to enhance oil recovery from the matrix blocks. The results indicate that modeling is needed to specify optimal chemical additives and processes to maximize recovery rates.
The document describes a study investigating the kinetics of the hydration of n-butene to secondary butanol (SBA) catalyzed by a sulfonic acid ion exchange resin in a multiphase reactor system. A laboratory plant was designed with a reactor that allows visualization of the separate liquid phases and precise control of reaction conditions. Kinetic experiments were performed under conditions where the surface reaction was found to be the rate-limiting step. The experimental results matched well with a four-parameter kinetic model based on a Langmuir-Hinshelwood rate expression.
This document discusses bubble column reactors. It covers bubble column fundamentals, types of bubble columns, gas spargers, bubble flow dynamics, CFD modeling, and comparisons of experiments vs simulations. Bubble columns mix gas and liquid by injecting gas into the liquid in the form of bubbles. Gas is sparged at the bottom to create bubbles and distribute them uniformly. CFD modeling can simulate bubble column fluid dynamics using Eulerian or Lagrangian approaches. Experiments are used to validate simulations and better understand bubble column behavior.
This document discusses different types of chemical reactors, including plug flow reactors and continuous stirred tank reactors (CSTR). It provides information on their design considerations, advantages, disadvantages, and equations. Plug flow reactors allow minimal back mixing and each particle has the same residence time. CSTRs ensure proper mixing through the use of an impeller and assume perfect mixing. The document also provides examples of design equations for ideal reactors and discusses factors to consider for reactor selection like yield, cost, and safety.
This document discusses various types of reactors used for gas-solid catalytic reactions, with a focus on packed bed reactors. It summarizes:
1) The main types of reactors are adiabatic packed beds, wall cooled tubular reactors, fluidized beds, and risers.
2) Key design considerations for adiabatic packed beds include controlling the adiabatic temperature rise, pressure drop, and explosion potential.
3) Wall cooled tubular reactors require plug flow and careful control of wall cooling to prevent hot spots from forming.
4) Scale up of these reactors aims to maintain the same conditions as the laboratory scale, such as space time and flow distribution. Novel designs and operation methods aim
This document provides information about an oil reservoir in West Africa and enhanced oil recovery techniques being considered to increase production. It summarizes:
1) The reservoir began production in 1977 with 6 platforms and 49 wells currently. Polymer flooding is being evaluated as an enhanced oil recovery method.
2) Simulations of polymer flooding were run on two extended sectors, with better results in Sector B. The best strategies were HPAM injection and xanthan polymer injection.
3) An economic analysis found polymer flooding in Sector B could be profitable over the evaluation period, while polymer flooding was not advantageous compared to water flooding in Sector A. Future work may include laboratory tests and full field implementation in Sector B
The document summarizes a collaboration between Sandia National Laboratories (SNL) and Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) to develop a common set of Features, Events, and Processes (FEPs) relevant to the disposal of heat-generating waste in salt repositories. It outlines the objectives of developing a generic FEP matrix and catalog, as well as an online FEP database and knowledge archive. Recent work includes completing a full set of approximately 450 generic FEPs organized by thermal-hydrological-chemical-mechanical-biological processes and host rock features, and defining over 2,000 associated processes for screening and modeling.
EPA reviewed DOE's 2014 application to recertify the Waste Isolation Pilot Plant (WIPP) for radioactive waste disposal. EPA conducted a completeness review and requested four sensitivity studies from DOE to address issues. The studies found that mean total releases increased under some modified assumptions but did not exceed limits. As a result, EPA recertified WIPP in July 2017 while recommending areas for DOE to improve in future applications.
This document describes a study on treating synthetic wastewater using an activated sludge process in a laboratory-scale jet loop reactor. The researchers tested COD (chemical oxygen demand) removal efficiency at different mixed liquor volatile suspended solids (MLVSS) concentrations and a hydraulic retention time of 60 minutes. They found that over 95% COD removal could be achieved with an MLVSS of 3000 mg/L. Tables of results show COD levels decreasing over 5 hours as MLVSS increased from 1000 mg/L to 3000 mg/L. Graphs illustrate the relationships between time and COD or MLVSS. The reactor demonstrated high wastewater treatment efficiency under the conditions tested.
This document discusses slurry reactors. It begins with introducing what a slurry is - a mixture of a pulverized solid with a liquid, often used to handle solids in bulk. It then discusses the theory behind slurry reactors, which can carry out two-phase or three-phase catalytic reactions with solids, liquids, and gases. It describes the components of a slurry reactor and different types like bubble column, Fischer-Tropsch, and batch reactors. Design equations for slurry reactors are presented. Advantages include good temperature control and potential for high reaction rates. Disadvantages include issues like abrasion and filtration. Applications include hydrogenation, polymerization, and waste water treatment. References on slurry
The document describes a plan to inter-compare the PFLOTRAN and RepoTREND reactive transport codes. The plan involves:
1) A batch waste form simulation to compare radionuclide release from a instantly breaching nuclear waste form.
2) A full simulation of a generic salt repository with a mined drift, shaft, and aquifer to compare breakthrough curves and dose calculations.
3) PFLOTRAN has provided first results for the batch simulation showing radionuclide source terms and cumulative release over time. The next step is setting up the full repository simulation in PFLOTRAN.
Penga Ž, Tolj I, Barbir F, Computational fluid dynamics study of PEM fuel cel...Željko Penga
This computational fluid dynamics study examines PEM fuel cell performance under isothermal and non-uniform temperature boundary conditions. The study finds that implementing a non-uniform temperature profile along the cathode channel, as calculated from a Mollier h-u chart, results in close to 100% relative humidity without external humidification and improves fuel cell performance. The model polarization curve and relative humidity distribution agree well with experimental results. Different current collector materials and membrane thickness influence temperature and relative humidity distributions through their effects on thermal conductivity and water transport.
This document summarizes the RepoTREND code package and its intercomparison with PFLOTRAN for modeling radionuclide transport in a salt repository system. RepoTREND includes modules for modeling near-field processes like canister corrosion and radionuclide mobilization, as well as transport through the near field and far field. It describes initial CLAYPOS and LOPOS models run for the test case, finding generally good agreement with PFLOTRAN results except for Am-241. The LOPOS models with an additional shaft showed increased outflow for some radionuclides but the shaft acts mainly as a sorbing buffer. Suggestions are made to modify the test case for higher model output comparison
This document provides an overview of slurry reactors, including their types, construction, operation, start up and shut down procedures, troubleshooting, advantages and disadvantages, applications, and an incident involving a slurry reactor explosion. Slurry reactors can react solids, liquids, and gases simultaneously using a solid suspended in a liquid with gas bubbled through. Common types include bubble column reactors and Fischer-Tropsch reactors. The document describes the typical components of a slurry reactor and procedures for operation and maintenance. Potential problems that can occur and their solutions are also outlined. Applications include methanol production and waste water treatment.
This document reviews the development and use of the anaerobic baffled reactor (ABR) for wastewater treatment. Some key points:
- The ABR was developed in the 1980s as an alternative to systems like the upflow anaerobic sludge blanket (UASB) reactor. It provides better resilience to shocks and longer biomass retention times.
- Various modifications to the original ABR design have been made to improve performance, such as narrowing downflow chambers, adding settling zones, and using different packing materials. These modifications aim to enhance solids retention and the reactor's ability to treat more difficult wastewaters.
- A key advantage of the ABR is its
This document provides an overview of the solvent and surfactant models in reservoir simulation. It discusses the objectives and applications of the solvent model, which models miscible displacement processes. It describes the Todd & Longstaff model for representing miscibility and outlines how to treat relative permeability and PVT data. It then discusses the surfactant model, how it models surfactant distribution and its effects on water viscosity, capillary pressure, relative permeability and adsorption.
The document provides an overview of reservoir engineering concepts related to waterflooding projects for oil recovery. It discusses primary, secondary, and tertiary recovery categories. For waterflooding projects specifically, it outlines key factors to consider like reservoir geometry, fluid properties, depth, lithology, fluid saturations, uniformity, and natural driving mechanisms. It provides details on evaluating these factors and their implications for project suitability and design.
Q913 rfp w3 lec 12, Separators and Phase envelope calculationsAFATous
This document outlines course material on reservoir fluid properties, separators, and phase envelope calculations. It covers topics such as PT flash processes, mixture saturation points, phase envelope determination using Michelsen's technique, and separator calculations to optimize pressure and determine stock tank oil properties. Examples of phase envelopes are shown for oil and gas condensate mixtures, illustrating properties like critical points. The document provides information to understand fluid behavior relevant to production operations.
Hydrate Formation During Transport of Natural Gas Containing Water And Impuri...IJERDJOURNAL
ABSTRACT: The upper limit of water content permitted in a natural gas stream during its pipeline transport without a risk of hydrate formation is a complex issue. We propose a novel thermodynamic scheme for investigation of different routes to hydrate formation, with ideal gas used as reference state for all components in all phases including hydrate phase. This makes comparison between different hydrate formation routes transparent and consistent in free energy changes and associated enthalpy change. From a thermodynamic point of view natural gas hydrate can form directly from water dissolved in natural gas but quite unlikely due to limitations in mass and. The typical industrial way to evaluate risk of hydrate formation involves calculation of water condensation from gas and subsequent evaluation of hydrate from condensed water and hydrate formers in the natural gas. Transport pipes are rusty even before they are mounted together to transport pipelines. This opens up for even other routes to hydrate formation which starts with water adsorbing to rust and then leads to hydrate formation with surrounding gas. Rust consist on several iron oxide forms but Hematite is one of the most stable form and is used as a model in this study, in which we focus on maximum limits of water content in various natural gas mixtures that can be tolerated in order to avoid water dropping out as liquid or adsorbed and subsequently forming hydrate. Calculations for representative gas mixtures forming structure I and II hydrates are discussed for ranges of conditions typical for North Sea. The typical trend is that the estimated tolerance for water content is in the order of 20 times higher if these numbers are based on water dew-point rather than water dropping out as adsorbed on Hematite. For pure methane the maximum limits of water to be tolerated decrease with increasing pressures from 50 to 250 bars at temperatures above zero Celsius and up to six Celsius. Pure ethane and pure propane show the opposite trend due to the high density non-polar phase at the high pressures. Typical natural gas mixtures is, however, dominated by the methane so for systems of 80 per cent methane or more the trend is similar to that of pure methane with some expected shifts in absolute values of water drop-out mole-fractions.
Variational Solution of Axisymmetric Fluid Flow in Tubes with Surface So...Santosh Verma
The problem of axisymmetric heat conduction with internal surface solidification in the regions of tube is discussed. An approximate analytical solution is presented to this
nonlinear, two dimensional free boundary problem. The analysis employs a variational technique which extends the Lagrangian formalism to treat the internal flow, two-dimensional moving-interface problems. The solution is expressed in the terms of the short-time and steady-state components. Two forms of the variational solution are presented. One has limited validity in the entrance region of the tube, and the other, while less general , is more accurate.
An insight into spray pulsed reactor through mathematical modeling of catalyt...Siluvai Antony Praveen
This document presents a mathematical model developed to study the impact of nozzle-catalyst distance and bulk gas temperature on the conversion and hydrogen evolution rate in a spray pulse reactor for the catalytic dehydrogenation of cyclohexane. The model was able to predict the effects of reactor configuration and operating parameters on conversion and evolution rate with over 90% accuracy. Reactor optimization analysis identified an optimal design of 5 cm nozzle-catalyst distance and 50°C bulk gas temperature, which was predicted to increase conversion from approximately 32% to 74%. The model provides a means to design endothermic heterogeneous catalytic reactions in spray pulse reactors.
This Powerpoint describes what is Flow chemistry, what are its advantages over batch method, Continuous flow reactor and Applications of Continuous flow chemistry.
This document discusses bubble column reactors. It covers bubble column fundamentals, types of bubble columns, gas spargers, bubble flow dynamics, CFD modeling, and comparisons of experiments vs simulations. Bubble columns mix gas and liquid by injecting gas into the liquid in the form of bubbles. Gas is sparged at the bottom to create bubbles and distribute them uniformly. CFD modeling can simulate bubble column fluid dynamics using Eulerian or Lagrangian approaches. Experiments are used to validate simulations and better understand bubble column behavior.
This document discusses different types of chemical reactors, including plug flow reactors and continuous stirred tank reactors (CSTR). It provides information on their design considerations, advantages, disadvantages, and equations. Plug flow reactors allow minimal back mixing and each particle has the same residence time. CSTRs ensure proper mixing through the use of an impeller and assume perfect mixing. The document also provides examples of design equations for ideal reactors and discusses factors to consider for reactor selection like yield, cost, and safety.
This document discusses various types of reactors used for gas-solid catalytic reactions, with a focus on packed bed reactors. It summarizes:
1) The main types of reactors are adiabatic packed beds, wall cooled tubular reactors, fluidized beds, and risers.
2) Key design considerations for adiabatic packed beds include controlling the adiabatic temperature rise, pressure drop, and explosion potential.
3) Wall cooled tubular reactors require plug flow and careful control of wall cooling to prevent hot spots from forming.
4) Scale up of these reactors aims to maintain the same conditions as the laboratory scale, such as space time and flow distribution. Novel designs and operation methods aim
This document provides information about an oil reservoir in West Africa and enhanced oil recovery techniques being considered to increase production. It summarizes:
1) The reservoir began production in 1977 with 6 platforms and 49 wells currently. Polymer flooding is being evaluated as an enhanced oil recovery method.
2) Simulations of polymer flooding were run on two extended sectors, with better results in Sector B. The best strategies were HPAM injection and xanthan polymer injection.
3) An economic analysis found polymer flooding in Sector B could be profitable over the evaluation period, while polymer flooding was not advantageous compared to water flooding in Sector A. Future work may include laboratory tests and full field implementation in Sector B
The document summarizes a collaboration between Sandia National Laboratories (SNL) and Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) to develop a common set of Features, Events, and Processes (FEPs) relevant to the disposal of heat-generating waste in salt repositories. It outlines the objectives of developing a generic FEP matrix and catalog, as well as an online FEP database and knowledge archive. Recent work includes completing a full set of approximately 450 generic FEPs organized by thermal-hydrological-chemical-mechanical-biological processes and host rock features, and defining over 2,000 associated processes for screening and modeling.
EPA reviewed DOE's 2014 application to recertify the Waste Isolation Pilot Plant (WIPP) for radioactive waste disposal. EPA conducted a completeness review and requested four sensitivity studies from DOE to address issues. The studies found that mean total releases increased under some modified assumptions but did not exceed limits. As a result, EPA recertified WIPP in July 2017 while recommending areas for DOE to improve in future applications.
This document describes a study on treating synthetic wastewater using an activated sludge process in a laboratory-scale jet loop reactor. The researchers tested COD (chemical oxygen demand) removal efficiency at different mixed liquor volatile suspended solids (MLVSS) concentrations and a hydraulic retention time of 60 minutes. They found that over 95% COD removal could be achieved with an MLVSS of 3000 mg/L. Tables of results show COD levels decreasing over 5 hours as MLVSS increased from 1000 mg/L to 3000 mg/L. Graphs illustrate the relationships between time and COD or MLVSS. The reactor demonstrated high wastewater treatment efficiency under the conditions tested.
This document discusses slurry reactors. It begins with introducing what a slurry is - a mixture of a pulverized solid with a liquid, often used to handle solids in bulk. It then discusses the theory behind slurry reactors, which can carry out two-phase or three-phase catalytic reactions with solids, liquids, and gases. It describes the components of a slurry reactor and different types like bubble column, Fischer-Tropsch, and batch reactors. Design equations for slurry reactors are presented. Advantages include good temperature control and potential for high reaction rates. Disadvantages include issues like abrasion and filtration. Applications include hydrogenation, polymerization, and waste water treatment. References on slurry
The document describes a plan to inter-compare the PFLOTRAN and RepoTREND reactive transport codes. The plan involves:
1) A batch waste form simulation to compare radionuclide release from a instantly breaching nuclear waste form.
2) A full simulation of a generic salt repository with a mined drift, shaft, and aquifer to compare breakthrough curves and dose calculations.
3) PFLOTRAN has provided first results for the batch simulation showing radionuclide source terms and cumulative release over time. The next step is setting up the full repository simulation in PFLOTRAN.
Penga Ž, Tolj I, Barbir F, Computational fluid dynamics study of PEM fuel cel...Željko Penga
This computational fluid dynamics study examines PEM fuel cell performance under isothermal and non-uniform temperature boundary conditions. The study finds that implementing a non-uniform temperature profile along the cathode channel, as calculated from a Mollier h-u chart, results in close to 100% relative humidity without external humidification and improves fuel cell performance. The model polarization curve and relative humidity distribution agree well with experimental results. Different current collector materials and membrane thickness influence temperature and relative humidity distributions through their effects on thermal conductivity and water transport.
This document summarizes the RepoTREND code package and its intercomparison with PFLOTRAN for modeling radionuclide transport in a salt repository system. RepoTREND includes modules for modeling near-field processes like canister corrosion and radionuclide mobilization, as well as transport through the near field and far field. It describes initial CLAYPOS and LOPOS models run for the test case, finding generally good agreement with PFLOTRAN results except for Am-241. The LOPOS models with an additional shaft showed increased outflow for some radionuclides but the shaft acts mainly as a sorbing buffer. Suggestions are made to modify the test case for higher model output comparison
This document provides an overview of slurry reactors, including their types, construction, operation, start up and shut down procedures, troubleshooting, advantages and disadvantages, applications, and an incident involving a slurry reactor explosion. Slurry reactors can react solids, liquids, and gases simultaneously using a solid suspended in a liquid with gas bubbled through. Common types include bubble column reactors and Fischer-Tropsch reactors. The document describes the typical components of a slurry reactor and procedures for operation and maintenance. Potential problems that can occur and their solutions are also outlined. Applications include methanol production and waste water treatment.
This document reviews the development and use of the anaerobic baffled reactor (ABR) for wastewater treatment. Some key points:
- The ABR was developed in the 1980s as an alternative to systems like the upflow anaerobic sludge blanket (UASB) reactor. It provides better resilience to shocks and longer biomass retention times.
- Various modifications to the original ABR design have been made to improve performance, such as narrowing downflow chambers, adding settling zones, and using different packing materials. These modifications aim to enhance solids retention and the reactor's ability to treat more difficult wastewaters.
- A key advantage of the ABR is its
This document provides an overview of the solvent and surfactant models in reservoir simulation. It discusses the objectives and applications of the solvent model, which models miscible displacement processes. It describes the Todd & Longstaff model for representing miscibility and outlines how to treat relative permeability and PVT data. It then discusses the surfactant model, how it models surfactant distribution and its effects on water viscosity, capillary pressure, relative permeability and adsorption.
The document provides an overview of reservoir engineering concepts related to waterflooding projects for oil recovery. It discusses primary, secondary, and tertiary recovery categories. For waterflooding projects specifically, it outlines key factors to consider like reservoir geometry, fluid properties, depth, lithology, fluid saturations, uniformity, and natural driving mechanisms. It provides details on evaluating these factors and their implications for project suitability and design.
Q913 rfp w3 lec 12, Separators and Phase envelope calculationsAFATous
This document outlines course material on reservoir fluid properties, separators, and phase envelope calculations. It covers topics such as PT flash processes, mixture saturation points, phase envelope determination using Michelsen's technique, and separator calculations to optimize pressure and determine stock tank oil properties. Examples of phase envelopes are shown for oil and gas condensate mixtures, illustrating properties like critical points. The document provides information to understand fluid behavior relevant to production operations.
Hydrate Formation During Transport of Natural Gas Containing Water And Impuri...IJERDJOURNAL
ABSTRACT: The upper limit of water content permitted in a natural gas stream during its pipeline transport without a risk of hydrate formation is a complex issue. We propose a novel thermodynamic scheme for investigation of different routes to hydrate formation, with ideal gas used as reference state for all components in all phases including hydrate phase. This makes comparison between different hydrate formation routes transparent and consistent in free energy changes and associated enthalpy change. From a thermodynamic point of view natural gas hydrate can form directly from water dissolved in natural gas but quite unlikely due to limitations in mass and. The typical industrial way to evaluate risk of hydrate formation involves calculation of water condensation from gas and subsequent evaluation of hydrate from condensed water and hydrate formers in the natural gas. Transport pipes are rusty even before they are mounted together to transport pipelines. This opens up for even other routes to hydrate formation which starts with water adsorbing to rust and then leads to hydrate formation with surrounding gas. Rust consist on several iron oxide forms but Hematite is one of the most stable form and is used as a model in this study, in which we focus on maximum limits of water content in various natural gas mixtures that can be tolerated in order to avoid water dropping out as liquid or adsorbed and subsequently forming hydrate. Calculations for representative gas mixtures forming structure I and II hydrates are discussed for ranges of conditions typical for North Sea. The typical trend is that the estimated tolerance for water content is in the order of 20 times higher if these numbers are based on water dew-point rather than water dropping out as adsorbed on Hematite. For pure methane the maximum limits of water to be tolerated decrease with increasing pressures from 50 to 250 bars at temperatures above zero Celsius and up to six Celsius. Pure ethane and pure propane show the opposite trend due to the high density non-polar phase at the high pressures. Typical natural gas mixtures is, however, dominated by the methane so for systems of 80 per cent methane or more the trend is similar to that of pure methane with some expected shifts in absolute values of water drop-out mole-fractions.
Variational Solution of Axisymmetric Fluid Flow in Tubes with Surface So...Santosh Verma
The problem of axisymmetric heat conduction with internal surface solidification in the regions of tube is discussed. An approximate analytical solution is presented to this
nonlinear, two dimensional free boundary problem. The analysis employs a variational technique which extends the Lagrangian formalism to treat the internal flow, two-dimensional moving-interface problems. The solution is expressed in the terms of the short-time and steady-state components. Two forms of the variational solution are presented. One has limited validity in the entrance region of the tube, and the other, while less general , is more accurate.
An insight into spray pulsed reactor through mathematical modeling of catalyt...Siluvai Antony Praveen
This document presents a mathematical model developed to study the impact of nozzle-catalyst distance and bulk gas temperature on the conversion and hydrogen evolution rate in a spray pulse reactor for the catalytic dehydrogenation of cyclohexane. The model was able to predict the effects of reactor configuration and operating parameters on conversion and evolution rate with over 90% accuracy. Reactor optimization analysis identified an optimal design of 5 cm nozzle-catalyst distance and 50°C bulk gas temperature, which was predicted to increase conversion from approximately 32% to 74%. The model provides a means to design endothermic heterogeneous catalytic reactions in spray pulse reactors.
This Powerpoint describes what is Flow chemistry, what are its advantages over batch method, Continuous flow reactor and Applications of Continuous flow chemistry.
B van Woezik_Runaway and thermally safe operation of a nitric acid oxidation ...Bob van Woezik
The document discusses runaway reactions that can occur in batch and semi-batch reactors due to a competition between the heat generated by an exothermic reaction and the heat removed from the reaction vessel. It introduces the concept of thermally stable and unstable operating points based on the relationship between heat production and heat removal rates. The Seveso accident in 1976 is presented as an example of an uncontrolled runaway reaction that contaminated a nearby village due to inadequate safety systems and understanding of reaction kinetics and thermal behavior.
Reactor kinetics & ; different types of reactor traysPrem Baboo
1. High efficiency trays (HET) are designed to improve redistribution of unreacted carbon dioxide and reduce back mixing in urea reactors. They increase urea output and reduce steam consumption.
2. Siphon jet pump trays, a new generation of HET, improve mixing rates in reactor compartments through draft tubes that create a two-phase flow with lower density than the liquid outside, enhancing liquid circulation and mixing. This avoids issues with previous tray designs.
3. Installation of HET and siphon jet pump trays in several plants increased urea production capacity and reduced steam consumption compared to conventional reactor tray designs.
This document summarizes a study that evaluated gas-liquid mass transfer and scale up of a biotransformation process from shake flasks to a 5 L stirred tank bioreactor. The study used a yeast isolate capable of converting benzaldehyde to l-phenyl acetyl carbinol (l-PAC) in both growth and biotransformation media. Experiments characterized gas holdup, power input, and mass transfer coefficient (KLa) for the media using different impeller combinations and operating parameters. Results were used to optimize conditions for maximal cell growth and l-PAC production in the bioreactor, which were then compared to shake flask studies. Correlations developed could predict mass transfer and be applied to scale up the process.
This report outlines the procedure followed during the distilla.docxherthalearmont
This report outlines the procedure followed during the distillation column laboratory and the results and conclusions of the laboratory. Operation of a pilot-plant scale trayed distillation column under total reflux conditions was investigated at various boil-up rates, so as to determine the effect of an increase in boil-up rate upon the minimum number of theoretical stages required to effect a given separation of methanol and 2-propanol and the overall efficiency of operation with regard to product separation. The McCabe-Thiele graphical method, the Fenske equation, and a given equation were employed so as to determine the required minimum number of stages, NT, while this graphical method and a given equation were employed so as to determine the actual number of stages, NA. The overall efficiency, no, was determined according to its definition and a given equation for no.
The operating lines pertaining to each investigated boil-up rate reasonably approximated the 45o reference line, which is indicative of total reflux conditions. According to the Fenske equation and the given equation for NT, an increase in the boil-up rate over the investigated range was seen to decrease the minimum number of theoretical stages required to effect a given separation. The average overall efficiency, on the other hand, was seen to increase with a similar increase in the boil-up rate. The McCabe-Thiele graphical approach quite accurately predicted the actual number of stages, which was known to be eight.
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Abstract
In this laboratory, a pilot-plant scale trayed distillation column was investigated at total reflux conditions, namely with regard to the separation of methanol and 2-propanol at different boil-up rates or different rates of vapor exiting the reboiler within the column. Analysis of the separation of these two species was made possible by varying the power input to the reboiler within the column, which ultimately varied the boil-up rate. Such an analysis involved study of the pressure drop across the column and study of samples of the liquid and vapor and the temperature at all stages within the column, including the reboiler stage, at each investigated power input to the reboiler.
The operating lines pertaining to each of the investigated boil-up rates were seen to be approximately coincident with the 45o reference line, which was theoretically expected, given that the rectifying and stripping operating lines are coincident with this line under conditions of total reflux. Through the use of the given equation for NT, the minimum number of stages required to effect the separation achieved at boil-up rates of 0.270 mL/s, 0.350 mL/s, and 0.410 mL/s were determined to be 1.97, 1.71, and 1.55, respectively. The Fenske equation predicted values of NT of 0.604, 0.555, and 0.396, respectively, with regard to these boil-up rates. It was thus concluded that the required number of such stages decreased as the boil-up rate increased. With regar ...
The document proposes an anaerobic-aerobic process for treating domestic sewage using LEVAPOR biofilm technology. The process involves pre-treating sewage under anaerobic conditions in a biofilm reactor to reduce energy use and excess sludge production compared to conventional aerobic treatment. Sewage would then undergo post-treatment under aerobic conditions to further reduce pollutants before discharge. This process could achieve up to 75% lower energy use and 67% less sludge than aerobic treatment alone, while also producing biogas as an energy source.
Arsenic removal by adsorption on activated carbon in a rotating packed bedSoumyadeep Mukherjee
This document summarizes a study that used a rotating packed bed contactor to optimize the removal of arsenic from water using activated carbon adsorption. Five parameters were investigated using Taguchi method to determine the optimal conditions: rotating speed, feed rate, packing density, initial arsenic concentration, and initial pH. The optimal conditions found were a rotating speed of 1600 rpm, feed rate of 50 L/h, packing density of 510 kg/m3, initial concentration of 150 mg/L, and pH of 3 based on the highest signal to noise ratio. The initial concentration was found to be the least affecting factor.
The experiment investigated the characteristics of a reverse osmosis membrane system with one, two, and three membranes. A calibration curve was generated to relate conductivity to salt concentration. For a single membrane, the water permeability was found to be 0.245 g/s-psi-m2 and the salt rejection coefficient was 0.879 on average. The salt mass transfer coefficient was 15.248 m/s. For two membranes, the second membrane had a lower rejection coefficient due to its more concentrated feed. The third membrane in a three membrane system had an even lower rejection coefficient. Overall, the rejection coefficient decreased as more membranes were added due to increasing feed concentration.
This document presents a comparative study of the performance of activated sludge processes in a bubble column reactor and compact jet loop reactor. Experiments were conducted using synthetic wastewater in laboratory scale models of each reactor type. The chemical oxygen demand (COD) removal efficiency was measured at different mixed liquor volatile suspended solids (MLVSS) concentrations and hydraulic retention times. The results showed that a COD removal efficiency of over 85% could be achieved in the bubble column reactor, and over 95% in the compact jet loop reactor, when operated at an MLVSS of 3000 mg/L and aeration time of 1 hour. The compact jet loop reactor demonstrated better COD reduction performance than the bubble column reactor under the conditions tested.
The document discusses using minifluidic channels as an alternative process for extracting Omega-3 PUFA from fish oils. The preliminary experiments were conducted in Tygon tubing, but it was found to soften over time when exposed to fish oil esters. Larger scale experiments will use a plate and frame design constructed of a suitable material. Minifluidic channels offer improved mixing, a higher surface area to volume ratio, and reduced solvent usage compared to conventional extraction processes. Experimental results show the extraction yield from minifluidic channels is satisfactory compared to batch stirred tank reactors. Further development of the minifluidic extraction process design and scale up is ongoing.
Review of research on bio reactors used in wastewater ijsit 2.4.6IJSIT Editor
This document reviews various types of bioreactors used in wastewater treatment for biohydrogen production, including batch, continuous stirred tank, plug flow, biofilm, suspended growth, upflow anaerobic sludge blanket, anaerobic baffled, upflow packed bed, fluidized bed, sequencing batch, and membrane separation reactors. It discusses the operating principles and advantages/limitations of these different reactor configurations. The review concludes that significant progress has been made in developing advanced high-rate anaerobic reactors to improve wastewater treatment efficiency and biogas production for hydrogen fuel applications.
Mass transfer coefficient evaluation for lab scale fermenter using sodium sul...Alexander Decker
This document discusses using the sodium sulfite oxidation method and response surface methodology to evaluate the volumetric mass transfer coefficient in a lab-scale fermenter. 13 experiments were conducted using a central composite design to determine the effects of impeller speed and airflow rate on the mass transfer coefficient. An empirical expression was developed and found to explain over 92% of the variability in the responses. The mass transfer coefficient was found to increase with decreasing impeller speed and increasing airflow rate. The study aimed to optimize the mass transfer coefficient using statistical experimental design.
11.mass transfer coefficient evaluation for lab scale fermenter using sodium ...Alexander Decker
This document discusses using the sodium sulfite oxidation method and response surface methodology to evaluate the volumetric mass transfer coefficient in a lab-scale fermenter. 13 experiments were conducted using a central composite design to determine the effects of impeller speed and airflow rate on the mass transfer coefficient. An empirical expression was developed and found to explain over 92% of the variability in the responses. The results showed that the mass transfer coefficient increases with decreasing impeller speed and increasing airflow rate. The study aimed to optimize conditions for the maximum mass transfer coefficient.
Mass transfer coefficient evaluation for lab scale fermenter using sodium sul...Alexander Decker
This document discusses using the sodium sulfite oxidation method and response surface methodology to evaluate the volumetric mass transfer coefficient in a lab-scale fermenter. 13 experiments were conducted using a central composite design to determine the effects of impeller speed and airflow rate on the mass transfer coefficient. An empirical expression was developed and found to explain over 92% of the variability in the responses. The mass transfer coefficient was found to increase with decreasing impeller speed and increasing airflow rate. The study aimed to optimize the mass transfer coefficient using statistical experimental design.
International Refereed Journal of Engineering and Science (IRJES)irjes
International Refereed Journal of Engineering and Science (IRJES) is a leading international journal for publication of new ideas, the state of the art research results and fundamental advances in all aspects of Engineering and Science. IRJES is a open access, peer reviewed international journal with a primary objective to provide the academic community and industry for the submission of half of original research and applications
Treatment of domestic wastewater in an up flow anaerobic sludgeAlvaro Huete
This document summarizes a study that evaluated the performance of a laboratory-scale sewage treatment system combining an upflow anaerobic sludge blanket (UASB) reactor and a moving bed biofilm reactor (MBBR). The system was operated at different hydraulic retention times (HRTs) from 5-13.3 hours. Overall, COD removal increased from 80-86% at a 5 hour HRT to 92% at a 13.3 hour HRT. Ammonia removal in the MBBR was significantly influenced by the organic loading rate, with 62% removal at 4.6 g COD/m2-day and lower removal at higher loading rates. Fecal coliform counts in the final efflu
Heat is generated during fermentation that must be controlled. Common heat transfer configurations for bioreactors include jacketed vessels, internal coils, and external heat exchangers. External heat exchangers are best for heat transfer but require careful control of sterility and oxygen transfer. Internal coils can interfere with mixing and cleaning. Mass transfer in fermentation involves the diffusion of gases like oxygen across phase boundaries according to Fick's law and two-film theory. Downstream processing after fermentation includes steps like filtration, centrifugation, chromatography, and crystallization to isolate and purify products.
This paper describes a novel flow switch for paper microfluidics based on selective wetting of folded paper actuator strips. The actuator is made entirely of chromatography paper and contains uniquely sized folds. By dropping a small volume of liquid on the crest or trough of a fold, the actuator tip is raised or lowered, allowing it to engage or break fluidic connections between channels. This achieves fast switching within two seconds using only 4 microliters of liquid. Six switch configurations are implemented including single-pole single-throw and single-pole double-throw. An autonomous colorimetric assay is built to detect three analytes in artificial saliva using six parallel actuators activated by two delay strips.
Similar to Yap triphasic millireactors greenchem2014 (20)
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
An improved modulation technique suitable for a three level flying capacitor ...IJECEIAES
This research paper introduces an innovative modulation technique for controlling a 3-level flying capacitor multilevel inverter (FCMLI), aiming to streamline the modulation process in contrast to conventional methods. The proposed
simplified modulation technique paves the way for more straightforward and
efficient control of multilevel inverters, enabling their widespread adoption and
integration into modern power electronic systems. Through the amalgamation of
sinusoidal pulse width modulation (SPWM) with a high-frequency square wave
pulse, this controlling technique attains energy equilibrium across the coupling
capacitor. The modulation scheme incorporates a simplified switching pattern
and a decreased count of voltage references, thereby simplifying the control
algorithm.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
Rainfall intensity duration frequency curve statistical analysis and modeling...bijceesjournal
Using data from 41 years in Patna’ India’ the study’s goal is to analyze the trends of how often it rains on a weekly, seasonal, and annual basis (1981−2020). First, utilizing the intensity-duration-frequency (IDF) curve and the relationship by statistically analyzing rainfall’ the historical rainfall data set for Patna’ India’ during a 41 year period (1981−2020), was evaluated for its quality. Changes in the hydrologic cycle as a result of increased greenhouse gas emissions are expected to induce variations in the intensity, length, and frequency of precipitation events. One strategy to lessen vulnerability is to quantify probable changes and adapt to them. Techniques such as log-normal, normal, and Gumbel are used (EV-I). Distributions were created with durations of 1, 2, 3, 6, and 24 h and return times of 2, 5, 10, 25, and 100 years. There were also mathematical correlations discovered between rainfall and recurrence interval.
Findings: Based on findings, the Gumbel approach produced the highest intensity values, whereas the other approaches produced values that were close to each other. The data indicates that 461.9 mm of rain fell during the monsoon season’s 301st week. However, it was found that the 29th week had the greatest average rainfall, 92.6 mm. With 952.6 mm on average, the monsoon season saw the highest rainfall. Calculations revealed that the yearly rainfall averaged 1171.1 mm. Using Weibull’s method, the study was subsequently expanded to examine rainfall distribution at different recurrence intervals of 2, 5, 10, and 25 years. Rainfall and recurrence interval mathematical correlations were also developed. Further regression analysis revealed that short wave irrigation, wind direction, wind speed, pressure, relative humidity, and temperature all had a substantial influence on rainfall.
Originality and value: The results of the rainfall IDF curves can provide useful information to policymakers in making appropriate decisions in managing and minimizing floods in the study area.