Effects Of Liquid Swirling On Gas-To-Liquid Mass Transfer In Three-Phase Fluidized Beds,
2010
School of Chemical Engineering, Chungnam National University, Daejon 305-764, Korea.
Effects Of Liquid Swirling On Gas-To-Liquid Mass Transfer In Three-Phase Fluidized Beds, Yong Kang, Myung-Jae Seo, Hyung Oh Lim, Sung-Mo Son, Yong Jun Cho, Hi Chul Yang, Sang-Done Kim, Heon Jung, Ho Tae Lee
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The swirling flow mode of liquid phase was adopted to promote the gas-to-liquid mass transfer in three-phase(gas-liquid-solid) fluidized beds. Effects of gas(0.01-0.09m/s) and liquid(0.035-0.172m/s) velocities, particle size(1.7-6.0mm) and swirling ratio of liquid phase(0-0.5) on the volumetric gas-to-liquid mass transfer coefficient in the bed were examined. The mass transfer coefficient increased up to 70% by adjusting the swirling flow of liquid phase, especially when the gas velocity is relatively low range. The value of gas-to-liquid mass transfer coefficient was well correlated in terms of dimensionless groups which were derived from the dimensional analysis on the mass transfer system.
Radial Distribution Of Particle Clusters In A Downer Reactor Unit,
2010
The University of Western Ontario
Radial Distribution Of Particle Clusters In A Downer Reactor Unit, Mohammad Ashraful Islam, Stefan Krol, Hugo Ignacio De Lasa
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
This study investigates the formation of clusters at 11 radial positions in a 2.63 cm ID downer reactor using the CREC-GS-Optiprobes. Cluster properties such as dimensions, drag coefficients and velocity across the downer unit radius are established based on the reported data and a probabilistic based model.
Pressure Balance Of A Multiple-Loop Chemical Reactor,
2010
CSIRO Process Science and Engineering
Pressure Balance Of A Multiple-Loop Chemical Reactor, Trevor D. Hadley, Ken Chiang, Nick R. Burke, Kok-Seng Lim
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
For a chemical looping (CL) process it is important to determine the optimum reactor configuration that would offer good pressure balance to ensure smooth transfer of the solids between the reactor loops as well as satisfying the oxygen carrier and heat requirements. A variation of the CL process for production of enriched hydrogen stream is investigated which adopts multiple reactor loops. A pressure balance model is developed and a methodology is proposed to find a feasible reactor configuration at an industrial scale production of hydrogen.
Steam Gasification Of Low Rank Coal Chars In A Thermobalance Reactor And A Fluidized Bed Reactor,
2010
Kunsan National University
Steam Gasification Of Low Rank Coal Chars In A Thermobalance Reactor And A Fluidized Bed Reactor, Byungho Song, Xueyan Zhu, Woongsig Moon, Won Yang
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The six chars of low rank coals have been gasified with steam in a thermobalance reactor and one lignite in a fluidized bed to obtain the kinetic information needed for a design of coal gasifier. The gas-solid reaction models have been compared for their prediction ability of the gasification reaction behavior. The apparent reaction rate equations have been presented.
Numerical Experiment On Effect Of Surface Roughness For Heat And Flow Around Two Contacting Particles,
2010
Okayama University of Science
Numerical Experiment On Effect Of Surface Roughness For Heat And Flow Around Two Contacting Particles, Azri Bin Alias, Kuwagi K., Bin Mokhtar M.A. Takami T., Horio M.
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The aim of the present work is to establish a model of heat transfer between particles by using the numerical simulation that can be incorporated in the discrete element method (DEM). The contact heat transfer between particles can be regarded as a contact thermal resistance problem. In the thermal resistance model, the local characteristics, e.g. exact contact area and heat flux distribution on particle surface, are important. However, it is difficult to measure such factors in detail. Accordingly, the authors utilized a numerical simulation. The thermal resistance was modeled by placing a small solid block between the contacting areas in …
Study Of The Minimum Spouting Velocity In A Draft Tube Conical Spouted Bed,
2010
University of the Basque Country
Study Of The Minimum Spouting Velocity In A Draft Tube Conical Spouted Bed, Haritz Altzibar, G. Lopez, M. Olazar, J. Bilbao
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A study has been carried out on the hydrodynamics of conical spouted beds with a non-porous draft-tube. A hydrodynamic correlation has been proposed for calculating the minimum spouting velocity as a function of dimensionless moduli that take into account geometric factors, particle characteristics and operating conditions. A statistical analysis of the data obtained following a design of experiments shows that the inlet diameter, particle diameter and the height of the entrainment zone are the parameter of greater influence on the minimum spouting velocity.
Dem-Cfd Modelling Of A Fluidized Bed Spray Granulator,
2010
Hamburg University of Technology
Dem-Cfd Modelling Of A Fluidized Bed Spray Granulator, Lennart Fries, Sergiy Antonyuk, Stefan Heinrich, Stefan Palzer
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Coupled DEM-CFD simulations have been performed to study the hydrodynamics of a Wurster granulator on the scale of individual particles. Based on extensive material tests, the collision behaviour of dry "Gamma"-Al2O3 particles is identified and incorporated into the model. The effect of process parameters like air flow rate and geometry details like the Wurster position is studied. Based on a physical description of the material properties, an effective tool for design and scale-up of a Wurster granulator is obtained.
Computational Study Of Layer Inversion In Two-Component Liquid-Fluidized Beds By Dem-Cfd,
2010
Università della Calabria, Italy
Computational Study Of Layer Inversion In Two-Component Liquid-Fluidized Beds By Dem-Cfd, Alberto Di Renzo, Fernando Cello, Francesco Paolo Di Maio
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
In the present work the layer inversion phenomenon observed in experiments from the literature is reproduced via discrete element simulations, in which a novel drag force model valid for bi- and poly-disperse particle systems is used. The simulations serve both as validation of the drag model and as a tool to analyze the dynamics of the phenomenon. The comparison with published data is carried out in terms of bed height and component distributions as functions of the liquid velocity, showing very good agreement.
Zero-Dimensional Modeling Of Indirect Fluidized Bed Gasification,
2010
Chalmers University of Technology, Sweden
Zero-Dimensional Modeling Of Indirect Fluidized Bed Gasification, Anton Larsson, David Pallarés, Daniel Neves, Martin Seemann, Henrik Thunman
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Zero-dimensional models has been developed to investigate mass balance and fuel (biomass) Chalmers a 2-4MW indirect fluidized bed gasifier. The result from this work is that more than 95%(Mass) of the tars is converted in the gasifier and that the water gas shift reaction is far from equilibrium.
Dem Fluidization Of Smart Particles,
2010
Tokyo University of Agriculture and Technology
Dem Fluidization Of Smart Particles, Amit Suri, Masayuki Horio
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Numerical simulations using DEM for smart particles/bodies having a capability to induce a repulsive force on the particle based on the cognition were simulated. A particle-particle interaction type repulsive force was used to induce self fluidization and it was found that if the repulsive force is sufficiently high, fluidization of particles can be achieved.
Inside Photo,
2010
Korea Advanced Institute of Science and Technology
Inside Photo, Sang Done Kim
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Inside Photo
High Temperature Water Gas Shift Catalysts With Alumina,
2010
Brigham Young University
High Temperature Water Gas Shift Catalysts With Alumina, Morris D. Argyle, Tiberiu Popa, Guoqing Xu, Thomas F. Barton
Faculty Publications
Alumina (Al2O3) was added as a component of conventional iron oxide based high temperature water gas shift (WGS) catalysts. The catalysts contained Fe-Al-Cr-Cu-O and were synthesized by coprecipitation. A series of catalysts were prepared with 5 to 50 wt% Al2O3, 8 wt% Cr2O3, 4 wt% CuO, and the balance Fe2O3. One catalyst was prepared in which the chromia was replaced by alumina. All of the catalysts were compared to a reference WGS catalyst (88 wt% FeOX, 8 wt% Cr2O3, and 4 wt% CuO) with no alumina. The catalysts were characterized using temperature programmed reduction (TPR), surface area analysis using nitrogen …
The Impact Of Thermal Coupling On Catalyst Behavior In Wall-Coated Heat-Exchanger Microreactors,
2010
University of Connecticut - Storrs
The Impact Of Thermal Coupling On Catalyst Behavior In Wall-Coated Heat-Exchanger Microreactors, Gregory S. Honda
Honors Scholar Theses
This thesis presents a numerical study of reaction and diffusion phenomena in wall-coated heat-exchanger microreactors. Specifically, the interactions between an endothermic and exothermic catalyst layer separated by an impermeable wall is studied to understand the inherent behavior of the system. Two modeling approaches are presented, the first under the assumption of a constant thermal gradient and neglecting heat of reaction and the second considering both catalyst layers and reaction heat. Both studies found that thicker, more thermally insulating catalyst layers increase the effectiveness of the exothermic reaction by allowing for accumulation of reaction heat while thinner catalyst layers for the …
Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus,
2010
Technological University Dublin
Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy
Articles
A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor Uf and Ua, current density j and steam to carbon ratio STCR were varied and …
Rapid Diagnosis Of Tuberculosis In A Peripheral Setting,
2010
University of Nebraska-Lincoln
Rapid Diagnosis Of Tuberculosis In A Peripheral Setting, Elsje Pienaar
Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research
Tuberculosis is an ancient and worldwide epidemic affecting millions of people in mainly the developing world, killing almost 2 million people in 2008. Current diagnostic techniques are outdated and have proven insufficient to control the disease. Smear microscopy has poor sensitivity and culture is slow to yield results. Modern diagnostic techniques are making great strides in shortening time to result but are restricted by two qualities: 1) prohibitively high costs prevent implementation in resource poor areas, and 2) equipment and technician requirements limit application to centralized laboratories. There exists a divide between new technologies and the people that need them …
Liquid-Liquid Equilibrium For Iodine-Hydroiodic Acid-Water Mixtures At Elevated Temperatures And Pressures For The Sulfur-Iodine Cycle,
2010
Clemson University
Liquid-Liquid Equilibrium For Iodine-Hydroiodic Acid-Water Mixtures At Elevated Temperatures And Pressures For The Sulfur-Iodine Cycle, Sarah Mena
All Theses
An alternative scenario to the overdependence on fossil fuels is the use of thermochemical cycles to split water into hydrogen and oxygen. The Sulfur-Iodine (SI) cycle, developed at General Atomics in the mid 1970s, is a leading candidate of international interest for the centralized production of hydrogen from nuclear and/or solar power. For a comprehensive assessment of the SI cycle, thermodynamic data for I2-HI-H2O mixtures at elevated temperatures and pressures have been identified as a basic research need.
The focus of this study was liquid-liquid equilibrium (LLE) measurements for the above system. To carry out the measurements, a continuous-flow apparatus …
Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction,
2010
Clemson University
Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo
All Dissertations
Petroleum pitches are carbonaceous materials that serve as precursors for advanced carbon products. Because of their highly graphitic nature, such pitches are of particular interest for producing high thermal conductivity carbon fibers for thermal management applications, such as microelectronics packaging for hybrid and plug-in vehicles.
Even though the properties of the final carbon products are impacted by the molecular composition of the starting pitch precursor, a fundamental understanding of this relationship has yet to be established. To this end, dense-gas extraction (DGE), a fractionation technique that allows for the production of pitches of controlled composition for both analytical and rheological …
Transesterification And Recovery Of Intracellular Lipids Using A Single Step Reactive Extraction,
2010
Utah State University
Transesterification And Recovery Of Intracellular Lipids Using A Single Step Reactive Extraction, Daniel R. Nelson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A single-step, extractive reaction for extraction of lipids such as biodiesel components, omega-3 fatty acids, or other triglycerides from microbial cells was examined. Conventional methods for lipid extraction use toxic solvents, and require multiple steps and long processing times. When the goal is to produce fatty acid methyl esters or FAMEs, the extracted lipids are subjected to a separate transesterification reaction with simple alcohols in the presence of an acid or base catalyst. A simplified, single-step reactive extraction method can be applied that combines the sequential extraction followed by transesterification using acidified alcohols - a process known as in situ …
Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation,
2010
Utah State University
Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation, Shantanu Wahal
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Nutrients present in digested animal waste can be utilized for algae cultivation under suitable conditions. Algal growth, however, depends on the chemical forms and speciation of these nutrients. In this study a chemical equilibrium model was first used to describe nutrient speciation and predict conditions that enhance the solubility of nutrients in anaerobic digester effluent. Dilution with water and separation of large particulates greatly improved nutrient availability and light penetration - conditions favorable for algal cultivation. Algae growth was tested using three strains - Scenedesmus dimorphous (UTEX # 417), Chlorella vulgaris (UTEX# 265), and an algal isolate (designated as LLAI …
Comparative Studies On Oxygen Mass Transfer For The Design And Development Of A Single-Use Fermentor,
2010
Utah State University
Comparative Studies On Oxygen Mass Transfer For The Design And Development Of A Single-Use Fermentor, Kristan L. Sorenson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Accurate experimental oxygen mass transfer coefficient, a measure of how quickly oxygen travels from a gas bubble to the bulk liquid, is important for comparing performance and for evaluating the oxygen transfer capability of a fermentor. Delays in probe response and changing gas volumes upon start-up of gassing affect the accuracy of oxygen transfer measurements. To mitigate these inaccuracies, a standard correction procedure for oxygen mass transfer data was established for highly oxygenated, well-mixed fermentation systems. Probe response time correction was generated by applying a second-order response model to dissolved oxygen probes and shown to be effective within 4%. By …
