Numerical And Experimental Steady State Flow And Heat Transfer In A Continuous Spouted Bed,
2010
Federal University of São Carlos, Rod.
Numerical And Experimental Steady State Flow And Heat Transfer In A Continuous Spouted Bed, Cezar A. Rosa, José T. Freire, Hamid Arastoopour
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Experimental measurements on heat transfer and flow properties and CFD simulations based on the two-fluid model (Eulerian-Eulerian approach) were performed in a draft tube continuous spouted bed system. The simulated results on the gas-particle flow patterns and the temperature distribution in the bed agreed well with our experimental data.
Numerical Study Of Bubbling Fluidized Beds: Influence Of Immersed Tubes, Extraction Methods And Averaging Periods,
2010
Brandenburg University of Technology Cottbus
Numerical Study Of Bubbling Fluidized Beds: Influence Of Immersed Tubes, Extraction Methods And Averaging Periods, Matthias Schreiber, Teklay Weldeabzgi Asegehegn, Hans Joachim Krautz
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Numerical simulations using the Two Fluid Model were performed for 2D gas-solid fluidized beds with and without immersed horizontal tubes. The results were compared with experimental data available in the literature. Different techniques of extracting the time-averaged values of pressure drop and bed expansion and the influence of averaging time were investigated. Furthermore, the influence of tubes on the solids motion and distribution were studied.
Basic Study For Coal Moisture Control Integrating Pneumatic Classification Technique,
2010
Chinese Academy of Sciences
Basic Study For Coal Moisture Control Integrating Pneumatic Classification Technique, Zhou-En Liu, Yin Wang, Yajun Tian, Yimin Xie, Wenfeng Ji, Guangwen Xu
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A technique of coal moisture control integrating pneumatic classification with flue gas as heating medium was put forward. With this technique, refined coal moisture control can be realized accompanying classification in one process, and considerable high-quality energy can be saved in coking and milling procedure. In this paper, coal classification and moisture control behaviors was investigated at different conditions. Based on experimental results, the basic parameters for the technique were worked out accordingly.
Numerical Study Of Bubble Hydrodynamics For Gas-Solid Fluidized Beds With And Without Horizontal Tubes,
2010
Brandenburg University of Technology Cottbus
Numerical Study Of Bubble Hydrodynamics For Gas-Solid Fluidized Beds With And Without Horizontal Tubes, Teklay W. Asegehegn, Hans Joachim Krautz
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The paper deals with numerical simulations using the Eulerian-Eulerian Two Fluid Model (TFM) of 2D gas-solid bubbling fluidized beds with and without immersed horizontal tubes. The bubble diameters and rise velocities obtained from the simulations presented good agreement when compared with experiments and correlations available in the literature. The presence of horizontal tubes inside the bed was found to be the main cause of bubble breakup, which eventually reduce the bubble diameter and rise velocity.
Biomass Gasification In Rotating Fluidized Bed,
2010
Ecole Polytecnique Montreal
Biomass Gasification In Rotating Fluidized Bed, Mania Abdollahi, Christophe Guy, Jamal Chaouki
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A steady-state mathematical model is developed for a rotating fluidized bed gasifier. Integrating reactor hydrodynamics with devolatilization kinetics, char gasification and combustion of both char and gas species; the model is used to present the gas-solid phenomena in novel reactor and investigates the reactor application in gasification processes. Model outputs are compared with experimental and simulation results of existing fluidized bed gasifier. It is observed that for the same equivalence ratio, the gasification process in RFB-SG is improved as a result of improved heat and mass transfer and gas-solid contact.
Direct Numerical Simulation Of Fluidized Bed With Immersed Boundary Method,
2010
Okayama University of Science
Direct Numerical Simulation Of Fluidized Bed With Immersed Boundary Method, Kenya Kuwagi, H. Utsunomiya, Y. Shimoyama, H. Hirano, T. Takami
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The applicability of the immersed boundary (IB) method, which is one of direct numerical simulations (DNS) for multiphase flow analyses, has been examined to simulate a fluidized bed. The volumetric-force type IB method developed by Kajishima et al. (2001) has been applied in the present work. While particle-fluid interaction force is calculated with the surface integral of fluid stress at the interface between particle and fluid in the standard IB method, the volume integral of interaction force is used in the volumetric-force type IB method. In order to validate the present simulation code, drag force and lift force firstly were …
Time-Averaged Modelling Of Cfbs – Analysis Of The Terms In The Momentum Equations,
2010
VTT, Finland
Time-Averaged Modelling Of Cfbs – Analysis Of The Terms In The Momentum Equations, Sirpa Kallio, Maiju Seppälä, Veikko Taivassalo
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The features of the terms in the time-averaged momentum equation for the solid phase are examined for three CFB units ranging from a laboratory-scale unit to a small CFB boiler. The CFD simulations were based on the Eulerian granular model of the Fluent software. The time-averaged terms calculated during the time dependent simulations are analysed and conclusions on their relative importance are drawn. An analysis of the terms in the vertical solids momentum equation in the central region of a CFB is presented.
Cfd Simulation Of The Reacting Flow Process Of Coal Pyrolysis To Acetylene In Hydrogen Plasma Downer Reactors,
2010
Tsinghua University
Cfd Simulation Of The Reacting Flow Process Of Coal Pyrolysis To Acetylene In Hydrogen Plasma Downer Reactors, Binhang Yan, Yi Cheng, Yong Jin, Yi Cheng
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A comprehensive computational fluid dynamics (CFD) model was established to describe the reacting flow of coal pyrolysis in hydrogen plasma downer reactors. The model predictions showed good accordance with the experimental results of the 2-MW and 5-MW pilot-plant reactors. The operating conditions were optimized to improve the 5-MW reactor performance.
Cfd-Dem Simulation Of Syngas-To-Methane Process In A Fluidized-Bed Reactor,
2010
Tsinghua University
Cfd-Dem Simulation Of Syngas-To-Methane Process In A Fluidized-Bed Reactor, Changning Wu, Dayong Tian, Yi Cheng
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The CFD-DEM coupled approach was used to simulate the gas-solid reacting flows in a lab-scale fluidized-bed reactor for syngas-to-methane (STM) process. The simulation results captured the major features of the reactor performance including unwanted defluidization. The fluidized-bed reactor showed good performances, such as in preventing the catalyst particles from overheating and sintering.
Cfd Simulation Of A Liquid-Fluidized Bed Of Binary Particles,
2010
University of British Columbia
Cfd Simulation Of A Liquid-Fluidized Bed Of Binary Particles, Long Fan, John Grace, Norman Epstein
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The ability of computational fluid dynamics to predict the expansion and segregation of a binary solids mixture in a liquid-solid fluidized bed is investigated. Unsteady laminar flow is simulated by a modified two-dimensional Eulerian-Eulerian model in Fluent 6.3. The predictions are compared with experimental results for binary particles in the same narrow (1.00-1.18 mm) size range, but with different densities, 1600 and 1900 kg/m3, fluidized by water (1). The voidages and heights of two layers which form, each dominated by one particle species, were found to be sensitive to small changes in particle properties (diameter, density, sphericity), as well as …
Fluidization Technology For Stable Startup Of Commercial Fcc Unit,
2010
SK energy Institute of Technology
Fluidization Technology For Stable Startup Of Commercial Fcc Unit, Sung Won Kim, Gyung Rok Kim, Jae Wook Shin, Ik Sang Yoo, Hun Sik Kang, Sang Hoon Park
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Conditions for maintaining good fluidization in the start-up of FCC have been determined. Catalyst defluidization and consequent catalyst losses from reactor cyclone are mainly affected by catalyst properties and stripper operating condition based on previous commercial startup experiences. Effect of fine catalyst contents on bed fluidity was determined. Bed fluidity in stripper was analyzed with slip velocity. Finally new startup guide was proposed and it was successfully applied to commercial FCC process of SK energy, Korea.
Performance Comparison Of Syngas Methanation On Fluidized And Fixed Bed Reactors,
2010
Chinese Academy of Sciences
Performance Comparison Of Syngas Methanation On Fluidized And Fixed Bed Reactors, Yingli Wang, Jiao Liu, Qiang Li, Jian Yu, Fabing Su, Guangwen Xu
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The performance was compared on Syngas Completely Methanation at atmospheric pressure on fluidized and fixed bed reactors. From space-time yield of CH4, coke content and hot spots of bed temperature, fluidized bed technology was demonstrated to be more applicable to Syngas Completely Methanation. Characterization results showed that different carbon deposition forms were presented on the two operation modes.
Film Coating Onto Cohesive Fine Particles By A Novel Rotating Fluidized Bed Coater,
2010
Osaka Prefecture University
Film Coating Onto Cohesive Fine Particles By A Novel Rotating Fluidized Bed Coater, Tetsufumi Kondo, Hideya Nakamura, Tomohiro Iwasaki, Satoru Watano, Daisuke Iwamoto
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
In this study, film coating onto cohesive fine particles was conducted by using a novel rotating fluidized bed coater (RFBC). In order to avoid the formation of agglomeration, baffle plates were equipped inside the RFBC. Coating experiments were conducted under various operating conditions and the coated particles were evaluated based on their physical properties. As a result, coated particles having extremely small degree of agglomeration and favorable prolonged release property of a tracer material could be obtained.
Syngas Production With A Dual Fluidized Bed Gasifier For Polygeneration,
2010
Korea Institute of Industrial Technology
Syngas Production With A Dual Fluidized Bed Gasifier For Polygeneration, Uendo Lee, Young Doo Kim, Hyo Jae Jeong, In Soo Choi, Yeon Kyung Sung, Tae U Yoo, Jae Hun Song
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A pilot scale dual fluidized bed gasification system was developed for polygeneration with biomass. The gasification system is designed for supplying syngas for Fischer Tropsch (F-T) synthesis of bio-diesel and power generation with a syngas engine. Characteristics of biomass steam gasification were investigated in a lab scale bubbling fluidized bed, and hydrodynamics of a dual fluidized bed were investigated in a cold flow model. Based on the results from the lab scale test and cold flow model, a pilot scale dual fluidized bed gasifier was designed. In this paper, the developing process of the gasifier and preliminary results of system …
Fluidized Bed Combustion Of C1-C4 N-Alkanes,
2010
École Polytechnique de Montréal
Fluidized Bed Combustion Of C1-C4 N-Alkanes, Jean-Philippe Laviolette, Gregory S. Patience, Jamal Chaouki
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
The non-premixed combustion of C1 to C4 n-alkanes was investigated inside a bubbling fluidized bed of inert sand particles at intermediate temperatures: 923 K (650oC) ≤ TB ≤ 1123 K (850oC). Lower (T1) and upper (T2) critical transition bed temperatures were measured for ethane, propane and n-butane as 923 K (650oC) and 1073 K (800oC), respectively. The values for methane were significantly higher with T1 = 1023 K (750oC) and T2 > 1123 K (850oC). Alkane conversion was accurately modeled with first-order kinetics and C2 to C4 n-alkanes combustion rates were characterized by a uniform Arrhenius expression: (. The reaction rate …
High Performance Computing: Clean Coal Gasifier Designs Using Hybrid Parallelization,
2010
National Energy Technology Laboratory
High Performance Computing: Clean Coal Gasifier Designs Using Hybrid Parallelization, Madhava Syamlal, C. Guenther, A. Gel, S Pannala
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
One of the targets for coal gasification in the near future is capturing 90% of the carbon with less than a 10% increase in cost of electricity. Aggressive goals like this will require innovative gasifier designs to reach the market place quickly, with less risk, and in an economically viable way. Researchers at the National Energy Technology Laboratory (NETL) are collaborating with industry, academia, and other national labs on multiphase computational models like the legacy code MFIX (Multiphase Flow with Interphase eXchange) which can help design, operate, and scale-up clean coal gasifiers to meet the challenges or a carbon constrained …
Fluidized Bed Gasification Of Biomass: A Substance Flow Analysis,
2010
Second University of Naples
Fluidized Bed Gasification Of Biomass: A Substance Flow Analysis, Umberto Arena, Fabrizio Di Gregorio, Lucio Zaccariello, M.Laura Mastellone
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A natural biomass was fed in a pilot scale bubbling fluidized bed gasifier, having a maximum feeding capacity of 100kg/h. Measurements included the syngas composition, the mass flow rate and composition of entrained fines collected at the cyclone and purge material from the wet scrubber, and the bed material characterization. The performance of the whole gasification plant and of its specific components as well as the validity of some design solutions and operating criteria have been quantitatively assessed by means of a substance flow analysis.
One-Dimensional Modeling Of Oxy-Fuel Fluidized Bed Combustion For Co2 Capture,
2010
Chalmers University of Technology
One-Dimensional Modeling Of Oxy-Fuel Fluidized Bed Combustion For Co2 Capture, Sadegh Seddighi, David Pallarès, Filip Johnsson
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A one-dimensional model has been developed with the aim of investigating oxyfuel circulating fluidized bed (CFB) combustion for CO2 capture with the main focus of assessing the heat balance of the CFB loop. For different oxygen concentrations in the gas flow fed to the furnace, the model calculates the external solids recirculation and the heat load in the furnace and in external particle coolers.
Numerical Computation Of Hydrodynamic Behavior Of Biomass Particles In Circulating Fluidized Beds,
2010
Nigde University
Numerical Computation Of Hydrodynamic Behavior Of Biomass Particles In Circulating Fluidized Beds, Afsin Gungor Dr.
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
A model using a particle based approach is developed to accurately predict the hydrodynamic behavior of biomass particles in CFBs. Generally, the change in the pressure gradient with height in CFB riser is small. Numerical results are in good agreement with experiments, both in form and magnitude.
Tailored Synthesis Of Precipitated Magnesium Carbonates As Carbon-Neutral Filler Materials During Carbon Mineral Sequestration,
2010
Columbia University, New York
Tailored Synthesis Of Precipitated Magnesium Carbonates As Carbon-Neutral Filler Materials During Carbon Mineral Sequestration, Huangjing Zhao, Nathan Dadap, Ah-Hyung Alissa Park
The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering
Predictions of global energy usage and demand trends suggest that fossil fuels will remain as the main energy source for the foreseeable future. Unfortunately, the increased amount of anthropogenic carbon emitted during the energy production leads to environmental issues, including climate change. Thus, reducing carbon dioxide emissions in order to stabilize atmospheric CO2 levels is crucial, and this would not be achieved without significant changes in the energy conversion processes and the implementation of carbon capture and storage (CCS) technologies. Currently, the geological storage of carbon dioxide is considered to be the most economical method of carbon sequestration, while mineral …
